Conveyor

Abstract

To provide a carrier device that can reduce work for removing pieces of paper remaining in a printing system when jamming occurs, without additionally installing a mechanism for dealing with jamming.SOLUTION: A control part, when jamming of pieces of paper P occurs in a downstream-side conveying part 102, controls a motion of a switch-back roller 52 in accordance with an operation situation of the switch-back roller 52 at the time when the jamming occurs, so that the pieces of paper P in a downstream-side conveying part 102 are ejected through an intermediate ejection port 43, and then controls a conveying part 103 so that the part stops conveying of the pieces of paper P.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a transport device that transports paper. [Background technology]

[0002] 2. Description of the Related Art Printing systems in which a plurality of printing devices are connected in series are known.

[0003] Such printing systems are required to realize a variety of functions along with faster printing speeds, and to meet these needs, multiple optional devices such as image inspection devices and paper discharge devices can be connected.

[0004] In a printing system including the above-mentioned optional device, the system becomes larger and the paper transport path becomes longer. Therefore, when a paper jam occurs and the paper transport operation is stopped, a lot of paper remains in the transport path, and the work of removing the paper becomes a heavy burden.

[0005] In this regard, Patent Document 1 discloses a printing system in which an intermediate paper output tray is provided in an intermediate device that is disposed between two printing devices and turns over paper. In this printing system, when a paper jam occurs, the paper is output to the intermediate paper output tray so that it is not transported to the inkjet head unit of the upstream printing device or the inkjet head unit of the downstream printing device. This technology makes it possible to reduce the amount of paper remaining in the device when a jam occurs, and to reduce the work of removing the paper. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2019-130755 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, the technology of Patent Document 1 requires the provision of a drive mechanism that is not required for the actual printing operation in order to transport paper from the downstream printing device to the intermediate paper output tray in the opposite direction to the printing operation. Providing an additional mechanism to deal with such jams leads to an increase in the size of the device.

[0008] The present invention has been made in consideration of the above, and aims to provide a conveying device that can reduce the work of removing paper remaining in a printing system when a jam occurs, without having to provide an additional mechanism to deal with the jam. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, the conveying device of the present invention is characterized in that it comprises a conveying unit having an upstream conveying unit that conveys paper, a switchback roller that receives and conveys paper from the upstream conveying unit in a forward rotation operation and then switches the paper back by rotating in a reverse direction, and a downstream conveying unit that conveys the paper switched back by the switchback roller, an outlet located downstream of the switchback roller in the paper conveying direction when the switchback roller rotates in the forward direction, and a control unit that, when a paper jam occurs in the downstream conveying unit, controls the operation of the switchback roller in accordance with the operating status of the switchback roller at the time the jam occurs to discharge the paper from the upstream conveying unit from the outlet, and then controls the conveying unit to stop conveying the paper. Effect of the Invention

[0010] According to the conveying device of the present invention, it is possible to prevent the size of the printing system from increasing, while reducing the workload of removing paper remaining in the printing system when a jam occurs. [Brief description of the drawings]

[0011] [Figure 1] 1 is a schematic configuration diagram of a printing system according to an embodiment. [Diagram 2] FIG. 2 is a control block diagram of the printing system shown in FIG. [Diagram 3] 2 is a schematic configuration diagram of a reversing device of the printing system shown in FIG. 1. [Figure 4] 10 is a flowchart for explaining the operation of the printing system when a paper jam occurs in the downstream transport section. [Diagram 5] FIG. 13 is a diagram showing a state in which the switchback roller is rotating in the forward direction. [Figure 6] 13A and 13B are diagrams illustrating a state in which the switchback rollers are performing a reverse operation and the sheet being transported by the switchback rollers has not yet reached the upstream most transport roller of the reversing downstream transport section. [Figure 7] 13 is a diagram showing a state in which the switchback rollers are performing a reverse operation and the sheet being transported by the switchback rollers has reached the upstream-most transport roller of the reversing downstream transport section; FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The same or equivalent parts and components are denoted by the same or equivalent reference numerals throughout the drawings.

[0013] The following embodiments are examples of devices for embodying the technical idea of ​​the present invention, and the technical idea of ​​the present invention does not limit the material, shape, structure, arrangement, etc. of each component to those described below. The technical idea of ​​the present invention can be modified in various ways within the scope of the claims.

[0014] Fig. 1 is a schematic diagram of a printing system provided with a conveying device according to an embodiment of the present invention. Fig. 2 is a control block diagram of the printing system shown in Fig. 1. Fig. 3 is a schematic diagram of an inversion device of the printing system shown in Fig. 1. In the following description, the top, bottom, left, and right directions on the paper surface in Fig. 1 are defined as the top, bottom, left, and right directions.

