JP7386033B2 - Conveyance device - Google Patents

Description

The present invention relates to a conveyance device that conveys sheets.

2. Description of the Related Art As a conveyance device for conveying sheets, an air suction type conveyance device is known. For example, in a line-type inkjet printing device that prints by ejecting ink onto the paper from an inkjet head while conveying the paper, an air suction type conveyance device is used to convey the paper.

As a conveyance device of this type, Patent Document 1 describes a conveyance belt 101 having a plurality of belt holes 101a as shown in FIG. A conveyance device is disclosed that includes a platen 102 having a fan (not shown) and a fan (not shown) provided below the platen 102. This conveyance device generates negative pressure in the recess 103 by driving a fan, and moves the conveyance belt 101 while holding the paper P on the conveyance belt 101 by suction force generated in the belt hole 101a due to this negative pressure. to convey the paper P.

In the conveying device of Patent Document 1, as shown in FIG. Two or more belt holes 101a are prevented from overlapping. Therefore, the recess 103 where the belt hole 101a covered by the paper P overlaps is closed by the conveyor belt 101 and the paper P, so that loss of negative pressure within the recess 103 is suppressed. As a result, a decrease in the attraction force of the paper P to the conveyor belt 101 is suppressed.

JP2009-280321A

However, in the conveyance device of Patent Document 1, the belt hole 101a closest to the leading edge of the paper P (the most downstream side in the conveyance direction of the paper P) out of the belt holes 101a covered with the paper P overlaps with the belt hole 101a located downstream of the recess 103. The belt hole 101a also overlaps the concave portion 103 adjacent to the side. Since this recess 103 is open to the atmosphere through the belt hole 101a, no negative pressure is generated (including a state where the negative pressure is weak).

For this reason, the top surface of the platen 102 and the recess 103 adjacent to the downstream side of the belt hole 101a covered by the sheet P overlap with the belt hole 101a closest to the leading end of the sheet P. A gap is created between the belt hole 101a and the conveyor belt 101, and as shown in FIG. Air may flow in from the adjacent recess 103. As a result, the negative pressure in the recess 103 where the belt hole 101a closest to the leading edge of the paper P overlaps among the belt holes 101a covered by the paper P may become small. As a result, the adsorption force of the paper P to the conveyor belt 101 may be reduced at the leading end of the paper P.

Further, in the conveying device of Patent Document 1, the belt hole 101a closest to the leading edge of the paper P out of the belt holes 101a covered with the paper P overlaps the recess 103, so that the recess 103 is closed and the negative energy inside the recess 103 is Pressure generation begins. That is, as shown in FIG. 9, among the belt holes 101a covered by the paper P, the recess 103, which the belt hole 101a closest to the leading edge of the paper P next overlaps, is opened to the atmosphere by the belt hole 101a. Therefore, with respect to the arrival of the leading edge of the paper P in the recess 103, the generation of the suction force by the belt hole 101a against the leading edge of the paper P may be delayed. This may also reduce the adsorption force of the paper P to the conveyor belt 101 at the leading end of the paper P.

When the adsorption force of paper to the conveyor belt decreases, the paper may float off the conveyor belt. When the paper floats, the paper may come into contact with the inkjet head, causing damage to the inkjet head. Furthermore, floating paper may be detected as a conveyance jam, and paper conveyance may be stopped.

The present invention has been made in view of the above, and an object of the present invention is to provide a conveyance device that can reduce sheet floating.

In order to achieve the above object, the conveyance device of the present invention has a plurality of belt holes arranged along the conveyance direction of the sheet, and a conveyance belt that conveys the sheet in the conveyance direction and the belt hole pass through. a support plate that supports the conveyor belt, the support plate having a plurality of recesses disposed along the conveyance direction and sucking air at the conveyor belt side, and an interval between the belt holes in the conveyor direction; is greater than or equal to the distance between the upstream end of the upstream recess and the downstream end of the downstream recess of the two recesses adjacent to each other in the conveyance direction.

