Aftertreatment Device

Abstract

To provide a post-processing device adapted to appropriately reduce skewing of a medium.SOLUTION: A post-processing device 4 comprises a side-end aligning unit 45 allowed to move to a first position L1 to abut at both sides in a width direction against side ends E2, a second position L2 lying more distant from the side ends E2 in the width direction than the first position L1 and for resting a medium P on a loading unit 35, and a third position L3 between the first position L1 and the second position L2 in the width direction and to contact a medium P when it is carried skewing by the first transport unit 40, so as to execute an adjustment operation to move the side-end aligning unit 45 from the second position L2 to the third position L3 and an alignment operation to align the medium P by abutting the side-end aligning unit 45 against the medium P in the first position L1. The adjustment operation is executed in the course the first transport unit 40 is carrying the medium P, and the alignment operation is executed following the adjustment operation and after the medium P arrives at a front-end aligning unit 38.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a post-processing device that performs post-processing on a medium onto which liquid has been ejected and recorded. [Background technology]

[0002] Various post-processing devices have been used in the past to perform post-processing on media onto which liquid has been ejected and recorded. For example, there is a device that sequentially transports multiple media onto which liquid has been ejected and recorded, aligns the leading edges of each media, and then performs post-processing such as stapling on the aligned leading edges of the media. In conventional post-processing devices, the media may be transported at an angle when being transported. Therefore, for example, Patent Document 1 discloses a post-processing device that includes a width adjustment cursor that can narrow the media transport path in the width direction by pinching the media in the width direction that intersects with the media transport direction to reduce skew of the media. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-188237 Summary of the Invention [Problem to be solved by the invention]

[0004] However, even if a component that narrows the media transport path in the width direction, such as the width alignment cursor of the post-processing device in Patent Document 1, is provided, there are cases where skewed media transport in the post-processing device cannot be appropriately reduced. Specifically, depending on the timing, amount, and manner of movement of the component, a corner of the media being transported skewed may come into contact with the component and be damaged, or the corner may get under already loaded media, preventing the media from being properly aligned. [Means for solving the problem]

[0005] a control unit for controlling the position of the side edge alignment unit in the width direction, and wherein the side edge alignment unit has a first position where it abuts against the side edges of the medium on both sides in the width direction, and a second position where it abuts against the side edges of the medium on both sides in the width direction, and a third position where it abuts against the side edges of the medium on both sides in the width direction, and a fourth position where it abuts against the side edges of the medium on both sides in the width direction, and a fourth position where it abuts against the side edges of the medium on both sides in the width direction, and a fifth ... and a third position in the width direction between the first position and the second position and capable of contacting the medium when the medium is transported at an angle by the first transport unit, wherein the control unit is capable of performing an adjustment operation to move the side edge alignment unit from the second position to the third position and an alignment operation to align the medium by abutting the side edge alignment unit against the medium at the first position, wherein the control unit performs the adjustment operation while the first transport unit is transporting the medium, and performs the alignment operation after the adjustment operation and after the medium has reached the leading edge alignment unit. [Brief explanation of the drawings]

[0006] [Figure 1] 1 is a schematic diagram of a recording system according to an embodiment of the present invention. [Figure 2] 1 is a side cross-sectional view showing a processing unit as a post-processing device according to an embodiment of the present invention. [Figure 3] FIG. 1 is a schematic side cross-sectional view showing a processing unit according to an embodiment of the present invention. [Figure 4] FIG. 1 is a perspective view showing a processing unit according to an embodiment of the present invention. [Figure 5] 10 is a flowchart showing an example of an operation for suppressing skew performed using a processing unit according to an embodiment of the present invention. [Figure 6] FIG. 4 is a schematic diagram illustrating a state in which a side edge alignment section is in a second position in a processing unit according to an embodiment of the present invention. [Figure 7] FIG. 4 is a schematic diagram illustrating a state in which a side edge aligning section is in a third position in a processing unit according to an embodiment of the present invention. [Figure 8] FIG. 2 is a schematic diagram illustrating a state in which a side edge alignment section is in a first position in a processing unit according to an embodiment of the present invention. [Figure 9] 3A and 3B are schematic diagrams showing the positional relationship among a first position, a second position, a third position, a fourth position, and a fifth position of a side edge alignment portion of a processing unit according to an embodiment of the present invention. [Figure 10] FIG. 3 is a schematic diagram illustrating a first region and a second region of a medium. DETAILED DESCRIPTION OF THE INVENTION

[0007] The present invention will be briefly described below. a first transport unit that contacts the medium to apply a transport force to the medium and transports the medium in a transport direction; a leading edge alignment unit that aligns a leading edge of the medium placed on the placing unit on a downstream side in the transport direction; a side edge alignment unit that is configured to be movable in a width direction perpendicular to the transport direction of the medium and that aligns the medium in the width direction by abutting against side edges of the medium from both sides in the width direction; and a control unit that controls the position of the side edge alignment unit in the width direction, and a third position in the width direction that is between the first position and the second position and can contact the medium when the medium is transported at an angle by the first transport unit, and the control unit is capable of performing an adjustment operation to move the side edge alignment unit from the second position to the third position, and an alignment operation to align the medium by abutting the side edge alignment unit against the medium at the first position, and the control unit performs the adjustment operation while the first transport unit is transporting the medium, and performs the alignment operation after the adjustment operation and after the medium has reached the leading edge alignment unit.

[0008] According to this aspect, in addition to the alignment operation performed after the leading edge of the medium reaches the leading edge alignment section, an adjustment operation is performed prior to the alignment operation to move the side edge alignment section from the second position to the third position while the medium is being transported. In other words, the operation to suppress skew of the medium is performed in stages. By performing the operation to suppress skew of the medium in stages in this way, it is possible to reduce the risk of the corner of the medium being transported skewed coming into contact with the side edge alignment section and being damaged, or the risk of the corner getting under already loaded media and causing the media to be improperly aligned. Therefore, it is possible to effectively reduce skew of the medium in the post-processing device.