[0015] 1 and 2, printing system 1 according to this embodiment includes a paper feeder 2, an upstream printing device 3, an inverting device 4, a downstream printing device 5, an image inspection device 6, a paper discharge device 7, and a control unit 8. Note that a conveying device is configured by each unit of printing system 1 except for upper paper feeder 11, lower paper feeder 12, printing units 32, 62, inspection units 72, 73, upstream stacker 82, downstream lower stacker 83, and downstream upper stacker 84, which will be described later.

[0016] The paper feed device 2 feeds paper P to the upstream printing device 3. The paper feed device 2 includes an upper paper feed section 11, a lower paper feed section 12, and a paper feed transport section .

[0017] The upper paper feed section 11 sends out the paper P to an upper paper feed path 21, which will be described later. The upper paper feed section 11 includes an upper paper feed tray 16 and an upper paper feed roller 17.

[0018] The upper paper feed tray 16 is configured to be capable of being raised and lowered, and is configured to hold sheets of paper P used for printing.

[0019] The upper paper feed roller 17 takes the paper P from the upper paper feed tray 16 and sends it to the upper paper feed path 21 .

[0020] The lower paper feed section 12 sends out the paper P to a lower paper feed path 22, which will be described later. The lower paper feed section 12 includes a lower paper feed tray 18 and a lower paper feed roller 19.

[0021] The lower paper feed tray 18 is configured so that the paper P used for printing is stacked on it. The lower paper feed tray 18 is configured so as to be able to rise and fall. The lower paper feed tray 18 is disposed below the upper paper feed tray 16.

[0022] The lower paper feed roller 19 takes the paper P from the lower paper feed tray 18 and sends it to the lower paper feed path 22 .

[0023] The paper feed transport unit 13 transports the paper P taken out from the upper paper feed tray 16 and the paper P taken out from the lower paper feed tray 18 to the upstream printing device 3. The paper feed transport unit 13 includes an upper paper feed path 21, a lower paper feed path 22, a common paper feed path 23, a plurality of transport rollers 24, and a plurality of paper sensors 25.

[0024] The upper paper feed path 21 is a transport path for transporting the paper P from the upper paper feed tray 16 to the common paper feed path 23 .

[0025] The lower paper feed path 22 is a transport path for transporting the paper P from the lower paper feed tray 18 to the common paper feed path 23 .

[0026] The common paper feed path 23 is a transport path for transporting the paper P transported along the upper paper feed path 21 and the paper P transported along the lower paper feed path 22 to the upstream printing device 3. The common paper feed path 23 is connected to the downstream end of the upper paper feed path 21 and the downstream end of the lower paper feed path 22 in the transport direction of the paper P.

[0027] A plurality of transport rollers 24 are arranged along the upper paper feed path 21, the lower paper feed path 22, and the common paper feed path 23, and transport the paper P toward the upstream printing device 3.

[0028] A plurality of paper sensors 25 are arranged along the upper paper feed path 21 , the lower paper feed path 22 and the common paper feed path 23 , and detect the paper P transported in the paper feed transport section 13 .

[0029] The upstream printing device 3 prints on one side of the paper P while transporting the paper P fed by the paper feeder 2. The upstream printing device 3 includes a print transport unit 31 and a printing unit 32.

[0030] The print transport unit 31 receives and transports the paper P from the paper feeder 2. The print transport unit 31 includes a print transport path 36, a plurality of transport rollers 37, a belt platen unit 38, and a plurality of paper sensors 39.

[0031] The print transport path 36 is a transport path for transporting the paper P below the printing unit 32. The upstream end of the print transport path 36 is connected to the downstream end of the common paper feed path 23.

[0032] Some of the multiple transport rollers 37 are arranged along the print transport path 36 on the upstream side of the belt platen unit 38, and transport the paper P toward the belt platen unit 38. The remaining transport rollers 37 are arranged along the print transport path 36 on the downstream side of the belt platen unit 38, and transport the paper P toward the reversing device 4.

[0033] The belt platen unit 38 adsorbs and holds the paper P on the belt to transport it. The belt platen unit 38 is disposed below the printing unit 32 and faces the printing unit 32.

[0034] A plurality of paper sensors 39 are arranged along the print transport path 36 and detect the paper P transported in the print transport section 31 .

[0035] The printing unit 32 has an inkjet head (not shown), and performs printing by ejecting ink from the inkjet head onto the paper P transported by the belt platen unit .

[0036] The reversing device 4 turns over the paper P transported from the upstream printing device 3 and transports it to the downstream printing device 5. As shown in FIG. 3, the reversing device 4 includes a reversing upstream transport section 41, a switchback transport section 42, an intermediate discharge outlet (corresponding to a discharge outlet) 43, and a reversing downstream transport section 44.

