Conveying device, liquid ejecting device

Abstract

To provide a conveying device improved in removal property of residual sheet material caused by conveying failure.SOLUTION: A conveying device has: a carrier rotor carrying a sheet material; an inlet rotor transferring the sheet material to the carrier rotor from an upstream side; an outlet rotor transferring the sheet material to the downstream side from the carrier rotor; downstream side conveying means carrying the sheet material to the downstream side from the outlet rotor; and inching control means carrying the sheet material present in a carrying route including at least downstream side conveying means by inching operation. The inching control means, in the inching operation, interlocks at least carrying operation by the outlet rotor with the carrying operation by the downstream side conveying means.SELECTED DRAWING: Figure 12

Description

[Technical Field]

[0001] The present invention relates to a transport device and a liquid ejection device. [Background technology]

[0002] Conveying devices that convey sheet material as a sheet-like medium are known. One example of a conveying device is one in which a conveying rotor such as a cylinder or drum is provided with a gripper or other gripping portion, and the conveying rotor is rotated while the gripper grips the sheet material, thereby conveying the sheet material. Another known liquid ejecting device is equipped with a conveying device and ejects liquid onto the conveyed sheet material. The liquid ejecting device forms an image on the sheet material by ejecting liquid onto the sheet material being conveyed by the rotation of the conveying rotor.

[0003] In the above-described conveying device, if a sheet material floats or becomes wrinkled or folded during conveyance, this can cause conveyance problems. Therefore, some devices are known that, when a condition that causes conveyance problems, such as floating, wrinkles, or creases, occurs, stop conveyance of the sheet material and eject the subsequent sheet material to a designated purge tray. Note that, in this specification, a condition in which media cannot be conveyed normally, such as when the media floats, wrinkles, or creases, is sometimes simply referred to as a "conveyance problem."

[0004] To deal with sheet material transport failures during transport, a device is known that includes a first transport section that transports the sheet material to an image forming area, a second transport section that prevents the sheet material from passing through the image forming area, and a switching section that is provided upstream of the image forming area and guides sheet material determined to be transport failures to the second transport section and guides sheet material determined to be transported normally to the first transport section (Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0005] In the device described in Patent Document 1, when a sheet transport failure occurs, the transport of the sheet is stopped, but if the sheet straddles the switching section and stops, the sheet collides with the following sheet, causing a jam, which deteriorates the processability of the remaining sheet, resulting in a decrease in productivity.

[0006] SUMMARY OF THE INVENTION An object of the present invention is to improve the ease of removing remaining sheet material caused by conveyance failure. [Means for solving the problem]

[0007] The present invention relates to a conveying device comprising a carrying rotor that carries sheet material, an entrance rotor that transfers the sheet material from the upstream side to the carrying rotor, an exit rotor that transfers the sheet material from the carrying rotor to the downstream side, downstream conveying means that conveys the sheet material from the exit rotor to the downstream side, and inching control means that conveys the sheet material in a conveying path that includes at least the downstream conveying means by an inching operation, wherein the inching control means links the conveying operations of at least the exit rotor and the downstream conveying means during the inching operation.

[0008] According to the present invention, it is possible to improve the removal efficiency of remaining sheet material caused by transport failure. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic explanatory diagram of a first embodiment of a liquid ejection device according to the present invention; [Figure 2] FIG. 2 is an enlarged explanatory view of a transport device included in the liquid ejection device according to the first embodiment. [Figure 3] FIG. 10 is an explanatory diagram illustrating a conveyance failure of a sheet material. [Figure 4] FIG. 4 is a block diagram showing an example of a control unit that controls an inching operation and a purging operation. [Figure 5] FIG. 10 is an explanatory diagram showing an example of the position of the sheet material remaining in the liquid ejection device when the conveying operation is stopped. [Figure 6] FIG. 4 is an explanatory diagram illustrating an inching operation. [Figure 7] FIG. 10 is an explanatory diagram showing a state after an inching operation. [Figure 8] FIG. 4 is a flowchart illustrating the flow of a control process for a purge operation. [Figure 9] FIG. 10 is an explanatory diagram illustrating an example when the purge switch is pressed. [Figure 10] FIG. 10 is an explanatory diagram illustrating a state when a purge switch is operated in the second embodiment of the transport device according to the present invention. [Figure 11] FIG. 10 is an explanatory diagram illustrating a comparative example of an inching operation. [Figure 12] FIG. 2 is an enlarged explanatory view of the first embodiment of the conveying device. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic explanatory diagram showing a first embodiment of the present invention. FIG. 1 illustrates the overall configuration of an image forming system 1 as a liquid ejection device that includes a drum-type conveying device 100 as an embodiment of a conveying device according to the present invention and that ejects liquid onto a sheet-like medium conveyed by the drum-type conveying device 100. FIG. 2 is an enlarged explanatory diagram of the drum-type conveying device 100 and its surrounding configuration that is included in the image forming system 1. FIG. 12 is an enlarged explanatory diagram showing the configuration of the main parts of the drum-type conveying device 100. FIG. 12 is a diagram in which the configuration of the ejection unit 33 and the like is omitted from FIG. 2.