[0009] In a second aspect, in the post-processing device of the first aspect, the side edge alignment section extends in the conveying direction, and the control section performs the adjustment operation after the leading edge has passed the downstream end of the side edge alignment section in the conveying direction throughout the entire width direction.

[0010] According to this aspect, because the side edge alignment portion extends in the conveying direction, the skew suppression operation can be performed effectively over a long distance. Furthermore, the adjustment operation is performed after the leading edge of the medium passes the downstream end of the side edge alignment portion in the conveying direction across the entire width. That is, because the adjustment operation is performed after the corners of the leading edge of the medium pass the side edge alignment portion, it is possible to prevent the corners of the leading edge of the medium from colliding with the side edge alignment portion, thereby reducing the risk of damage to the corners.

[0011] A third aspect is characterized in that, in the post-processing device of the first or second aspect, the side edge alignment section is movable to a fourth position between the second position and the third position in the width direction, and the control section moves the side edge alignment section to the fourth position after the alignment operation and performs the alignment operation again.

[0012] According to this aspect, by performing the alignment operation again after performing the alignment operation, it is possible to effectively reduce skew of media in the post-processing device. Also, by making the amount of movement of the side edge alignment section in the width direction greater in the re-executed alignment operation than in the previous alignment operation, it is possible to particularly effectively reduce skew of media in the post-processing device.

[0013] A fourth aspect is characterized in that, in the post-processing device described in any one of the first to third aspects, it is provided with a second conveying section that is arranged downstream of the first conveying section in the conveying direction, contacts the medium to apply a conveying force to the medium, and conveys the medium in the conveying direction, and the control section performs the adjustment operation before the medium comes into contact with the second conveying section.

[0014] According to this aspect, the adjustment operation is performed before the medium comes into contact with the second transport unit. If the adjustment operation is performed while the medium is in contact with the second transport unit, there is a risk that the adjustment operation will not be performed properly due to friction between the medium and the second transport unit, but this risk can be reduced.

[0015] A fifth aspect is characterized in that, in a post-processing device described in any one of the first to third aspects, a second conveying section is provided downstream of the first conveying section in the conveying direction, contacts the medium to apply a conveying force to the medium, and conveys the medium in the conveying direction, and the second conveying section is displaceable at a position facing the medium between a contact position where it contacts the medium and a separation position where it is separated from the medium, and the control section performs the adjustment operation when the second conveying section is in the separation position.

[0016] According to this aspect, the adjustment operation is performed when the second transport unit is in the separated position. If the adjustment operation is performed while the medium is in contact with the second transport unit, there is a risk that the adjustment operation will not be performed properly due to friction between the medium and the second transport unit, but this can reduce such a risk.

[0017] A sixth aspect is characterized in that, in the post-processing device described in any one of the first to fifth aspects, the first conveying unit is displaceable at a position facing the medium between a contact position where it contacts the medium and a separation position where it is separated from the medium, and the control unit performs the adjustment operation when the first conveying unit is in the separation position.

[0018] According to this aspect, the adjustment operation is performed when the first transport unit is in the separated position. If the adjustment operation is performed while the medium is in contact with the first transport unit, there is a risk that the adjustment operation will not be performed properly due to friction between the medium and the first transport unit, but this risk can be reduced.

[0019] The seventh aspect is characterized in that, in a post-processing device described in any one of the first to sixth aspects, it is provided with an estimation unit that estimates the amount of skew that will occur in the medium, and the control unit performs the alignment operation without performing the adjustment operation when the amount of skew estimated by the estimation unit is less than or equal to a first threshold value.

[0020] According to this aspect, when the amount of skew estimated by the estimation unit is equal to or less than the first threshold, the alignment operation is performed without performing the adjustment operation. When the amount of skew is small, the alignment operation can be performed effectively without performing the adjustment operation, so that it is possible to simplify the control when the adjustment operation does not need to be performed while still enabling an effective alignment operation.

[0021] An eighth aspect is characterized in that, in the post-processing device described in the seventh aspect, the recording unit records on the medium by ejecting liquid, the estimation unit estimates the amount of skew using the ejection ratio of the liquid per unit area of ​​the medium, one area relative to the center in the width direction of the medium is designated as a first area and the other area is designated as a second area, the ejection ratio in the first area is designated as a first ejection ratio and the ejection ratio in the second area is designated as a second ejection ratio, and the control unit performs the adjustment operation when a difference ratio, which is the difference between the first ejection ratio and the second ejection ratio, is greater than or equal to a second threshold value.

[0022] According to this aspect, an adjustment operation is performed when the difference ratio is equal to or greater than the second threshold. As the difference ratio increases, the difference in the coefficient of friction between the medium and the first conveying unit in the first and second regions increases, making the medium more likely to skew. By performing the adjustment operation in such a case, skew of the medium in the post-processing device can be effectively reduced.

[0023] A ninth aspect is characterized in that, in a post-processing device described in any one of the first to sixth aspects, the control unit performs the adjustment operation and then the alignment operation when there is already loaded media below the medium transported by the first conveying unit, and performs the alignment operation without performing the adjustment operation when there is no already loaded media below the medium transported by the first conveying unit.

[0024] According to this aspect, when there is already loaded media below the media being transported by the first transport unit, an adjustment operation is performed before an alignment operation is performed, and when there is no already loaded media below the media being transported by the first transport unit, the alignment operation is performed without performing an adjustment operation. When there is already loaded media, skewing of media is more likely to occur than when there is no already loaded media, but by performing an adjustment operation when there is already loaded media, skewing of media in the post-processing device can be effectively reduced.

[0025] The tenth aspect is characterized in that, in the post-processing device described in any one of the first to ninth aspects, a low-friction member is provided at a position that contacts the underside of the medium in the transport area of ​​the medium transported by the first transport section.