According to the conveyance device of the present invention, floating of sheets can be reduced.

1 is a schematic configuration diagram of an inkjet printing device according to an embodiment. FIG. 2 is a partially enlarged cross-sectional view of the conveyance section of the inkjet printing apparatus shown in FIG. 1. FIG. FIG. 3 is a partially enlarged cross-sectional view of the conveyance section taken along the line AA in FIG. 2. FIG. FIG. 6 is a diagram showing how negative pressure is generated in a recess near the leading edge of a sheet of paper. FIG. 7 is a diagram illustrating how negative pressure is generated in a recess near the leading edge of a sheet in a comparative example. FIG. 7 is a diagram showing the experimental results of an experimental example and a comparative example in which the pressure loss rate was measured in a concave portion of the belt holes covered by the paper, where the belt hole closest to the leading edge of the paper overlaps. FIG. 3 is a diagram showing the experimental results of an experimental example and a comparative example in which paper floating height was measured. FIG. 1 is a diagram showing an example of the configuration of a conventional transport device. 9 is a diagram showing how negative pressure is generated in a recess near the leading edge of a sheet in the conveyance device shown in FIG. 8; FIG.

Embodiments of the present invention will be described below with reference to the drawings. The same or equivalent parts and components are designated by the same or equivalent symbols throughout the drawings.

The embodiments shown below exemplify devices etc. for embodying the technical idea of this invention, and the technical idea of this invention includes the material, shape, structure, arrangement etc. of each component. shall not be specified as: The technical idea of this invention can be modified in various ways within the scope of the claims.

FIG. 1 is a schematic configuration diagram of an inkjet printing apparatus provided with a conveying device according to an embodiment of the present invention. FIG. 2 is a partially enlarged sectional view of the conveyance section of the inkjet printing apparatus shown in FIG. 1. FIG. FIG. 3 is a partially enlarged sectional view of the conveyance section taken along line AA in FIG. In the following description, the direction perpendicular to the paper plane of FIG. 1 will be referred to as the front-back direction. Moreover, the top, bottom, left and right of the paper surface in FIG. 1 are defined as the top, bottom, left and right directions. In FIG. 1, the direction from left to right is the paper conveyance direction. Upstream and downstream in the following description mean upstream and downstream in the paper conveyance direction.

As shown in FIG. 1, an inkjet printing apparatus 1 according to the present embodiment includes a printing section 2 and a transport section 3 (corresponding to a transport device).

The printing unit 2 prints an image on the paper P conveyed by the conveyance unit 3. The printing section 2 includes a plurality of inkjet heads 11.

The inkjet head 11 prints an image by ejecting ink onto the paper P. The inkjet head 11 has a plurality of nozzles (not shown) and ejects ink from the nozzles. The inkjet head 11 is arranged above the transport section 3.

The conveyance section 3 conveys a paper (corresponding to a sheet) P fed from a paper feed section (not shown) while holding it by suction using air suction.

The conveyance unit 3 includes a conveyance belt 21, a drive roller 22, driven rollers 23 to 25, a platen (corresponding to a support plate) 26, a plate template 27, a chamber 28, a fan 29, and a plurality of paper pressing rollers. 30.

The conveyance belt 21 attracts and holds the paper P and conveys it. The conveyor belt 21 is an annular belt that is stretched around a driving roller 22 and driven rollers 23 to 25. A large number of belt holes 21a are formed in the conveyor belt 21. The conveyance belt 21 attracts and holds the paper P on the conveyance surface 21b by the suction force generated in the belt hole 21a by the drive of the fan 29. The conveying surface 21b is the upper surface of the horizontal portion of the conveying belt 21 between the driving roller 22 and the driven roller 23. The conveyor belt 21 rotates clockwise (endlessly moves) in FIG. 1 to convey the suction-held paper P in the conveyance direction from left to right.