[0011] The image forming system 1 includes an input section 10 that inputs sheet material P as a sheet-like medium, a printing section 70 that ejects liquid onto the sheet material P to form an image, and an output section 50 that outputs the sheet material P with the image formed thereon.

[0012] The printing unit 70 is a printing device in the narrow sense and corresponds to a part of the configuration of the liquid ejection device according to the present invention. The printing unit 70 also includes a drum-type conveying device 100 that conveys the sheet material P. The drum-type conveying device 100 conveys the sheet material P to the image forming unit 30, which then prints on the conveyed sheet material P. Since the sheet material P on which the image has been formed needs to be dried to fix the liquid to the sheet material P, the printing unit 70 also includes a drying unit 40 as a fixing unit. The printing unit 70 also includes a double-sided mechanism unit 60 for printing on both sides of the sheet material. A pre-treatment unit that applies (coats) a coating liquid such as a pre-treatment liquid to the sheet material P can be disposed between the loading unit 10 and the printing unit 70.

[0013] The printing unit 70 is also provided with a control means 80 that controls the overall operation of the image forming system 1 and the drum-type conveying device 100. The control means 80 will be described in detail later. The control means 80 may be provided in the drum-type conveying device 100, the carry-in unit 10, or the carry-out unit 50.

[0014] The image forming system 1 applies liquid to the sheet material P transported (supplied) from the transport section 10 in the image forming section 30 of the printing section 70 to perform the required printing, dries (fixes) the liquid adhering to the sheet material P in the drying section 40, and then discharges the sheet material P to the transport section 50.

[0015] The loading section 10 includes an input tray 11 (lower input tray 11A, upper input tray 11B) that stores multiple sheet materials P, and a feeding device 12 (12A, 12B) that separates and sends out the sheet materials P one by one from the input tray 11, and supplies the sheet materials P to the image forming section 30.

[0016] The image forming section 30 includes a liquid ejection section 32 that ejects liquid toward the sheet material P carried on the drum 31, which is a carrying member that serves as a carrying rotating body that carries the sheet material P on its circumferential surface and rotates.

[0017] As shown in FIG. 2, the image forming section 30 includes a liquid ejection section 32. The liquid ejection section 32 includes ejection units 33 (33A to 33D) each including a liquid ejection head, which is a liquid ejection means. For example, the ejection unit 33A ejects cyan (C) liquid, the ejection unit 33B ejects magenta (M) liquid, the ejection unit 33C ejects yellow (Y), and the ejection unit 33D ejects black (K) liquid. In addition, ejection units that eject special liquids such as white and gold (silver) liquid can also be used.

[0018] The image forming section 30 also includes caps 38 that cap the ejection surfaces (nozzle surfaces) of the ejection units 33 of the liquid ejection section 32. The ejection units 33 are arranged so that they can advance and retreat in the directions of the arrows, and the caps 38 are arranged so that they can move in the axial direction of the drum 31. During capping, the ejection units 33 move in a direction away from the circumferential surface of the drum 31, and the caps 38 move below them to perform capping.

[0019] The ejection operation of each ejection unit 33 of the liquid ejection section 32 is controlled by a drive signal corresponding to the printing information. When the sheet material P carried on the drum 31 passes through an area facing the liquid ejection section 32, liquid of each color is ejected from the ejection unit 33, and an image corresponding to the printing information is formed (printed).

[0020] As shown in Figure 12, the drum-type conveying device 100 is equipped with an inlet rotor 34 that receives the sheet material P sent from the upstream side and transfers the sheet material P between the inlet rotor 34 and the drum 31, and an outlet rotor 35 that receives the sheet material P conveyed by the drum 31 and transfers it to the drying section 40.

[0021] The entrance rotor 34 is provided with a gripper 341 as a gripping means on its outer periphery. The leading end of the sheet material P conveyed by a pair of conveying rollers 302 or the like along a carry-in path 301 serving as a conveying path upstream of the entrance rotor 34 is configured to be gripped by the gripper 341 at a receiving position a (see FIG. 2).

[0022] The sheet material P is conveyed in the rotation direction as the inlet rotor 34, which grips the leading edge of the sheet material P, rotates. The conveyed sheet material P is then delivered to the drum 31 at a position where the drum 31 and the inlet rotor 34 face each other.

[0023] When the sheet material P is transported through the carry-in path 301, the transport speed of the transport roller pair 302 is adjusted to adjust the timing between the gripper 341 of the entrance rotor 34 and the leading edge position of the sheet material P. The sheet material P is transported to the receiving position while correcting the inclination and transport position of the sheet material P in a direction perpendicular to the transport direction using a skew detection means and a correction means.