[0026] According to this aspect, a low-friction member is provided at a position that contacts the underside of the medium in the transport area of ​​the medium transported by the first transport unit, which makes it easier for the medium to move in the transport area, making it possible to effectively correct the transport direction of the medium and effectively reduce skew of the medium.

[0027] An eleventh aspect is characterized in that, in the post-processing device described in any one of the first to tenth aspects, the control unit slows the movement speed of the side edge alignment unit when performing the alignment operation compared to the movement speed of the side edge alignment unit when performing the adjustment operation.

[0028] According to this aspect, the movement speed of the side edge alignment unit when performing the alignment operation is slower than the movement speed of the side edge alignment unit when performing the adjustment operation. In other words, by performing the adjustment operation, which can be performed with low accuracy, at high speed, there is no need to reduce the media transport speed, and a decrease in throughput can be suppressed, and by performing the alignment operation, which requires high accuracy, at low speed and reliably, skew of the media can be effectively reduced.

[0029] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the XYZ coordinate system shown in each drawing, the X axis direction is horizontal and indicates the width direction, the Y axis direction is horizontal and indicates the direction perpendicular to the X axis direction, and the Z axis direction is vertical.

[0030] <<<Outline of the Recording System>>> 1 includes, as an example, a recording unit 2, an intermediate unit 3, and a processing unit 4 as a post-processing device, in that order from right to left in FIG. 1. The recording unit 2 includes a line head 10 as a recording section that records on the medium P. The intermediate unit 3 receives the medium P after recording from the recording unit 2 and passes it to the processing unit 4. The processing unit 4 includes a medium transport device 30 that transports the medium P after recording in the recording unit 2, and a processing unit 36 ​​that performs a predetermined process on the medium P placed on a placement section 35 of the medium transport device 30. In the recording system 1, the recording unit 2, the intermediate unit 3, and the processing unit 4 are connected to each other and are configured to be able to transport the medium P from the recording unit 2 to the processing unit 4.

[0031] The recording system 1 is configured so that recording operations on the medium P in the recording unit 2, intermediate unit 3, and processing unit 4 can be input from an operation panel (not shown). As an example, the operation panel can be provided in the recording unit 2. Below, the schematic configuration of each of the recording unit 2, intermediate unit 3, and processing unit 4 will be explained in that order.

[0032] <<<About the recording unit>>> 1 is configured as a multifunction device including a printer section 5 having a line head 10 that performs recording by ejecting liquid ink onto a medium P, and a scanner section 6. In this embodiment, the printer section 5 is configured as a so-called inkjet printer that performs recording by ejecting liquid ink from the line head 10 onto a medium P.

[0033] A plurality of medium storage cassettes 7 are provided below the recording unit 2. The medium P stored in the medium storage cassette 7 is sent to a recording area by the line head 10 through a feeding path 11 shown by a solid line in the recording unit 2 in Fig. 1, where the recording operation is performed. After recording by the line head 10, the medium P is sent to either a first discharge path 12, which is a path for discharging the medium P to a post-recording discharge tray 8 provided above the line head 10, or a second discharge path 13, which is a path for sending the medium P to the intermediate unit 3. In the recording unit 2 in Fig. 1, the first discharge path 12 is shown by a dashed line, and the second discharge path 13 is shown by a dashed line.

[0034] 1, the recording unit 2 is provided with a reversing path 14, which is indicated by a two-dot chain line, and is configured to enable double-sided recording in which, after recording on a first side of the medium P, the medium P is reversed and recording is performed on a second side. Note that the feeding path 11, the first discharge path 12, the second discharge path 13, and the reversing path 14 each have one or more pairs of transport rollers (not shown) disposed therein as an example of a means for transporting the medium P. The recording unit 2 is provided with a control unit 15 that controls operations related to transporting the medium P and recording in the recording unit 2.

[0035] <<<About the intermediate unit>>> 1 is disposed between the recording unit 2 and the processing unit 4, and is configured to receive the recorded medium P handed over from the second discharge path 13 of the recording unit 2 at a receiving path 20 and transport it to the processing unit 4. The receiving path 20 is indicated by a solid line in the intermediate unit 3 shown in FIG.

[0036] In the intermediate unit 3, there are two transport paths for transporting medium P. The first transport path is a path from the receiving path 20 via the first switchback path 21 to the discharge path 23. The second path is a path from the receiving path 20 via the second switchback path 22 to the discharge path 23. The first switchback path 21 is a path that receives medium P in the direction of arrow D1 and then switches medium P back in the direction of arrow D2. The second switchback path 22 is a path that receives medium P in the direction of arrow B1 and then switches medium P back in the direction of arrow B2.

[0037] The receiving path 20 branches into a first switchback path 21 and a second switchback path 22 at a branching section 24. The first switchback path 21 and the second switchback path 22 merge at a junction 25. Therefore, regardless of which switchback path the medium P is sent to from the receiving path 20, the medium P can be delivered to the processing unit 4 from the common discharge path 23. The receiving path 20, the first switchback path 21, the second switchback path 22, and the discharge path 23 each have one or more pairs of conveying rollers (not shown).

[0038] When recording is performed continuously on multiple media P in the recording unit 2, the media P that enters the intermediate unit 3 are alternately sent to a transport path that passes through the first switchback path 21 and a transport path that passes through the second switchback path 22. This increases the throughput of media transport in the intermediate unit 3. The recording system 1 can also be configured without the intermediate unit 3. That is, the recording unit 2 and the processing unit 4 can be connected, and the medium P after recording in the recording unit 2 can be sent directly to the processing unit 4 without going through the intermediate unit 3. When the medium P after recording in the recording unit 2 is sent to the processing unit 4 via the intermediate unit 3, as in the present embodiment, the transport time is longer than when the medium P is sent directly from the recording unit 2 to the processing unit 4, and therefore the ink on the medium P can be dried more thoroughly before being transported to the processing unit 4.