The belt holes 21a are arranged at a predetermined pitch (interval) K in each row along the conveyance direction (left-right direction). Further, two rows of belt holes 21a adjacent to each other in the paper width direction (front-back direction) orthogonal to the conveying direction are arranged so as to be shifted by a half pitch in the left-right direction. That is, the belt holes 21a are arranged in a staggered manner.

The drive roller 22 rotates the conveyor belt 21. The drive roller 22 is rotationally driven by a motor (not shown). The driven rollers 23 to 25 support the conveyor belt 21 together with the drive roller 22. The driven rollers 23 to 25 rotate as a result of the conveyor belt 21. The driven roller 23 is located 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 arranged below the driving roller 22 and the driven roller 23, spaced apart from each other in the left-right direction, and at the same height.

The platen 26 is a plate-shaped member that is disposed below the conveyor belt 21 between the drive roller 22 and the driven roller 23 and supports the conveyor belt 21 in a slidable manner. The platen 26 has a plurality of recesses 31 and a plurality of suction holes 32.

The recessed portion 31 is formed by digging down toward the back surface (lower surface) on the front surface (upper surface) of the platen 26 on the conveyor belt 21 side. The recessed portion 31 is a portion where air is sucked in by driving the fan 29 and negative pressure is generated. The recess 31 is formed in a rectangular shape in plan view, having sides parallel to the left-right direction and sides perpendicular to the left-right direction (sides parallel to the front-rear direction). The length L in the left-right direction and the length W in the front-back direction of the recessed portion 31 are both greater than or equal to the diameter D of the belt hole 21a. That is, "D≦L and D≦W". Here, the diameter D of the belt hole 21a corresponds to the length of the belt hole 21a in the left-right direction (conveyance direction) and the length in the front-rear direction (paper width direction).

The recesses 31 are arranged at a predetermined pitch along the left-right direction. Further, two rows of recesses 31 adjacent to each other in the front-rear direction are arranged so as to be shifted by a half pitch in the left-right direction. That is, the recesses 31 are arranged in a staggered manner 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 recess 31 is arranged at a location through which the belt hole 21a of the conveyor belt 21 passes.

Here, the belt hole 21a of the conveyor belt 21 and the recessed part 31 of the platen 26 are such that the upstream belt hole 21a of the two belt holes 21a adjacent to each other in the left-right direction overlaps with the upstream belt hole 21a. When reaching the downstream end of the recess 31, the downstream belt hole 21a of the two horizontally adjacent belt holes is located downstream of the recess 31 where the upstream belt hole 21a overlaps. It is formed so as to extend downstream from the adjacent recess 31 .

Specifically, the belt hole 21a and the recess 31 are formed to satisfy "K≧R and D≦L".

Here, R is the distance between the upstream end of the upstream recess 31 and the downstream end of the downstream recess 31 of the two recesses 31 adjacent to each other in the left-right direction, as shown in FIG. . In other words, the distance R is the distance between the upstream wall 33 of the upstream recess 31 and the downstream wall 33 of the downstream recess 31 of the two recesses 31 adjacent to each other in the left-right direction. It is. The wall 33 separates the recesses 31 adjacent to each other in the left-right direction.

Further, the belt hole 21a and the recess 31 are formed such that the area of the belt hole 21a in plan view is less than or equal to the area of the recess 31 in plan view.

The suction hole 32 is a hole for sucking air from the recess 31. The suction hole 32 is formed so as to penetrate from a part of the bottom surface of the recess 31 to the back surface of the platen 26 . One suction hole 32 is formed in each recess 31 .

The plate template 27 is a plate-shaped member that is disposed below the platen 26 and supports the platen 26 via a plurality of spacers 36. A plurality of through holes 27a are formed in the plate template 27 through which air sucked by the fan 29 passes.

The chamber 28 forms a negative pressure chamber for generating suction force in the belt hole 21a of the conveyor belt 21. The chamber 28 is provided on the back side of the plate template 27 between the drive roller 22 and the driven roller 23.