[0024] Also arranged in the carry-in path 301 are a sheet length detection means for detecting the length of the sheet material P in the conveying direction, and a sheet width detection means for detecting the width, which is the length in the direction perpendicular to the conveying direction, of the sheet material P. When the measured values differ from the set sheet size, the sheet length detection means and the sheet width detection means stop the printing operation, thereby preventing the ejection of liquid onto the drum 31.

[0025] Grippers 311, which are gripping means, are also provided on the surface of the drum 31, and are configured so that the leading edge of the sheet material P is gripped by the grippers 311. A plurality of suction holes are formed in a dispersed manner on the surface of the drum 31, and the suction means generates a suction airflow that flows inward from required suction holes in the drum 31. The sheet material P transferred from the inlet rotor 34 to the drum 31 has its leading edge gripped by the grippers 311, and is adsorbed and held on the circumferential surface of the drum 31 by the suction airflow generated by the suction means, and is transported as the drum 31 rotates.

[0026] The sheet material P on which the image has been formed is delivered from the drum 31 to the exit rotator 35. The exit rotator 35 receives the sheet material P from the drum 31 with a gripper 351, which is a gripping means provided on the outer periphery. Then, as the exit rotator 35 rotates, the sheet material P is delivered to the drying unit 40 at a delivery position b.

[0027] The drying section 40 includes a conveyor belt 41 that conveys the sheet material P delivered from the outlet rotor 35, and a heating means 42 that heats the sheet material P conveyed by the conveyor belt 41. The conveyor belt 41 is an endless belt that is wound around a drive roller 401 and a driven roller 402.

[0028] The drying section 40 dries the liquid that has adhered to the sheet material P in the image forming section 30. This evaporates the water content and other liquid components in the liquid, fixes the colorant contained in the liquid onto the sheet material P, and also suppresses curling of the sheet material P. The sheet material P that has passed through the drying section 40 is transported to the discharge section 50 via a discharge path 701, or is sent to the duplex mechanism section 60.

[0029] When the conveying operation of the sheet material P is being performed, the conveying belt 41 conveys the sheet material P received from the outlet rotor 35 toward the heating means 42 located downstream so that the sheet material P passes through the heating means 42 at a predetermined conveying speed. The conveying speed of the sheet material P by the conveying belt 41 is set by the rotation speed of the drive roller 401. In addition, the rotation speed of the drive roller 401 is controlled by the control means 80.

[0030] When the leading edge of the sheet material P leaves the exit rotator 35 and is handed over to the conveyor belt 41, the rotation speed of the drive roller 401 is adjusted so that the conveyor belt 41 operates at a predetermined conveying speed. Furthermore, when an inching operation, which will be described later, is performed, the rotation speed of the drive roller 401 is also set to match the rotation speed of the exit rotator 35. As a result, the sheet material P handed over from the exit rotator 35 to the conveyor belt 41 during the inching operation is conveyed downstream in the conveying direction. As the leading edge of the sheet material P is conveyed downstream, the trailing edge of the sheet material that subsequently leaves the exit rotator 35 is also easily moved in the conveying direction of the conveyor belt 41 without moving in the circumferential direction due to the rotation of the drum 31.

[0031] The double-sided mechanism unit 60 includes a reversing path 61 that receives the sheet material P that has passed through the drying unit 40 and turns it over when printing on both sides of the sheet material P, and a double-sided path 62 that feeds the sheet material P that has been turned over on the reversing path 61 back to the conveying path 340. A plurality of conveying roller pairs 601 are arranged on the reversing path 61 and the double-sided path 62.

[0032] The discharge section 50 includes a discharge tray 51 on which a plurality of sheet materials P are stacked. The sheet materials P conveyed from the drying section 40 are successively stacked and held on the discharge tray 51.

[0033] Next, the first transport path 111 in this embodiment will be described.

[0034] In this embodiment, the entrance rotor 34 , the drum 31 , the circumferential surfaces of the exit rotor 35 and the conveyor belt 41 form a first conveying path 111 .

[0035] Here, the entrance rotator 34 and the exit rotator 35 are connected by gears, and the drum 31, the entrance rotator 34, and the exit rotator 35 are driven to convey in conjunction with each other, utilizing a conveyance drive source provided in the drum 31, so that the sheet material P is conveyed along the first conveyance path 111. However, the entrance rotator 34, the drum 31, and the exit rotator 35 may also be driven by individual drive sources.

[0036] In addition, the drive source of the drive roller 401 that drives the conveying belt 41 is a drive source independent of the drive sources of the drum 31, etc., but is controlled by the control means 80 so as to be linked to the drive of the drum 31, etc.

[0037] Any of the drive sources of the first transport path 111 can be driven independently by operating an inching switch 81 as an inching operation means. As a result, even when the image forming system 1 is stopped, the entrance rotor 34, the drum 31, and the exit rotor 35 can be driven to rotate (inching operation) by operating the inching switch 81 in a predetermined manner.

