Conveying device

Abstract

To provide a conveying device that can stably suck and convey a sheet member and prevent deterioration of the image quality due to mist.SOLUTION: A conveying device includes: a conveying belt 21 which has a plurality of belt holes 21a, and sucks and conveys a sheet member P by negative pressure generated within the belt holes 21a; and a platen 26 which is provided on the opposite side of the conveying belt 21 to a suction surface of the sheet member P, supports the conveying belt 21, and has a plurality of suction holes 32. The belt holes 21a and the suction holes 32 are formed at positions where they do not overlap in a direction (front-to-back direction) perpendicular to a conveying direction of the sheet member P when viewed vertically from the suction surface side of the conveying belt 21.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a conveying device that conveys a sheet member by suction holding the sheet member. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there has been proposed an inkjet printing apparatus that prints by ejecting ink from an inkjet head onto a sheet member made of paper, film, or the like while conveying the sheet member.

[0003] A conveying device using a conveying belt has been proposed as a conveying device for conveying sheet materials in such inkjet printing devices. Specifically, a suction fan is provided on the back side of the conveying surface of the conveying belt that conveys the sheet material, and negative pressure is generated in a number of belt holes formed in the conveying belt by rotation of the suction fan, thereby sucking and adhering the sheet material to the conveying belt.

[0004] In this type of suction conveying method, a platen is provided under the conveying belt, and a number of intermediate pressure chambers called cells are provided on the sliding surface side with the conveying belt, generating negative pressure across the entire conveying surface and achieving adsorption of the sheet material. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-038607 Summary of the Invention [Problem to be solved by the invention]

[0006] In the suction transport method described above, the force (adsorption force) that attracts the sheet material is determined by the output of the suction fan that generates negative pressure. Since a high adsorption force is required to transport the sheet material stably so that it does not separate from the transport surface, it is desirable for the output of the suction fan to be as high as possible.

[0007] However, when the output of the suction fan is increased, a suction wind (suction wind) is generated on the upper surface of the conveyor belt, and the higher the fan output, the faster the suction wind speed. In suction conveyance, mist (tiny ink droplets other than the main droplets) generated when ink is ejected is blown away by the suction wind and lands at a position away from the main droplets, causing image degradation and blurring.

[0008] Furthermore, when the speed of the suction air is increased, the distance that the mist is blown increases, causing the mist to land at a position farther away from the main droplet, resulting in further deterioration of image quality.

[0009] Therefore, for example, in Patent Document 1, an opening for generating negative pressure is provided in the cell of the platen, and the cross-sectional area of ​​the opening is set to 0.8 mm 2 The following methods have been proposed to suppress the suction wind.

[0010] However, if the head gap, which is the gap between the inkjet head nozzle surface and the sheet material, becomes wider (for example, 1.4 mm or more), the time and distance that the floating mist is sucked in by the suction air becomes longer, making it more likely that the mist will land in a position away from the main droplet, worsening mist contamination.For this reason, even if the head gap becomes wider, it is necessary to keep the mist contamination to a level that is not visible to the naked eye.

[0011] In addition, as in Patent Document 1, it is possible to suppress the suction wind by reducing the opening size of the platen cells or by reducing the output of the suction fan, but reducing the opening size of the platen cells requires high processing precision, which increases costs, and reducing the output of the suction fan reduces the sheet material adsorption performance.

[0012] In view of the above circumstances, an object of the present invention is to provide a conveying device that can stably suck and convey a sheet member and prevent deterioration of image quality due to mist. [Means for solving the problem]

[0013] The conveying device of the present invention comprises a conveying belt having a plurality of belt holes that adsorbs and conveys sheet materials by negative pressure generated within the belt holes, and a support member that is provided on the opposite side of the conveying belt from the adsorption surface of the sheet material, supports the conveying belt, and has a plurality of suction holes, and the belt holes and suction holes are formed in positions that do not overlap in a direction perpendicular to the conveying direction of the sheet material when viewed vertically from the suction surface side of the conveying belt. [Effects of the Invention]

