Image forming apparatus and control method thereof

Abstract

To ensure that the adverse effects of fluff on the side edges of the recording media are reduced.SOLUTION: An image forming apparatus 1 includes: an adhesive belt 6 that adhesively holds a recording medium 5 and transports it in a predetermined transport direction; a printing unit 9 that prints on the recording medium 5 at a predetermined position in the transport direction of the recording medium 5; and pressing units 10a and 10b that press the side edges 5a, 5b in the width direction perpendicular to the transport direction of the recording medium 5 toward the outside of the recording medium 5 before printing is performed by the printing unit 9.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an image forming apparatus that forms an image on a recording medium composed of fabric by an inkjet recording method and a control method thereof.

Background Art

[0002] Conventionally, an image forming apparatus that uses fabric as a recording medium and forms an image on the fabric by an inkjet recording method is known (for example, Patent Document 1). This image forming apparatus conveys a recording medium composed of fabric while adhering it to an adhesive belt, and forms an image by printing on the recording medium by discharging ink from an inkjet head at a predetermined position. When using fabric as the recording medium, if the lint on the side edge of the fabric comes into contact with the inkjet head, the ink ejection performance will deteriorate, and a stable image cannot be formed. Therefore, when using fabric as the recording medium, it is desirable not to allow the lint on the side edge of the fabric to interfere with the inkjet head.

[0003] The conventional image forming apparatus disclosed in Patent Document 1 includes a pressing roller that presses the side edge of the recording medium against an adhesive belt on the upstream side in the conveyance direction of the recording medium from the inkjet head. The rotation axis of this pressing roller is provided parallel to the width direction orthogonal to the conveyance direction of the recording medium. As the recording medium is conveyed together with the adhesive belt, the pressing roller rotates while pressing the side edge of the recording medium. At this time, the pressing roller presses down the standing lint conveyed from the upstream side, so that the lint adheres to the adhesive belt.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the above-described conventional image forming apparatus, the rotation axis of the pressing roller is parallel to the width direction orthogonal to the conveyance direction of the recording medium. Therefore, the lint pushed down by the pressing roller is pushed upstream in the conveyance direction. When the lint is pushed upstream, for example, the lint on the downstream side may be pushed down while overlapping the lint on the upstream side. When a large number of lint overlap, it may not be possible to adhere all the lint to the adhesive belt. In that case, after passing through the pressing roller, the lint may return to the standing state again and may come into contact with the inkjet head on the downstream side. Therefore, the conventional image forming apparatus has a problem that the adverse effect caused by the lint at the side edge portion of the recording medium cannot be surely reduced.

[0006] Therefore, the present invention has been made to solve the above problems, and an object thereof is to provide an image forming apparatus and a control method thereof that can surely reduce the adverse effect caused by the lint at the side edge portion of the recording medium.

Means for Solving the Problems

[0007] In order to achieve the above object, the invention according to claim 1 is an image forming apparatus, comprising an adhesive belt that adhesively holds a recording medium and conveys it in a predetermined conveyance direction, a printing unit that performs printing on the recording medium at a predetermined position in the conveyance direction, and pressing means that presses the side edge portion in the width direction orthogonal to the conveyance direction of the recording medium outward from the recording medium before printing is performed by the printing unit. , the pressing means is movable from a first position inside the side edge of the recording medium in the width direction to a second position outside the side edge of the recording medium, and is movable forward and backward with respect to the recording medium. By moving from the first position to the second position while advancing toward the recording medium, the side edge of the recording medium is pressed outward It is a configuration characterized by that. The invention according to claim 2 is an image forming apparatus, comprising: an adhesive belt that adhesively holds a recording medium and conveys it in a predetermined conveyance direction; a printing unit that performs printing on the recording medium at a predetermined position in the conveyance direction; and a pressing means that presses a side edge portion in the width direction, which is orthogonal to the conveyance direction of the recording medium, outward of the recording medium before printing is performed by the printing unit. The adhesive belt intermittently conveys the recording medium in the conveyance direction, the printing unit performs printing on the recording medium when the conveyance of the recording medium by the adhesive belt has stopped, and the pressing means performs an operation of pressing the side edge portion of the recording medium outward in parallel with the printing operation by the printing unit. The invention according to claim 3 is an image forming apparatus, comprising: an adhesive belt that adhesively holds a recording medium and conveys it in a predetermined conveyance direction; a printing unit that performs printing on the recording medium at a predetermined position in the conveyance direction; a pressing means that presses a side edge portion in the width direction, which is orthogonal to the conveyance direction of the recording medium, outward of the recording medium before printing is performed by the printing unit; and a detection sensor that detects the height of the side edge portion of the recording medium. The pressing means performs an operation of pressing the side edge portion of the recording medium outward based on the detection result by the detection sensor.

[0008] Claim 4 The invention according to is the image forming apparatus according to claim 1 any one of 3 to 3 characterized in that the recording medium is a fabric.

[0009] Claim 5 The invention according to is claim 1any one of 4 to 4 In the image forming apparatus, the pressing means is configured to tilt the fluff generated at the side edge of the recording medium outward of the recording medium and adhere it to the adhesive belt.

[0010] Claim 6 The invention according to claim is in any one of the image forming apparatuses according to claims 1 to 5 wherein the pressing means is configured to include a pressing roller.

[0011] Claim 7 The invention according to claim is in the image forming apparatus according to claim 6 wherein the surface of the pressing roller is made of a non-adhesive material.

[0014] The invention according to claim 8 is in the image forming apparatus according to claim 1 wherein the pressing means is configured to retract from the recording medium when moving from the second position to the first position.

[0016] Claim 9 The invention according to claim is in any one of the image forming apparatuses according to claims 1 to 8 wherein the pressing means is arranged upstream of the printing unit in the conveying direction.

[0017] Claim 10 The invention according to claim is in the image forming apparatus according to claim 2 wherein the printing unit performs printing by scanning on the surface of the recording medium in the width direction when the conveyance of the recording medium is stopped, the pressing means is provided at both ends in the width direction of the printing unit, and the pressing means performs an operation of pressing the side edge of the recording medium outward as the printing unit scans in the width direction.

[0018] Claim 11 The invention according to claim is in the image forming apparatus according to claim 10In the image forming apparatus, it further includes a support member that supports the printing unit and the pressing means so as to be movable in the width direction, and the pressing means is supported by the support member at both end positions of the printing unit.

[0019] Claim 12 The invention according to 10 or 11 In the image forming apparatus, the length of the pressing means in the conveyance direction is longer than the printing width in the conveyance direction by the printing unit.

[0020] Claim 13 The invention according to 10 to 12 In any of the image forming apparatuses, the length of the pressing means in the conveyance direction has a length equal to or greater than the amount of movement of the recording medium when the intermittent conveyance by the adhesive belt is performed twice.

[0022] Claim 14 The invention according to 3 In the image forming apparatus, when the detection sensor detects that the height of the side edge portion is equal to or greater than a predetermined value, the pressing means performs an operation of pressing the side edge portion of the recording medium outward, and when the detection sensor detects that the height of the side edge portion is less than the predetermined value, the pressing means does not perform an operation of pressing the side edge portion of the recording medium outward.

[0023] Claim 15 The invention according to 6 or 7 In the image forming apparatus, the pressing roller is arranged to press the side edge portion on the upstream side of the printing unit in the conveyance direction, the rotation axis of the pressing roller is inclined with respect to the width direction, and the end portion located outside the recording medium is located on the downstream side in the conveyance direction than the end portion located inside the recording medium.

