JP7722147B2 - Conveying device, liquid ejecting device - Google Patents

Description

The present invention relates to a conveying device and a liquid ejection device.

Conveying devices that convey sheet material as sheet-like media are known. One example of a conveying device is one in which a gripping unit such as a gripper is provided on a rotating conveying body such as a cylinder or drum, and the rotating conveying body is rotated while the gripping unit grips the sheet material, thereby conveying the sheet material. Also known is a liquid ejection device that is equipped with a conveying device and ejects liquid onto the sheet material being conveyed. This liquid ejection device forms an image on the sheet material by ejecting liquid onto the sheet material being conveyed by the rotation of the rotating conveying body.

In a conveying device like the one described above, if a sheet material floats or becomes wrinkled or folded during conveyance, this can cause conveyance problems. Therefore, some devices are known that stop conveyance of the sheet material when a condition that causes conveyance problems, such as floating, wrinkled, or folded sheet material, occurs and ejects the subsequent sheet material into 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 folds, is sometimes simply referred to as a "conveyance problem."

To address sheet transport failures during transport, a device is known that includes a first transport section that transports the sheet to the image formation area, a second transport section that prevents the sheet from passing through the image formation area, and a switching section that is located upstream of the image formation area and guides sheet material determined to be transported improperly to the second transport section and sheet material determined to be transported normally to the first transport section (Patent Document 1).

In the device described in Patent Document 1, if a sheet transport error occurs, the transport of the sheet is stopped, but if the sheet straddles the switching section and stops, that sheet will collide with the following sheet, causing a jam, which worsens the processability of the remaining sheet. As a result, productivity decreases.

The present invention aims to improve the removal of residual sheet material caused by transport failure.

The present invention relates to a conveying device comprising a carrier rotor that carries sheet material, an entrance rotor that transfers the sheet material from the upstream side to the carrier rotor, an exit rotor that transfers the sheet material downstream from the carrier rotor, downstream conveying means that conveys the sheet material downstream from the exit rotor, 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, and the inching control means links the conveying operations of at least the exit rotor and the downstream conveying means during the inching operation.

This invention improves the ability to remove residual sheet material caused by transport problems.

1 is a schematic explanatory diagram of a first embodiment of a liquid ejection device according to the present invention; FIG. 2 is an enlarged explanatory view of a transport device included in the liquid ejection device according to the first embodiment. FIG. 10 is an explanatory diagram illustrating a conveyance failure of a sheet material. FIG. 4 is a block diagram showing an example of a control unit that controls an inching operation and a purging operation. 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. FIG. 4 is an explanatory diagram illustrating an inching operation. FIG. 10 is an explanatory diagram showing a state after an inching operation. FIG. 4 is a flowchart illustrating the flow of a control process for a purge operation. FIG. 10 is an explanatory diagram illustrating an example when the purge switch is pressed. 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. FIG. 10 is an explanatory diagram illustrating a comparative example of an inching operation. FIG. 2 is an enlarged explanatory view of the first embodiment of the conveying device.

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a schematic diagram illustrating 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 ejection unit 33 and other components have been omitted from FIG. 2.

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

The printing unit 70 is a printing device in the narrow sense and corresponds to 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 sheet material P being conveyed. Since the sheet material P on which the image has been formed must be dried to fix the liquid to the sheet material P, the printing unit 70 also includes a drying unit 40 as a fixing means. 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 also be located between the loading unit 10 and the printing unit 70.

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

In the image forming system 1, the image forming section 30 of the printing unit 70 applies liquid to the sheet material P carried in (supplied) from the carry-in section 10 to perform the required printing, and the liquid adhering to the sheet material P is dried (fixed) in the drying section 40, after which the sheet material P is discharged to the carry-out section 50.

The loading section 10 includes a loading tray 11 (lower loading tray 11A, upper loading 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 loading tray 11, and supplies the sheet materials P to the image forming section 30.

The image forming unit 30 includes a liquid ejection unit 32 that ejects liquid toward the sheet material P held on the drum 31, which is a rotating support member that holds the sheet material P on its circumferential surface and rotates.