[0038] The inching switch 81 is a switching means that switches between "start (ON)" and "stop (OFF)" of the inching operation when the user performs a predetermined operation. The predetermined operations on the inching switch 81 are a first operation of pressing the inching switch 81 and a second operation of releasing the inching switch 81. The first operation turns the inching switch 81 "ON", and the second operation turns it "OFF". Note that the first and second operations for ON-OFF operation may be reversed. Furthermore, the first operation may be when the user touches the inching switch 81, and the second operation may be when the user does not touch it, or vice versa.

[0039] By a first operation of the inching switch 81, the drive roller 401 also rotates in the same manner, causing the conveyor belt 41 to rotate at the same speed as the inching operation, thereby conveying the sheet material P downstream. Then, by a second operation, the drive roller 401 is stopped.

[0040] The inching operation is a type of transport operation in which the sheet material P is transported at a slower speed than during normal printing operations by a first operation of the inching switch 81. More specifically, the drum 31 and other components are rotated at a slower speed than during printing operations only while the user is performing the first operation of the inching switch 81. Then, when the user performs a second operation of the inching switch 81, the rotation of the drum 31 and other components is stopped. In the inching operation, the drum 31, the entrance rotor 34, and the exit rotor 35 are driven in conjunction with each other. The drive roller 401 also operates in conjunction with each other.

[0041] Furthermore, the rotation direction selection means is configured to allow rotation not only in the transport direction during printing but also forward or reverse rotation, which allows for disposal of sheet material P remaining on the circumferential surfaces of the drum 31, entrance rotor 34, and exit rotor 35, inspection and replacement of grippers 341, 311, and 351 during maintenance, cleaning of the circumferential surface of the drum 31, and cleaning and replacement of the plate with suction holes, etc.

[0042] The image forming system 1 is also provided with a display unit 83 that displays the conveyance status of the sheet material. The display unit 83 is controlled by a display control unit 813, which will be described later. The status of the device can be notified to the user through the display unit 83.

[0043] Next, the configuration of the second transport path 92 of this embodiment will be described.

[0044] A purge tray 91 serving as a purge discharge section is disposed below the drum 31, between the entrance rotor 34 and the exit rotor 35. A second transport path 92 extending from the carry-in path 301 and extending obliquely downward from the receiving position of the entrance rotor 34 is provided, and a pair of transport rollers 93 is disposed on the second transport path 92. A purge discharge sensor 94 for detecting the sheet material P is disposed on the purge tray 91, and detects that the sheet material P to be purged has been discharged onto the purge tray 91.

[0045] Further, a switching section 95 that switches between the first conveying path 111 and the second conveying path 92 is located downstream of the receiving position a where the inlet rotor 34 receives the sheet material P, and a branch claw 96 is disposed as a switching means in the switching section 95. The switching section 95 switches the conveying destination of the sheet material P.

[0046] A purge switch 82 is provided as a purge operation means for issuing an instruction to discharge the sheet material P onto the purge tray 91. The reversing path 61 is also provided with a reversing purge tray 97.

[0047] Next, a configuration for detecting the sheet material in the first conveying path 111 will be described with reference to Fig. 3. Fig. 3 is an explanatory diagram for explaining a conveyance failure of the sheet material.

[0048] A transport failure detection means 112 is disposed on the first transport path 111 to detect displacement of the sheet material P in the thickness direction on the circumferential surface of the drum 31. As shown in Fig. 3(a), the transport failure detection means 112 detects transport failures such as lifting e1, wrinkles e2, and folded edges e3 of the sheet material P. Note that the "transport failure" mentioned here does not mean that the sheet material is actually unable to be transported, but rather means that the sheet material is in a state that causes a transport failure.

[0049] In other words, if the sheet material P is tilted when it is adsorbed onto the drum 31, the leading edge of the sheet material P may come off the gripper 311, causing a bent edge e3, or causing lifting e1 or wrinkles e2.

[0050] In this state, if the sheet material P enters the gap G between the peripheral surface of the drum 31 and the head of the discharge unit 33, as shown in Figure 3(b), the head may be damaged due to interference between the sheet material P and the discharge unit 33.

[0051] Therefore, when a transport failure is detected on the drum 31, the transport drive is stopped before the sheet material P enters the gap G between the circumferential surface of the drum 31 and the head of the most upstream discharge unit 33A.

[0052] Further, a first sensor 113 and a second sensor 114 that constitute sheet material detecting means for detecting the presence or absence of the sheet material P at the switching section 95 are arranged.

[0053] The first sensor 113 is disposed upstream of the switching unit 95. Here, the first sensor 113 is disposed upstream of the entrance rotator 34 at a position where it can detect the presence or absence of the sheet material P on the carry-in path 301.

[0054] The second sensor 114 is disposed downstream of the switching unit 95. Here, the second sensor 114 is disposed at a position where it can detect the presence or absence of the sheet material P on the circumferential surface of the inlet rotor .

[0055] When both the first sensor 113 and the second sensor 114 detect the sheet material P, it means that the sheet material P is present at the switching section 95 .