[0037] The reversing upstream transport section 41 transports the paper P to the switchback transport section 42. The reversing upstream transport section 41 includes a reversing upstream path 46, a plurality of transport rollers 47, and a plurality of paper sensors 48.

[0038] The reverse upstream path 46 is a transport path for transporting the paper P from the upstream printing device 3 to the switchback transport section 42. The upstream end of the reverse upstream path 46 is connected to the downstream end of the print transport path 36 of the upstream printing device 3, and the downstream end of the reverse upstream path 46 is connected to one end (upper end) of a switchback path 51 described later.

[0039] A plurality of conveying rollers 47 are disposed along the reversing upstream path 46 and convey the paper P toward the switchback conveying section 42.

[0040] A plurality of paper sensors 48 are arranged along the reversing upstream path 46 and detect the paper P transported in the reversing upstream transport section 41 .

[0041] The switchback conveyance section 42 switches back the paper P conveyed from the reversing upstream conveyance section 41 and conveys it to the reversing downstream conveyance section 44. The switchback conveyance section 42 includes a switchback path 51, a switchback roller 52, and a paper sensor 53.

[0042] The switchback path 51 is a transport path for switching back the paper P. One end (upper end) of the switchback path 51 is connected to the downstream end of the reversing upstream path 46 and the upstream end of a reversing downstream path 56 described later, and the other end (lower end) of the switchback path 51 has an intermediate discharge port 43 formed therein.

[0043] The switchback roller 52 is a roller that switches back the paper P. The switchback roller 52 is configured to be capable of rotating forward and backward in order to switch back the paper P. Here, the operation of the switchback roller 52 to transport the paper P in the direction from the reversing upstream path 46 toward the switchback path 51 is referred to as a forward operation, and the operation of the switchback roller 52 to transport the paper P in the direction from the switchback path 51 toward the reversing downstream path 56 described later is referred to as a reverse operation.

[0044] That is, the switchback roller 52 receives the paper P from the conveying roller 47 of the reversing upstream conveying section 41 by rotating in the forward direction and conveys it, and then rotates in the reverse direction to switch back the paper P and convey it to the conveying roller 57 of the reversing downstream conveying section 44 described later.

[0045] The paper sensor 53 detects the paper P being conveyed near the downstream side of the switchback roller 52 in the conveying direction of the paper P when the switchback roller 52 rotates in the forward direction.

[0046] The intermediate discharge outlet 43 is an outlet for discharging the paper P from the transport path in the reversing device 4. As described above, the intermediate discharge outlet 43 is formed at the other end (lower end) of the switchback path 51. That is, the intermediate discharge outlet 43 is disposed downstream of the switchback rollers 52 in the transport direction of the paper P when the switchback rollers 52 rotate in the forward direction.

[0047] The paper P discharged from the intermediate discharge port 43 is stacked on the bottom plate of the housing 45 of the reversing device 4. A stacking table on which the paper P discharged from the intermediate discharge port 43 is stacked may be provided.

[0048] The reversing downstream transport section 44 transports the paper P switched back by the switchback transport section 42 to the downstream-side printing device 5. The reversing downstream transport section 44 includes a reversing downstream path 56, a plurality of transport rollers 57, and a plurality of paper sensors 58.

[0049] The reverse downstream path 56 is a transport path for transporting the paper P from the switchback transport section 42 to the downstream printing device 5. An upstream end of the reverse downstream path 56 is connected to one end (upper end) of the switchback path 51.

[0050] The multiple transport rollers 57 are arranged along the reverse downstream path 56, and transport the paper P toward the downstream printing device 5. In this embodiment, each transport roller 57 is configured to transport the paper P only in the direction toward the downstream printing device 5. The most upstream transport roller 57 among the multiple transport rollers 57 corresponds to the downstream transport roller that receives and transports the paper P from the switchback rollers 52.

[0051] A plurality of paper sensors 58 are arranged along the reverse downstream path 56 and detect the paper P transported in the reverse downstream transport section 44 .

[0052] The downstream printing device 5 prints on the other side of the paper P while transporting the paper P that has been inverted by the inversion device 4. The downstream printing device 5 includes a print transport unit 61 and a printing unit 62.

[0053] The print transport unit 61 receives and transports the paper P from the reversing device 4. The print transport unit 61 includes a print transport path 66, a plurality of transport rollers 67, a belt platen unit 68, and a plurality of paper sensors 69.

[0054] The print transport path 66 is a transport path for transporting the paper P below the printing unit 62. The upstream end of the print transport path 66 is connected to the downstream end of the reverse downstream path 56.

[0055] Some of the multiple transport rollers 67 are arranged along the print transport path 66 on the upstream side of the belt platen unit 68, and transport the paper P toward the belt platen unit 68. The remaining transport rollers 67 are arranged along the print transport path 66 on the downstream side of the belt platen unit 68, and transport the paper P toward the image inspection device 6.