As shown in FIG. 2, the image forming unit 30 includes a liquid ejection section 32. The liquid ejection section 32 includes ejection units 33 (33A-33D) that include liquid ejection heads, which serve as liquid ejection means. For example, ejection unit 33A ejects cyan (C) liquid, ejection unit 33B ejects magenta (M) liquid, ejection unit 33C ejects yellow (Y), and ejection unit 33D ejects black (K) liquid. It is also possible to use ejection units that eject special liquids such as white and gold (silver).

The image forming unit 30 also includes caps 38 that cap the ejection surfaces (nozzle surfaces) of each ejection unit 33 of the liquid ejection unit 32. The ejection units 33 are arranged so that they can move back and forth 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 away from the circumferential surface of the drum 31, and the caps 38 move in underneath them to perform capping.

Each ejection unit 33 of the liquid ejection section 32 has its ejection operation controlled by a drive signal corresponding to the printing information. When the sheet material P carried on the drum 31 passes through the 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).

As shown in Figure 12, the drum-type conveying device 100 includes an entrance rotor 34 that receives the sheet material P fed from the upstream side and transfers the sheet material P between the entrance rotor 34 and the drum 31, and an exit rotor 35 that receives the sheet material P conveyed by the drum 31 and transfers it to the drying section 40.

The entrance rotor 34 is provided with a gripper 341 as a gripping means on its outer periphery. The leading edge of the sheet material P, which is conveyed by a pair of conveying rollers 302 or the like along the carry-in path 301, which serves as a conveying path upstream of the entrance rotor 34, is grasped by the gripper 341 at the receiving position a (see Figure 2).

As the inlet rotor 34, which is gripping the leading edge of the sheet material P, rotates, the sheet material P is transported in the rotational direction. The transported sheet material P is then transferred to the drum 31 at a position where the drum 31 and the inlet rotor 34 face each other.

When sheet material P is transported along 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. Furthermore, the skew detection means and correction means correct the tilt and transport position of the sheet material P in a direction perpendicular to the transport direction, while the sheet material P is transported to the receiving position.

In addition, the carry-in path 301 is provided with a sheet length detection means that detects the length of the sheet material P in the conveying direction, and a sheet width detection means that detects the width of the sheet material P, which is the length in the direction perpendicular to the conveying direction. The sheet length detection means and sheet width detection means stop the printing operation when the measured value differs from the set sheet size, preventing liquid from being ejected onto the drum 31.

Grippers 311, which serve as 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. Multiple suction holes are formed at various locations on the surface of the drum 31, and the suction means generates a suction airflow that flows inward from the 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 to the circumferential surface of the drum 31 by the suction airflow generated by the suction means, and is transported as the drum 31 rotates.

The sheet material P on which the image has been formed is transferred from the drum 31 to the exit rotor 35. The exit rotor 35 receives the sheet material P from the drum 31 using a gripper 351, which is a gripping means provided on the outer periphery. As the exit rotor 35 rotates, the sheet material P is transferred to the drying section 40 at transfer position b.

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.

The drying unit 40 dries the liquid that has been deposited on the sheet material P in the image forming unit 30. This evaporates the water and other liquid components in the liquid, fixes the colorant contained in the liquid onto the sheet material P, and also prevents the sheet material P from curling. After passing through the drying unit 40, the sheet material P is transported to the discharge unit 50 via the discharge path 701, or sent to the duplexing mechanism unit 60.

When the sheet material P is being transported, the transport belt 41 transports the sheet material P received from the outlet rotor 35 toward the downstream heating means 42 so that the sheet material P passes through the heating means 42 at a predetermined transport speed. The transport speed of the sheet material P by the transport belt 41 is set by the rotational speed of the drive roller 401. The rotational speed of the drive roller 401 is also controlled by the control means 80.

When the leading edge of the sheet material P leaves the exit rotor 35 and is handed over to the conveyor belt 41, the rotational speed of the drive roller 401 is adjusted so that the conveyor belt 41 operates at a predetermined conveying speed. Furthermore, when the inching operation described below is performed, the rotational speed of the drive roller 401 is also set to match the rotational speed of the exit rotor 35. As a result, the sheet material P handed over from the exit rotor 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, which subsequently leaves the exit rotor 35, is also more likely to move in the conveying direction of the conveyor belt 41 without moving circumferentially due to the rotation of the drum 31.