[0056] [Detailed Description of Control Means 80] Next, the control means 80 for controlling the purge operation will be described with reference to the functional block diagram of Fig. 4. The purge operation is an operation for removing remaining sheet material from the conveying path and returning the sheet material P to normal when the sheet material P has become unconveyable.

[0057] The control means 80 controls the overall operation of the image forming system 1. The following mainly describes the configuration that controls the purge operation. The control means 80 includes, as an example, a purge control means 801, a conveyance system drive unit 802, a display control unit 811 as a display control means, and a switch drive unit 812.

[0058] The purge control means 801 controls the purge operation and also serves as a means for controlling the switching between the first transport path 111 and the second transport path 92 in the switching unit 95 .

[0059] When the conveying failure detection means 112 detects a conveying failure, the purge control means 801 stops the operation of the drum 31, conveying belt 41, and conveying roller pair group 803 (conveying roller pair 302, conveying roller pair 601, etc.) via the conveying system drive unit 802, thereby stopping the conveying operation.

[0060] The purge control means 801, as inching control means, controls the execution of the inching operation when it receives a predetermined operation on the inching switch 81. The predetermined operation refers to, for example, a user pressing the inching switch 81. That is, while the inching switch 81 is pressed, the purge control means 801 controls the inching operation of driving the drum 31 and the inlet rotator 34 and outlet rotator 35, which move in unison with the drum 31, via the conveyance system drive unit 802. While the inching switch 81 is pressed, the purge control means 801, as inching means, drives the drive roller 401 in conjunction with the driving of the drum 31, etc., to move the conveyor belt 41, as conveyance means, at a predetermined speed. The rotational speed of the drive roller 401 that drives the conveyor belt 41 may be equal to or faster than the rotational speed of the outlet rotator 35. That is, the conveyance speed of the sheet material P by the conveyor belt 41 may be faster than the rotational speed of the outlet rotator 35 during the inching operation.

[0061] When a purge operation is instructed by the purge switch 82, and when the sheet material detection means 115 (first sensor 113, second sensor 114) detects that there is sheet material P at the switching section 95, the purge control means 801 displays on the display means 83 an instruction to perform an inching operation.

[0062] When a purge operation is instructed by the purge switch 82, the purge control means 801 switches the branch claw 96 via the switching drive unit 812 so that the sheet material P is transported from the first transport path 111 to the second transport path 92 after the sheet material detection means 115 (first sensor 113, second sensor 114) detects that there is no sheet material P in the switching unit 95.

[0063] When a transport operation is stopped due to a detected transport failure, the purge control means 801 controls operations such as transporting the required remaining sheet material P to the discharge section 50, discharging it to the inverted purge tray 97, or discharging it to the purge tray 91.

[0064] Next, an example of when a transport failure occurs in the printing unit 70 of the image forming system 1 and the transport operation is stopped will be described with reference to Fig. 5. Fig. 5 is an explanatory diagram showing an example of the position of the sheet material remaining in the device when the transport operation is stopped.

[0065] Here, it is assumed that the transport failure detection means 112 detects that the sheet material P10 on the first transport path 111 has a transport failure with a lift e2 at the trailing edge.

[0066] At this time, in order to prevent the floating portion e2 of the sheet material P from entering the gap G between the drum 31 and the discharge unit 33, when the transport failure detection means 112 determines that a transport failure of the sheet material P has occurred, the purge control means 801 immediately stops the rotational drive of the drum 31, etc.

[0067] However, because a certain distance is required as a braking distance due to the inertial forces of the drum 31, the entrance rotor 34, and the exit rotor 35, the sheet material P stops at a position where it has not been transported properly, slightly further than the transport failure detection means 112. Therefore, the distance from the transport failure detection means 112 to the head of the discharge unit 33 must be longer than this braking distance.

[0068] Meanwhile, by the purge control means 801, of the sheet materials P remaining in the drying section 40, the discharge path 701, and the duplex mechanism section 60, the sheet material P1 on which printing has already been completed successfully is conveyed to the discharge section 50, and the sheet materials P8 and P9 on which printing on the back side (second side) has not been completed are conveyed to the reversing purge tray (second purge tray) 97 below the reversing path 61. The sheet materials P7, P6, P5, P4, and P11 remaining from the duplex path 62 to the carry-in path 301 are stopped on the spot.

[0069] Furthermore, after the discharge unit 33 moves upward, the nozzle surface is capped with the cap 38, so that even if the sheet material P enters the drum 31, the head will not be damaged.

[0070] After these processes are completed, the display control unit 813 displays the positions of the remaining sheets P (remaining sheets) and the jam state on the display means 83 to notify the user.

[0071] [Detailed example of inching operation] Next, processing of the sheet material P remaining on the first conveying path 111 will be described with reference to Figures 6 and 7. Figure 6 is an explanatory diagram for explaining the inching operation, and Figure 7 is an explanatory diagram showing the state after the inching operation.