[0014] According to the conveying device of the present invention, the belt holes in the conveying belt and the suction holes in the support member are formed in positions that do not overlap in a direction perpendicular to the conveying direction of the sheet material, so that the suction wind can be suppressed while maintaining the adhesive force of the sheet material, thereby allowing the sheet material to be suction-conveyed stably and preventing deterioration of image quality due to mist. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of an inkjet printing apparatus using an embodiment of a conveying device of the present invention; [Figure 2] FIG. 1 is a diagram showing a schematic configuration of an image forming unit; [Figure 3] A partially enlarged top view of the belt holes in the conveyor belt and the recesses and suction holes in the platen. [Figure 4] Enlarged cross-sectional view of the conveyor belt, platen, and platen plate along line AA in Figure 3. [Figure 5] FIG. 4A is an enlarged cross-sectional view of the recess and suction hole along the line BB shown in FIG. 3, and FIG. 4B is a view showing a case where the belt hole and the suction hole are formed at the same position in the front-rear direction. [Figure 6] A block diagram showing the schematic configuration of a control system of an inkjet printing device. [Figure 7] FIG. 10 is a diagram showing an example in which a suction hole is formed at the center of the bottom surface of a recess. [Figure 8] A diagram showing an example of a belt with larger hole diameter. [Figure 9] FIG. 10 is a diagram showing an example of a specific configuration that allows the distance between the belt hole and the suction hole in the front-rear direction to be changed. [Figure 10] Graph showing the relationship between the head gap (HG), the suction air speed at the belt holes, and the amount of mist contamination [Figure 11] FIG. 10 is a diagram showing an example of a table that associates the head gap with the movement amount of the belt abutment portion. DETAILED DESCRIPTION OF THE INVENTION

[0016] An inkjet printing apparatus using an embodiment of the conveying device of the present invention will be described in detail below with reference to the drawings. The inkjet printing apparatus of this embodiment is characterized by the configuration of its conveying unit, but its overall configuration will be described first. FIG. 1 is a schematic diagram of an inkjet printing apparatus 1 of this embodiment. The up, down, left, and right directions indicated by arrows in FIG. 1 are the up, down, left, and right directions of the inkjet printing apparatus 1 of this embodiment. The front side of the paper surface of FIG. 1 is the forward direction, and the back side is the rear direction. In this embodiment, the direction from left to right is the conveying direction of the sheet material P.

[0017] As shown in FIG. 1, the inkjet printing apparatus 1 of this embodiment includes an image forming unit 2 and a conveying unit 3.

[0018] The image forming unit 2 prints an image on a sheet member P (for example, a printing paper) conveyed by the conveying unit 3. The image forming unit 2 includes a plurality of line heads 11. In this embodiment, the image forming unit 2 includes four line heads 11.

[0019] The line heads 11 eject ink onto the sheet material P to print an image. The four line heads 11 eject ink of different colors (for example, black, cyan, magenta, and yellow). The four line heads 11 extend in a direction (front-rear direction) perpendicular to the transport direction (left-right direction) of the sheet material P, and are arranged in parallel above the transport unit 3 along the transport direction of the sheet material P. Each line head 11 has a plurality of inkjet heads 12. In this embodiment, each line head 11 has six inkjet heads 12. In this embodiment, the inkjet heads 12 correspond to the ejection unit of the present invention.

[0020] The six inkjet heads 12 in each line head 11 are arranged in a staggered pattern in the front-to-rear direction, as shown in Fig. 2. That is, in each line head 11, the six inkjet heads 12 arranged in the front-to-rear direction are arranged with their positions shifted alternately in the left-to-right direction.

[0021] Each inkjet head 12 has a plurality of nozzles (not shown) that open to a discharge surface 12a, which is the lower surface facing a transport surface 21b of a transport belt 21 (described later), and discharges ink from the nozzles.

[0022] The conveying section 3 conveys the sheet material P fed from a paper feed section (not shown) while holding it by suction.