[0039] <<<About the processing unit>>> The processing unit 4 shown in FIG. 1 includes a control unit 60, a medium conveying device 30, and a processing unit 36, and is configured such that the processing unit 36 ​​performs post-processing on the medium P conveyed by the medium conveying device 30 under the control of the control unit 60. Examples of post-processing performed by the processing unit 36 ​​include stapling and punching. The medium P is transferred from the discharge path 23 of the intermediate unit 3 to a conveying path 31 of the processing unit 4 and conveyed by the medium conveying device 30. A pair of conveying rollers 32 that conveys the medium P is provided upstream of the conveying path 31 in the conveying direction. Furthermore, a pair of discharge rollers 33 that discharges the medium P onto a loading unit 35 is provided downstream of the conveying path 31 in the conveying direction.

[0040] The processing unit 4 will be described in more detail below with reference to Figures 2 to 4. The processing unit 4 shown in Figure 2 includes a pair of discharge rollers 33, and discharges medium P, represented by medium P2 in the figure, from the pair of discharge rollers 33 in a discharge direction A1. The medium P discharged from the pair of discharge rollers 33 is then placed on the placement unit 35, represented by medium P1 in the figure. The medium P placed on the placement unit 35 is transported in the transport direction A2 by an upstream paddle 40 and a downstream paddle 44, which will be described later, serving as a first transport unit, and the leading edge E1 on the downstream side in the transport direction A2 abuts against a leading edge alignment unit 38.

[0041] During this process, the medium P may become skewed as it is being transported. This skew can occur when the skew that occurred when the medium was discharged by the discharge roller pair 33 is not corrected, or when the medium is transported by the upstream paddle 40 and downstream paddle 44. Skew that occurs when the medium is transported by the upstream paddle 40 and downstream paddle 44 is particularly noticeable in the case of a medium P recorded by an inkjet printer. This is particularly noticeable in the case of an inkjet printer. In an inkjet printer, the coefficient of friction of the surface of the medium P increases as the medium P absorbs ink. Therefore, the friction between the medium P and the previously loaded media Ps, or between the medium P and the loading section 35, changes depending on the recording pattern of the medium P, and the load during transport also changes. Furthermore, because the coefficient of friction between the medium P and the upstream paddle 40 and downstream paddle 44 also changes, skew may occur when multiple upstream paddles 40 and downstream paddles 44 are provided in the width direction.

[0042] A guide member 41 is provided above the placement unit 35, contacting the medium P discharged by the discharge roller pair 33 from above and guiding the medium P to the placement unit 35. As shown in FIG. 2, the guide member 41 is configured to be movable between a retracted position where it does not interfere with the discharge of the medium P by the discharge roller pair 33, and an advanced position where it advances in a direction closer to the placement unit 35 than the retracted position, as shown in FIG. 3. In FIG. 3, the guide member 41 in the retracted position is indicated by a dotted line. When the medium P is transported in the discharge direction A1 by the discharge roller pair 33, the guide member 41 is positioned in the retracted position shown in FIG. 2, and when guiding the medium P discharged from the discharge roller pair 33 to the placement unit 35, the guide member 41 is displaced from the retracted position indicated by the dotted line in FIG. 2 and 3 to the advanced position indicated by the solid line in FIG. 3.

[0043] As shown in FIGS. 2 and 3, the upstream paddle 40 and the guide member 41 overlap in the discharge direction of the medium P, and are offset in the X-axis direction, which is the width direction intersecting the discharge direction A1 and the conveying direction A2, as shown in FIG. 4. In FIG. 4, the upstream paddle 40 and the guide member 41 are arranged symmetrically with respect to the center C in the width direction, with one on each side of the center C. A paddle 40a and a guide member 41a are provided on the +X side of the center C, and a paddle 40b and a guide member 41b are provided on the -X side. The upstream paddle 40 is a plate-like body, and multiple plate-like bodies are attached at intervals along the outer periphery of the rotation shaft 40A. The guide member 41 is attached to the swing shaft 41A on the +Y side, which is downstream in the discharge direction, and is configured to swing with the -Y side as a free end.

[0044] An upper roller 42 is provided above the upstream paddle 40 and the guide member 41, downstream in the discharge direction of the medium P. The upper roller 42 is a roller for nipping one or more sheets of medium P placed on the placement unit 35 between itself and a lower roller 43 provided on the placement unit 35 side, and discharging the sheets of medium P onto the tray 37. As shown in FIGS. 2 and 3 , the tray 37 that receives the medium P discharged from the placement unit 35 is provided on the +Y direction side of the placement unit 35.

[0045] The medium P to be discharged by the discharge roller pair 33 is placed on the placement section 35. In this embodiment, the discharge roller pair 33 as a discharge section is provided in the processing unit 4, which is a post-processing device, but the discharge section may also be provided in the recording unit 2 or the intermediate unit 3. The leading edge E1 of the medium P discharged to the placement section 35 comes into contact with the leading edge alignment section 38 and its position is aligned. When multiple sheets of medium P are placed on the placement section 35, the leading edges E1 of the multiple sheets of medium P are aligned by the leading edge alignment section 38.

[0046] The medium conveying device 30 also includes a side edge alignment unit 45 that aligns the side edge E2, which is the end in the width direction of the medium P. As shown in FIG. 4 , the side edge alignment unit 45 is composed of a first alignment unit 45a that is provided in the +X direction, which is a first direction in the width direction, relative to the loading unit 35, and a second alignment unit 45b that is provided in the -X direction, which is a second direction that is opposite to the first direction, relative to the loading unit 35. The control unit 60 controls a side edge alignment unit movement mechanism (not shown) so that after the medium P is placed between the first alignment unit 45a and the second alignment unit 45b, the first alignment unit 45a and the second alignment unit 45b approach each other and come into contact with the side edge E2 of the medium P, thereby aligning the side edge E2 of the medium P.