[0056] The belt platen unit 68 attracts and holds the paper P on the belt to transport it. The belt platen unit 68 is disposed below the printing unit 62 and faces the printing unit 62.

[0057] A plurality of paper sensors 69 are arranged along the print transport path 66 and detect the paper P transported in the print transport section 61 .

[0058] The printing unit 62 has an inkjet head (not shown), and ejects ink from the inkjet head onto the paper P transported by the belt platen unit 68 to perform printing.

[0059] The image inspection device 6 inspects images printed on both sides of the paper P by the upstream printing device 3 and the downstream printing device 5. The image inspection device 6 includes an inspection transport unit 71, and inspection units 72 and 73.

[0060] The inspection transport unit 71 receives and transports the paper P from the downstream printing device 5. The inspection transport unit 71 includes an inspection transport path 76, belt platen units 77 and 78, and a plurality of paper sensors 79.

[0061] The inspection transport path 76 is a transport path for transporting the paper P so as to pass through the reading areas of the inspection units 72 and 73. The upstream end of the inspection transport path 76 is connected to the downstream end of the print transport path 66.

[0062] The belt platen unit 77 adsorbs and holds on the belt the paper P transported by the downstream printing device 5, and transports the paper P. The belt platen unit 77 is installed with the transport surface that adsorbs and holds the paper P facing upward.

[0063] The belt platen unit 78 receives and transports the paper P from the belt platen unit 77. The belt platen unit 78 is installed with its transport surface facing downward, and transports the paper P by suction and holding it on the downward transport surface.

[0064] A plurality of paper sensors 79 are arranged along the inspection transport path 76 and detect the paper P transported in the inspection transport section 71 .

[0065] The inspection unit 72 reads, for inspection, an image of the upward facing surface of the paper P transported by the belt platen unit 77. The inspection unit 73 reads, for inspection, an image of the downward facing surface of the paper P transported by the belt platen unit 78.

[0066] The paper discharge device 7 discharges paper P printed by the upstream printing device 3 and the downstream printing device 5. The paper discharge device 7 includes a paper discharge transport section 81, an upstream stacking section 82, a downstream lower stacking section 83, and a downstream upper stacking section 84.

[0067] The paper discharge conveyance section 81 receives and conveys the paper P from the image inspection device 6, and selectively discharges the paper P to an upstream stacking section 82, a downstream lower stacking section 83, or a downstream upper stacking section 84. The paper discharge conveyance section 81 includes a common paper discharge path 86, an upstream paper discharge path 87, a downstream common paper discharge path 88, a downstream lower paper discharge path 89, a downstream upper paper discharge path 90, switching sections 91 and 92, a plurality of conveyance rollers 93, and a plurality of paper sensors 94.

[0068] The common paper discharge path 86 is a transport path common to the paper P transported to the upstream stacking section 82, the downstream lower stacking section 83, and the downstream upper stacking section 84 in the paper discharge transport section 81. The upstream end of the common paper discharge path 86 is connected to the downstream end of the inspection transport path 76.

[0069] The upstream discharge path 87 is a transport path for transporting and discharging the paper P to the upstream stacking unit 82. The upstream end of the upstream discharge path 87 is connected to the downstream end of the common discharge path 86.

[0070] The downstream common paper discharge path 88 is a transport path common to the paper P transported to the downstream lower stacking unit 83 and the downstream upper stacking unit 84. The upstream end of the downstream common paper discharge path 88 is connected to the downstream end of the common paper discharge path 86.

[0071] The downstream lower discharge path 89 is a transport path for transporting and discharging the paper P to the downstream lower stacking unit 83. The upstream end of the downstream lower discharge path 89 is connected to the downstream end of the downstream common discharge path 88.

[0072] The downstream upper discharge path 90 is a transport path for transporting and discharging the paper P to the downstream upper stacking unit 84. The upstream end of the downstream upper discharge path 90 is connected to the downstream end of the downstream common discharge path 88.

[0073] The switching unit 91 switches the destination of the paper P transported downstream from the common paper discharge path 86 between the upstream paper discharge path 87 and the downstream common paper discharge path 88. The switching unit 92 switches the destination of the paper P transported downstream from the downstream common paper discharge path 88 between the downstream lower paper discharge path 89 and the downstream upper paper discharge path 90.

[0074] Multiple conveying rollers 93 are arranged along the common paper discharge path 86, the upstream paper discharge path 87, the downstream common paper discharge path 88, the downstream lower paper discharge path 89, and the downstream upper paper discharge path 90, and convey the paper P discharged in the paper discharge device 7.

[0075] Multiple paper sensors 94 are arranged along the common paper discharge path 86, the upstream paper discharge path 87, the downstream common paper discharge path 88, the downstream lower paper discharge path 89, and the downstream upper paper discharge path 90, and detect paper P being transported in the paper discharge conveying section 81.