[0023] The conveying section 3 includes a conveying belt 21, a driving roller 22, driven rollers 23 to 25, a platen 26, a platen plate 27, a suction section 28, and a plurality of paper pressure rollers 29. In this embodiment, the platen 26 corresponds to the support member of the present invention.

[0024] The conveyor belt 21 holds and conveys the sheet material P by suction. The conveyor belt 21 is a circular belt that is stretched over a drive roller 22 and driven rollers 23 to 25. The conveyor belt 21 has a large number of belt holes 21a formed therein. FIG. 3 is a partially enlarged top view of the belt holes 21a of the conveyor belt 21 and recesses 31 and suction holes 32, which will be described later, of the platen 26. In FIG. 3, the belt holes 21a of the conveyor belt 21 are indicated by dotted circles, the recesses 31 are indicated by solid squares, and the suction holes 32 are indicated by solid circles.

[0025] 3, the belt holes 21a are arranged at a predetermined pitch in each row along the conveying direction (left-right direction). In addition, two rows of belt holes 21a adjacent to each other in a direction perpendicular to the conveying direction are arranged so as to be shifted by half a pitch in the left-right direction. In other words, the belt holes 21a are arranged in a staggered pattern.

[0026] The conveyor belt 21 sucks and adsorbs the sheet material P onto the conveying surface 21b by negative pressure generated in the belt holes 21a by driving the fan 38 of the suction unit 28, which will be described later. The conveying surface 21b is the surface of the conveyor belt 21 on which the sheet material P is placed, and is the upper surface of the horizontal part of the conveyor belt 21 between the drive roller 22 and the driven roller 23. In this embodiment, the conveying surface 21b corresponds to the suction surface of the present invention. The conveyor belt 21 rotates (moves endlessly) in the clockwise direction in FIG. 1, thereby conveying the held sheet material P in a conveying direction from left to right.

[0027] The drive roller 22 rotates the conveyor belt 21. The drive roller 22 is driven to rotate by a drive motor 30 (see FIG. 6). The driven rollers 23 to 25 support the conveyor belt 21 together with the drive roller 22. The driven rollers 23 to 25 are rotated by the conveyor belt 21. The driven roller 23 is disposed at the same height as the drive roller 22 and to the left of the drive roller 22. The driven rollers 24 and 25 are disposed below the drive roller 22 and the driven roller 23, spaced apart from each other in the left-right direction, and at the same height.

[0028] The platen 26 is a plate-like member that is disposed below the conveyor belt 21 (on the opposite side to the conveying surface 21b) between the drive roller 22 and the driven roller 23 and slidably supports the conveyor belt 21. The platen 26 has a plurality of recesses 31 and a plurality of suction holes 32. FIG. 4 is an enlarged cross-sectional view of the conveyor belt 21, the platen 26, and the platen plate 27 taken along line AA in FIG. 3.

[0029] As shown in FIG. 4, the recess 31 is formed by digging down from the front surface (upper surface) of the platen 26, which is the surface facing the conveyor belt 21, toward the back surface (lower surface). The recess 31 is a portion where air is sucked in by driving the fan 38 to generate negative pressure. The recess 31 is formed in a rectangular shape with sides parallel to the left-right direction and sides perpendicular to the left-right direction (sides parallel to the front-rear direction). The length of the recess 31 in the left-right direction and the length of the recess 31 in the front-rear direction are both equal to or greater than the diameter of the belt hole 21a. Furthermore, the belt hole 21a and the recess 31 are formed so that the area (opening area) of the belt hole 21a is equal to or less than the area of ​​the opening of the recess 31.

[0030] 3, the recesses 31 are arranged at a predetermined pitch in the left-right direction. Two rows of recesses 31 adjacent to each other in the front-rear direction are arranged so as to be offset by half a pitch in the left-right direction. That is, the recesses 31 are arranged in a staggered pattern on the surface of the platen 26. The pitch of the recesses 31 in the front-rear direction is equal to the pitch of the belt holes 21a in the front-rear direction. The recesses 31 are arranged at locations where the belt holes 21a of the conveyor belt 21 pass through.