Fan 29 evacuates chamber 28 . As a result, the fan 29 generates negative pressure in the chamber 28, and the paper P is attracted to the conveyor belt 21 by the suction force generated in the belt hole 21a due to this negative pressure.

The paper pressing roller 30 presses the paper P transported by the transport belt 21 against the transport surface 21b. The paper pressing roller 30 rotates as a result of the rotating conveyor belt 21 .

Next, the operation of the inkjet printing apparatus 1 will be explained.

When printing with the inkjet printing device 1, first, the drive roller 22 and the fan 29 start driving.

By driving the drive roller 22, the conveyance belt 21 rotates in the clockwise direction in FIG. 1 and moves in the conveyance direction of the paper P between the drive roller 22 and the driven roller 23. When the conveyor belt 21 rotates, the belt hole 21a passes over the recess 31 of the platen 26 from left to right.

On the other hand, when the fan 29 is driven to exhaust air from the chamber 28, negative pressure is generated within the chamber 28.

Since the recess 31 communicates with the chamber 28 via the suction hole 32 and the through hole 27a of the plate template 27, when negative pressure is generated in the chamber 28, the belt holes 21a do not overlap and the conveyor belt 21 Negative pressure is generated in the recess 31 that is closed. The recess 31 where the belt hole 21a overlaps is opened to the atmosphere by the belt hole 21a, and no negative pressure is generated.

After the drive roller 22 and the fan 29 start driving, when the paper P is fed from the paper feed section (not shown) to the transport section 3, some of the belt holes 21a are covered by the fed paper P. . Since the recess 31 overlapping the belt hole 21a covered by the paper P is closed by the conveyor belt 21 and the paper P, the recess 31 becomes under negative pressure. As a result, a suction force is generated in the belt hole 21a, and the paper P is attracted to the belt hole 21a.

The conveyance belt 21 attracts and holds the paper P on the conveyance surface 21b by the attraction force generated in the belt hole 21a covered with the paper P. By rotating clockwise in FIG. 1, the conveyor belt 21 conveys the suction-held paper P to the right.

The inkjet head 11 prints an image by ejecting ink onto the paper P conveyed by the conveyance belt 21. The printed paper P is discharged by a paper discharge section (not shown).

Here, FIG. 4 shows how negative pressure is generated in the recess 31 near the leading end (downstream end) of the sheet P being conveyed. In the example of FIG. 4, K=R. In this case, at the timing when one belt hole 21a entirely overlaps one recess 31, the belt hole 21a overlaps every other recess 31 in the left-right direction. In this case, as shown in FIG. 4, there is a negative impact on the concave portion 31 adjacent to the downstream side of the concave portion 31 overlapping with the belt hole 21a on the leading edge side of the paper P among the belt holes 21a covered with the paper P. The state can be such that pressure is being generated.

Unlike this embodiment, in the case where the interval between the belt holes 21a and the interval between the recesses 31 in the conveyance direction are equal, an example of how negative pressure is generated in the recess 31 near the leading edge of the sheet P being conveyed is shown below. Shown in Figure 5. In this case, among the belt holes 21a covered by the paper P, negative pressure is not generated in the recess 31 adjacent to the downstream side with respect to the recess 31 where the belt hole 21a closest to the leading edge of the paper P overlaps. .

Therefore, in the configuration of FIG. 5, the upper end surface of the wall 33 on the downstream side of the recess 31 and the upper end surface of the downstream wall 33 of the recess 31 where the belt hole 21a closest to the tip of the paper P out of the belt holes 21a covered with the paper P overlap. A gap is created between the belt holes 21a covered by the paper P, and air can flow into the concave part 31 where the belt hole 21a closest to the leading end of the paper P overlaps from the concave part 31 adjacent to the downstream side. be. This may cause a loss of negative pressure within the recess 31 where the belt hole 21a closest to the tip of the paper P overlaps among the belt holes 21a covered by the paper P. As a result, the adsorption force of the paper P to the conveyor belt 21 may be reduced at the leading end of the paper P.