The duplex mechanism unit 60 includes a reversing path 61 that receives the sheet material P that has passed through the drying unit 40 and reverses it when printing on both sides of the sheet material P, and a duplex path 62 that feeds the sheet material P reversed by the reversing path 61 back to the conveying path 340. Multiple conveying roller pairs 601 are arranged in the reversing path 61 and the duplex path 62.

The discharge section 50 is equipped with a discharge tray 51 on which multiple sheet materials P are stacked. The sheet materials P conveyed from the drying section 40 are stacked and held on the discharge tray 51 in order.

Next, we will explain the first transport path 111 in this embodiment.

In this embodiment, the first conveying path 111 is formed by the circumferential surfaces of the entrance rotor 34, the drum 31, the exit rotor 35, and the conveying belt 41.

Here, the entrance rotor 34 and the exit rotor 35 are connected by gears, using the transport drive source provided on the drum 31, and the drum 31, entrance rotor 34, and exit rotor 35 are driven in conjunction to transport the sheet material P along the first transport path 111. However, the entrance rotor 34, drum 31, and exit rotor 35 can also be driven by separate drive sources.

In addition, the drive source of the drive roller 401 that drives the conveyor 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 that it operates in conjunction with the drive of the drum 31, etc.

All of the drive sources for the first transport path 111 can be driven independently by operating the inching switch 81, which serves as an inching operation means. This means that even when the image forming system 1 is stopped, the entrance rotor 34, drum 31, and exit rotor 35 can be driven to rotate (inching operation) by operating the inching switch 81 in a specific manner.

The inching switch 81 is a switching device that switches the inching operation between "start (ON)" and "stop (OFF)" when the user performs a predetermined operation. The predetermined operations for 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 switch "ON," and the second operation turns it "OFF." Note that the first and second operations for ON-OFF operations may be reversed. Furthermore, the first operation may be the user touching the inching switch 81, and the second operation may be the user not touching it, or vice versa.

A first operation of the inching switch 81 causes the drive roller 401 to rotate in the same manner, rotating the conveyor belt 41 at the same speed as the inching operation and transporting the sheet material P downstream. Then, a second operation stops the drive roller 401.

Inching operation is a type of transport operation in which sheet material P is transported at a slower speed than during normal printing operations by operating the inching switch 81 in a first manner. More specifically, the drum 31 and other components rotate at a slower speed than during printing operations only while the user is operating the inching switch 81 in a first manner. Then, when the user operates the inching switch 81 in a second manner, the rotation of the drum 31 and other components is stopped. During 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.

In addition to rotating in the transport direction during printing, the rotation direction selection means is also capable of selecting forward or reverse rotation. This makes it possible to process sheet material P remaining on the circumferential surfaces of the drum 31, entrance rotor 34, and exit rotor 35, inspect and replace grippers 341, 311, and 351 during maintenance, clean the circumferential surface of the drum 31, and clean and replace plates with suction holes.

The image forming system 1 is also equipped with a display unit 83 that displays the transport 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 via the display unit 83.

Next, we will explain the configuration of the second conveying path 92 in this embodiment.

Below the drum 31, between the entrance rotor 34 and the exit rotor 35, a purge tray 91 is located as a purge discharge section. A second transport path 92 is provided on the extension of the carry-in path 301, extending diagonally downward from the receiving position of the entrance rotor 34, and a pair of transport rollers 93 is arranged on the second transport path 92. A purge discharge sensor 94 that detects sheet material P is also arranged on the purge tray 91, and detects when the sheet material P to be purged has been discharged onto the purge tray 91.

Furthermore, downstream of the receiving position a where the entrance rotor 34 receives the sheet material P, a switching section 95 is provided that switches between the first conveying path 111 and the second conveying path 92, and a branching claw 96 is provided as a switching means in the switching section 95. The switching section 95 switches the conveying destination of the sheet material P.