[0072] As described above, when a conveyance failure is detected by the conveyance failure detection means 112, the conveyance of the sheet material P is stopped. At this time, in this example, as shown in FIG. 6, the sheet material P3 stops across the switching unit 95. Therefore, when an attempt is made to convey the sheet material P11 on the carry-in path 301 and the sheets P4 to P7 on the duplex path 62 to the purge tray 91, they collide with the sheet material P3 and a jam occurs.

[0073] Therefore, the inching switch 81 is used to process the remaining sheet material P on the first transport path 111 formed by the circumferential surfaces of the entrance rotor 34, the drum 31, and the exit rotor 35.

[0074] A second transport path 92 leading to a purge tray 91 is disposed on the extension of the carry-in path 301, and the sheet material P on the carry-in path 301 and the double-sided path 62 can be transported to the purge tray 91 below the drum 31.

[0075] When the sheet material P is stopped in the state shown in Figure 5 described above, by operating the inching switch 81, the entrance rotor 34, the drum 31, the exit rotor 35, and the drive roller 401 perform an inching operation in the direction of the arrows, as shown in Figure 6.

[0076] As a result, even if the leading edge of the sheet material P2 has been sent out onto the conveyor belt 41 and the trailing edge remains on the drum 31, the sheet material P2 is sequentially sent out onto the conveyor belt 41 by the rotation of the drive roller 401 which rotates in conjunction with the rotation of the drum 31 by inching operation.

[0077] The same applies to sheet material P10 following sheet material P2; even if the leading edge side is sent from the exit rotator 35 to the conveyor belt 41 by the inching operation, if the inching operation is performed thereafter, the leading edge side is conveyed downstream by the conveyor belt 41, and even when the trailing edge side subsequently leaves the drum 31 and is handed over to the exit rotator 35, it is possible to prevent the trailing edge side from being caught up in the rotation of the drum 31 and entangled. The same applies to sheet material P3 following sheet material P10.

[0078] Then, as shown in FIG. 7, the sheet materials P2, P10, and P3 are sequentially moved to the conveyor belt 41 of the drying section 40 and removed from the first conveying path 111, and all of the sheet materials P spanning the switching section 95 are removed.

[0079] Therefore, by operating the purge switch 82, the branch claw 96 of the switching unit 95 switches to the second conveying path 92 side, and the subsequent purge operation causes the sheet material P11 on the input path 301 and the sheet materials P4 to P7 on the double-sided path 62 to be discharged onto the purge tray 91.

[0080] The effect of performing the inching operation when a conveyance failure occurs as described above will now be described. Figure 11 illustrates a state slightly earlier than the state illustrated in Figure 6, and assumes a state in which the drive roller 401 is not rotating during the inching operation or is not linked to the inching operation of the drum 31.

[0081] When sheet material P is fed by inching, depending on the thickness, rigidity, and surface properties of sheet material P, the trailing edge of sheet material P may be dragged toward drum 31 while it is being fed downstream from exit rotor 35. That is, in the case of sheet material P2, when it stops due to a conveyance problem, its leading edge is near the delivery position and its trailing edge is on drum 31, sagging of sheet material P2 is likely to occur on exit rotor 35.

[0082] The subsequent inching operation, along with the rotation of the drum 31, is likely to cause "dragging" of the rear end of the sheet P2 in the circumferential direction of the drum 31. If the inching operation continues in this state, the sheet P2 may become entangled with the drum 31, or an unfixed image formed by the liquid adhering to the sheet P2 may rub against other components within the device, soiling the inside of the device or causing the image to become visible.

[0083] Therefore, as in the printing unit 70 according to this embodiment, the downstream conveying means is constituted by the conveying belt 41 arranged downstream from the delivery position b. When the inching switch 81 is manually operated to rotate and drive the entrance rotator 34, the drum 31, and the exit rotator 35 to perform the inching operation, the driving roller 401 as the conveying means is further driven to synchronize the conveyance of the sheet material P by the conveying belt 41 with the conveyance of the drum 31, etc.

[0084] With the above configuration, the leading edge of the sheet material P2 is sent downstream of the delivery position b by the conveyor belt 41 as a conveying means, along with the inching operation. As a result, the slack in the sheet material P2 on the outlet rotor 35 is eliminated, and the sheet material P2 is prevented from being caught in the drum 31.

[0085] As a conveying means provided in the printing unit 70, instead of the conveying belt 41, a configuration in which the sheet is sandwiched and conveyed by a pair of conveying rollers can also be adopted.

[0086] Next, the control of the purge operation will be described with reference to Figures 8 and 9. Figure 8 is a flow chart illustrating the control of the purge operation, and Figure 9 is an explanatory diagram illustrating an example of the control when the purge switch 82 is pressed.

[0087] When the purge switch 82 is pressed down, it is determined whether or not there is a sheet material P across the switching section 95 based on the detection results of the sheet material detection means 115 (first sensor 113 and second sensor 114) (S801). Here, it is determined whether or not there is a sheet material P at the receiving position a (in FIG. 8, for the sake of simplicity, it is written as "receiving position (switching section)").