In addition, in the configuration of FIG. 5, among the belt holes 21a covered by the paper P, the belt hole 21a closest to the tip of the paper P overlaps the recess 31, so that the recess 31 is closed and negative pressure is generated in the recess 31. is started. Therefore, with respect to the arrival of the leading edge of the paper P in the recess 31, the generation of the suction force by the belt hole 21a against the leading edge of the paper P may be delayed. This may also reduce the suction force of the paper P to the conveyor belt 21 at the leading end of the paper P.

When the adsorption force of the paper P to the transport belt 21 decreases, the paper P may float from the transport belt 21. If the paper P floats, the paper P may come into contact with the inkjet head 11 and the inkjet head 11 may be damaged. Furthermore, floating of the paper P may be detected as a conveyance jam, and the paper conveyance may be stopped.

On the other hand, in the inkjet printing apparatus 1 of the present embodiment, as described above, among the belt holes 21a covered by the paper P, the belt hole 21a closest to the leading edge of the paper P is entirely overlapped with the recess 31. On the other hand, the belt hole 21a does not overlap the concave portion 31 adjacent to the downstream side. Therefore, the recessed portion is closed by the conveyor belt 21, and negative pressure is generated.

Therefore, a gap is created between the conveyor belt 21 and the upper end surface of the downstream wall 33 of the recess 31 where the belt hole 21a closest to the tip of the paper P overlaps among the belt holes 21a covered by the paper P. can be suppressed. Therefore, in the recess 31 where the belt hole 21a closest to the leading edge of the paper P overlaps among the belt holes 21a covered by the paper P, pressure loss due to air flowing from the recess 31 adjacent to the downstream side is suppressed. It will be done.

Furthermore, in the inkjet printing apparatus 1, among the belt holes 21a covered by the paper P, a negative pressure is already generated in the recess 31 where the belt hole 21a closest to the leading end of the paper P overlaps next. Therefore, with respect to the arrival of the leading edge of the paper P in the recess 31, the generation of the suction force by the belt hole 21a against the leading edge of the paper P is prevented from being delayed.

Therefore, in the inkjet printing apparatus 1, a decrease in the adsorption force of the paper P to the conveyor belt 21 at the leading end of the paper P is suppressed. As a result, lifting of the paper P from the conveyor belt 21 is suppressed.

Here, as described above, since "D≦W", a part of belt holes 21a in a row adjacent to the row of belt holes 21a in the front-rear direction overlaps with the row of belt holes 21a passing through the recess 31. This prevents the concave portion 31 from being exposed to the atmosphere and causing loss of negative pressure.

FIG. 6 shows the experimental results of an experimental example in which the pressure loss rate in the inkjet printing apparatus 1 was measured in the recess 31 where the belt hole 21a closest to the leading end of the paper P overlaps among the belt holes 21a covered by the paper P. . FIG. 6 also shows the results of a similar experiment using the configuration of FIG. 5 as a comparative example.

The pressure loss rate in FIG. 6 is the ratio of the loss of negative pressure in the recess 31 to the negative pressure generated in the chamber 28. FIG. 6 shows the results of measuring the pressure loss rate when the output of the fan 29 is A1 to A4 [%] in each of the experimental example and the comparative example.

As shown in FIG. 6, in the experimental example using the inkjet printing apparatus 1, the pressure loss rate was suppressed to be smaller than in the comparative example.

Further, FIG. 7 shows the experimental results of an experimental example in which the paper floating height, which is the height of the leading end of the paper P from the conveying surface 21b, was measured in the inkjet printing apparatus 1. FIG. 7 also shows the results of a similar experiment using the configuration of FIG. 5 as a comparative example.

The conveyance position in FIG. 7 is a position on the conveyance surface 21b in the conveyance direction (left-right direction). In FIG. 7, the position where the paper floating height is almost 0 (zero) corresponds to the position where the paper pressing roller 30 is arranged.

As shown in FIG. 7, in the experimental example using the inkjet printing apparatus 1, lifting of the paper P from the conveyor belt 21 was suppressed to a smaller extent than in the comparative example.