[0031] The suction holes 32 are holes for sucking air from the recesses 31. The suction holes 32 are formed so as to penetrate from the bottom surface of the recesses 31 to the rear surface of the platen 26. One suction hole 32 is formed to open on the bottom surface of each recess 31. The suction holes 32 are formed so that the opening cross-sectional area is smaller than that of the belt holes 21a. In this embodiment, the opening cross-sectional area of ​​the suction holes 32 is 0.8 mm 2 It is formed by

[0032] 3, the belt holes 21a and the suction holes 32 are formed at positions that do not overlap in the front-to-rear direction when viewed vertically (viewed from above) from the conveying surface 21b side of the conveyor belt 21. Specifically, as shown in FIG. 3, the belt holes 21a are formed at positions that pass behind the center of the bottom surface of the recessed portion 31 in the front-to-rear direction, and the suction holes 32 are formed forward of the center of the bottom surface of the recessed portion 31 in the front-to-rear direction.

[0033] Fig. 5A is an enlarged cross-sectional view of the recess 31 and the suction hole 32 taken along line BB in Fig. 3. As shown in Fig. 5A, in this embodiment, the belt hole 21a and the suction hole 32 are formed at positions offset from each other in the front-to-back direction. On the other hand, Fig. 5B shows a case where the belt hole 210a and the suction hole 320 are formed at positions aligned in the front-to-back direction.

[0034] Here, we will explain the wind speed of the suction wind generated at the belt hole 21a when the positional relationship between the belt hole 21a and the suction hole 32 is as shown in FIG. 5A, and the wind speed of the suction wind generated at the belt hole 21a when the positional relationship is as shown in FIG. 5B.

[0035] The wind speed level of the suction air generated at the belt holes is expressed by the following formula. Air velocity level = belt hole opening cross-sectional area × suction hole opening cross-sectional area ÷ distance between belt hole and suction hole

[0036] Therefore, if the cross-sectional opening area of ​​belt hole 21a in Fig. 5A is the same as the cross-sectional opening area of ​​belt hole 210a in Fig. 5B, and the cross-sectional opening area of ​​suction hole 32 in Fig. 5A is the same as the cross-sectional opening area of ​​suction hole 320 in Fig. 5B, the distance between belt hole 21a and suction hole 32 is longer in Fig. 5A than in Fig. 5B, so the speed of the suction air generated at belt hole 21a due to flow path resistance can be reduced. For example, if the speed of the suction air in Fig. 5B is 2.0 m / s, the speed of the suction air in Fig. 5A can be 0.7 m / s.

[0037] Table 1 below shows an example of the relationship between the opening cross-sectional area of ​​the suction hole 32 and the wind speed of the suction air in this embodiment (where the belt holes 21a and suction holes 32 are positioned differently), and the relationship between the opening cross-sectional area of ​​the suction hole 320 and the wind speed of the suction air in the configuration shown in FIG. 5B (where the belt holes 210a and suction holes 320 are positioned the same). Note that the suction negative pressure generated by the suction unit 28, which will be described later, is assumed to be the same. As shown in Table 1 below, in the configuration shown in FIG. 5B, in order to suppress the wind speed to the same level as in this embodiment, the opening cross-sectional area of ​​the suction hole 320 needs to be increased to 0.2 mm 2 However, achieving such machining precision would increase costs. [Table 1]

[0038] On the other hand, the suction performance of the belt holes 21a is expressed by the following formula. Suction performance = negative suction pressure x cross-sectional area of ​​belt holes

[0039] Therefore, if the opening cross-sectional area of ​​belt hole 21a in FIG. 5A is the same as the opening cross-sectional area of ​​belt hole 210a in FIG. 5B and the negative suction pressure generated by suction section 28, which will be described later, is the same, the suction performance of belt hole 21a in FIG. 5A is the same as the suction performance of belt hole 210a in FIG. 5B.