[0088] At this time, if there is a sheet material P straddling the receiving position a (switching section 95) (S801: N), it is necessary to remove the sheet material P straddling the receiving position a (switching section 95) by operating the inching switch 81, and this fact is displayed on the display means 83 to notify the user (S802).

[0089] On the other hand, if there is no sheet material P straddling the receiving position a (switching portion 95) (S801: Y), it is determined whether or not the branch claw 96 can be switched to the second conveying path 92 (S803).

[0090] 9, if the gripper 341 of the entrance rotator 34 is at the receiving position a (switching unit 95) when the purge switch 82 is pressed, the second conveying path 92 is blocked. Therefore, it is necessary to move the gripper 341 of the entrance rotator 34 to a position where the gripper 341 opens the second conveying path 92.

[0091] The position of the gripper 341 of the entrance rotor 34 is detected by a reflective sensor to determine whether the gripper 341 is in the retracted position. The position of the gripper 341 can also be detected by detecting the phase of the rotation angle of the entrance rotor 34 or the drum 31.

[0092] When the branch claw 96 cannot be switched to the second conveying path 92 (S803: N), the display means 83 displays a message to notify the user to move the gripper 341 to the retracted position by operating the inching switch 81 (S804).

[0093] On the other hand, when the branch claw 96 can be switched to the second transport path 92 (S803: Y), the branch claw 96 is switched to the second transport path 92 side (S805).

[0094] Thereafter, the driving of the conveying roller pair 302 of the carry-in path 301 and the conveying roller pair 601 of the double-sided path 62 is started (S806). As a result, the sheets P11, P4, P5, P6, and P7 are conveyed to the purge tray 91 and collected.

[0095] Then, it is determined whether or not a specified time has elapsed (S807), and if the specified time has elapsed (S807: Y), the driving of the conveying roller pair 302 of the carry-in path 301, the conveying roller pair 601 of the double-sided path 62, etc. is terminated and stopped (S808).

[0096] Thereafter, it is determined whether or not there is sheet material P stored in the purge tray 91 (S809), and if there is sheet material P stored in the purge tray 91 (S809: Y), the user is notified to remove the sheet material P from the purge tray 91 (S810).

[0097] In this way, after the sheet material detection means detects that no sheet material is present, control is performed to switch from the first conveying path 111 to the second conveying path 92, thereby preventing jams when processing remaining sheet material and suppressing a decrease in productivity.

[0098] If there is sheet material P passing from the drum 31 to the outlet rotor 35 during the inching operation when the above-mentioned purging operation is performed, the drive roller 401 as downstream conveying means is also operated in conjunction with the inching operation. As already explained, this prevents the sheet material P near the delivery position b from being dragged by the rotation of the drum 31 during the inching operation and winding around the purge tray 91. This improves the removal efficiency of the remaining sheet material.

[0099] Next, a second embodiment of the present invention will be described with reference to Fig. 10. Fig. 10 is an explanatory diagram illustrating a state when a purge switch 82a provided in a drum-type conveying device 100a according to the second embodiment is pressed.

[0100] In this embodiment, the second transport path 92 is formed by a vertically movable member 98 that moves back and forth between a position shown by a solid line and a position shown by a broken line relative to the inlet rotor 34 .

[0101] The vertically movable member 98 can move between, for example, a first position where there is a gap of about 1 mm relative to the circumferential surface of the inlet rotor 34 (a position where the sheet material P is guided to the first conveying path 111), and a retracted position where there is a gap of about 3 to 10 mm (a position where the sheet material P is guided to the second conveying path 92).

[0102] Then, when the purge switch 82 is pressed, as shown in Figure 10, the vertically movable member 98 moves downward to a first position away from the circumferential surface of the inlet rotor 34, and the sheet material P drips down onto the second conveying path 92 under its own weight and is guided thereon.

[0103] This allows the second conveying path 92 to be lowered to a position where it is not affected by the gripper 341 of the entrance rotor 34, and even if the gripper 341 is at the receiving position a, the sheet material P can move along the second conveying path 92 under its own weight.

[0104] That is, in this embodiment, the vertically movable member 98 constitutes a switching means for switching between the first transport path 111 and the second transport path 92 .

[0105] Therefore, in the flow diagram described in FIG. 8 of the first embodiment, when the purge switch 82 is pressed, the vertically movable member 98 is lowered, thereby eliminating the need to move the gripper 341 to the retracted position.

[0106] This allows for further reduction in downtime.

[0107] Also in this embodiment, when the inching switch 81 is operated to perform the inching operation as in the first embodiment, if there is sheet material P passing from the drum 31 to the outlet rotor 35, the drive roller 401 as downstream conveying means is also operated in conjunction with the inching operation. As already explained, this prevents the sheet material P near the delivery position b from being dragged by the rotation of the drum 31 during the inching operation and winding around the purge tray 91. This improves the ease of removing remaining sheet material.