[0076] The upstream stacking section 82 stores the paper sheet P discharged from the upstream paper discharge path 87. The upstream stacking section 82 includes a paper discharge tray 96 that can be raised and lowered. The paper sheet P is discharged and stacked on the paper discharge tray 96. The upstream stacking section 82 also includes an end fence that regulates the position of the leading edge (downstream end) of the paper sheet P discharged onto the paper discharge tray 96, a guide member that regulates the position of the trailing edge (upstream end) of the paper sheet P, and a pair of side fences (none of which are shown) that regulate the position of the paper sheet P in the width direction.

[0077] The downstream lower stacking section 83 stores the paper P discharged from the downstream lower paper discharge path 89. The downstream lower stacking section 83 includes a paper discharge tray 97 that can be raised and lowered. The paper P is discharged and stacked on the paper discharge tray 97. Similarly to the upstream stacking section 82, the downstream lower stacking section 83 also includes an end fence, a guide member, and a pair of side fences (none of which are shown).

[0078] The downstream upper stacking section 84 stores the paper P discharged from the downstream upper paper discharge path 90. The downstream upper stacking section 84 includes an end fence 98 and a pair of side fences 99.

[0079] The end fence 98 regulates the position of the leading edge (downstream end) of the paper P discharged to the downstream-side upper stacking section 84. The end fence 98 is configured to be movable in the left-right direction.

[0080] The pair of side fences 99 regulates the widthwise position of the sheet P discharged to the downstream upper stacking section 84. The side fences 99 are configured to be movable in the widthwise direction of the sheet P.

[0081] Here, in the printing system 1, the paper feed transport unit 13, the printing transport unit 31 of the upstream printing device 3, and the reversing upstream transport unit 41 form an upstream transport unit 101. The reversing downstream transport unit 44, the printing transport unit 61 of the downstream printing device 5, the inspection transport unit 71, and the paper discharge transport unit 81 form a downstream transport unit 102. The upstream transport unit 101, the switchback rollers 52, and the downstream transport unit 102 form a transport unit 103.

[0082] The control unit 8 controls the operation of each device in the printing system 1 (the paper feeder 2, the upstream printing device 3, the inverting device 4, the downstream printing device 5, the image inspection device 6, and the paper discharge device 7). The control unit 8 is composed of a microcomputer provided in each device in the printing system 1.

[0083] When a jam of paper P occurs in the downstream conveying section 102, the control section 8 controls the operation of the switchback roller 52 according to the operating condition of the switchback roller 52 at the time the jam occurs to discharge the paper P in the upstream conveying section 101 from the intermediate discharge outlet 43, and then controls the conveying section 103 to stop conveying the paper P.

[0084] Here, the operating status of the switchback roller 52 is determined as to whether the switchback roller 52 is rotating in the forward direction or in the reverse direction, and if it is rotating in the reverse direction, whether the paper P being transported by the switchback roller 52 has reached the upstream-most transport roller 57 of the reversing downstream transport section 44 or not.

[0085] Next, the operation of the printing system 1 will be described.

[0086] When printing is performed in the printing system 1, the paper feeder 2 takes out paper P from the upper paper feed section 11 or the lower paper feed section 12, and feeds the paper P to the upstream printing device 3. The upstream printing device 3 prints on one side of the paper P using the printing section 32 while transporting the paper P.

[0087] The inversion device 4 inverts the paper P, one side of which has been printed by the upstream printing device 3, using a switchback transport section 42, and transports the paper P with the other side (unprinted side) facing up to the downstream printing device 5. While transporting the paper P, the downstream printing device 5 prints on the other side of the paper P using a printing section 62. As a result, images are printed on both sides of the paper P.

[0088] The image inspection device 6 inspects the images printed on both sides of the paper P, and conveys the paper P to the paper discharge device 7. The paper discharge device 7 discharges the printed paper P to any one of the upstream stacking section 82, the downstream lower stacking section 83, and the downstream upper stacking section 84.

[0089] Next, the operation of the printing system 1 when a jam of the paper P occurs in the downstream transport section 102 during the above-mentioned printing operation will be described.

[0090] Here, during printing operation, if the detection timing of paper P in at least any of the multiple paper sensors 58 in the inversion downstream conveying section 44 of the inversion device 4, the multiple paper sensors 69 in the downstream printing device 5, the multiple paper sensors 79 in the image inspection device 6, and the multiple paper sensors 94 in the paper discharge device 7 is delayed from the theoretical value by more than a threshold value, the control unit 8 determines that a jam has occurred in the downstream conveying section 102 (downstream of the switchback roller 52).

[0091] FIG. 4 is a flowchart for explaining the operation of the printing system 1 when a jam of the paper P occurs in the downstream transport section 102.

[0092] When it is determined that a jam has occurred in the downstream transport section 102, in step S1 of FIG. 4, the control section 8 determines whether or not the switchback roller 52 is rotating forward when the jam has occurred.

[0093] When it is determined that the switchback rollers 52 are rotating in the forward direction (step S1: YES), the control unit 8 causes the switchback rollers 52 to continue rotating in the forward direction in step S2, and causes the paper P in the upstream conveying unit 101 to be discharged from the intermediate discharge port 43.

[0094] 5, if the switchback rollers 52 are rotating in the forward direction when a jam occurs in the downstream conveyance section 102 and there is a sheet of paper P being conveyed by the switchback rollers 52, the forward rotation is continued so that the sheet of paper P is discharged from the intermediate discharge outlet 43, and then the sheet of paper P conveyed from the upstream conveyance section 101 is conveyed to and discharged by the switchback rollers 52 to the intermediate discharge outlet 43. Note that when a jam occurs, the upper paper feed section 11 and the lower paper feed section 12 stop sending out the sheet of paper P.

[0095] Unlike the state in Figure 5, when the switchback roller 52 is rotating in the forward direction and is not transporting paper P, the forward rotation is continued, so that the paper P transported from the upstream transport section 101 is transported by the switchback roller 52 to the intermediate discharge outlet 43 and discharged.

[0096] Here, the switchback rollers 52 wait for the paper P in a forward rotation operation after the switched-back paper P passes through the switchback rollers 52 until the next paper P arrives. For this reason, the switchback rollers 52 may be rotating forward in a state where the paper P is not being transported.

[0097] After all of the sheets P that were in the upstream conveyance section 101 when the jam occurred in the downstream conveyance section 102 have been discharged from the intermediate discharge port 43, in step S3 of Fig. 4, the control section 8 stops the conveyance of the sheets P by the conveyance section 103. This ends the series of operations.

[0098] Here, in the downstream conveyance section 102, the paper P downstream of the jam occurrence position is discharged by the paper discharge device 7 to any one of the upstream stacking section 82, the downstream lower stacking section 83, or the downstream upper stacking section 84. If the discharge of all the papers P downstream of the jam occurrence position in the downstream conveyance section 102 has not been completed at the time when all the papers P in the upstream conveyance section 101 have been discharged from the intermediate discharge outlet 43, the control section 8 stops the conveyance of the papers P by the conveyance section 103 after the discharge of all the papers P downstream of the jam occurrence position has been completed.

[0099] Incidentally, the paper P remaining on the upstream side of the jam occurrence position in the downstream transport section 102 is removed by the user.

[0100] Furthermore, the paper P discharged from the intermediate discharge port 43 is stacked on the bottom plate of the housing 45 of the reversing device 4 as described above, and can be easily removed by the user.

[0101] If it is determined in step S1 that the switchback rollers 52 are in the reverse rotation when the jam occurs (step S1: NO), then in step S4 the control unit 8 determines whether the paper P being transported by the switchback rollers 52 has reached the upstream most transport rollers 57 of the reversing downstream transport unit 44. Here, for example, the control unit 8 can determine whether the paper P being transported by the switchback rollers 52 has reached the upstream most transport rollers 57 of the reversing downstream transport unit 44 based on the elapsed time from the start of the reverse operation of the switchback rollers 52.

[0102] 6 shows a state in which the paper P being transported by the switchback rollers 52 during the reverse operation has not yet reached the most upstream transport rollers 57 of the reversing downstream transport section 44. FIG. 7 shows a state in which the paper P being transported by the switchback rollers 52 during the reverse operation has reached the most upstream transport rollers 57 of the reversing downstream transport section 44.

[0103] 6, when it is determined that the paper P being transported by the switchback rollers 52 has not reached the most upstream transport rollers 57 of the reversing downstream transport section 44 (step S4: NO), in step S5 of Fig. 4, the control section 8 switches the switchback rollers 52 to a forward rotation operation before the paper P being transported by the switchback rollers 52 reaches the most upstream transport rollers 57 of the reversing downstream transport section 44, and causes the switchback rollers 52 to discharge the paper P being transported from the intermediate discharge outlet 43, and then causes the paper P in the upstream transport section 101 to be discharged from the intermediate discharge outlet 43. After this, the control section 8 proceeds to step S3.

[0104] 7, when it is determined that the paper P being conveyed by the switchback rollers 52 has reached the most upstream conveying rollers 57 of the reverse downstream conveying section 44 (step S4: YES), in step S6, the control section 8 switches the switchback rollers 52 to a forward rotation operation after the paper P being conveyed by the switchback rollers 52 passes through the switchback rollers 52, and discharges the paper P in the upstream conveying section 101 from the intermediate discharge port 43. After this, the control section 8 proceeds to step S3.

[0105] Here, for example, the control unit 8 can determine whether or not the paper P being transported by the switchback rollers 52 has passed through the switchback rollers 52 based on the elapsed time since the rear end of the paper P being transported by the switchback rollers 52 was detected by the paper sensor 53 of the switchback transport unit 42.

[0106] As described above, the conveying rollers 57 can only convey the paper P in the direction toward the downstream printing device 5. For this reason, in the situation of Fig. 7, the switchback rollers 52 cannot convey and discharge the paper P being conveyed to the intermediate discharge outlet 43. In contrast, as described above, the switchback rollers 52 can be switched to a forward rotation operation after the paper P being conveyed by the switchback rollers 52 passes through the switchback rollers 52, thereby discharging the paper P from the upstream conveying section 101 from the intermediate discharge outlet 43.

[0107] As described above, in the printing system 1, when a jam of paper P occurs in the downstream transport section 102, the control section 8 controls the operation of the switchback rollers 52 according to the operating state of the switchback rollers 52 at the time the jam occurred, to discharge the paper P in the upstream transport section 101 from the intermediate discharge port 43, and then controls the transport section 103 to stop transport of the paper P. This makes it possible to reduce the amount of paper P remaining in the printing system 1 after transport of the paper P is stopped due to the occurrence of a jam, without providing an additional mechanism for dealing with the jam. As a result, it is possible to reduce the work of removing paper P remaining in the printing system 1 when a jam occurs, while preventing the printing system 1 from becoming larger.

[0108] Specifically, if the switchback rollers 52 are rotating in the forward direction when a jam occurs in the downstream conveyance section 102, the control section 8 continues the forward rotation of the switchback rollers 52, and if there is paper P being conveyed by the switchback rollers 52 when the jam occurs, the control section 8 causes the paper P to be discharged from the intermediate discharge outlet 43, and then causes the paper P in the upstream conveyance section 101 to be discharged from the intermediate discharge outlet 43. This makes it possible to realize a process of discharging the paper P in the upstream conveyance section 101 from the intermediate discharge outlet 43 according to the operating status of the switchback rollers 52, which are rotating in the forward direction when the jam occurs.

[0109] Furthermore, when the switchback rollers 52 are in the reverse rotation when a jam occurs in the downstream conveyance section 102 and the sheet P being conveyed by the switchback rollers 52 has not reached the most upstream conveyance rollers 57 of the reverse downstream conveyance section 44, the control section 8 switches the switchback rollers 52 to the forward rotation before the sheet P being conveyed by the switchback rollers 52 reaches the most upstream conveyance rollers 57, and after the switchback rollers 52 have discharged the sheet P being conveyed by the switchback rollers 52 from the intermediate discharge outlet 43, the control section 8 discharges the sheet P of the upstream conveyance section 101 from the intermediate discharge outlet 43. This makes it possible to realize a process of discharging the sheet P of the upstream conveyance section 101 from the intermediate discharge outlet 43 according to the operating status of the switchback rollers 52, that is, when a jam occurs in the downstream conveyance section 102, the switchback rollers 52 are in the reverse rotation and the sheet P being conveyed has not reached the most upstream conveyance rollers 57 of the reverse downstream conveyance section 44.

[0110] Furthermore, if the switchback rollers 52 are in the reverse rotation when a jam occurs in the downstream conveyance section 102 and the sheet P being conveyed by the switchback rollers 52 has reached the most upstream conveyance rollers 57 of the reversing downstream conveyance section 44, the control section 8 switches the switchback rollers 52 to the forward rotation operation after the sheet P being conveyed by the switchback rollers 52 passes through the switchback rollers 52, and discharges the sheet P in the upstream conveyance section 101 from the intermediate discharge opening 43. This makes it possible to realize the process of discharging the sheet P in the upstream conveyance section 101 from the intermediate discharge opening 43 even in an operating state of the switchback rollers 52 in which the switchback rollers 52 are in the reverse rotation when a jam occurs in the downstream conveyance section 102 and the sheet P being conveyed has reached the most upstream conveyance rollers 57 of the reversing downstream conveyance section 44.

[0111] The present invention is not limited to the above-described embodiment, and the components can be modified and embodied in the implementation stage without departing from the gist of the invention. In addition, various inventions can be formed by appropriately combining the multiple components disclosed in the above-described embodiment. For example, some components may be deleted from all the components shown in the embodiment.

[0112] [Note] This application discloses the following inventions.