[0047] Next, the width direction adjustment operation of the medium P by the side edge alignment unit 45 will be described using the flowchart of FIG. 5 with reference to FIGS. 6 to 10. Hereinafter, the width direction adjustment operation of the medium P by the side edge alignment unit 45 and the above-described alignment operation for aligning the medium P will be described as the skew suppression operation. When the skew suppression operation is started, first, in step S110, the side edge alignment unit 45 is moved from fifth position L5, which is the standby position of the side edge alignment unit 45 when the power is off, to second position L2. Note that although the positional relationship between second position L2 and fifth position L5 is shown in FIG. 9, the arrangement of fifth position L5 relative to second position L2 is not limited to such an arrangement outside second position L2.

[0048] When the side edge alignment unit 45 moves to the second position L2, in step S120, the medium P is discharged from the discharge roller pair 33 and placed on the placement unit 35. Next, in step S130, the upstream paddle 40 starts transporting the medium P in the transport direction A2. As shown in FIG. 4 and other figures, the processing unit 4 of this embodiment is provided with a downstream paddle 44 downstream of the upstream paddle 40 in the transport direction A2. When transporting the medium P in the transport direction A2, the downstream paddle 44 can be used in addition to the upstream paddle 40. As shown in FIG. 4, the downstream paddles 44 are arranged symmetrically with respect to the center C in the width direction, one on each side of the center C. A paddle 44a is provided on the +X side of the center C, and a paddle 44b is provided on the -X side. Like the upstream paddle 40, the downstream paddle 44 is also a plate-shaped body, and multiple plate-shaped bodies are attached at intervals along the outer periphery of the rotation shaft 44A.

[0049] FIG. 6 shows a state immediately after conveyance of the medium P in the conveying direction A2 has begun, in which the side edge alignment unit 45 is positioned at the second position L2. As the medium P continues to be conveyed from this state, the entire leading edge E1 of the medium P on the downstream side in the conveying direction A2, i.e., both of the two corners H on the leading edge E1 side, passes the downstream end 45E of the side edge alignment unit 45 in the conveying direction A2. In step S140, the side edge alignment unit 45 is moved from the second position L2 to the third position L3. FIG. 7 shows a state in which the side edge alignment unit 45 is positioned at the third position L3. In other words, step S140 corresponds to an adjustment operation for reducing skew of the medium P by moving the side edge alignment unit 45 from the second position L2 to the third position L3 while the upstream paddle 40 is conveying the medium P.

[0050] Then, as the transport of medium P continues and the leading edge E1 reaches the leading edge alignment unit 38, in step S150, the side edge alignment unit 45 is moved from the third position L3 to the first position L1. Here, FIG. 8 shows a state in which the side edge alignment unit 45 is disposed at the first position L1. By completing step S150, medium P, whose transport began in step S130, is aligned in an appropriate position. In other words, step S150 corresponds to an alignment operation for aligning medium P. In step S150, the alignment operation is performed after the adjustment operation in step S140 and after the leading edge E1 reaches the leading edge alignment unit 38. The alignment operation here is an operation for aligning medium P by bringing the side edge alignment unit 45 into contact with medium P at the first position L1. In the alignment operation, the timing for moving the side edge alignment unit 45 to the first position may be any timing as long as it is after the adjustment operation. Therefore, during the alignment operation, the side edge alignment section 45 may start moving from the third position L3 toward the first position L1 before the leading edge E1 of the medium P reaches the leading edge alignment section .

[0051] Next, in step S160, the control unit 60 determines whether the medium P being transported is the last medium P. If the control unit 60 determines that there is a subsequent medium P but that it is not the last medium P, the process returns to step S130 and repeats steps S130 to S160 until the control unit 60 determines that it is the last medium. If the control unit 60 determines in step S160 that it is the last medium P, the process proceeds to step S170.

[0052] In step S170, the side edge alignment unit 45 is moved from the first position L1 to the fourth position L4. Then, in step S180, the side edge alignment unit 45 is moved from the fourth position L4 to the first position L1. That is, steps S170 and S180 correspond to a second alignment operation in which the side edge alignment unit 45 is moved again to the first position L1. Then, with the completion of step S180, the skew suppression operation of this embodiment is completed.

[0053] To summarize, the processing unit 4 of this embodiment is a post-processing device that performs post-processing on a medium P on which liquid has been ejected and recorded. The processing unit 4 of this embodiment includes a mounting section 35 on which the medium P to be post-processed is mounted, and an upstream paddle 40 that contacts the medium P and applies a conveying force to the medium P to convey the medium P in the conveying direction A2. The processing unit 4 of this embodiment also includes a leading edge alignment section 38 that aligns the leading edge E1 of the medium P mounted on the mounting section 35 on the downstream side in the conveying direction A2, a side edge alignment section 45 that is configured to be movable in the X-axis direction, which is the width direction of the medium P perpendicular to the conveying direction A2, and that abuts against the side edges E2 of the medium P from both sides in the width direction to align the medium P in the width direction, and a control section 60 that controls the position of the side edge alignment section 45 in the width direction.

[0054] Here, the side edge alignment unit 45 is movable to a first position L1 where it abuts the side edge E2 on both sides in the width direction, a second position L2 where the medium P is placed on the placement unit 35 and is farther away from the side edge E2 in the width direction than the first position L1, and a third position L3 between the first position L1 and the second position L2 in the width direction. Note that the third position L3 is a position where the side edge alignment unit 45 can come into contact with the medium P if the medium P transported by the upstream paddle 40 is transported at a large skew. The control unit 60 can also perform an adjustment operation of moving the side edge alignment unit 45 from the second position L2 to the third position L3 while the upstream paddle 40 is transporting the medium P, as represented in step S140, and an alignment operation after the adjustment operation and after the leading edge E1 reaches the leading edge alignment unit 38, as represented in step S150.