[0024] Claim 16 The invention according to claim 1 is a control method for an image forming apparatus having an adhesive belt that adhesively holds a recording medium and conveys it in a predetermined conveyance direction, a printing unit that performs printing on the recording medium at a predetermined position in the conveyance direction, and pressing means that performs an operation of pressing a side edge portion in the width direction orthogonal to the conveyance direction of the recording medium outward of the recording medium, wherein before printing by the printing unit, the pressing means is caused to perform an operation of pressing the side edge portion of the recording medium outward of the recording medium. has a process, and the process enables the pressing means to move from a first position inside the side edge of the recording medium in the width direction to a second position outside the side edge of the recording medium, and enables the pressing means to move forward and backward with respect to the recording medium. By moving the pressing means from the first position to the second position while advancing toward the recording medium, an operation of pressing the side edge portion of the recording medium outward is performed It is a configuration characterized by this. The invention according to claim 17 is a control method for controlling an image forming apparatus having an adhesive belt that adhesively holds a recording medium and conveys it in a predetermined conveyance direction, a printing unit that performs printing on the recording medium at a predetermined position in the conveyance direction, and pressing means that performs an operation of pressing a side edge portion in the width direction orthogonal to the conveyance direction of the recording medium outward of the recording medium, the control method being configured such that, before printing by the printing unit is performed, the pressing means is caused to perform an operation of pressing the side edge portion of the recording medium outward of the recording medium, the adhesive belt is intermittently driven to intermittently convey the recording medium in the conveyance direction, the printing unit is driven to perform printing on the recording medium when conveyance of the recording medium by the adhesive belt is stopped, and an operation of pressing the side edge portion of the recording medium outward is performed by driving the pressing means in parallel with the printing operation by the printing unit. The invention according to claim 18 is a control method for controlling an image forming apparatus having an adhesive belt that adhesively holds a recording medium and conveys it in a predetermined conveyance direction, a printing unit that performs printing on the recording medium at a predetermined position in the conveyance direction, pressing means that performs an operation of pressing a side edge portion in the width direction orthogonal to the conveyance direction of the recording medium outward of the recording medium, and a detection sensor that detects the height of the side edge portion of the recording medium, the control method being configured such that, before printing by the printing unit is performed, the pressing means is caused to perform an operation of pressing the side edge portion of the recording medium outward of the recording medium, and based on the detection result by the detection sensor, it is determined whether or not to cause the pressing means to perform an operation of pressing the side edge portion of the recording medium outward.

[0025] The invention according to claim 19 is the control method according to claim Any one of 16 to 18 wherein by causing the pressing means to perform an operation of pressing the side edge portion of the recording medium outward of the recording medium, the fluff generated at the side edge portion of the recording medium is tilted outward of the recording medium and adhered to the adhesive belt. It is a configuration characterized by this.

[0028] Claim 20 The invention according to claim is the control method according to claim 16 wherein when moving the pressing means from the second position to the first position, the pressing means is retracted from the recording medium. It is a configuration characterized by this.

[0031] Claim 21 The invention according to claim is the control method according to claim 18 wherein when it is detected by the detection sensor that the height of the side edge portion is equal to or greater than a predetermined value, the pressing means is caused to perform an operation of pressing the side edge portion of the recording medium outward, and when it is detected by the detection sensor that the height of the side edge portion is less than the predetermined value, the pressing means is not caused to perform an operation of pressing the side edge portion of the recording medium outward. It is a configuration characterized by this.

Effect of the Invention

[0032] According to the present invention, since the lint on the side edge of the recording medium can be surely adhered to the adhesive belt, it is possible to reduce the adverse effects caused by the lint.

Brief Description of the Drawings

[0033]

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Figure 19

Mode for Carrying Out the Invention

[0034] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the embodiments described below, elements common to each other are denoted by the same reference numerals, and redundant descriptions thereof are omitted.

[0035] (First Embodiment) First, the first embodiment of the present invention will be described. FIG. 1 is a schematic diagram showing an example of the overall configuration of the image forming apparatus 1 in this embodiment. This image forming apparatus 1 uses a cloth as the recording medium 5 and forms an image on the recording medium 5 by an inkjet recording method. For example, the image forming apparatus 1 conveys the recording medium 5, which is a cloth, in a roll-to-roll manner along a predetermined conveyance path, and forms an image by printing on the recording medium at a predetermined position in the conveyance path, that is, at the printing unit 9. The XYZ three-dimensional coordinate system shown in FIG. 1 is a coordinate system common to the three-dimensional coordinate systems shown in other figures such as FIG. 2, and is, for example, a coordinate system in which the XY plane is a horizontal plane and the Z direction is a vertical direction.

[0036] As shown in FIG. 1, the image forming apparatus 1 includes an image forming unit 2 that forms an image on the recording medium 5, a recording medium supply unit 3 that feeds out the long recording medium 5 to the image forming unit 2, and a recording medium recovery unit 4 that recovers the recording medium 5 on which an image has been formed in the image forming unit 2. The image forming unit 2 is disposed between the recording medium supply unit 3 and the recording medium recovery unit 4. Further, the image forming apparatus 1 includes a control unit 30 that controls the operations of the image forming unit 2, the recording medium supply unit 3, and the recording medium recovery unit 4, respectively.

[0037] The recording medium supply unit 3 includes a supply roll 3a around which a recording medium 5 is wound. The supply roll 3a is rotationally driven in a predetermined direction by a motor (not shown), thereby feeding out the recording medium 5 to the downstream side of the conveyance path. In the present embodiment, the case where the recording medium 5 is conveyed in the Y direction is illustrated.

[0038] The image forming unit 2 includes an adhesive belt 6, rollers 7a and 7b, a recording medium pressing roller 8, a printing unit 9, and a side edge pressing unit 10. The image forming unit 2 conveys the recording medium 5 supplied from the recording medium supply unit 3 while adhering it to the adhesive belt 6, and forms an image on the recording medium 5 by performing printing in the printing unit 9. Details of the image forming unit 2 will be described later.

[0039] The recording medium recovery unit 4 includes a roll 3b for winding up the recording medium 5 on which an image has been formed. The roll 3b is rotationally driven in a predetermined direction by a motor (not shown), thereby sequentially winding up the recording medium 5 sent out from the image forming unit 2.

[0040] The control unit 30 includes a CPU 31 and a storage unit 32. The CPU 31 is a hardware processor that executes a computer program. The storage unit 32 stores a computer program executed by the CPU 31, various data, and the like. The control unit 30 controls the recording medium supply unit 3, the image forming unit 2, and the recording medium recovery unit 4 to perform synchronized operations by the CPU 31 executing the computer program.

[0041] Next, the details of the image forming unit 2 will be described. FIG. 2 is a perspective view of the image forming unit 2 viewed obliquely from above. The adhesive belt 6 is configured as an endless belt and has an adhesive layer on its surface that can adhesively hold the recording medium 5. The rollers 7a and 7b are provided at positions spaced apart by a predetermined distance along the conveyance direction (Y direction) of the recording medium 5 and hold the adhesive belt 6. For example, the roller 7b is provided on the upstream side in the conveyance direction of the recording medium 5, and the roller 7a is provided on the downstream side in the conveyance direction of the recording medium 5. The adhesive belt 6 is stretched between the two rollers 7a and 7b and installed in a state where a certain tension is applied. At least one of the rollers 7a and 7b is rotationally driven in a predetermined direction by a motor (not shown). Thereby, the adhesive belt 6 circulates and moves between the two rollers 7a and 7b. The recording medium 5 supplied from the recording medium supply unit 3 is conveyed downstream in the conveyance direction while being adhesively held on the upper surface of the adhesive belt 6.

[0042] The recording medium pressing roller 8 is located above the roller 7b on the upstream side in the conveyance direction among the two rollers 7a and 7b and has a length substantially equal to or longer than the width dimension of the adhesive belt 6 in the width direction orthogonal to the conveyance direction. The recording medium pressing roller 8 is movable up and down in the vertical direction (Z direction) by lifting means (not shown). Then, the recording medium pressing roller 8 presses the recording medium 5 supplied from the recording medium supply unit 3 against the upper surface of the adhesive belt 6, thereby adhesively attaching the entire back surface of the recording medium 5 to the adhesive belt 6 in the width direction orthogonal to the conveyance direction.

