JP2020093408A - Image formation device - Google Patents

Abstract

To provide an image formation device that allows a medium to be properly adsorbed onto a belt and can suppress a landing deviation of liquid droplets caused by suction force.SOLUTION: A printer comprises: a conveyance plate 23 having a plurality of first suction holes 26 formed therein; a conveyance belt 24 having a plurality of second suction holes 27 formed therein, which slides on one surface of the conveyance plate 23; a suction part that suctions a sheet S on the conveyance belt 24 through the first suction holes 26 and the second suction holes 27; and an inkjet head 50, arranged to oppose to the conveyance plate 23 across the conveyance belt 24, which discharges ink droplets toward the sheet S being conveyed while being adsorbed onto the conveyance belt 24. The first suction holes 26 are formed so that opening areas thereof are smaller than opening areas of the second suction holes 27.SELECTED DRAWING: Figure 6

Description

The present invention relates to an inkjet image forming apparatus.

The inkjet printer described in Patent Document 1 includes a medium suction device that includes a medium suction portion that suctions a medium, an inkjet head that faces a part of the medium suction portion with the medium sandwiched, and a medium suction portion that is wrapped around the medium suction portion. And an endless conveyor belt. The transport belt is formed by weaving members into a mesh shape. The suction panel included in the medium suction unit has a plurality of suction holes. The negative pressure generating device included in the medium suction device sucks the medium on the conveyor belt through the suction holes and the mesh.

JP, 2016-163984, A

In the above-described inkjet printer, it is not clear whether the suction hole of the medium suction portion is larger or smaller than the mesh opening (mesh opening diameter) of the conveyor belt. However, since the conveyor belt is woven, it is estimated that the mesh opening of the conveyor belt is smaller than the opening area of the suction holes. In such a case, the suction force generated by the negative pressure generator directly acts on the medium from the large suction hole through the mesh of the small conveyor belt, so that the suction force (the flow rate of air related to suction) on the conveyor belt is more than necessary. Can become large. Then, not only the medium is adsorbed on the conveyor belt, but also the ink droplets ejected from the inkjet head may be sucked. As a result, the landing position of the ink droplet on the medium is displaced (landing deviation occurs), which causes a problem that the image is disturbed.

In order to solve the above problems, the present invention provides an image forming apparatus capable of properly adsorbing a medium onto a belt and suppressing deviation of landing of droplets due to suction force.

In order to achieve the above-mentioned object, the image forming apparatus of the present invention is a belt in which a transport plate having a plurality of first suction holes and a plurality of second suction holes are formed and which slides on one surface of the transport plate. A suction unit that sucks the medium on the belt through the first suction hole and the second suction hole, and a suction unit that is disposed so as to face the transport plate with the belt sandwiched therebetween, and is transported while being suctioned on the belt. A droplet discharge head for discharging droplets toward the medium, and the first suction hole is formed to have an opening area smaller than that of the second suction hole.

In this case, it is preferable that the second suction holes are formed in such a size that two or more first suction holes can be seen from one second suction hole.

In this case, the transport plate includes a plate body having a plurality of fitting grooves formed therein, and a plurality of opening members having the plurality of first suction holes formed therein and mounted in the plurality of fitting grooves. Is preferred.

In this case, the opening member has the plurality of first suction holes formed therein, and an opening surface portion that forms the same plane as the upper surface of the plate body in a state of being mounted in the fitting groove, and a downward direction from the opening surface portion. It is preferable to include a pair of fixing pieces formed in an extended state and hooked on the lower surface of the plate body in a state of being mounted in the fitting groove.

According to the present invention, the medium can be properly adsorbed on the belt, and the landing deviation of the droplet due to the suction force can be suppressed.

It is a schematic diagram (front view) showing an internal structure of a printer concerning one embodiment of the present invention. FIG. 1 is a schematic view (front view) showing an inkjet head and a suction conveyance unit of a printer according to an embodiment of the present invention. FIG. 3 is a plan view showing an adsorption conveyance unit (excluding a conveyance belt) according to the embodiment of the present invention. It is a top view which expands and shows a part of adsorption conveyance unit which concerns on one Embodiment of this invention. It is a perspective view showing an opening member of a suction conveyance unit concerning one embodiment of the present invention. FIG. 5 is a VI-VI sectional view of FIG. 4.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, "Fr" indicates "front", "Rr" indicates "rear", "L" indicates "left", "R" indicates "right", and "U" indicates " “Up” and “D” indicate “down”. Further, the “conveyance direction” refers to a direction in which the sheet S is conveyed, and “upstream” and “downstream” and similar terms refer to “upstream” and “downstream” in the conveyance direction and similar concepts. ..

[Outline of Printer]
An overall configuration of a printer 1 as an inkjet image forming apparatus will be described with reference to FIGS. 1 to 4. FIG. 1 is a schematic view (front view) showing the internal structure of the printer 1. FIG. 2 is a schematic view (front view) showing the inkjet head 50 and the suction transport unit 20. FIG. 3 is a plan view showing the suction transport unit 20 (excluding the transport belt 24 and the like). FIG. 4 is an enlarged plan view showing a part of the suction conveyance unit 20.

As shown in FIG. 1, the printer 1 includes an apparatus main body 2 having a substantially rectangular parallelepiped appearance. At the lower part of the apparatus main body 2, a paper feed cassette 3 for accommodating a paper sheet S (medium) is detachably provided. A paper discharge tray 4 is provided on the upper left side of the apparatus body 2.

Further, the printer 1 includes a paper feeding device 10, a transport device 11, a recording device 12, a maintenance device 13, and a control device 14 inside the device body 2. The paper feeding device 10 is provided on the upstream side of the conveyance path 5 extending from the paper feeding cassette 3. The transport device 11 and the recording device 12 are provided in a substantially central portion of the device body 2. The maintenance device 13 is provided between the transport device 11 and the paper discharge tray 4. The control device 14 centrally controls the operation of the printer 1 based on a program stored in advance.

The transport path 5 has a supply path 5A formed in a substantially U shape between the paper feed cassette 3 and the transport device 11, and a discharge path 5B formed between the transport device 11 and the discharge tray 4. Is included. A registration roller pair 16 that temporarily blocks the sheet S and aligns the leading end positions is provided on the downstream side of the supply path 5A. In the supply path 5A and the discharge path 5B, a plurality of conveyance roller pairs 17 and 18 for rotating and conveying the sheet S while sandwiching the sheet S are provided at appropriate places.

<Conveyor>
As shown in FIG. 1, the transfer device 11 includes a suction transfer unit 20, a discharge unit 30, and an elevating unit 40. The suction conveyance unit 20 is provided below the recording device 12. The discharge unit 30 is provided on the left side of the suction conveyance unit 20. The elevating unit 40 is provided below the suction conveyance unit 20.

<Suction transfer unit>
As shown in FIGS. 1 to 3, the suction transport unit 20 includes a transport frame 21, a drive mechanism 22, a transport plate 23, a transport belt 24, and a suction unit 25.

(Conveyor frame)
The transport frame 21 is formed in a frame shape by bridging an erection frame (not shown) between a pair of main frames 21A (see FIG. 3) that are spaced apart in the front-rear direction. The transport frame 21 is supported by a lifting unit 40 so as to be liftable (see FIG. 1).

(Drive mechanism)
As shown in FIGS. 2 and 3, the drive mechanism 22 includes a drive roller 22A, a driven roller 22B, and three tension rollers 22C. These rollers 22A, 22B, 22C are rotatably supported by the pair of main frames 21A. The drive roller 22A is arranged on the upper left side of the transport frame 21, and is connected to the transport motor M via a gear train (not shown). The driven roller 22B is arranged on the lower right side of the transport frame 21. The three tension rollers 22C are arranged below the drive roller 22A, above the driven roller 22B, and to the left.

(Conveyor plate)
As shown in FIG. 3, the carrier plate 23 is formed of, for example, a synthetic resin material into a substantially rectangular flat plate shape when viewed from a plane. The transport plate 23 is arranged between the pair of main frames 21A and is fixed to the pair of main frames 21A. The transport plate 23 is disposed below and facing the inkjet head 50 included in the recording device 12 (see FIG. 2 ). A plurality of first suction holes 26 are formed in the carrier plate 23 (see FIG. 4). The first suction hole 26 is a circular hole that penetrates the transport plate 23 in the thickness direction. The details of the carrier plate 23 and the first suction holes 26 will be described later.

(Conveyor belt)
As shown in FIG. 2, the conveyor belt 24 (belt) is formed of, for example, a synthetic resin material in an endless shape (annular shape). The conveyor belt 24 is wound around the conveyor plate 23 and the plurality of rollers 22A, 22B, 22C. The upper surface of the transport belt 24 constitutes a substantially horizontal transport surface 24A on which the sheet S is in close contact. The conveyor belt 24 slides on the upper surface (one surface) of the conveyor plate 23 by operating the conveyor motor M and rotating the drive roller 22A (see the arrow in FIG. 1). The transport belt 24 has a plurality of second suction holes 27 (see FIG. 4). The second suction hole 27 is a circular hole that penetrates the conveyor belt 24 in the thickness direction.

(Suction part)
As shown in FIG. 2, the suction unit 25 is provided below the transport plate 23 at a position surrounded by the transport belt 24. The suction unit 25 includes four blower fans 28 that make the space below the transport plate 23 a negative pressure (see FIG. 3 ). The suction unit 25 (blower fan 28) sucks the sheet S on the transport belt 24 (transport surface 24A) through the first suction hole 26 and the second suction hole 27. The sheet S is transported together with the transport belt 24 while being attracted to the transport surface 24A of the transport belt 24.

<Discharge unit>
As shown in FIG. 1, the discharge unit 30 includes a discharge driving roller 30A, a discharge driven roller 30B, and a discharge conveyance belt 31 wound around these rollers 30A and 30B. The discharge drive roller 30A is connected to the transport motor M via a gear train or the like (not shown). The discharge/conveyance belt 31 runs in the direction of the arrow in FIG. 1 by operating the conveyance motor M and rotating the discharge driving roller 30A. A drying device 32 for drying the ink on the sheet S is provided above the discharge/conveyance belt 31.

<Elevating unit>
Although the detailed description of the structure is omitted, the elevating unit 40 has a function of elevating the suction conveyance unit 20 between the recording position and the retreat position. The recording position is a position for causing the suction conveyance unit 20 to approach the inkjet head 50 and forming an image on the sheet S. The retracted position is a position where the suction conveyance unit 20 is separated from the inkjet head 50 and a maintenance operation (described later) can be performed.

<Recording device>
As shown in FIGS. 1 and 2, the recording device 12 includes a plurality of inkjet heads 50 (droplet ejection heads). The plurality of inkjet heads 50 are provided so as to correspond to inks of four colors (yellow, magenta, cyan, black). The four color inks are stored in the four ink tanks 51. The four ink tanks 51 are arranged on the upper portion of the apparatus main body 2. An ink tank 51 that stores ink of a corresponding color is connected to the inkjet head 50.

The inkjet head 50 is arranged so as to face the transport plate 23 with the transport belt 24 interposed therebetween. The inkjet head 50 has a nozzle surface 50A that faces the transport belt 24 (transport surface 24A) with a predetermined gap therebetween (see FIG. 2). The nozzle surface 50A is provided parallel to the transport surface 24A. On the nozzle surface 50A, a plurality of ejection nozzles (not shown) that eject ink droplets onto the sheet S on the transport surface 24A are formed. The inkjet head 50 is arranged so as to be able to eject ink droplets in a wider range than the width (length in the front-rear direction) of the sheet S.

<Maintenance device>
As shown in FIG. 1, the maintenance device 13 includes a cap unit 55, a wipe unit 56, and a slide unit 57.

The cap unit 55 includes a plurality of caps 55A that are in close contact with the nozzle surfaces 50A of the plurality of inkjet heads 50. The plurality of caps 55A have a function of preventing ink in the ejection nozzles from drying and preventing clogging of the ejection nozzles. The wipe unit 56 includes a plurality of wipers 56A that move while being in contact with the nozzle surfaces 50A of the plurality of inkjet heads 50. The wiper 56A has a function of wiping off ink or the like adhering to the nozzle surface 50A to clean the nozzle surface 50A. The slide unit 57 includes a cap carriage on which the cap unit 55 is mounted and a wipe carriage on which the wipe unit 56 is mounted (both not shown). The slide unit 57 has a function of moving the cap unit 55 or the wipe unit 56 directly below the inkjet head 50.

[Print operation]
Here, the operation of the printer 1 will be described with reference to FIG. The control device 14 executes the image forming process (printing operation) as follows. The suction transport unit 20 is assumed to be located at the recording position.

The sheet feeding device 10 separates the sheets S in the sheet feeding cassette 3 one by one and sends them to the supply path 5A. The sheet S passes through the supply path 5A and is temporarily blocked by the registration roller pair 16. After performing skew correction on the sheet S, the registration roller pair 16 sends the sheet S toward the suction conveyance unit 20 (conveyance surface 24A) in accordance with the ink ejection operation. The suction unit 25 (blower fan 28) generates a negative pressure and applies a suction force to the sheet S on the transport surface 24A. The transport belt 24 transports the sheet S adsorbed on the transport surface 24A in the arrow direction of FIG. The inkjet head 50 ejects ink droplets (droplets) toward the sheet S that is conveyed while being attracted to the conveyance belt 24. As a result, an ink image is formed on the sheet S that is transported while being attracted to the transport surface 24A.

The image-formed sheet S is sent from the carrying belt 24 to the discharging and carrying belt 31. The drying device 32 dries the ink on the sheet S passing through the discharge/conveyance belt 31. Then, the sheet S is discharged from the discharge/conveyance belt 31 to the discharge tray 4 through the discharge path 5B.

[Maintenance operation]
Next, the maintenance operation of the inkjet head 50 will be described. Specifically, a capping operation for mounting the cap 55A on the inkjet head 50 and a wiping operation for wiping off the ink adhering to the nozzle surface 50A will be described. The maintenance operation (capping operation, wiping operation) is automatically (or based on a user's instruction) started by the controller 14 while the printing operation is stopped.

First, the capping operation will be described. The elevating unit 40 lowers the suction conveyance unit 20 from the recording position to the retracted position. The slide unit 57 moves the cap carriage directly below the inkjet head 50. Then, the elevating unit 40 raises the suction conveyance unit 20 and pushes up the cap unit 55 mounted on the cap carriage. The cap 55A of the cap unit 55 is in close contact with the nozzle surface 50A of the inkjet head 50 and seals the ejection nozzle. The cap carriage is returned to its original position.

As described above, the ink in the ejection nozzle is kept moist, and clogging of the ejection nozzle can be prevented. To end the capping operation, the inside of the cap 55A is opened to the atmosphere by an atmosphere communication mechanism (not shown), and then the reverse procedure of the capping operation is executed.

The wiping operation is performed in the same procedure as the capping operation described above. That is, after the elevating unit 40 lowers the suction conveyance unit 20 to the retracted position, the slide unit 57 moves the wipe carriage to directly below the inkjet head 50. After that, the elevating unit 40 raises the suction/conveyance unit 20 and pushes up the wipe unit 56 mounted on the wipe carriage to bring the tip end portion of the wiper 56A into close contact with the nozzle surface 50A. The wipe unit 56 moves the tip of the wiper 56A while contacting the nozzle surface 50A, and wipes off the ink adhering to the nozzle surface 50A. When the wiping operation is ended, the reverse procedure of the wiping operation described above is executed.

By the way, in the printing operation, the suction force exerted by the suction unit 25 on the transport surface 24A acts not only on the sheet S but also on the ink droplets ejected from the inkjet head 50 (ejection nozzle). If a large suction force acts on the ink droplets ejected from the ejection nozzles, the landing position of the ink droplets on the sheet S may shift and the image may be disturbed. On the contrary, if the suction force is too weak, the sheet S cannot be attracted to the transport surface 24A, and the sheet S may be wrinkled or the sheet S may slip on the transport belt 24. Even in this case, the landing position of the ink droplet is displaced, which causes the image to be disturbed. Therefore, the printer 1 according to the present embodiment is provided with a configuration in which the sheet S can be properly adsorbed on the transport belt 24 and the landing deviation of ink droplets due to the suction force can be suppressed.

[Details of carrier plate]
First, the details of the carrier plate 23 will be described with reference to FIGS. 3 to 6. FIG. 5 is a perspective view showing the opening member 65 of the suction conveyance unit 20. FIG. 6 is a sectional view taken along line VI-VI in FIG.

As described above, the carrier plate 23 is made of synthetic resin, and is manufactured by injecting thermoplastic synthetic resin into the mold. The volume of the molten resin filled in the mold shrinks when it is cooled and solidified (molding shrinkage). If the carrier plate 23 is formed as one member, it is difficult to accurately form the plurality of first suction holes 26 and the like because the dimensional change (tolerance) due to molding shrinkage is large. Therefore, the transport plate 23 has a structure in which another component having the first suction hole 26 is attached to the plate body 60.

As shown in FIGS. 3 and 4, the transport plate 23 includes a plate body 60 and a plurality of opening members 65. Note that FIG. 3 illustrates a state in which the transport belt 24 and the opening member 65 are removed. Further, FIG. 4 shows only the plate body 60, the state in which the opening member 65 is attached to the plate body 60, and the state in which the transport belt 24 is attached in one sheet.