[0055] In this way, the processing unit 4 of this embodiment not only performs an alignment operation after the leading edge E1 of the medium P reaches the leading edge alignment section 38, but also performs an adjustment operation prior to the alignment operation, moving the side edge alignment section 45 from the second position L2 to the third position L3 while the medium P is being transported. In other words, the operation to suppress skew of the medium P is performed in stages. By performing the operation to suppress skew of the medium P in stages in this way, it is possible to reduce the risk of the corner H of the medium P being transported skewed coming into contact with the side edge alignment section 45 and being damaged, or the risk of the corner H getting under already stacked media Ps, causing the medium P to be improperly aligned. Therefore, the processing unit 4 of this embodiment can effectively reduce skew of the medium P. In this embodiment, already stacked media Ps refer to media P that have been stacked after the alignment operation has been completed and can be considered to be media P in a standby state before post-processing is performed.

[0056] Here, being able to contact the medium P when the medium P is transported skewed specifically means that contact can occur when the medium P is skewed at the maximum expected amount, and does not necessarily mean that contact is required when the medium P is not skewed or when the amount of skew is small. For example, in the state shown in FIG. 7 , the side edge alignment unit 45 does not contact the medium P because the amount of skew is small. However, if the medium P is transported at a large skew, the side edge alignment unit 45 is positioned to contact the medium P. Furthermore, moving the side edge alignment unit 45 to the first position L1 after the leading edge E1 reaches the leading edge alignment unit 38 not only refers to the case where the operation of moving the side edge alignment unit 45 to the first position L1 is started after the leading edge E1 reaches the leading edge alignment unit 38, but also refers to the case where the operation of moving the side edge alignment unit 45 to the first position L1 is started before the leading edge E1 reaches the leading edge alignment unit 38, and the leading edge E1 reaches the leading edge alignment unit 38 by the end of the operation.

[0057] 6 to 10 , the side edge alignment section 45 extends in the conveying direction A2. The control section 60 performs the adjustment operation after the leading edge E1 of the medium P passes the downstream end 45E of the side edge alignment section 45 in the conveying direction A2 across the entire width direction. Because the side edge alignment section 45 extends in the conveying direction A2 in this manner, the processing unit 4 of this embodiment can effectively perform the skew suppression operation over a long distance. Furthermore, the processing unit 4 of this embodiment performs the adjustment operation after the leading edge E1 of the medium P passes the downstream end 45E of the side edge alignment section 45 in the conveying direction A2 across the entire width direction. In other words, the adjustment operation is performed after the corner H of the leading edge E1 of the medium P passes the side edge alignment section 45. This prevents the corner H of the leading edge E1 of the medium P from colliding with the side edge alignment section 45, reducing the risk of damage to the corner H.

[0058] As described above, the side edge alignment unit 45 can move to a fourth position L4 between the second position L2 and the third position L3 in the width direction. After the alignment operation of step S150, the control unit 60 moves the side edge alignment unit 45 to the fourth position L4 in step S170, and then performs a second alignment operation in step S180, moving the side edge alignment unit 45 to the first position L1. By performing the alignment operation of step S150 and then performing the alignment operation of step S180 again, skew of the medium P in the post-processing device can be effectively reduced. Also, as shown in FIG. 9 , the fourth position L4 is located farther from the side edge E2 of the medium P than the third position L3. That is, the amount of movement of the side edge alignment unit 45 in the width direction during the second alignment operation is increased compared to the previous alignment operation. In this way, increasing the amount of movement of the side edge alignment unit 45 can reduce deformation of the medium P that has been caused by being pressed by the side edge alignment unit 45. Then, by having the side edge alignment unit 45 perform the alignment operation again, it is possible to align the media P with the deformation eliminated, thereby improving alignment accuracy. By performing such an operation, it is possible to separate the functions, for example, by suppressing skew of the media P and suppressing the growth of skew of the media P in the first alignment operation, and then reliably aligning the media P in the second alignment operation.

[0059] As described above, the processing unit 4 of this embodiment is provided downstream of the upstream paddle 40 in the transport direction A2 and includes the downstream paddle 44 as a second transport unit that contacts the medium P to apply a transport force to the medium P and transport the medium P in the transport direction A2. The control unit 60 then performs an adjustment operation before the medium P comes into contact with the downstream paddle 44. If the adjustment operation is performed while the medium P is in contact with the downstream paddle 44, there is a risk that the adjustment operation will not be performed properly due to friction between the medium P and the downstream paddle 44, but the processing unit 4 of this embodiment can reduce this risk. Note that the second transport unit in the processing unit 4 of this embodiment is a paddle in which multiple plate-shaped bodies are attached at intervals along the outer periphery of a rotating shaft, but is not limited to this configuration and may be, for example, a roller.

[0060] To put the above another way, the downstream paddle 44 of this embodiment is a paddle in which multiple plate-shaped bodies are attached at intervals along the outer periphery of the rotation shaft. Therefore, as the downstream paddle 44 rotates along the rotation shaft, the attitude of the plate-shaped bodies of the downstream paddle 44 relative to the medium P changes. This change in attitude changes the distance between the contact position where the plate-shaped bodies contact the medium P and the separation position where the plate-shaped bodies are separated from the medium P. In other words, the downstream paddle 44 can be displaced between the separation position where the plate-shaped bodies are separated from the medium P and the contact position where the downstream paddle 44 is in contact with the medium P. Here, the control unit 60 performs the adjustment operation when the downstream paddle 44 is in the separation position. In this way, the processing unit 4 of this embodiment performs the adjustment operation when the downstream paddle 44 is in the separation position. If the adjustment operation is performed while the medium P is in contact with the downstream paddle 44, there is a risk that the adjustment operation will not be performed properly due to friction between the medium P and the downstream paddle 44, but the processing unit 4 of this embodiment can reduce this risk. Furthermore, the downstream paddle 44 may be configured to switch between the separated position and the contact position by moving the downstream paddle 44 up and down. Note that, for example, if the second transport unit is a roller, it may be configured so that the roller, at a position facing the medium P, can be displaced between a contact position where the roller contacts the medium P and a separated position where the roller is separated from the medium P.