[0043] The printing unit 9 forms an image by performing printing on the recording medium 5 that is conveyed while being adhesively held on the adhesive belt 6. The printing unit 9 is provided at a predetermined position on the downstream side that is separated from the recording medium pressing roller 8 by a predetermined distance in the conveyance direction of the recording medium 5. Further, the printing unit 9 has a support member 21 that is arranged so as to cross above the adhesive belt 6 in the width direction orthogonal to the conveyance direction of the recording medium 5. The support member 21 has a rail portion 22 that extends in the width direction orthogonal to the conveyance direction. And an inkjet head 20 that is movable in the width direction (X direction) orthogonal to the conveyance direction of the recording medium 5 is provided on the rail portion 22. By driving a motor (not shown), this inkjet head 20 can reciprocate in the X direction at a predetermined height position above the adhesive belt 6 while being supported by the support member 21.

[0044] The inkjet head 20 forms an image on the recording medium 5 by performing a printing operation of discharging ink while moving in the width direction (X direction) of the recording medium 5 by the support member 21. That is, the image forming apparatus 1 of the present embodiment is a scanning type image forming apparatus that forms an image on the recording medium 5 by scanning the inkjet head 20 in the scanning direction (X direction) orthogonal to the conveyance direction (Y direction) of the recording medium 5. For example, the inkjet head 20 discharges four colors of ink, Y (yellow), M (magenta), C (cyan), and K (black), to form a color image on the recording medium 5. The inkjet head 20 forms an image with a predetermined print width L1 in the conveyance direction of the recording medium 5 by a printing operation of discharging ink while scanning in the width direction (X direction) of the recording medium 5.

[0045] Therefore, the image forming apparatus 1 of the present embodiment makes the operation of conveying the recording medium 5 in the conveyance direction an intermittent operation. That is, the image forming apparatus 1 makes the conveyance amount of sending the recording medium 5 to the downstream side in the conveyance direction in one conveyance operation coincide with the print width L1 of the inkjet head 20, and forms a predetermined image on the recording medium 5 by alternately repeating the conveyance operation of the recording medium 5 and the printing operation of the inkjet head 20.

[0046] The side edge pressing part 10 is a pressing means for pressing the side edges 5a and 5b in the width direction orthogonal to the conveyance direction of the recording medium 5 outward of the recording medium 5 before printing is performed by the printing part 9. This side edge pressing part 10 is provided between the recording medium pressing roller 8 and the printing part 9 in the conveyance direction of the recording medium 5. Further, the side edge pressing part 10 includes a pressing part 10a for pressing one side edge 5a in the width direction of the recording medium 5 and a pressing part 10b for pressing the other side edge 5b. That is, the side edge pressing part 10 individually presses the side edges 5a and 5b at both ends in the width direction of the recording medium 5 by these two pressing parts 10a and 10b.

[0047] Also, the side edge pressing part 10 includes a support member 14 arranged so as to cross above the adhesive belt 6 in the width direction orthogonal to the conveyance direction of the recording medium 5. The support member 14 has a rail part 15 extending in the width direction orthogonal to the conveyance direction. The above-described two pressing parts 10a and 10b are attached to the rail part 15 and are movable in the width direction (X direction) orthogonal to the conveyance direction of the recording medium 5. Therefore, when a motor (not shown) is driven, the two pressing parts 10a and 10b can reciprocate individually in the X direction. For example, the side edge pressing part 10 can move the pressing part 10a in the -X direction and at the same time move the pressing part 10b in the +X direction. Conversely, it is also possible to move the pressing part 10a in the +X direction and at the same time move the pressing part 10b in the -X direction.

[0048] The two pressing parts 10a and 10b include a pressing roller 11 and a lifting drive part 12 for lifting the pressing roller 11. The rotation axis of the pressing roller 11 is installed in a direction parallel to the conveyance direction (Y direction) of the recording medium 5. The lifting drive part 12 can move the pressing roller 11 forward and backward toward the recording medium 5 by lifting and lowering the pressing roller 11. By lowering the pressing roller 11, the lifting drive part 12 can bring the pressing roller 11 into contact with the surface of the recording medium 5 and press the recording medium 5 against the adhesive belt 6. Also, by raising the pressing roller 11, the lifting drive part 12 can retract the pressing roller 11 from the surface of the recording medium 5. The surface of such a pressing roller 11 is made of a non-adhesive material. For example, non-adhesiveness can be imparted by applying a silicone rubber material, a nylon resin material, or a fluorine-coated material to the surface of the pressing roller 11. Since the pressing roller 11 has non-adhesiveness, the recording medium 5 does not adhere to the surface of the pressing roller 11 even when the pressing roller 11 descends and contacts the recording medium 5. Therefore, the pressing roller 11 can roll while in contact with the surface of the recording medium 5.

[0049] Moreover, the length L2 of the pressing roller 11 in the conveyance direction of the recording medium 5 is equal to or greater than the printing width L1 by the inkjet head 20 of the printing part 9. That is, the relationship between the length L2 of the pressing roller 11 and the printing width L1 of the inkjet head 20 is L2 ≥ L1. And when the conveyance of the recording medium 5 stops and printing by the inkjet head 20 is being performed, the side edge pressing part 10 drives the two pressing parts 10a and 10b and performs an operation of pressing the side edges 5a and 5b of the recording medium 5 outward in the width direction of the recording medium 5.

[0050] FIG. 3 is a diagram showing an example of the pressing operation by the side edge pressing portion 10. When the recording medium 5 is conveyed, as shown in FIG. 3(a), the side edge pressing portion 10 holds the pressing rollers 11 of the two pressing portions 10a and 10b at an upper position spaced a predetermined distance from the surface of the recording medium 5. Then, when the conveyance of the recording medium 5 stops, the side edge pressing portion 10 drives the two pressing portions 10a and 10b to perform an operation of pressing the side edges 5a and 5b of the recording medium 5 outward in the width direction of the recording medium 5. As shown in FIG. 3(b), the side edge pressing portion 10 lowers the pressing roller 11 at a position inside the side edges 5a and 5b of the recording medium 5 as indicated by the arrow F1. Thereby, the pressing rollers 11 of the pressing portions 10a and 10b come into contact with the surface of the recording medium 5 at a position inside the side edges 5a and 5b of the recording medium 5. Subsequently, as indicated by the arrow F2 in FIG. 3(c), the side edge pressing portion 10 moves each of the pressing portions 10a and 10b outward toward the outside of the recording medium 5. At this time, the pressing roller 11 is in a state of pressing the surface of the recording medium 5. When the pressing portions 10a and 10b move outward toward the outside of the recording medium 5, the pressing roller 11 moves outward toward the outside of the recording medium 5 while rolling on the surface of the recording medium 5. Then, the pressing roller 11 moves further outward beyond the positions of the side edges 5a and 5b of the recording medium 5.

[0051] FIG. 4 is a diagram showing an example of the pressing roller 11 pressing the side edge 5a of the recording medium 5. When the pressing roller 11 moves from the position inside the recording medium 5 (the first position) shown in FIG. 4(a) to the position outside the recording medium 5 (the second position) shown in FIG. 4(b), the standing hairs at the side edge 5a of the recording medium 5 are pushed down by the pressing roller 11 and tilted outward toward the outside of the recording medium 5. As a result, the hairs adhere to the adhesive belt 6 outside the recording medium 5. At this time, since each of the plurality of hairs at the side edge 5a of the recording medium 5 can be pushed down to the outside of the recording medium 5, all the hairs can be surely adhered to the adhesive belt 6, and it is possible to suppress the hairs from restoring to the standing state again. In FIG. 4, only the pressing portion 10a is illustrated, but the same applies to the pressing portion 10b.

[0052] Return to Fig. 3. When the pressing roller 11 is moved further outward beyond the positions of the side edges 5a, 5b of the recording medium 5, next, as shown in Fig. 3(d), the side edge pressing portion 10 raises the pressing roller 11 at a position outside (the second position) the side edges 5a, 5b of the recording medium 5 as indicated by the arrow F3. As a result, the pressing rollers 11 of the pressing portions 10a, 10b retract above the recording medium 5 at a position outside the side edges 5a, 5b of the recording medium 5. Since the surface of the pressing roller 11 is made of a non-sticky material as described above, when the pressing roller 11 retracts upward as indicated by the arrow F3, the lint does not stand up together with the pressing roller 11.