Further, in the comparative example, the paper floating height is particularly increased in the area surrounded by the broken line in FIG. This is because, as described above, in the configuration of FIG. 5, the generation of the suction force by the belt hole 21a against the leading edge of the paper P is delayed with respect to the arrival of the leading edge of the paper P in the recess 31. . In the experimental example using the inkjet printing apparatus 1, such a temporary increase in paper floating height did not occur.

As explained above, in the inkjet printing device 1, the belt hole 21a and the recess 31 are formed so as to satisfy "K≧R and D≦L". As a result, negative pressure is generated in the concave portion 31 adjacent to the downstream side of the concave portion 31 overlapping with the belt hole 21a closest to the tip of the paper P among the belt holes 21a covered by the paper P. be able to.

Therefore, in the recess 31 where the belt hole 21a closest to the leading edge of the paper P overlaps among the belt holes 21a covered by the paper P, pressure loss due to air flowing from the adjacent recess 31 on the downstream side is caused. It can be suppressed. This suppresses a decrease in the attraction force of the paper P to the conveyor belt 21 at the leading end of the paper P. Further, as described above, among the belt holes 21a covered by the paper P, the concave portion 31 where the belt hole 21a closest to the leading edge of the paper P overlaps next is already in a state where negative pressure is generated. With respect to the arrival of the leading edge of the paper P in the recess 31, the generation of the suction force by the belt hole 21a against the leading edge of the paper P is prevented from being delayed. As a result, in the inkjet printing apparatus 1, floating of the paper P from the conveyor belt 21 can be reduced.

Note that, conventionally, the belt hole 21a is formed with a size that can ensure suction and conveyance properties, and generally D≦L. Under such general conditions, by forming the belt holes 21a and the recesses 31 so that K≧R is satisfied, it is possible to reduce the floating of the paper P from the conveyor belt 21 as described above. It will be done.

In addition, in the inkjet printing apparatus 1, the pressure loss rate in the recess 31 where the belt hole 21a closest to the tip of the paper P overlaps among the belt holes 21a covered with the paper P is suppressed, so that the output of the fan 29 can be suppressed. This makes it possible to suppress power consumption.

Further, in the inkjet printing device 1, the belt hole 21a and the recess 31 are formed so as to satisfy D≦W. As a result, a part of the row of belt holes 21a adjacent to the row of belt holes 21a passing through the recess 31 in the front-rear direction overlaps with the recess 31, so that the recess is opened to the atmosphere and negative pressure is lost. can be suppressed. Note that even if a part of the belt holes 21a in a row adjacent to the row of belt holes 21a passing through the recess 31 overlaps with the row of belt holes 21a passing through the recess 31, the size of the overlapping area is larger than the negative side of the recess 31. D>W may be satisfied as long as the influence on pressure is sufficiently small.

Further, in the inkjet printing device 1, the area of the belt hole 21a in plan view is less than or equal to the area of the recess 31 in plan view. This prevents the belt hole 21a from protruding beyond the recess 31, so that sufficient suction force can be ensured in the belt hole 21a, making it possible to carry out stable suction conveyance of the paper P.

Further, in the above-described embodiment, the belt hole 21a has a circular shape in a plan view and the recess 31 has a rectangular shape in a plan view, but the shapes of the belt hole 21a and the recess 31 are not limited to this.

Furthermore, in the above-described embodiments, an inkjet printing apparatus that transports sheets has been described, but the present invention is not limited to this, and any transport apparatus that transports sheets may be used.

The present invention is not limited to the above-described embodiments as they are, but can be embodied by modifying the constituent elements within the scope of the invention at the implementation stage. Moreover, various inventions can be formed by appropriately combining the plurality of components disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiments.

[Additional notes]
This application discloses the following invention.