[0061] Similarly to the downstream paddle 44, in the processing unit 4 of this embodiment, the upstream paddle 40 as a first transport unit is displaceable between a contact position where it contacts the medium P and a separated position where it is separated from the medium P when facing the medium P. The control unit 60 then performs the adjustment operation when the upstream paddle 40 is in the separated position. If the adjustment operation is performed while the medium P is in contact with the upstream paddle 40, there is a risk that the adjustment operation will not be performed properly due to friction between the medium P and the upstream paddle 40, but the processing unit 4 of this embodiment can reduce this risk. Note that the upstream paddle 40 may be configured to switch between the separated position and the contact position by moving the upstream paddle 40 up and down.

[0062] Similarly to the downstream paddle 44, the upstream paddle 40 serving as the first transport part in the processing unit 4 of this embodiment is a paddle in which a plurality of plate-shaped bodies are attached at intervals along the outer periphery of a rotation shaft, but is not limited to this configuration and may be, for example, a roller. If the first transport part is a roller, for example, it can be configured so that, at a position facing the medium P, the roller is displaceable between a contact position where it contacts the medium P and a separation position where it is separated from the medium P.

[0063] The control unit 60 is electrically connected to the control unit 15 of the recording unit 2 and can function as an estimation unit that estimates the amount of skew occurring in the medium P from recording data input to the control unit 15, etc. If the amount of skew estimated by the control unit 60 itself is equal to or less than a first threshold, the control unit 60 can execute the alignment operation of step S150 without executing the adjustment operation of step S140. Since the alignment operation can be performed effectively without executing the adjustment operation when the amount of skew is small, the processing unit 4 of this embodiment can simplify control when the adjustment operation does not need to be performed while enabling effective alignment operation. Note that, while the control unit 60 is configured to also function as the estimation unit in this embodiment, this is not limited to this configuration, and an estimation unit may be provided separately from the control unit 60. Alternatively, a camera capable of reading ink ejected on the medium P may be provided, and the amount of skew may be estimated based on the image data captured by the camera.

[0064] When estimating the amount of skew occurring on the medium P, the control unit 60 can estimate the amount of skew using the ejection ratio of ink (liquid) per unit area of ​​the medium P. As shown in FIG. 10 , one region of the medium P at the center in the width direction is designated as a first region S1, and the other region is designated as a second region S2. The ejection ratio in the first region S1 is designated as a first ejection ratio, and the ejection ratio in the second region S2 is designated as a second ejection ratio. The control unit 60 can control the adjustment operation to be performed when the difference ratio between the first ejection ratio and the second ejection ratio is equal to or greater than a second threshold. As the difference ratio increases, the difference in the coefficient of friction between the medium P and the upstream paddle 40, etc., in the first region S1 and the second region S2 increases, making skew more likely. Performing the adjustment operation in such a case can effectively reduce skew of the medium P in the post-processing device. The ejection ratio here may be the ejection ratio on either the front or back surface of the medium P. The ejection ratio may also be the ratio of the number of ink dots actually ejected to the maximum number of ink dots that can be ejected.

[0065] Furthermore, as shown in FIG. 6 and other figures, the control unit 60 can perform an adjustment operation and then an alignment operation when there are previously loaded media Ps below the medium P being transported by the upstream paddle 40, and can perform an alignment operation without performing an adjustment operation when there are no previously loaded media Ps below the medium P being transported by the upstream paddle 40. When there are previously loaded media Ps, skew is more likely to occur than when there are no previously loaded media Ps. This is particularly noticeable in inkjet printers. In inkjet printers, the coefficient of friction on the surface of the medium increases as the medium absorbs ink. Therefore, the friction between the medium P and the previously loaded media Ps changes depending on the printing pattern of the topmost medium Ps1 of the previously loaded media Ps, and the load during transport changes. If the transport load changes in the width direction, the medium P is more likely to skew during transport. Therefore, by performing an adjustment operation when there are previously loaded media Ps, skew of the medium P can be effectively reduced.

[0066] Furthermore, the control unit 60 slows the movement speed of the side edge alignment unit 45 when performing the alignment operation compared to the movement speed of the side edge alignment unit 45 when performing the adjustment operation. In other words, by performing the adjustment operation, which can be performed with low accuracy, at high speed, there is no need to reduce the transport speed of the medium P, and a decrease in throughput is suppressed, and by reliably performing the alignment operation, which must be performed with high accuracy, at low speed, skew of the medium P is effectively reduced. However, the present invention is not limited to such control.

[0067] As shown in FIG. 4, the processing unit 4 of this embodiment is provided with low-friction members 50 at positions that come into contact with the underside of the medium P in the transport area of ​​the medium P transported by the upstream paddle 40. Therefore, the processing unit 4 of this embodiment makes it easier for the medium P to move in the transport area of ​​the medium P, so that the transport direction of the medium P can be effectively corrected and skew of the medium P can be effectively reduced. In the processing unit 4 of this embodiment, the low-friction members 50 are provided at both ends in the width direction and are composed of a low-friction member 50a on the +X side and a low-friction member 50b on the -X side. However, the configuration is not limited to this.

[0068] Furthermore, although this embodiment uses a line head 10 as the recording section, a serial type head may also be used. Furthermore, the recording unit 2 may not be an inkjet printer that records by ejecting ink, but may be a laser printer that records by fixing toner. When a laser printer is used as the recording unit 2, the recording section is, for example, a portion that corresponds to printing, such as a photosensitive drum.