[0040] That is, by positioning the belt holes 21a and the suction holes 32 in the positional relationship shown in FIG. 5A, the suction air generated at the belt holes 21a can be reduced while maintaining the suction performance of the belt holes 21a.

[0041] 1 and 4, the platen plate 27 is a plate-like member that is disposed below the platen 26 and supports the platen 26 via a plurality of spacers 36. The platen plate 27 has a plurality of through holes 27a formed therein to allow air to pass through the through holes 27a, which are sucked in by the fan 38. The area of ​​the through holes 27a is larger than the area of ​​the belt holes 21a and the area of ​​the suction holes 32.

[0042] The suction unit sucks air through the suction holes 32 and the belt holes 21a to adsorb the sheet member P to the conveyor belt 21. The suction unit includes a chamber 37 and a fan .

[0043] The chamber 37 forms a negative pressure chamber for generating negative pressure in the belt holes 21a of the conveyor belt 21. The chamber 37 is provided on the rear surface side of the platen plate 27 between the drive roller 22 and the driven roller 23.

[0044] The fan 38 exhausts air from the chamber 37. As a result, the fan 38 sucks air through the suction holes 32 and the belt holes 21a, generating negative pressure in the belt holes 21a and causing the sheet material P to be attracted to the conveyor belt 21.

[0045] The paper pressure roller 29 presses the sheet material P, which is conveyed by the conveyor belt 21, onto the conveying surface 21b. The paper pressure roller 29 rotates in accordance with the conveyor belt 21 that is rotating.

[0046] 6 is a block diagram showing a schematic configuration of a control system of the inkjet printing apparatus 1 of this embodiment. The control unit 40 includes a CPU (Central Processing Unit), a semiconductor memory, a hard disk, etc. The control unit 40 controls the operation of each part of the inkjet printing apparatus 1 by executing a program stored in advance in a storage medium such as the semiconductor memory or the hard disk, and by operating electric circuits.

[0047] Next, the operation of the inkjet printing apparatus 1 of this embodiment will be described.

[0048] When printing is performed by the inkjet printing apparatus 1, first, the drive roller 22 and the fan 38 start to be driven.

[0049] 1, and moves in the conveying direction of the sheet material P between the drive roller 22 and the driven roller 23. As the conveying belt 21 rotates, the belt holes 21a pass over the recesses 31 of the platen 26 from left to right.

[0050] On the other hand, when the fan 38 is driven to exhaust air from the chamber 37, a negative pressure is generated within the chamber 37.

[0051] Since the recess 31 is connected to the chamber 37 via the suction hole 32 and the through hole 27a of the platen plate 27, when negative pressure is generated in the chamber 37, negative pressure is generated in the recess 31 where the belt holes 21a do not overlap and are blocked by the conveying belt 21.

[0052] After the drive roller 22 and the fan 38 start to operate, when a sheet material P is fed from a paper feed unit (not shown) to the conveying unit 3, some of the belt holes 21a are covered by the fed sheet material P, which generates negative pressure in the recess 31 and the belt holes 21a, and the sheet material P is adsorbed to the belt holes 21a.

[0053] The conveyor belt 21 attracts and holds the sheet material P on the conveying surface 21b by the attraction force generated in the belt holes 21a covered by the sheet material P. The conveyor belt 21 rotates in the clockwise direction in FIG. 1, thereby conveying the attracted and held sheet material P to the right.

[0054] The inkjet head 12 prints an image by ejecting ink onto the sheet material P being conveyed by the conveyor belt 21. The printed sheet material P is discharged to a paper discharge unit (not shown).

[0055] In the above embodiment, as shown in Fig. 3, the suction holes 32 are formed forward of the center of the bottom surface of the recessed portion 31 in the front-to-rear direction, but this is not limiting, and the suction holes 32 may be formed at the center of the bottom surface of the recessed portion 31 as shown in Fig. 7. In other words, the suction holes 32 may be formed anywhere on the bottom surface of the recessed portion 31 as long as they are not overlapping in the front-to-rear direction when viewed vertically from the conveying surface 21b side of the conveyor belt 21.