[0113] (Appendix 1) a conveying section including an upstream conveying section that conveys paper, a switchback roller that receives the paper from the upstream conveying section in a forward rotation operation, conveys the paper, and then switches the paper back by a reverse rotation, and a downstream conveying section that conveys the paper switched back by the switchback roller; a discharge port disposed downstream of the switchback roller in a sheet conveying direction during forward rotation of the switchback roller; a control unit that, when a paper jam occurs in the downstream transport unit, controls an operation of the switchback roller according to an operating state of the switchback roller at the time the jam occurs, to discharge the paper in the upstream transport unit from the discharge port, and then controls the transport unit to stop transporting the paper; A conveying device comprising:

[0114] (Appendix 2) The control unit, if the switchback roller is rotating in the forward direction when a jam occurs in the downstream transport section, continues the forward rotation of the switchback roller, and if there is paper being transported by the switchback roller when a jam occurs, discharges the paper from the discharge outlet, and then discharges the paper from the upstream transport section from the discharge outlet.

[0115] (Appendix 3) the downstream transport section includes downstream transport rollers that receive the paper from the switchback rollers and transport the paper; The control unit, when the switchback rollers are in reverse rotation when a jam occurs in the downstream transport section and the paper being transported by the switchback rollers has not reached the downstream transport rollers, switches the switchback rollers to forward rotation before the paper being transported by the switchback rollers reaches the downstream transport rollers, and discharges the paper being transported by the switchback rollers when a jam occurs from the discharge outlet, and then discharges the paper from the upstream transport section from the discharge outlet.

[0116] (Appendix 4) the downstream transport section includes downstream transport rollers that receive the paper from the switchback rollers and transport the paper; The control unit, when the switchback roller is in reverse rotation when a jam occurs in the downstream transport section and the paper being transported by the switchback roller has reached the downstream transport roller, switches the switchback roller to forward rotation after the paper being transported by the switchback roller when the jam occurs has passed the switchback roller, and discharges the paper from the upstream transport section from the discharge outlet. [Explanation of symbols]

[0117] 1 Printing System 2 Paper feeder 3 Upstream printing device 4. Inversion device 5 Downstream printing device 6. Image inspection equipment 7 Paper ejection device 8. Control Unit 41 Reversing upstream transport section 42 Switchback conveyor 43 Intermediate outlet 44 Reversing downstream conveying section 41 Reversing upstream transport section 47,57 Transport roller 51 Switchback Route 52 Switchback roller 56 Reversed downstream route 101 Upstream conveying section 102 Downstream conveying section 103 Conveyor

Claims

1. A conveying section having an upstream conveying section for conveying paper, a switchback roller which receives and conveys paper from the upstream conveying section in a forward rotation motion and then switches the paper back by a reverse rotation motion, and a downstream conveying section which conveys the paper switched back by the switchback roller and discharges it to a stacking section; a discharge port disposed downstream of the switchback roller in a sheet conveying direction during forward rotation of the switchback roller; a control unit that, when a paper jam occurs in the downstream transport unit, controls the operation of the switchback roller according to the operating state of the switchback roller at the time the jam occurs to discharge the paper in the upstream transport unit from the discharge outlet, and controls the transport unit to stop transporting the paper after discharging all the paper downstream of the jam occurrence position to the stacking unit while leaving the paper upstream of the jam occurrence position in the downstream transport unit; the downstream transport section includes downstream transport rollers that receive the paper from the switchback rollers and transport the paper; The control unit, when the switchback roller is operating in a reverse direction when a jam occurs in the downstream transport section and the paper being transported by the switchback roller has not reached the downstream transport roller, switches the switchback roller to a forward rotation direction before the paper being transported by the switchback roller reaches the downstream transport roller, and discharges the paper being transported by the switchback roller when a jam occurs from the discharge outlet, and then discharges the paper from the upstream transport section from the discharge outlet.

2. A conveying section having an upstream conveying section for conveying paper, a switchback roller which receives and conveys the paper from the upstream conveying section in a forward rotation motion and then switches the paper back by a reverse rotation motion, and a downstream conveying section which conveys the paper switched back by the switchback roller and discharges it to a loading section; a discharge port disposed downstream of the switchback roller in a sheet conveying direction during forward rotation of the switchback roller; a control unit that, when a paper jam occurs in the downstream transport unit, controls the operation of the switchback roller according to the operating state of the switchback roller at the time the jam occurs to discharge the paper in the upstream transport unit from the discharge outlet, and controls the transport unit to stop transporting the paper after discharging all the paper downstream of the jam occurrence position to the stacking unit while leaving the paper upstream of the jam occurrence position in the downstream transport unit; the downstream transport section includes downstream transport rollers that receive the paper from the switchback rollers and transport the paper; a control unit for controlling a conveying device, when the switchback roller is in reverse rotation when a jam occurs in the downstream conveying section and the paper being conveyed by the switchback roller reaches the downstream conveying roller, to switch the switchback roller to forward rotation after the paper being conveyed by the switchback roller when the jam occurs passes through the switchback roller, and discharges the paper from the upstream conveying section through the discharge outlet.

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