[0108] The invention of the present application described above was invented by the applicant in order to further improve upon the prior invention that was already invented in consideration of the problems of the prior art. The applicant's prior invention has the feature that, when a transport error occurs and sheet transport is stopped, remaining sheet material on a cylinder or drum is fed a required distance only while a specified user operation is being performed. This feature solves the problems of the prior art. This prior invention also makes it easy to remove remaining sheet material, thereby preventing a decrease in productivity. However, as already explained, the applicant has considered further improvements.

[0109] As a result, the applicant discovered a problem in the operation in which the leading edge of the sheet material gripped by the conveying rotor is finally released from the gripping portion and sent out onto a conveying path to a downstream fixing portion, etc. In other words, when the sheet material is sent downstream of the conveying rotor by this inching operation, depending on the thickness, rigidity, and surface properties of the sheet material, the trailing edge side of the sheet material may be dragged toward the conveying rotor.

[0110] In particular, when the sheet stops due to a transport problem, if the leading edge of the sheet is near the transfer position from the transport rotor to the downstream transport path and the trailing edge of the sheet is on the transport rotor, the sheet is likely to sag at the exit rotor that sends the leading edge of the sheet from the transport rotor to the downstream transport path.Even if an attempt is made to send the sheet downstream by inching while the sheet is slack, the trailing edge of the sheet is likely to be dragged along with the rotation of the transport rotor.

[0111] When dragging of the sheet material occurs, problems arise such as the sheet material becoming entangled in the conveying rotor, the unfixed image rubbing against components inside the device and becoming distorted, and unfixed liquid adhering to the inside of the device and causing contamination.

[0112] The present invention was made as a result of further investigation into the prior art that could solve the problems of the prior art described above. That is, it improves the removal of residual sheet material caused by transport failure, and also prevents unfixed liquid on the residual sheet material from adhering to and contaminating the device components.

[0113] The present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the technical gist thereof. The present invention covers all technical matters included in the technical ideas described in the claims. The above-described embodiments are preferred examples, but a person skilled in the art can realize various modifications from the disclosed contents. Such modifications are also included in the technical scope described in the claims. [Explanation of symbols]

[0114] 1: Image forming system 33: Discharge unit 34: Inlet rotor 35: Exit rotor 41: Conveyor belt 70:Printing Department 80: Control means 81: Inching switch 82, 82a: Purge switch 83:Display means 91: Purge tray 92: Second transport route 93: conveying roller pair 94: Purge discharge sensor 95: Switching section 96: Branch claw 97: Reverse purge tray 98: Vertical movement member 111: First transport route 112: Transport failure detection means 113: First sensor 114: Second sensor 115: Sheet material detection means 401: Drive roller 801: Purge control means 802: Transport system drive unit 803: Conveying roller pairs 811: Display control unit 812: Switching drive unit 813: Display control unit [Prior art documents] [Patent documents]

[0115] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-19172

Claims

1. A conveying device for conveying a sheet material, a supporting rotor that supports the sheet material; an inlet rotor that transfers the sheet material from the upstream side to the carrying rotor; an outlet rotor that transfers the sheet material downstream from the carrying rotor; downstream conveying means for conveying the sheet material downstream from the outlet rotating body; an inching control means for inching the sheet material in a conveying path including at least the downstream conveying means; The inching control means interlocks at least the outlet rotator with the conveying operation of the downstream conveying means during the inching operation. A conveying device characterized by:

2. an inching operation means for instructing the inching operation; the inching control means executes a conveying operation by at least the outlet rotator and the downstream conveying means while a predetermined first operation is being performed on the inching operation means, The conveying operation is stopped while a predetermined second operation is being performed on the inching operation means. The conveying device according to claim 1 .

3. a conveyance failure detection means for detecting a conveyance failure of the sheet material on a conveyance path along which the sheet material is conveyed; a display means for displaying the conveyance status of the sheet material; a control means for stopping the conveyance of the sheet material, the control means stops the conveyance of the sheet material when the conveyance failure is detected, and causes the display means to display information instructing the inching operation.

3. The conveying device according to claim 1 or 2.

4. a purge discharge section provided near the inlet rotor; a switching unit that switches the destination of the sheet material between the conveying path and the purge discharge unit, located upstream of the conveyance failure detection unit; when the conveyance failure detection means detects the conveyance failure, the control means switches the conveyance destination of the sheet material upstream of the inlet rotating body to the purge discharge portion. The conveying device according to claim 3 .

5. a purge control unit for controlling a purge operation for discharging the sheet material on the conveying path to the purge discharge unit; and purge operation means for instructing the purge operation, the purge control means, when the purge operation means is operated, switches the conveying direction of the sheet material and discharges the sheet material to the purge discharge section; The conveying device according to claim 4.

6. a conveying speed by the downstream conveying means is faster than a conveying speed of the outlet rotator; A conveying device according to any one of claims 1 to 5.

7. a liquid discharge unit that discharges liquid onto a conveyed sheet material; a conveying device according to claim 1 that conveys the sheet material to the liquid ejection unit; A liquid ejection device comprising:

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