[0069] Furthermore, it goes without saying that the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the invention described in the claims, and these are also included in the scope of the present invention. [Explanation of symbols]

[0070] 1...recording system, 2...recording unit, 3...intermediate unit, 4...processing unit (post-processing device), 5...printer section, 6...scanner section, 7...media storage cassette, 8...post-recording discharge tray, 10...line head, 11...feed path, 12...first discharge path, 13...second discharge path, 14...reversal path, 15...control section, 20...receiving path, 21...first switchback path, 22...second switchback path, 23...discharge path, 24...branch section, 25...merging section, 30...media conveying device, 31...conveying path, 32...conveying roller pair, 33...discharge roller pair, 35...placing section , 36...processing section, 37...tray, 38...leading edge alignment section, 40...upstream paddle (first conveying section), 41...guide member, 42...upper roller, 43...lower roller, 44...downstream paddle (second conveying section), 45...side edge alignment section, 45a...first alignment section, 45b...second alignment section, 45E...downstream edge, 50...low friction member, 50a...low friction member, 50b...low friction member, 60...control section, E1...leading edge, E2...side edge, H...corner, L1...first position, L2...second position, L3...third position, L4...fourth position, L5...fifth position, P...medium, P1...medium, P2...medium, Ps...already loaded media

Claims

1. A post-processing device that performs post-processing on a medium recorded by a recording unit, a mounting section on which the medium to be post-processed is mounted; a first transport unit that contacts the medium to apply a transport force to the medium and transports the medium in a transport direction; a leading edge alignment unit that aligns a leading edge of the medium placed on the placement unit on a downstream side in the transport direction; a side edge alignment unit configured to be movable in a width direction perpendicular to the conveyance direction of the medium and to align the medium in the width direction by contacting the side edges of the medium from both sides in the width direction; a control unit that controls a position of the side edge alignment unit in the width direction; Equipped with the side edge alignment section is movable to a first position where it abuts against the side edges on both sides in the width direction, a second position where it is positioned farther from the side edges in the width direction than the first position and where the medium is placed on the placement section, and a third position where it is positioned between the first position and the second position in the width direction and where it can come into contact with the medium when the medium is transported at an angle by the first transport section, the control unit is capable of performing, in a stepwise manner, an adjustment operation of moving the side edge alignment unit from the second position to the third position, and an alignment operation of aligning the medium by bringing the side edge alignment unit into contact with the medium at the first position; The adjustment operation is performed while the first transport unit is transporting the medium, and the alignment operation is performed after the adjustment operation and after the medium has reached the leading edge alignment unit, The side edge alignment portion extends in the conveying direction, the control unit performs the adjusting operation after the leading edge of the sheet passes a downstream end of the side edge aligning unit in the conveying direction over the entire width direction. A post-processing device characterized by:

2. 2. The post-processing device according to claim 1, the side edge alignment portion is movable to a fourth position between the second position and the third position in the width direction, The post-processing device, wherein the control unit moves the side edge aligning unit to the fourth position after the aligning operation, and performs the aligning operation again.

3. 3. The post-processing device according to claim 1, a second transport unit that is provided downstream of the first transport unit in the transport direction, contacts the medium to apply a transport force to the medium, and transports the medium in the transport direction; The post-processing device, wherein the control unit performs the adjustment operation before the medium comes into contact with the second transport unit.

4. 3. The post-processing device according to claim 1, a second transport unit that is provided downstream of the first transport unit in the transport direction, contacts the medium to apply a transport force to the medium, and transports the medium in the transport direction; the second transport unit is displaceable between a contact position where it contacts the medium and a separation position where it is separated from the medium at a position facing the medium, The post-processing device, wherein the control unit executes the adjustment operation when the second conveying unit is in the separated position.

5. 5. The post-processing device according to claim 1, the first transport unit is displaceable between a contact position where a plate-shaped body contacts the medium and a separation position where the plate-shaped body is separated from the medium by rotating along a rotation axis at a position facing the medium, when transporting the medium, the first transport unit alternately repeats one state during the transport operation in which the plate-like body is in the separated position and another state during the transport operation in which the plate-like body is in the contact position, The post-processing device, wherein the control unit executes the adjustment operation when the first conveying unit is in the separated position.

6. 6. The post-processing device according to claim 1, an estimation unit that estimates an amount of skew that occurs in the medium; The post-processing device, wherein the control unit executes the alignment operation without executing the adjustment operation when the skew amount estimated by the estimation unit is equal to or smaller than a first threshold value.

7. 7. The post-processing device according to claim 6, the recording unit performs recording on the medium by ejecting a liquid; the estimation unit estimates the amount of skew using a discharge ratio of the liquid per unit area of ​​the medium; one region relative to the center in the width direction of the medium is designated as a first region and the other region is designated as a second region, the ejection ratio in the first region is designated as a first ejection ratio and the ejection ratio in the second region is designated as a second ejection ratio, The post-processing device is characterized in that the control unit executes the adjustment operation when a difference ratio between the first discharge ratio and the second discharge ratio is equal to or greater than a second threshold value.

8. 6. The post-processing device according to claim 1, The control unit performs the adjustment operation and then the alignment operation when there is already loaded media below the medium transported by the first transport unit, and performs the alignment operation without performing the adjustment operation when there is no already loaded media below the medium transported by the first transport unit.

9. 9. The post-processing device according to claim 1, 10. A post-processing device comprising: a low-friction member positioned to come into contact with a bottom surface of the medium in a transport area of ​​the medium transported by the first transport unit.

10. 10. The post-processing device according to claim 1, The post-processing device, wherein the control unit slows down the movement speed of the side edge aligning unit when performing the aligning operation compared to the movement speed of the side edge aligning unit when performing the adjusting operation.

Images