A purge switch 82 is provided as a purge operation means for issuing instructions such as discharging sheet material P to the purge tray 91. A reversing purge tray 97 is also provided on the reversing path 61.

Next, the configuration related to detecting sheet material on the first conveying path 111 will be described with reference to Figure 3. Figure 3 is an explanatory diagram used to explain conveyance failures of the same sheet material.

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 Figure 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 "transport failure" here does not mean that the sheet material is actually unable to be transported, but rather that it is in a state where a transport failure occurs.

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.

In this state, if the sheet material P enters the gap G between the circumferential surface of the drum 31 and the head of the discharge unit 33, as shown in Figure 3(b), interference between the sheet material P and the discharge unit 33 may damage the head.

Therefore, if a transport problem 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 ejection unit 33A.

In addition, a first sensor 113 and a second sensor 114 are provided, which constitute sheet material detection means for detecting the presence or absence of sheet material P at the switching section 95.

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

The second sensor 114 is located downstream of the switching unit 95. Here, the second sensor 114 is located at a position where it can detect the presence or absence of sheet material P on the circumferential surface of the inlet rotor 34.

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

[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.

The control unit 80 controls the overall operation of the image forming system 1. Below, we will mainly explain the configuration that controls the purging operation. As an example, the control unit 80 includes a purge control unit 801, a conveyance system drive unit 802, a display control unit 811 as a display control unit, and a switching drive unit 812.

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

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

The purge control means 801, as inching control means, controls the execution of the inching operation when a predetermined operation is received on the inching switch 81. The predetermined operation refers, for example, to the 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 entrance rotator 34 and exit rotator 35, which move in unison with the drum 31, via the conveyance system drive unit 802. Furthermore, while the inching switch 81 is pressed, the purge control means 801 as inching means drives the drive roller 401 in conjunction with the drive 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 the same as or faster than the rotational speed of the exit 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 exit rotator 35 during the inching operation.

When the purge switch 82 commands a purge operation and the sheet material detection means 115 (first sensor 113, second sensor 114) detects that sheet material P is present in the switching section 95, the purge control means 801 displays a command on the display means 83 to perform an inching operation.

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.

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.

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

Here, the transport failure detection means 112 detects a transport failure of floating e2 at the trailing edge of sheet material P10 on the first transport path 111.

At this time, 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, if 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 rotation of the drum 31 and other components.

However, due to the inertial forces of the drum 31, entrance rotor 34, and exit rotor 35, a certain fixed distance is required as a braking distance, so the sheet material P stops at a position slightly further ahead than the transport failure detection means 112. Therefore, the distance from the transport failure detection means 112 to the head of the ejection unit 33 must be greater than this braking distance.

Meanwhile, the purge control means 801 transports sheet material P1, which has already been printed successfully, among the sheet materials P remaining in the drying section 40, discharge path 701, and duplex mechanism section 60, to the discharge section 50, while sheet materials P8 and P9, which have not yet been printed on their rear surfaces (second surfaces), are transported to the reversal purge tray (second purge tray) 97 located below the reversal path 61. Sheet materials P7, P6, P5, P4, and P11 remaining in the carry-in path 301 from the duplex path 62 are stopped on the spot.

In addition, after the ejection unit 33 moves upward, the nozzle surface is capped with the cap 38, so that the head will not be damaged even if the sheet material P enters the drum 31.

After these processes are completed, the display control unit 813 notifies the user by displaying the position of the remaining sheet material P (remaining sheets) and the jam status on the display means 83.

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

As described above, when a transport failure is detected by the transport failure detection means 112, transport of sheet material P is stopped. In this example, as shown in FIG. 6, sheet material P3 stops at this time, straddling the switching unit 95. Therefore, when sheet material P11 on the input path 301 and sheet materials P4 to P7 on the duplex path 62 are attempted to be transported to the purge tray 91, they collide with sheet material P3, causing a jam.

The inching switch 81 is then used to process the remaining sheet material P on the first conveying path 111, which is made up of the circumferential surfaces of the entrance rotor 34, drum 31, and exit rotor 35.