(Additional note 1)
a conveyance belt that has a plurality of belt holes arranged along the conveyance direction of the sheet and conveys the sheet in the conveyance direction;
a support plate that supports the conveyor belt and has a plurality of recesses disposed along the conveyance direction on a surface on the conveyor belt side where the belt hole passes through and sucks air;
The interval between the belt holes in the transport direction is equal to or greater than the distance between the upstream end of the upstream recess and the downstream end of the downstream recess of the two recesses adjacent to each other in the transport direction. A conveying device characterized by:

(Additional note 2)
The conveyance device according to supplementary note 1, wherein the length of the belt hole in the conveyance direction is equal to or less than the length of the recess in the conveyance direction.

(Appendix 3)
The length of the belt hole in the conveyance direction is equal to or less than the length of the recess in the conveyance direction,
The conveyance device according to appendix 1, wherein the length of the belt hole in the direction perpendicular to the conveyance direction is equal to or less than the length of the recess in the direction perpendicular to the conveyance direction.

(Additional note 4)
4. The conveyance device according to any one of Supplementary Notes 1 to 3, wherein an area of the belt hole in a plan view is less than or equal to an area of the recess in a plan view.

1 Inkjet printing device 2 Printing section 3 Conveyance section 11 Inkjet head 21 Conveyance belt 21a Belt hole 21b Conveyance surface 26 Platen 27 Platen plate 28 Chamber 29 Fan 31 Recess 32 Suction hole 33 Wall

Claims (4)

a conveyance belt that has a plurality of belt holes arranged along the conveyance direction of the sheet and conveys the sheet in the conveyance direction;
a plurality of recesses formed by digging down from the front surface that is the surface on the conveyor belt side toward the back surface and arranged along the conveyance direction at a place where the belt hole passes; and a bottom surface of each of the plurality of recesses. a support plate that supports the conveyor belt and has a plurality of suction holes penetrating the back surface from the recess to suck air from the recess;
The interval between the belt holes in the transport direction is equal to or greater than the distance between the upstream end of the upstream recess and the downstream end of the downstream recess of the two recesses adjacent to each other in the transport direction. A conveying device characterized by: a conveyance belt that has a plurality of belt holes arranged along the conveyance direction of the sheet and conveys the sheet in the conveyance direction;
a support plate that supports the conveyor belt and has a plurality of recesses disposed along the conveyance direction on a surface on the conveyor belt side where the belt hole passes through and sucks air;
The interval between the belt holes in the conveyance direction is equal to or greater than the distance between the upstream end of the upstream recess and the downstream end of the downstream recess of the two recesses adjacent to each other in the transport direction. ,
A conveyance device characterized in that the length of the belt hole in the conveyance direction is equal to or less than the length of the recess in the conveyance direction. a conveyance belt that has a plurality of belt holes arranged along the conveyance direction of the sheet and conveys the sheet in the conveyance direction;
a support plate that supports the conveyor belt and has a plurality of recesses disposed along the conveyance direction on a surface on the conveyor belt side where the belt hole passes through and sucks air;
The interval between the belt holes in the conveyance direction is equal to or greater than the distance between the upstream end of the upstream recess and the downstream end of the downstream recess of the two recesses adjacent to each other in the transport direction. ,
The length of the belt hole in the conveyance direction is equal to or less than the length of the recess in the conveyance direction,
A conveyance device characterized in that a length of the belt hole in a direction perpendicular to the conveyance direction is equal to or less than a length of the recess in a direction perpendicular to the conveyance direction. a conveyance belt that has a plurality of belt holes arranged along the conveyance direction of the sheet and conveys the sheet in the conveyance direction;
a support plate that supports the conveyor belt and has a plurality of recesses disposed along the conveyance direction on a surface on the conveyor belt side at locations through which the belt holes pass and from which air is sucked;
The interval between the belt holes in the conveyance direction is equal to or greater than the distance between the upstream end of the upstream recess and the downstream end of the downstream recess of the two recesses adjacent to each other in the transport direction. ,
A conveying device characterized in that an area of the belt hole in a plan view is less than or equal to an area of the recess in a plan view.