[0053] Thereafter, as shown in Fig. 3(e), the side edge pressing portion 10 moves the pressing portions 10a, 10b in the direction of the arrow F4 with the pressing roller 11 retracted from the recording medium 5, and returns the pressing portions 10a, 10b to a predetermined standby position (the first position). This standby position is the position of the pressing portions 10a, 10b shown in Fig. 3(a), which is a predetermined position inside the side edges 5a, 5b of the recording medium 5.

[0054] As described above, the pressing operation by the side edge pressing portion 10 is performed when the intermittent conveyance of the recording medium 5 is stopped. Specifically, when the intermittent conveyance of the recording medium 5 is stopped, the pressing roller 11 descends and contacts the recording medium 5, and an operation of moving the pressing roller 11 outward toward the recording medium 5 is performed. Incidentally, the resumption of the conveyance of the recording medium 5 may be performed after the pressing roller 11 retracts upward as shown in Fig. 3(d), or may be performed after the pressing portions 10a, 10b return to the standby position as shown in Fig. 3(e).

[0055] The side edge pressing part 10 presses the side edges 5a and 5b of the recording medium 5 outward at a position upstream of the printing part 9. Therefore, when the recording medium 5 is conveyed to the printing position by the printing part 9, the hairs on the side edges 5a and 5b are already in a state of sticking to the adhesive belt 6. Thus, during the scanning of the inkjet head 20, even when the inkjet head 20 passes through the positions of the side edges 5a and 5b of the recording medium 5, the hairs will not contact the inkjet head 20, and the adverse effects caused by the hairs can be reliably reduced.

[0056] By the way, in order to ensure that the side edge pressing part 10 can surely push down the hairs outward when the pressing roller 11 presses the side edges 5a and 5b of the recording medium 5, a configuration may be adopted in which a nozzle for blowing air or steam outward is provided at a position near the pressing roller 11.

[0057] FIG. 5 is a diagram showing an example of the side edge pressing part 10 provided with such a nozzle 18. In FIG. 5, a configuration in which a nozzle 18 for blowing air or steam is provided upstream of the pressing part 10a is illustrated. This nozzle 18 blows air or steam from the inside to the outside of the recording medium 5 at a position upstream of the pressing part 10a. Therefore, the hairs standing up at the side edge 5a of the recording medium 5 are tilted outward to some extent by the air or steam blown from the nozzle 18. That is, the nozzle 18 can tilt the hairs outward to some extent in advance before the pressing operation by the pressing part 10a is performed. Then, the pressing part 10a presses the hairs that have been tilted in advance by the air or steam blown from the nozzle 18. As a result, there is an advantage that the hairs can be surely stuck to the adhesive belt 6 outside the side edge 5a of the recording medium 5. In FIG. 5, only the pressing part 10a is shown, but the same applies to the pressing part 10b.

[0058] Next, the operation procedure of the image forming apparatus 1 will be described. FIG. 6 is a flowchart showing an example of the operation procedure of the image forming apparatus 1. The operation procedure shown in FIG. 6 is a procedure realized by the CPU 31 in the control unit 30 executing a predetermined computer program.

[0059] When the control unit 30 starts the operation shown in FIG. 6, first, it sets the position of the end portion in the width direction of the recording medium 5 (step S10). For example, based on the width dimension of the recording medium 5 input by the user, the control unit 30 specifies the position of the end portion in the width direction of the recording medium 5, and determines the standby positions of the pressing portions 10a and 10b based on the specified position. Then, the control unit 30 drives the pressing portions 10a and 10b in the X direction to make the pressing portions 10a and 10b standby at the standby positions.

[0060] Then, the control unit 30 starts the printing operation (step S11). When starting the printing operation, the control unit 30 conveys the recording medium 5 along the conveyance direction (step S12). At this time, the control unit 30 conveys the recording medium 5 by matching the conveyance amount per one conveyance of the recording medium 5 with the printing width L1 by the printing unit 9. And when the recording medium 5 is conveyed by the conveyance amount corresponding to the printing width L1, the control unit 30 stops the conveyance of the recording medium 5 (step S13).

[0061] Subsequently, the control unit 30 drives the inkjet head 20 of the printing unit 9 to perform a printing operation, and forms an image corresponding to the printing width L1 on the recording medium 5 (step S14). Further, in parallel with the printing operation by the inkjet head 20, the control unit 30 drives the side edge pressing unit 10 and performs an operation of pressing the side edge portions 5a and 5b of the recording medium 5 by the respective pressing portions 10a and 10b (step S15).

[0062] After that, the control unit 30 determines whether printing has ended (step S16). If printing has not ended yet (NO in step S16), it returns to step S12 and repeats the above-described process. Therefore, the operation of attaching the fluff on the side edges 5a and 5b of the recording medium 5 to the adhesive belt 6 is repeated while the intermittent conveyance of the recording medium 5 is stopped and the printing operation by the printing unit 9 is being performed. On the other hand, if printing has ended (YES in step S16), the control by the control unit 30 ends.

[0063] As described above, the image forming apparatus 1 of the present embodiment is configured to adhesively hold the recording medium 5 on the adhesive belt 6 and convey it in a predetermined conveyance direction, and the printing unit 9 performs printing on the recording medium 5 at a predetermined position in the conveyance direction. The image forming apparatus 1 includes pressing portions 10a and 10b that press the side edges 5a and 5b in the width direction orthogonal to the conveyance direction of the recording medium 5 outward of the recording medium 5 before the printing by the printing unit 9 is performed. The image forming apparatus 1 having such pressing portions 10a and 10b can push down the fluff on the side edges 5a and 5b of the recording medium 5 outward of the recording medium 5 and attach the fluff to the adhesive belt 6. Therefore, the inkjet head 20 provided in the printing unit 9 can perform the printing operation without interfering with the fluff, and it is possible to prevent damage to the inkjet head 20 and the like in advance.

[0064] Further, the image forming apparatus 1 of the present embodiment is configured to intermittently convey the recording medium 5 while adhesively holding the recording medium 5 on the adhesive belt 6, and drive the printing unit 9 to perform a printing operation on the recording medium 5 when the intermittent conveyance by the adhesive belt 6 is stopped. The image forming apparatus 1 drives the pressing portions 10a and 10b in parallel with the printing operation by the printing unit 9 to press the side edges 5a and 5b of the recording medium 5 outward. According to such a configuration, the operation of pressing the side edges 5a and 5b of the recording medium 5 can be performed during the period when the conveyance of the recording medium 5 is stopped and the printing operation by the printing unit 9 is being performed. Therefore, it is not necessary to spend time only for pressing the side edges 5a and 5b of the recording medium 5 outward, and the fluff can be efficiently attached to the adhesive belt 6.

[0065] (Second Embodiment) Next, a second embodiment of the present invention will be described. Note that the overall configuration of the image forming apparatus 1 in this embodiment is the same as that of the first embodiment.

[0066] FIG. 7 is a perspective view of the image forming unit 2 in the second embodiment as viewed obliquely from above. The image forming unit 2 of this embodiment is configured such that side edge pressing portions 10 are provided at both end positions of the inkjet head 20 of the printing unit 9. That is, the inkjet head 20 supports pressing portions 10a and 10b at both ends in the width direction orthogonal to the conveyance direction of the recording medium 5. Therefore, as the inkjet head 20 moves in the width direction of the recording medium 5, the pressing portions 10a and 10b move in the width direction of the recording medium 5 together with the inkjet head 20. The pressing portions 10a and 10b supported at both ends of the inkjet head 20 in the printing unit 9 include a pressing roller 11 and a lifting drive unit 12 for lifting and lowering the pressing roller 11, as in the first embodiment. Also, the point that the rotation axis of the pressing roller 11 is installed in a direction parallel to the conveyance direction (Y direction) of the recording medium 5 is the same as that of the first embodiment.

[0067] As described above, in this embodiment, the pressing portions 10a and 10b are provided at both ends of the printing unit 9. Therefore, the operation of pressing the side edge portions 5a and 5b of the recording medium 5 by the pressing portions 10a and 10b is performed in conjunction with the printing operation by the printing unit 9.

[0068] Also, as shown in FIG. 7, the image forming unit 2 of this embodiment includes detection sensors 19, 19 for detecting the heights of the side edge portions 5a, 5b of the recording medium 5 at a predetermined position upstream of the printing unit 9 in the conveyance direction of the recording medium 5. By detecting the heights of the side edge portions 5a and 5b by the detection sensors 19, 19, it becomes possible to determine whether or not the hairs are standing up. Note that the detection sensors 19, 19 are supported so as to be movable in the width direction of the recording medium 5 by a support member (not shown).

[0069] Figures 8 and 9 are diagrams showing an example of the pressing operation by the pressing parts 10a and 10b. Fig. 8(a) shows a state where the inkjet head 20 is in the standby position, and the intermittent conveyance of the recording medium 5 is performed in the state shown in Fig. 8(a). Then, when the intermittent conveyance of the recording medium 5 stops, the operation of the inkjet head 20 is started. As shown in Fig. 8(b), when operating the inkjet head 20, first, the pressing roller 11 of the pressing part 10a is lowered, and the pressing roller 11 of the pressing part 10a is brought into contact with the recording medium 5. At this time, the pressing roller 11 contacts the recording medium 5 at a position inside the side edge part 5a of the recording medium 5. Then, as shown in Fig. 8(c), the inkjet head 20 is moved toward one end of the recording medium 5. At this time, the pressing roller 11 of the pressing part 10a presses the side edge part 5a of the recording medium 5 outward of the recording medium 5. Thereby, the side edge part 5a of the recording medium 5 can be adhered to the adhesive belt 6. Incidentally, the pressing roller 11 of the pressing part 10a is driven to retract from the recording medium 5 after the side edge part 5a of the recording medium 5 is adhered to the adhesive belt 6.

[0070] After that, as shown in Fig. 8(d), the inkjet head 20 is further moved outward of the recording medium 5, and when the pressing part 10b reaches a predetermined position inside the side edge part 5a of the recording medium 5, the pressing roller 11 of the pressing part 10b is lowered. Thereby, the pressing roller 11 of the pressing part 10b contacts the recording medium 5 at a predetermined position inside the side edge part 5a of the recording medium 5. Then, as shown in Fig. 8(e), by further moving the inkjet head 20 outward, the pressing roller 11 of the pressing part 10b presses the side edge part 5a of the recording medium 5 outward of the recording medium 5. Thereby, the side edge part 5a of the recording medium 5 can be surely adhered to the adhesive belt 6. Incidentally, the pressing roller 11 of the pressing part 10b is driven to retract from the recording medium 5 after the side edge part 5a of the recording medium 5 is adhered to the adhesive belt 6.

[0071] In this way, the inkjet head 20 reaches one end of the support member 21. After that, as shown in Fig. 9(a), while moving the inkjet head 20 toward the other end of the support member 21, printing operation on the recording medium 5 is performed by discharging ink. Then, as shown in Fig. 9(b), when the pressing part 10b reaches a predetermined position inside the side edge part 5b of the recording medium 5, the pressing roller 11 of the pressing part 10b is lowered. Thereby, the pressing roller 11 of the pressing part 10b contacts the recording medium 5 at a predetermined position inside the side edge part 5b of the recording medium 5. Then, as shown in Fig. 9(c), while continuing the printing operation by the inkjet head 20, by moving the inkjet head 20 further outward of the recording medium 5, the pressing roller 11 of the pressing part 10b presses the side edge part 5b of the recording medium 5 toward the outside of the recording medium 5. Thereby, the side edge part 5b of the recording medium 5 can be adhered to the adhesive belt 6. Incidentally, the pressing roller 11 of the pressing part 10b is driven to retract from the recording medium 5 after the side edge part 5b of the recording medium 5 is adhered to the adhesive belt 6.

[0072] After that, as shown in Fig. 9(d), the inkjet head 20 is further moved toward the outside of the recording medium 5, and when the pressing part 10a reaches a predetermined position inside the side edge part 5b of the recording medium 5, the pressing roller 11 of the pressing part 10a is lowered. Thereby, the pressing roller 11 of the pressing part 10a contacts the recording medium 5 at a predetermined position inside the side edge part 5b of the recording medium 5. Then, as shown in Fig. 9(e), by moving the inkjet head 20 further outward, the pressing roller 11 of the pressing part 10a presses the side edge part 5b of the recording medium 5 toward the outside of the recording medium 5. Thereby, the side edge part 5b of the recording medium 5 can be surely adhered to the adhesive belt 6. Incidentally, the pressing roller 11 of the pressing part 10a is driven to retract from the recording medium 5 after the side edge part 5b of the recording medium 5 is adhered to the adhesive belt 6. After that, the inkjet head 20 returns to the standby position shown in Fig. 8(a).

[0073] FIG. 10 is a diagram showing an operation example when the standby position of the inkjet head 20 is set at a position different from that in FIG. 8. FIG. 10(a) shows a state where the inkjet head 20 is at the standby position. That is, the standby position of the inkjet head 20 is set at one end of the support member 21. When the inkjet head 20 is at the standby position, the recording medium 5 does not exist below the inkjet head 20. Therefore, even if there is a portion of the recording medium 5 floating from the adhesive belt 6, when the recording medium 5 is intermittently conveyed in the conveyance direction, it is possible to prevent the floating portion from interfering with the inkjet head 20.

[0074] When the intermittent conveyance of the recording medium 5 stops, the operation of the inkjet head 20 is started. As shown in FIG. 10(b), when the inkjet head 20 is driven, first, the pressing portion 10b is moved to a predetermined position inside the side edge portion 5a of the recording medium 5, and the pressing roller 11 of the pressing portion 10a is lowered at that predetermined position. Thereby, the pressing roller 11 of the pressing portion 10a contacts the recording medium 5 at a position inside the side edge portion 5a of the recording medium 5. Then, as shown in FIG. 10(c), the inkjet head 20 is moved again toward the standby position. At this time, the pressing roller 11 of the pressing portion 10a presses the side edge portion 5a of the recording medium 5 toward the outside of the recording medium 5. Thereby, the side edge portion 5a of the recording medium 5 can be adhered to the adhesive belt 6. Incidentally, the pressing roller 11 of the pressing portion 10a is driven to retract from the recording medium 5 after the side edge portion 5a of the recording medium 5 is adhered to the adhesive belt 6. Thereafter, in the same manner as in FIGS. 9(a) to (e), while moving the inkjet head 20 toward the other end of the support member 21, a printing operation on the recording medium 5 is performed by discharging ink. Then, by pressing the side edge portion 5b of the recording medium 5 with the pressing portions 10b and 10a, the side edge portion 5b of the recording medium 5 is adhered to the adhesive belt 6. Further, when the printing operation by the inkjet head 20 is being performed as shown in FIGS. 9(a) to (e), if there is a floating portion on the recording medium 5, the floating portion may be pressed by the pressing portion 10b and adhered to the adhesive belt 6.

[0075] Incidentally, when the pressing portions 10a and 10b are supported at both ends of the inkjet head 20 as described above, if the pressing portions 10a and 10b lower or raise the pressing roller 11 while the printing operation by the inkjet head 20 is being performed, the vibration is transmitted to the inkjet head 20, and there is a possibility that the landing position of the ink on the recording medium 5 will shift, deteriorating the image quality. Therefore, it is preferably to minimize the operation of raising and lowering the pressing roller 11.

[0076] Therefore, the image forming unit 2 of the present embodiment is provided with detection sensors 19, 19 on the upstream side of the printing unit 9, and the detection sensors 19, 19 are configured to detect the height of the fluff at the side edges 5a, 5b of the recording medium 5. If the height of the fluff detected by the detection sensors 19, 19 is a height that does not interfere with the inkjet head 20, the vibration of the inkjet head 20 can be suppressed by omitting the pressing operation by the pressing portions 10a, 10b.

[0077] FIG. 11 is a flowchart showing an example of the operation procedure of the image forming apparatus 1 in the present embodiment. The operation procedure shown in FIG. 11 is a procedure realized by the CPU 31 in the control unit 30 executing a predetermined computer program.

[0078] When starting the operation shown in FIG. 11, the control unit 30 sets the positions of the end portions in the width direction of the recording medium 5 (step S20). For example, based on the width dimension of the recording medium 5 input by the user, the control unit 30 specifies the positions of the end portions in the width direction of the recording medium 5 and moves the detection sensors 19, 19 to the specified positions.

[0079] Then, the control unit 30 starts the printing operation (step S21). When starting the printing operation, the control unit 30 detects the heights of the side edges 5a and 5b of the recording medium 5 by the detection sensors 19 and 19 (step S22). Then, the control unit 30 stores the heights of the side edges 5a and 5b detected by the detection sensors 19 and 19 in the storage unit 32 (step S23). Subsequently, the control unit 30 conveys the recording medium 5 along the conveyance direction (step S24). At this time, the control unit 30 conveys the recording medium 5 by matching the conveyance amount per one conveyance of the recording medium 5 with the printing width L1 by the printing unit 9. Then, when the recording medium 5 is conveyed by the conveyance amount corresponding to the printing width L1, the control unit 30 stops the conveyance of the recording medium 5 (step S25).

[0080] When the control unit 30 stops the conveyance of the recording medium 5, it drives the inkjet head 20 of the printing unit 9 to perform a printing operation and forms an image corresponding to the printing width L1 on the recording medium 5 (step S26). At this time, the control unit 30 operates the inkjet head 20 as shown in FIGS. 8 and 9 or as shown in FIGS. 10 and 9.

[0081] Meanwhile, the control unit 30 performs the processes of steps S27 to S29 in parallel with the printing operation by the inkjet head 20. That is, the control unit 30 reads the heights of the side edge portions 5a and 5b at the current position of the printing unit 9 from the storage unit 32 (step S27), and determines whether the heights of the side edge portions 5a and 5b are equal to or greater than a predetermined value (step S28). As a result, when the heights of the side edge portions 5a and 5b are equal to or greater than the predetermined value (YES in step S28), the control unit 30 drives the pressing rollers 11 of the pressing portions 10a and 10b to move up and down as shown in FIGS. 8 and 9, or as shown in FIGS. 10 and 9, and presses the side edge portions 5a and 5b toward the outside of the recording medium 5 (step S29). When only the height of one of the side edge portions 5a and 5b is equal to or greater than the predetermined value, the control unit 30 performs an operation of pressing only the side edge portion having the height equal to or greater than the predetermined value. Further, when the heights of the side edge portions 5a and 5b are less than the predetermined value (NO in step S28), the control unit 30 does not operate the pressing portions 10a and 10b when the printing operation by the inkjet head 20 is being performed. That is, if the heights of the side edge portions 5a and 5b measured in advance on the upstream side of the printing unit 9 are less than the predetermined value, the control unit 30 does not operate the pressing portions 10a and 10b, thereby reducing the vibration of the inkjet head 20. Thereby, it is possible to suppress a decrease in the image quality of the image formed on the recording medium 5.

[0082] Thereafter, the control unit 30 determines whether printing has ended (step S30). If printing has not ended yet (NO in step S30), the process returns to step S22 and the above-described processes are repeated. On the other hand, if printing has ended (YES in step S30), the control by the control unit 30 ends.

[0083] In the above, a case was exemplified in which the heights of the side edges 5a and 5b of the recording medium 5 are detected by the detection sensors 19 and 19, and based on the detection results, it is determined whether or not to perform the pressing operations by the pressing portions 10a and 10b. However, the present invention is not limited to this. When the detection sensors 19 and 19 are not mounted, each time the printing operation by the inkjet head 20 is performed, the pressing portions 10a and 10b may be driven to press the side edges 5a and 5b.

[0084] Also, in the above, a case was exemplified in which the inkjet head 20 supports the pressing portions 10a and 10b at both ends thereof. However, the pressing portions 10a and 10b are not necessarily limited to being supported by the inkjet head 20. FIG. 12 is a diagram showing another aspect in which the pressing portions 10a and 10b are arranged at both ends of the inkjet head 20. In the example shown in FIG. 12, a support portion 24 for supporting the pressing portions 10a and 10b is provided on a rail portion 22 of a support member 21. The support portion 24 is a member that supports the pressing portions 10a and 10b so as to be movable along the rail portion 22 separately from the inkjet head 20. However, the support portion 24 moves along the rail portion 22 in the width direction of the recording medium 5 together with the inkjet head 20. Therefore, in the example shown in FIG. 12, even if the pressing portions 10a and 10b are driven to raise and lower the pressing roller 11, the vibration transmitted to the inkjet head 20 can be reduced. Therefore, it is possible to suppress a decrease in the image quality of the image formed on the recording medium 5 by the printing unit 9.

[0085] Also, by making the length L2 of the pressing portions 10a and 10b in the conveyance direction of the recording medium 5 longer than the amount of movement of the recording medium 5 when the intermittent conveyance by the adhesive belt 6 is performed twice, the printing operation by the printing unit 9 can be efficiently performed.

[0086] FIG. 13 is a perspective view showing an example in which the pressing portions 10a and 10b are extended to the downstream side of the recording medium 5. FIG. 14 is a side view showing an enlarged view of the pressing portions 10a and 10b. In FIG. 13, a part of the support member 21 is not shown. As shown in FIGS. 13 and 14, the pressing portions 10a and 10b are provided at both ends of the inkjet head 20. The pressing portions 10a and 10b are extended downward of the support member 21 toward the downstream side in the conveyance direction of the recording medium 5. In the conveyance direction of the recording medium 5, the length L2 of the pressing roller 11 of the pressing portions 10a and 10b is equal to or greater than the moving amount of the recording medium 5 when the intermittent conveyance of the recording medium 5 by the adhesive belt 6 is performed twice. That is, since the moving amount of the recording medium 5 when the intermittent conveyance of the recording medium 5 is performed once is equal to the printing width L1 by the inkjet head 20, the length L2 of the pressing roller 11 is configured to be equal to or greater than twice the printing width L1.

[0087] The pressing portions 10a and 10b configured as described above can press the areas for two printing operations by the printing portion 9 in the conveyance direction of the recording medium 5 by pressing the side edge portions 5a and 5b of the recording medium 5 outward of the recording medium 5. Therefore, when the intermittent operation of the recording medium 5 is performed after the printing operation by the printing portion 9, the recording medium 5 is conveyed in a state where the fuzz of the side edge portions 5a and 5b is already adhered to the adhesive belt 6 in the area where the inkjet head 20 moves. Therefore, for example, when performing the operation of pressing the side edge portion 5a on one end side of the recording medium 5 first as shown in FIGS. 10(a) to 10(c), it is possible to prevent the fuzz of the side edge portion 5a from interfering with the inkjet head 20.

[0088] In FIGS. 13 and 14, the case where the pressing portions 10a and 10b are supported by the inkjet head 20 is illustrated, but the present invention is not limited thereto. For example, as shown in FIG. 12, a support portion 24 for supporting the pressing portions 10a and 10b may be provided on the rail portion 22 of the support member 21, and the pressing portions 10a and 10b may be supported by the support portion 24.

[0089] (Third Embodiment) Next, a third embodiment of the present invention will be described. The overall configuration of the image forming apparatus 1 in this embodiment is the same as that in the first embodiment.

[0090] FIG. 15 is a perspective view of the image forming unit 2 in the third embodiment viewed obliquely from above. FIG. 16 is a plan view of the image forming unit 2 in the third embodiment. However, in FIGS. 15 and 16, illustration of the printing unit 9 provided on the downstream side of the side edge pressing unit 10 in the conveyance direction of the recording medium 5 is omitted. For example, as the printing unit 9, the same configuration as that in the first embodiment can be adopted.

[0091] Similar to the first embodiment, the image forming unit 2 of this embodiment includes a side edge pressing unit 10 between the recording medium pressing roller 8 and the printing unit 9 in the conveyance direction of the recording medium 5. The side edge pressing unit 10 presses the side edges 5a and 5b in the width direction orthogonal to the conveyance direction of the recording medium 5 outward of the recording medium 5 before printing is performed by the printing unit 9. The side edge pressing unit 10 includes a pressing unit 10a that presses one side edge 5a in the width direction of the recording medium 5 and a pressing unit 10b that presses the other side edge 5b.

[0092] Further, the side edge pressing unit 10 includes a support member 14 disposed so as to cross above the adhesive belt 6 in the width direction orthogonal to the conveyance direction of the recording medium 5. The support member 14 has a rail portion 15 extending in the width direction orthogonal to the conveyance direction. The above-described two pressing units 10a and 10b are attached to the rail portion 15 and are movable in the width direction (X direction) orthogonal to the conveyance direction of the recording medium 5. Therefore, the two pressing units 10a and 10b can be provided at positions adapted to the width dimension of the recording medium 5 in the width direction orthogonal to the conveyance direction of the recording medium 5.

[0093] The two pressing parts 10a and 10b include a pressing roller 11 and a lifting drive part 12 for lifting the pressing roller 11. And the pressing roller 11 of the present embodiment is arranged in a state where its rotation axis is inclined with respect to the width direction of the recording medium 5. That is, as shown in FIG. 16, the rotation axis 11a of the pressing roller 11 is arranged in a state of being inclined at a predetermined angle θ with respect to the width direction of the recording medium 5. The predetermined angle θ may be in the range of, for example, 30 to 60 degrees, and preferably 45 degrees. Further, the pressing parts 10a and 10b are arranged such that the side edge portions 5a and 5b of the recording medium 5 pass through substantially the central positions of the inclined pressing rollers 11. And the end portion 11b of the pressing roller 11 located outside the recording medium 5 is located on the downstream side in the conveyance direction of the recording medium 5 than the end portion 11c located inside the recording medium 5.

[0094] When the printing operation is started, the pressing parts 10a and 10b configured as described above lower the pressing roller 11 and continue to press the side edge portions 5a and 5b of the recording medium 5. Therefore, as the recording medium 5 is conveyed in the conveyance direction, the pressing roller 11 rotates. By this rotation operation, the pressing roller 11 presses the side edge portions 5a and 5b of the recording medium 5 toward the outside of the recording medium 5.

[0095] FIG. 17 is an enlarged view showing an example of the pressing operation by the pressing roller 11 of the pressing portion 10b. In FIG. 17, a perspective view of the pressing roller 11 viewed from the upstream side is shown. As shown by an arrow F8 in FIG. 17, when the recording medium 5 is conveyed toward the downstream side in the conveyance direction, the pressing roller 11 rotates about the rotation axis 11a as the recording medium 5 moves. At this time, the surface of the pressing roller 11 rotates in the direction shown by an arrow F9 in FIG. 17. That is, when there are lint standing on the side edge portion 5b sent from the upstream side in the conveyance direction, the pressing roller 11 rotates in a direction to push down the lint toward the outside of the recording medium 5. Therefore, the pressing roller 11 can press the lint on the side edge portion 5b of the recording medium 5 toward the outside of the recording medium 5 and adhere it to the adhesive belt 6. Then, there is no lint standing on the side edge portion 5b of the recording medium 5 conveyed to the downstream side after passing through the pressing portion 10b, and it is possible to prevent the lint from interfering with the inkjet head 20 in the downstream printing portion 9. In FIG. 17, only one pressing portion 10b is shown, but the same applies to the other pressing portion 10a.

[0096] As described above, the pressing portions 10a and 10b of the present embodiment continue to press the pressing roller 11 against the side edge portions 5a and 5b of the recording medium 5, and rotate the pressing roller 11 by the conveyance operation of the recording medium 5, thereby pressing the side edge portions 5a and 5b of the recording medium 5 toward the outside of the recording medium 5. Therefore, as described in the first or second embodiment, the image forming apparatus 1 of the present embodiment does not need to move the pressing portions 10a and 10b in the width direction orthogonal to the conveyance direction of the recording medium 5 when pressing the side edge portions 5a and 5b of the recording medium 5.

[0097] Also, according to the pressing portions 10a and 10b of the present embodiment, a configuration can be adopted in which image formation is performed on the recording medium 5 while continuously conveying the recording medium 5. FIG. 18 is a diagram showing a configuration example of an image forming unit 2 that performs image formation while continuously conveying the recording medium 5. This image forming unit 2 includes a printing unit 9 on the downstream side of the side edge pressing unit 10. The printing unit 9 includes a plurality of inkjet heads 20Y, 20M, 20C, and 20K arranged so as to cross the upper surface side of the recording medium 5 along the width direction orthogonal to the conveyance direction of the recording medium 5. These plurality of inkjet heads 20Y, 20M, 20C, and 20K eject inks of respective colors of Y, M, C, and K over the entire width direction of the recording medium 5. Therefore, when forming an image on the recording medium 5 in the image forming unit 2, it is not necessary to intermittently convey the recording medium 5 as in the first or second embodiment, and an image can be formed while continuously conveying the recording medium 5. And the pressing portions 10a and 10b can send out the recording medium 5 to the downstream printing unit 9 in a state where the fluff on the side edge portions 5a and 5b of the recording medium 5 is adhered to the adhesive belt 6. Therefore, each of the inkjet heads 20Y, 20M, 20C, and 20K can eject ink onto the recording medium 5 without interfering with the fluff.

[0098] By arranging the pressing roller 11 of the pressing portions 10a and 10b in an inclined state with respect to the width direction of the recording medium 5 in this way, it is possible to appropriately adhere the fluff on the side edge portions 5a and 5b of the recording medium 5 to the adhesive belt 6 while continuously conveying the recording medium 5. Therefore, the image forming apparatus 1 can perform the printing operation efficiently. Therefore, there is an advantage that the throughput of the image forming apparatus 1 can be improved.

[0099] (Modification example) As described above, several preferred embodiments of the present invention have been described. However, the present invention is not limited to the content described in the above embodiments, and various modification examples are applicable.

[0100] For example, in the above embodiment, the image forming apparatus 1 that conveys the recording medium 5, which is a fabric, in a roll-to-roll manner along a predetermined conveyance path was exemplified. However, the image forming apparatus 1 is not necessarily limited to one that conveys the recording medium 5 in a roll-to-roll manner.

[0101] Also, the pressing roller 11 used in each of the above embodiments may be configured as a brush-shaped roller. FIG. 19 is a diagram showing the brush-shaped pressing roller 11. As shown in FIG. 19, the pressing roller 11 is provided with a large number of brushes protruding from its outer peripheral surface. The large number of brushes are preferably formed of an elastic body. Such a brush-shaped pressing roller 11 can entangle lint when rolling while pressing the side edge portions 5a, 5b of the recording medium 5. Therefore, by configuring the pressing roller 11 as a brush-shaped roller, there is an advantage that the lint can be more reliably adhered to the adhesive belt 6. Incidentally, even when the pressing roller 11 is configured as a brush-shaped roller, the large number of brushes protruding from the outer peripheral surface are preferably made of a non-adhesive material.

[0102] Also, in the above embodiment, an example in which the pressing roller 11 presses the side edge portions 5a, 5b of the recording medium 5 toward the outside of the recording medium 5 was described. However, the pressing portions 10a, 10b are not necessarily limited to those that press the side edge portions 5a, 5b of the recording medium 5 by the pressing roller 11. For example, the pressing portions 10a, 10b may be provided with spatula-shaped pressing means instead of the above-described pressing roller 11.

[0103] Also, a configuration in which the configuration described in any one of several of the above-described embodiments is applied to other embodiments may be adopted. For example, the nozzle 18 described in the first embodiment may be applied to the image forming apparatus 1 of the second or third embodiment.

Explanation of Reference Numerals

[0104] 1 Image forming apparatus 2 Image forming unit 5 Recording medium 5a, 5b Side edge portions 6 Adhesive Belt 9 Printing Section 10 Side Edge Pressing Section (Pressing Means) 10a, 10b Pressing Sections 11 Pressing Roller 19 Detection Sensor 20 Inkjet Head 21 Support Member 30 Control Section

Claims

1. An adhesive belt that adhesively holds a recording medium and conveys it in a predetermined conveyance direction, A printing unit that performs printing on the recording medium at a predetermined position in the conveyance direction, Pressing means for pressing the side edge portion in the width direction orthogonal to the conveyance direction of the recording medium outward before printing is performed by the printing unit, Comprising, The pressing means is movable from a first position inside the side edge portion of the recording medium in the width direction to a second position outside the side edge portion of the recording medium, and is retractable with respect to the recording medium. By moving from the first position to the second position while advancing toward the recording medium, the side edge portion of the recording medium is pressed outward. An image forming apparatus characterized by this.

2. An adhesive belt that adhesively holds a recording medium and conveys it in a predetermined conveyance direction, A printing unit that performs printing on the recording medium at a predetermined position in the conveyance direction, Pressing means for pressing the side edge portion in the width direction orthogonal to the conveyance direction of the recording medium outward before printing is performed by the printing unit, Comprising, The adhesive belt intermittently conveys the recording medium in the conveyance direction, The printing unit performs printing on the recording medium when the conveyance of the recording medium by the adhesive belt has stopped, The pressing means performs an operation of pressing the side edge portion of the recording medium outward in parallel with the printing operation by the printing unit. An image forming apparatus characterized by this.

3. An adhesive belt that adhesively holds a recording medium and conveys it in a predetermined conveyance direction, A printing unit that performs printing on the recording medium at a predetermined position in the conveyance direction, Pressing means for pressing the side edge portion in the width direction orthogonal to the conveyance direction of the recording medium outward before printing is performed by the printing unit, A detection sensor that detects the height of the side edge portion of the recording medium, Comprising, The pressing means performs an operation of pressing the side edge portion of the recording medium outward based on the detection result by the detection sensor. An image forming apparatus characterized by this.

4. The recording medium is a fabric. The image forming apparatus according to any one of Claims 1 to 3, characterized by this.

5. The pressing means tilts the fluff generated on the side edge portion of the recording medium outward and adheres it to the adhesive belt. The image forming apparatus according to any one of Claims 1 to 4, characterized by this.

6. The image forming apparatus according to any one of claims 1 to 5, wherein the pressing means includes a pressing roller.

7. The image forming apparatus according to claim 6, wherein the surface of the pressing roller is made of a non-sticky material.

8. The image forming apparatus according to claim 1, wherein the pressing means retracts from the recording medium when moving from the second position to the first position.

9. The image forming apparatus according to any one of claims 1 to 8, wherein the pressing means is disposed upstream of the printing unit in the transport direction.

10. The printing unit performs printing by scanning the surface of the recording medium in the width direction when the conveyance of the recording medium is stopped, The image forming apparatus according to claim 2, wherein the pressing means is provided at both ends in the width direction of the printing unit, and performs an operation of pressing the side edge portion of the recording medium outward as the printing unit scans in the width direction.

11. A support member that supports the printing unit and the pressing means so as to be scanable in the width direction, further comprising, The image forming apparatus according to claim 10, wherein the pressing means is supported at both end positions of the printing unit by the support member.

12. The image forming apparatus according to claim 10 or 11, wherein the length of the pressing means in the transport direction is longer than the printing width in the transport direction by the printing unit.

13. The image forming apparatus according to any one of claims 10 to 12, wherein the length of the pressing means in the transport direction is equal to or greater than the amount of movement of the recording medium when the intermittent conveyance by the adhesive belt is performed twice.

14. The image forming apparatus according to claim 3, wherein the pressing means performs an operation of pressing the side edge portion of the recording medium outward when the detection sensor detects that the height of the side edge portion is equal to or greater than a predetermined value, and does not perform an operation of pressing the side edge portion of the recording medium outward when the detection sensor detects that the height of the side edge portion is less than the predetermined value.

15. The pressing roller is disposed so as to press the side edge portion upstream of the printing unit in the transport direction, The rotation axis of the pressing roller is inclined with respect to the width direction, and the end portion located outside the recording medium is located downstream in the conveyance direction from the end portion located inside the recording medium. The image forming apparatus according to claim 6 or 7.

16. An adhesive belt that adhesively holds a recording medium and conveys it in a predetermined conveyance direction, A printing unit that performs printing on the recording medium at a predetermined position in the conveyance direction, Pressing means for performing an operation of pressing the side edge portion in the width direction orthogonal to the conveyance direction of the recording medium toward the outside of the recording medium, A control method for controlling an image forming apparatus having: Before printing by the printing unit is performed, the method includes a step of causing the pressing means to perform an operation of pressing the side edge portion of the recording medium toward the outside of the recording medium, In the step, the pressing means can be moved from a first position inside the side edge portion of the recording medium in the width direction to a second position outside the side edge portion of the recording medium, and the pressing means can be advanced and retracted with respect to the recording medium. By moving the pressing means from the first position to the second position while the pressing means is advancing toward the recording medium, an operation of pressing the side edge portion of the recording medium toward the outside is performed. A control method characterized by this.

17. An adhesive belt that adhesively holds a recording medium and conveys it in a predetermined conveyance direction, A printing unit that performs printing on the recording medium at a predetermined position in the conveyance direction, Pressing means for performing an operation of pressing the side edge portion in the width direction orthogonal to the conveyance direction of the recording medium toward the outside of the recording medium, A control method for controlling an image forming apparatus having: Before printing by the printing unit is performed, the pressing means is configured to perform an operation of pressing the side edge portion of the recording medium toward the outside of the recording medium, By intermittently driving the adhesive belt, the recording medium is intermittently conveyed in the conveyance direction, When the conveyance of the recording medium by the adhesive belt is stopped, the printing unit is driven to perform printing on the recording medium, By driving the pressing means in parallel with the printing operation by the printing unit, an operation of pressing the side edge portion of the recording medium toward the outside is performed. A control method characterized by this.

18. An adhesive belt that adhesively holds a recording medium and conveys it in a predetermined conveyance direction, A printing unit that performs printing on the recording medium at a predetermined position in the conveyance direction; Pressing means for performing an operation of pressing a side edge portion in the width direction orthogonal to the conveyance direction of the recording medium outward of the recording medium; A detection sensor for detecting the height of the side edge portion of the recording medium; A control method for controlling an image forming apparatus having the above, Before printing is performed by the printing unit, the pressing means is configured to perform an operation of pressing the side edge portion of the recording medium outward of the recording medium; Based on the detection result by the detection sensor, it is determined whether or not to cause the pressing means to perform an operation of pressing the side edge portion of the recording medium outward. A control method characterized by this.

19. By causing the pressing means to perform an operation of pressing the side edge portion of the recording medium outward of the recording medium, the fluff generated at the side edge portion of the recording medium is tilted outward of the recording medium and adhered to the adhesive belt. The control method according to any one of claims 16 to 18, characterized in that.

20. When moving the pressing means from the second position to the first position, the control method according to claim 16, characterized in that the pressing means is retracted from the recording medium.

21. When it is detected by the detection sensor that the height of the side edge portion is equal to or greater than a predetermined value, the pressing means is caused to perform an operation of pressing the side edge portion of the recording medium outward, and when it is detected by the detection sensor that the height of the side edge portion is less than a predetermined value, the pressing means is not caused to perform an operation of pressing the side edge portion of the recording medium outward. The control method according to claim 18, characterized in that.

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