A second transport path 92 leading to the purge tray 91 is located on the extension of the carry-in path 301, allowing sheet material P from the carry-in path 301 and double-sided path 62 to be transported to the purge tray 91 below the drum 31.

When the sheet material P is stopped in the state shown in Figure 5, operating the inching switch 81 causes the entrance rotor 34, drum 31, exit rotor 35, and drive roller 401 to perform an inching motion in the direction of the arrows, as shown in Figure 6.

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

The same is true for sheet material P10 following sheet material P2. Even if the leading edge is sent from the exit rotor 35 to the conveyor belt 41 by the inching operation, if the inching operation is subsequently performed, the leading edge will be conveyed downstream by the conveyor belt 41, and when the trailing edge subsequently leaves the drum 31 and is handed over to the exit rotor 35, it can be prevented from being caught up in the rotation of the drum 31 and becoming entangled. The same is true for sheet material P3 following sheet material P10.

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

Therefore, by operating the purge switch 82, the branch claw 96 of the switching unit 95 switches to the second transport path 92 side, and the subsequent purge operation ejects sheet material P11 from the carry-in path 301 and sheet materials P4 to P7 from the double-sided path 62 onto the purge tray 91.

As described above, the effect of performing inching when a conveyance failure occurs will be explained. Figure 11 illustrates a slightly earlier point in time than the state illustrated in Figure 6, and assumes a situation in which the drive roller 401 is not rotating during inching, or is not linked to the inching of the drum 31.

When sheet material P is fed using the inching operation, depending on the thickness, rigidity, and surface properties of the sheet material P, the trailing edge of the sheet material P may be dragged toward the drum 31 while it is being fed downstream from the exit rotor 35. In other words, in cases such as sheet material P2, where the leading edge is near the transfer position and the trailing edge is on the drum 31 when the sheet material P stops due to a transport error, sagging of the sheet material P2 is likely to occur on the exit rotor 35.

The subsequent inching operation, as the drum 31 rotates, is likely to cause the trailing edge of the sheet P2 to be dragged in the circumferential direction of the drum 31. If the inching operation continues, the sheet P2 may become entangled with the drum 31, or the 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.

As such, in the printing unit 70 according to this embodiment, the downstream conveying means is constituted by a conveying belt 41 positioned downstream from the transfer position b. When the inching switch 81 is manually operated to rotate and drive the entrance rotor 34, drum 31, and exit rotor 35 for inching operation, the drive roller 401, which serves 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.

With the above configuration, the leading edge of sheet material P2 is sent downstream from transfer position b by the conveyor belt 41, which serves as the conveying means, during the inching operation. As a result, any slack in sheet material P2 on the outlet rotor 35 is eliminated, preventing it from being caught in the drum 31.

In addition, the conveyor provided in the printing unit 70 can also be configured to sandwich and convey the sheet using a pair of conveyor rollers instead of the conveyor belt 41.

Next, the control of the purge operation will be explained with reference to Figures 8 and 9. Figure 8 is a flow diagram explaining the control of the purge operation, and Figure 9 is an explanatory diagram showing an example of what happens when the purge switch 82 is pressed.

When the purge switch 82 is pressed, it is determined whether or not there is 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 sheet material P at the receiving position a (referred to as the "receiving position (switching section)" in Figure 8 for simplicity).

At this time, if there is sheet material P straddling the receiving position a (switching unit 95) (S801: N), the sheet material P straddling the receiving position a (switching unit 95) must be removed by operating the inching switch 81, and this fact is displayed on the display means 83 to notify the user (S802).

On the other hand, if there is no sheet material P straddling the receiving position a (switching unit 95) (S801: Y), it is determined whether the branch claw 96 can be switched to the second conveying path 92 (S803).

In other words, as shown in Figure 9, if the gripper 341 of the entrance rotor 34 is in receiving position a (switching section 95) when the purge switch 82 is pressed, the second conveying path 92 will be blocked. Therefore, the gripper 341 of the entrance rotor 34 must be moved to a position where it opens the second conveying path 92.

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.

If the branch claw 96 cannot be switched to the second transport path 92 (S803: N), the display means 83 displays a message to notify the user that the gripper 341 should be moved to the retracted position by operating the inching switch 81 (S804).