<Board body>
As shown in FIG. 3, the plate body 60 is a substantially rectangular flat plate that forms the outer shape of the transport plate 23. A plurality of fitting grooves 61 are formed in the plate body 60. The fitting groove 61 is a rectangular recess elongated in the transport direction and having rounded corners. The plurality of fitting grooves 61 are arranged in a row in the transport direction (left-right direction) at substantially equal intervals. Further, the plurality of fitting grooves 61 (rows of the fitting grooves 61) arranged in a line are arranged in the front-rear direction at predetermined intervals. The rows of the fitting grooves 61 that are adjacent to each other in the front-rear direction are displaced in the transport direction. That is, the plurality of fitting grooves 61 are arranged in a zigzag shape.

As shown in FIGS. 4 and 6, two through holes 62 are formed in the bottom surface of the fitting groove 61. The through hole 62 is a circular hole and has an opening area (diameter) larger than that of the second suction hole 27 of the conveyor belt 24. Note that the number of the through holes 62 formed is not limited to two, and may be one or more. Further, the shape of the through hole 62 is not limited to a circular shape, and may be a polygonal shape (not shown).

<Opening member>
As shown in FIGS. 4 and 5, the opening member 65 is formed in a rectangular shape with rounded corners corresponding to the fitting groove 61 when seen in a plan view. The plurality of opening members 65 are components mounted (fitted) in the plurality of fitting grooves 61. The opening member 65 includes an opening surface portion 66 and a pair of fixing pieces 67.

As shown in FIG. 5, the opening surface portion 66 is a rectangular flat plate with rounded corners. A plurality of first suction holes 26 are formed in the opening surface portion 66. The pair of fixing pieces 67 are formed to extend downward from both ends of the opening surface portion 66 in the transport direction. 67 A of nail|claw parts are projected to the lower end part of a pair of fixing piece 67 at the conveyance direction outer side (direction which mutually separates). An inclined surface is formed on the outer surface of the claw portion 67A toward the outer side in the transport direction from the lower side to the upper side.

When the opening member 65 is inserted into the fitting groove 61, the pair of claw portions 67A (the inclined surfaces thereof) come into contact with the edges of the fitting groove 61 (opening surface portion 66), and the pair of fixing pieces 67 approach each other. Bend. When the pair of claw portions 67A get over the opening surface portion 66, the pair of fixing pieces 67 return to their original state by their elasticity. As shown in FIG. 6, when the opening member 65 is mounted in the fitting groove 61, the opening surface portion 66 forms substantially the same plane as the upper surface of the plate body 60. Further, in this state, the pair of claw portions 67A (the pair of fixing pieces 67) are hooked on the lower surface of the plate body 60. As a result, the opening member 65 is placed in the fitting groove 61.

[First suction hole, second suction hole]
As shown in FIG. 4, the plurality of first suction holes 26 are arranged in a staggered manner on the opening surface portion 66 of the opening member 65. Further, the first suction hole 26 is formed in a tapered shape whose diameter decreases from the lower surface to the upper surface of the opening surface portion 66. The plurality of second suction holes 27 are arranged in a staggered manner on the conveyor belt 24. Although the plurality of first suction holes 26 and the plurality of second suction holes 27 are arranged in a staggered pattern, the arrangement is not limited to this, and they may be arranged in a grid pattern (not shown).

As shown in FIGS. 4 and 6, the opening area of the first suction hole 26 is smaller than that of the second suction hole 27. Specifically, the second suction holes 27 are formed in such a size that the two first suction holes 27 can be seen from the one second suction hole 27. More specifically, the diameter of the second suction hole 27 is set to about 2 to 2.5 times the diameter of the first suction hole 26.

In addition, "it is possible to visually check the two first suction holes 26 from the one second suction hole 27" means that a part or all of the two first suction holes 26 are visually checked from the one second suction hole 27. It means that you can do it. In addition, it is not necessarily required that all or some of the two first suction holes 26 can be seen from all the second suction holes 27. That is, the sizes of the first and second suction holes 26, 27 may be set so that at least two first suction holes 26 are partially included in the range of one second suction hole 27. .. Further, the sizes of the first and second suction holes 26, 27 may be set so that two or more first suction holes 26 can be viewed from one second suction hole 27 (not shown). No). Further, the number, arrangement, size, etc. of the first and second suction holes 26, 27 can be freely adjusted. Further, the shapes of the first and second suction holes 26, 27 are not limited to circular shapes, and may be polygonal shapes (not shown).

In the printer 1 according to the present embodiment described above, the first suction hole 26 opened in the transport plate 23 is formed smaller than the second suction hole 27 opened in the transport belt 24. According to this configuration, the suction force dispersed through the plurality of first suction holes 26 acts on the sheet S on the belt through the second suction holes 27, so that the first suction holes 26 are larger than the second suction holes 27. Compared with the case, it is possible to suppress an unnecessary increase in the suction force acting on the conveyor belt 24. Therefore, the ink droplets ejected from the inkjet head 50 (ejection nozzle) are not sucked into the first and second suction holes 26 and 27, and the landing position of the ink droplet on the sheet S is suppressed. .. As a result, the sheet S can be properly adsorbed on the transport belt 24, and the deviation of landing of ink droplets due to the suction force can be suppressed. Then, it is possible to suppress image disturbance due to landing deviation of ink droplets,

Further, according to the printer 1 according to the present embodiment, the fitting groove 61 and the opening member 65 are divided into a plurality of parts, so that the fitting groove 61 and the opening member 65 are miniaturized. Shrinkage (molding shrinkage) at the time of molding (the plate body 60 and the opening member 65) can be reduced. Thereby, the dimensional tolerance due to molding shrinkage can be reduced. Further, since the opening member 65 is formed as a member different from the plate body 60, the arrangement of the fitting groove 61 and the opening member 65 can be freely set according to the size of the sheet S and the like. Furthermore, by preparing various types of opening members 65 in which the size and number of the first suction holes 26 are changed, it is possible to freely change the suction force applied to the sheet S simply by replacing the opening members 65. As a result, the suction force can be adjusted at a lower cost than in the case where all the transport plates 23 are replaced.

Further, according to the printer 1 according to the present embodiment, by hooking the fixing piece 67 on the lower edge of the fitting groove 61, the opening member 65 can be held in the fitting groove 61. Further, by releasing the catch of the fixing piece 67, the opening member 65 can be easily removed from the fitting groove 61. That is, the opening member 65 can be easily replaced.

In addition, in the printer 1 according to the present embodiment, the plate body 60 and the opening member 65 are formed separately in consideration of the fact that the transport plate 23 is made of synthetic resin, but the present invention is not limited to this. .. For example, when molding shrinkage is extremely small (when a synthetic resin having a small shrinkage ratio is used, when the transport plate 23 is small, etc.), the transport plate 23 may be integrally formed. Further, the transport plate 23 is not limited to synthetic resin, and may be formed of, for example, a metal or a porous body (pumice, etc.) having a large number of ventilation holes.

In the printer 1 according to the present embodiment, the inkjet head 50 is used as an example of the droplet discharge head, but the present invention is not limited to this. For example, the droplet discharge head may discharge liquid resin or the like. Further, the medium is not limited to paper and may be resin or glass.

It should be noted that the description of the above-described embodiment shows one aspect of the image forming apparatus according to the present invention, and the technical scope of the present invention is not limited to the above-described embodiment.

1 Printer (image forming device)
23 Conveyor Plate 24 Conveyor Belt (Belt)
25 suction part 26 1st suction hole 27 2nd suction hole 50 inkjet head (droplet discharge head)
60 plate body 61 fitting groove 65 opening member 66 opening surface portion 67 fixing piece S sheet (medium)

Claims (4)

A carrier plate having a plurality of first suction holes,
A belt having a plurality of second suction holes and sliding on one surface of the carrier plate;
A suction unit for sucking the medium on the belt through the first suction hole and the second suction hole;
A droplet discharge head that is arranged to face the transport plate with the belt interposed therebetween and that discharges droplets toward the medium that is transported while being attracted onto the belt;
The image forming apparatus, wherein the first suction hole is formed to have an opening area smaller than that of the second suction hole. The image forming according to claim 1, wherein the second suction holes are formed in a size such that two or more first suction holes can be viewed from one second suction hole. apparatus. The carrier plate is
A plate body having a plurality of fitting grooves formed therein,
The image forming apparatus according to claim 1 or 2, further comprising: a plurality of opening members formed with the plurality of first suction holes and fitted into the plurality of fitting grooves. The opening member is
An opening surface portion that forms the plurality of first suction holes and forms the same plane as the upper surface of the plate body in a state of being mounted in the fitting groove,
The pair of fixing pieces formed to extend downward from the opening surface portion and hooked on the lower surface of the plate main body in a state of being attached to the fitting groove are included. Image forming device.

Images