[0056] 3 and 7, when the conveyor belt 21 moves on the platen 26, the belt holes 21a of the conveyor belt 21 may overlap with the wall portions 33 that are parallel to the front-rear direction and form the recessed portions 31 of the platen 26. When the belt holes 21a and the wall portions 33 overlap in this way, no negative pressure is generated in the belt holes 21a, and therefore the suction force of the sheet material P becomes weaker.

[0057] Therefore, as shown in Fig. 8, the diameter of belt hole 21a may be made larger than in the examples shown in Fig. 3 and Fig. 7. In other words, it is preferable to set the size of belt hole 21a so that even when belt hole 21a overlaps wall portion 33 extending in the front-to-rear direction, the area where belt hole 21a overlaps with the opening of recess 31 has an area large enough to generate sufficient suction force in belt hole 21a.

[0058] Furthermore, in the above embodiment, by providing a distance in the front-to-back direction between the belt hole 21a and the suction hole 32, the wind speed of the suction wind generated at the belt hole 21a is suppressed, thereby preventing print smears due to mist. However, from the viewpoint of collecting floating mist, it is actually more desirable for the wind speed of the suction wind to be high.

[0059] Therefore, for example, as in the above embodiment, the distance between the belt holes 21a and the suction holes 32 in the front-to-rear direction may be increased during printing, and this distance may be decreased during mist collection. In other words, the distance between the belt holes 21a and the suction holes 32 in the front-to-rear direction may be configured to be changeable. The time when mist is collected may be, for example, when the printing operation is completed.

[0060] 9 is a diagram showing an example of a specific configuration that allows the distance between the belt holes 21a and the suction holes 32 in the front-rear direction to be changed. In the example of FIG. 9, belt abutment portions 21c that restrict the movement of the conveyor belt 21 in the front-rear direction are provided at the rear ends of the drive roller 22 and the driven roller 23. The conveyor belt 21 rotates while abutting against the belt abutment portions 21c. Therefore, by changing the position of the belt abutment portions 21c in the front-rear direction, the position of the conveyor belt 21 in the front-rear direction can be changed, and thereby the distance between the belt holes 21a and the suction holes 32 in the front-rear direction can be changed. The movement of the belt abutment portions 21c may be performed manually or automatically.

[0061] According to the inkjet printing device 1 of the above embodiment, the belt holes 21a of the conveying belt 21 and the suction holes 32 of the platen 26 are formed in positions where they do not overlap in a direction perpendicular to the conveying direction of the sheet material P. This makes it possible to suppress suction wind while maintaining the adhesive force of the sheet material P, thereby enabling the sheet material P to be suction-conveyed stably and preventing deterioration of image quality due to mist.

[0062] Furthermore, in the inkjet printing device 1 of the above embodiment, the distance between the belt holes and the suction holes is configured to be changeable, so that, for example, during printing, the effect of mist can be suppressed by increasing the distance and reducing the wind speed of the suction air, and when the printing operation is completed, the distance can be shortened and the wind speed of the suction air can be increased to collect the mist.

[0063] 10 is a graph showing the relationship between the head gap (HG), which is the distance between the inkjet head 12 and the sheet member P, the speed of the suction air at the belt holes 21a, and the amount of mist contamination. Line L shown in FIG. 10 indicates the boundary between whether mist contamination is visually discernible and the allowable range of mist contamination. As described above, the amount of mist contamination increases as the head gap becomes wider, but when the speed of the suction air at the belt holes 21a is set to 0.7 m / s as in the above embodiment, it can be seen that a head gap of up to 1.9 mm is allowable.

[0064] Furthermore, as described above, the amount of mist contamination increases as the head gap increases. Therefore, the larger the head gap, the slower the speed of the suction air through the belt holes 21a may be. That is, the larger the head gap, the slower the speed of the suction air may be by moving the belt abutment portion 21c shown in FIG. 9 rearward to increase the distance between the belt holes 21a and the suction holes 32. In this way, by changing the distance between the belt holes 21a and the suction holes 32 according to the head gap and controlling the speed of the suction air, the effects of mist can be more effectively suppressed.

[0065] For example, the control unit 40 may store a table as shown in FIG. 11 that associates the head gap with the movement amount of the belt abutment portion 21c, refer to the table according to the set head gap, and display the movement amount of the belt abutment portion 21c to present to the user, or automatically move the belt abutment portion 21c based on the movement amount.

[0066] As mentioned above, the larger the head gap, the greater the amount of mist contamination tends to be. Therefore, it is preferable to reduce the wind speed of the suction air through the belt holes 21a. However, the suction air through the belt holes 21a also serves to collect mist. Therefore, the relationship between the head gap and the wind speed of the suction air through the belt holes 21a does not necessarily have to be proportional, and a value that takes into account the mist collection effect may be used. In other words, the relationship between the head gap and the movement amount of the belt abutment portion 21c shown in FIG. 11 does not necessarily have to be proportional, and the movement amount may be a value that takes into account the mist collection effect.

[0067] The present invention is not limited to the above-described embodiments, and the components can be modified and embodied in practice without departing from the spirit of the invention. Furthermore, various inventions can be formed by appropriately combining the multiple components disclosed in the above-described embodiments. For example, all of the components shown in the embodiments can be appropriately combined. Naturally, various modifications and applications are possible without departing from the spirit of the invention.

[0068] The following additional notes are further disclosed regarding the conveying device of the present invention.

[0069] (Appendix 1) The conveying device of the present invention comprises a conveying belt having a plurality of belt holes that adsorbs and conveys sheet materials by negative pressure generated within the belt holes, and a support member that is provided on the opposite side of the conveying belt from the adsorption surface of the sheet material, supports the conveying belt, and has a plurality of suction holes, and the belt holes and suction holes are formed in positions that do not overlap in a direction perpendicular to the conveying direction of the sheet material when viewed vertically from the suction surface side of the conveying belt.

[0070] (Appendix 2) In the conveying device described in Supplementary Note 1, the distance between the belt hole and the suction hole can be configured to be changeable.

[0071] (Appendix 3) In the conveying device described in Supplementary Note 1 or Supplementary Note 2, the distance between the belt holes and the suction holes can be changed according to the distance between the conveying belt and the ejection unit that ejects liquid onto the sheet member. [Explanation of symbols]

[0072] 1. Inkjet printing device 2 Image forming unit 3. Conveyor 11 Line Head 12 Inkjet head 12a Discharge surface 21 Conveyor belt 21a belt hole 21b Conveying surface 21c Belt stop 22 Drive roller 23~25 Driven roller 26 Platen 27 Plastic Plate 27a Through hole 28 Suction part 29 Paper pressure roller 30 Drive motor 31 Recess 32 suction hole 33 Wall section 36 Spacer 37 Chamber 38 fans 38 Suction part 40 Control Unit 210a belt hole 320 suction hole P sheet material

Claims

1. a conveyor belt having a plurality of belt holes and adapted to adsorb and convey a sheet member by negative pressure generated within the belt holes; a support member provided on the opposite side of the conveyor belt from the adsorption surface of the sheet member, supporting the conveyor belt and having a plurality of suction holes; A conveying device in which the belt holes and the suction holes are formed at positions that do not overlap with each other in a direction perpendicular to a conveying direction of the sheet member when viewed vertically from the suction surface side of the conveying belt.

2. 2. The conveying device according to claim 1, wherein the distance between the belt hole and the suction hole is variable.

3. 3. The conveying device according to claim 2, wherein the distance between the belt holes and the suction holes is changed in accordance with the distance between the conveying belt and an ejection unit that ejects liquid onto the sheet member.

Images