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).

Then, the conveying roller pair 302 on the carry-in path 301 and the conveying roller pair 601 on the duplex path 62 are driven (S806). As a result, sheet materials P11, P4, P5, P6, and P7 are transported to the purge tray 91 and collected.

Then, it is determined whether the specified time has elapsed (S807), and if the specified time has elapsed (S807: Y), the drive of the conveying roller pair 302 on the carry-in path 301, the conveying roller pair 601 on the duplex path 62, etc. is terminated and stopped (S808).

Then, it is determined whether 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).

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, preventing jams when processing remaining sheet material and minimizing declines in productivity.

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, which serves as the downstream transport means, is also operated in conjunction with the inching operation. As already explained, this prevents the sheet material P near the transfer position b from being pulled 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.

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

In this embodiment, the second conveying path 92 is formed by a vertically movable member 98, which is a reciprocating member that moves between the position shown by the solid line and the position shown by the dashed line relative to the inlet rotor 34.

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

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 falls under its own weight onto the second transport path 92 and is guided there.

As a result, the second conveying path 92 is 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 receiving position a, the sheet material P can move along the second conveying path 92 under its own weight.

In other words, in this embodiment, the vertically movable member 98 constitutes a switching means for switching between the first conveying path 111 and the second conveying path 92.

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

This will allow for further reduction in downtime.

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, which serves as the downstream transport means, is also operated in conjunction with the inching operation. As already explained, this prevents the sheet material P near the transfer position b from being pulled 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.

The invention of the present application, as explained above, was invented by the applicant in order to provide further improvements to 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 out the required distance only while a specified user operation is being performed (during execution). This feature solves the problems of the prior art. This prior invention also makes it easy to remove remaining sheet material, preventing a decline in productivity. However, as already explained, the applicant has considered further improvements.

As a result, the applicant discovered an issue with the operation in which the leading edge of the sheet material held by the conveying rotor is finally released from the gripping section and sent out onto a conveyance path to a downstream fixing section, 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 of the sheet material may be dragged toward the conveying rotor.

In particular, if the leading edge of the sheet material is near the transfer position from the conveying rotor to the downstream conveying path when the conveying rotor stops due to a conveying problem, and the trailing edge of the sheet material is on the conveying rotor, sagging of the sheet material is likely to occur at the exit rotor, which sends the leading edge of the sheet material from the conveying rotor to the downstream conveying path. Even if an attempt is made to send the sheet material downstream by inching while the sheet material is sagging, the trailing edge of the sheet material is likely to be dragged along by the rotation of the conveying rotor.

When dragging of the sheet material occurs, it can cause problems such as the sheet material becoming tangled around the rotating conveyor, the unfixed image rubbing against components inside the device and causing image distortion, and unfixed liquid adhering to the inside of the device and causing contamination.

The present invention was therefore developed as a result of further investigation into prior inventions that could solve the problems of the prior art described above. Specifically, it improves the ability to remove residual sheet material caused by transport problems, and also prevents unfixed liquid on the residual sheet material from adhering to and contaminating the device components.

The present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the technical gist of the invention. The present invention covers all technical matters included in the technical concept described in the claims. The above-described embodiments are preferred examples, but those skilled in the art will be able to realize various modifications based on the disclosed content. Such modifications are also included within the technical scope described in the claims.

1: Image forming system 33: Discharge unit 34: Inlet rotator 35: Outlet rotator 41: Conveyor belt 70: Printing unit 80: Control means 81: Inching switch 82, 82a: Purge switch 83: Display means 91: Purge tray 92: Second conveying path 93: Conveyor roller pair 94: Purge discharge sensor 95: Switching unit 96: Branching claw 97: Reverse purge tray 98: Vertically moving member 111: First conveying path 112: Conveyor failure detection means 113: First sensor 114: Second sensor 115: Sheet material detection means 401: Drive roller 801: Purge control means 802: Conveyor system drive unit 803: Conveyor roller pair group 811: Display control unit 812: Switching drive unit 813: Display control unit

JP 2017-19172 A

Claims (7)

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: 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 . 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. 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 . 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. 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. 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: