Media discharge device

Abstract

The present invention provides a media discharge device that prevents media loading defects while avoiding a decrease in media discharge efficiency. [Solution] The media discharge device (1) includes a loading platform (11) on which media (P) are loaded, a restricting unit (13, 25) that restricts the position of at least one of the leading edge and trailing edge in the discharge direction of the media discharged onto the loading platform, and a media position correction unit (61, 70) that, when it detects that the media is leaning against the restricting unit, applies a force to move the leaning portion of the media vertically along the restricting unit to eliminate the leaning of the media.

Description

[Technical Field]

[0001] The present invention relates to a medium discharge device. [Background Art]

[0002] After performing predetermined processing such as image formation or sorting on a sheet-like medium such as paper, a medium discharge device is used for discharging and recovering the medium. The medium discharge device includes a stacking table (discharge tray) on which media are placed, and an end fence. The end fence is provided on an extension of the discharge direction of the medium discharged onto the stacking table (the traveling direction of conveyance during discharge), and regulates the position of the discharged medium by the leading end of the medium in the discharge direction coming into contact with the end fence.

[0003] There are cases where a discharged medium is not stacked at an appropriate position on the stacking table, and an end portion of the medium leans against the end fence or an opposing wall facing the end fence (hereinafter, this state is referred to as a leaning state).

[0004] When the number of media stacked on the stacking table is small, or when the leaning amount of the medium is small, the leaning state may resolve naturally. However, in recent years, large-capacity medium discharge devices connected to image forming apparatuses that form images on a large number of media at high speed have been used. In such large-capacity medium discharge devices that operate at high speed, the leaning amount of the medium becomes large, or the next medium is discharged and stacked before the leaning of the medium is resolved, so the leaning state cannot be easily resolved, which causes disordered stacking of the media, and it has been a problem that extra labor is required to rearrange the media on the stacking table afterward.

[0005] Patent Document 1 discloses a countermeasure in which, during the discharge operation of paper as a medium, it is determined whether leaning of the paper against the end fence or the opposing wall has occurred based on an output signal from a leaning detection sensor, and when it is determined that leaning of the paper has occurred, a control unit stops the discharge operation. After the discharge operation is stopped, the user resolves the leaning state through operation, and then the discharge operation is resumed.

[0006] Furthermore, Patent Document 1 discloses a measure to suppress the recurrence of paper sagging by determining whether the paper is sagging against the end fence or the opposing wall based on the output signal of a sagging detection sensor, and changing at least one of the paper ejection speed by the paper ejection roller or the degree of paper curvature by the stiffening section according to the determination result.

[0007] Patent Document 2 discloses a countermeasure that, when it is detected that a medium is leaning against a movable fence (end fence), controls the movable fence to move from the restricted position to the retracted position and then back to the restricted position, thereby eliminating the leaning of the medium. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2014-210624 [Patent Document 2] Japanese Patent Publication No. 2021-080091 [Overview of the project] [Problems that the invention aims to solve]

[0009] When a leaning issue with the media is detected, methods such as those described in Patent Document 1, which involve temporarily stopping the discharge operation and having the user resolve the loading problem, have problems such as increased downtime, decreased productivity in media processing, and a heavy workload for the user. Furthermore, even when the leaning issue with the media resolves itself naturally, stopping the discharge operation and requiring user verification results in wasted time and effort. In addition, measures such as changing the discharge speed or the degree of curvature of the media during discharge do not correct media leaning that has already occurred.

[0010] When a leaning motion of the media is detected, if the control system moves the movable fence to a retracted position and then back to the restricted position, as described in Patent Document 2, a predetermined waiting time is required during the movement of the movable fence, which could become a bottleneck in speeding up media discharge. Therefore, there is a need for measures to eliminate leaning that can further improve the efficiency of media discharge.

[0011] The object of the present invention is to provide a media discharge device that prevents poor loading of the media while avoiding a decrease in the discharge efficiency of the media. [Means for solving the problem]

[0012] One embodiment of the media discharge device of the present disclosure includes a loading platform on which media are loaded, a regulating unit that restricts the position of at least one of the leading and trailing ends of the media discharged onto the loading platform in the discharge direction, and a media position correction unit that, when it detects that the media is leaning against the regulating unit, applies a force to move the leaning portion of the media vertically along the regulating unit to eliminate the leaning of the media. [Effects of the Invention]

[0013] According to the above embodiment, a media discharge device can be obtained that prevents media loading defects while avoiding a decrease in media discharge efficiency. [Brief explanation of the drawing]

[0014] [Figure 1] This is a diagram illustrating the configuration of an image forming system, including a media ejection device and an image forming apparatus. [Figure 2] This is a block diagram showing the control system for a media discharge device. [Figure 3] This is a perspective view showing the internal structure of the media discharge device. [Figure 4] This is a perspective view showing the internal structure of the media discharge device. [Figure 5] This diagram shows the state in the media ejection device of the reference example where the edge of the paper is leaning against the restricting section. [Figure 6]It is a diagram illustrating the operation of a medium position correcting unit eliminating upward sag at the leading edge sag portion of a sheet. [Figure 7] It is a diagram illustrating the operation of a medium position correcting unit eliminating downward sag at the leading edge sag portion of a sheet. [Figure 8] It is a diagram illustrating the operation of a medium position correcting unit eliminating upward sag at the trailing edge sag portion of a sheet. [Figure 9] It is a flowchart showing control contents of a medium discharge device. Mode for Carrying Out the Invention

[0015] Hereinafter, the medium discharge device of the present disclosure will be described with reference to the illustrated embodiments. The X-axis direction, Y-axis direction, and Z-axis direction shown in each drawing are directions perpendicular to each other, and the Z-axis direction is the vertical direction of the medium discharge device.

[0016] The medium discharged to the medium discharge device of the present disclosure is made of paper or a material other than paper, and may be a sheet of single-wafer sheet, or may be an envelope having a folded portion, or the like. The sheet P shown in the illustrated embodiment is an example of the medium, and sheet discharge in this specification can be read as discharge of the medium.

[0017] As shown in Fig. 1, the medium discharge device 1 according to the present embodiment is connected to an image forming apparatus 2 that prints on the sheet P and forms an image, and constitutes an image forming system together with the image forming apparatus 2. The sheet P on which an image has been formed in the image forming apparatus 2 is discharged to the medium discharge device 1. Fig. 2 schematically shows a control system of the medium discharge device 1, and Figs. 3 and 4 show the internal structure of the medium discharge device 1.

[0018] As shown in Fig. 1, the medium discharge device 1 includes, inside an apparatus housing 3, a discharge unit 10, a stacking table 11, side fences 12, and a leading end side fence 13. A carriage 17 is provided at a lower portion of the stacking table 11 and can be pulled out from the apparatus housing 3.

[0019] As shown in Figure 3, the media discharge device 1 includes a loading platform drive unit 14 that drives the loading platform 11, a side fence drive unit 15 that drives the side fence 12, and a front-end fence drive unit 16 that drives the front-end fence 13. In other words, the side fence 12 and the front-end fence 13 are movable fences. The loading platform drive unit 14, the side fence drive unit 15, and the front-end fence drive unit 16 are not shown in Figures other than Figure 3.

[0020] As shown in Figure 1, the paper P transported from the image forming apparatus 2 to the media discharge apparatus 1 moves along the discharge path R in the paper discharge section 10, and is discharged from the paper discharge section 10 toward the stacking table 11 in roughly the X-axis direction and stacked on the stacking table 11. In the following description, the direction of travel of the paper P moving from the paper discharge section 10 toward the stacking table 11 is referred to as the discharge direction F1, and the direction of travel of the paper P returning from the stacking table 11 toward the paper discharge section 10 in the opposite direction to the discharge direction F1 is referred to as the return direction F2. For the paper P discharged toward the stacking table 11, the end on the discharge direction F1 side is referred to as the leading edge (leading edge in the discharge direction), and the end on the return direction F2 side is referred to as the trailing edge (trailing edge in the discharge direction). The Y-axis direction is referred to as the width direction of the paper P.

[0021] Each part of the media ejection device 1 is controlled by the control unit 4 (Figure 2). The control unit 4 may be mounted on the media ejection device 1, or it may be mounted on the image forming apparatus 2 to comprehensively control both the media ejection device 1 and the image forming apparatus 2. The control unit 4 has a processor (e.g., CPU: Central Processing Unit) that functions as an arithmetic processing unit that controls the operation of the entire media ejection device 1, and controls each part of the media ejection device 1 by reading a predetermined program from the storage unit and executing it.

[0022] As shown in Figure 3, the paper discharge unit 10 includes a plurality of transport roller pairs 20 and a discharge platform 21. The transport roller pairs 20 nip the paper P and are rotated by a transport motor 22 (Figure 2) to transport the paper P along the discharge path R. The discharge platform 21 is provided at the exit portion of the discharge path R. Paper guides 23 are provided on both edges of the discharge platform 21 in pairs in the width direction of the paper P. The pair of paper guides 23 have inclined surfaces that increase in height upward and narrow in distance from each other as they move in the discharge direction F1.

[0023] The paper P, transported by the transport roller pair 20, passes over the discharge platform 21 and is discharged toward the stacking platform 11 along a pair of paper guides 23. At this time, the paper P is guided by the inclined surfaces of the pair of paper guides 23 and flies in the discharge direction F1 at a predetermined speed, forming a U-shape with both edges higher than the center in the width direction.

[0024] A partition wall 24 is provided between the paper discharge section 10 and the stacking tray 11. The partition wall 24 is positioned opposite the rear end of the paper P discharged onto the stacking tray 11. The upper end of the partition wall 24 is located below the flight path of the paper P discharged from the paper discharge section 10 to the stacking tray 11, and the partition wall 24 does not obstruct the movement of the paper P from the paper discharge section 10 to the stacking tray 11.

[0025] The loading platform 11 comprises a base plate 30 and a central support portion 31 and an inclined support portion 32 provided on the base plate 30. The base plate 30 is generally a flat, horizontal plate. The central support portion 31 and the inclined support portion 32 are parts that protrude upward from the upper surface of the base plate 30. The central support portion 31 is located in the center of the base plate 30 in the Y-axis direction and extends in the X-axis direction. The upper surface of the central support portion 31 is a substantially horizontal mounting surface 31a. Multiple inclined support portions 32 are arranged on both sides of the central support portion 31 in the Y-axis direction and are provided at predetermined intervals in the X-axis direction. Each inclined support portion 32 extends in the Y-axis direction and has a wedge shape that gradually increases in height as it moves away from the central support portion 31 in the Y-axis direction. Therefore, the upper surface of the inclined support portion 32 is a mounting surface 32a that is inclined with respect to the horizontal direction. The mounting surface 31a of the central support section 31 and the mounting surfaces 32a of the multiple inclined support sections 32 form a mounting surface on the loading platform 11 for loading the paper P. This mounting surface has a shape in which the center of the paper P in the width direction (Y-axis direction) is lower and becomes higher as it moves towards both sides in the width direction. When the paper P discharged onto the loading platform 11 is viewed along the X-axis direction, it is loaded onto the mounting surface in a roughly U-shape.

[0026] A rear-end fence 25 is attached to the bulkhead 24. The rear-end fence 25 is fixed to the bulkhead 24. The rear-end fence 25 is positioned approximately at the same location as the central support 31 in the Y-axis direction, and above the central support 31 in the Z-axis direction. The rear-end fence 25 has a restricting surface 25a facing the discharge direction F1, and the movement of the paper P in the return direction F2 is restricted when the rear end of the paper P in the discharge direction F1 comes into contact with the restricting surface 25a. In other words, the rear-end fence 25 functions as a restricting part that restricts the position of the rear end of the paper P discharged to the loading platform 11 in the discharge direction F1.

[0027] As shown in Figure 3, the loading platform drive unit 14 comprises a rack 33, a pinion 34, and a lifting motor 35. The rack 33 extends vertically and is fixed inside the device housing 3. The pinion 34 and the lifting motor 35 are supported by a connecting plate 36 connected to the bottom plate 30. The pinion 34 meshes with the teeth 33a of the rack 33. The pinion 34 is rotationally driven by the lifting motor 35. The loading platform 11 is supported so as to be movable in the Z-axis direction by a guide mechanism (not shown), and when the pinion 34 rotates, the loading platform 11 moves up and down along the rack 33 together with the connecting plate 36.

[0028] A pair of side fences 12 are provided above the loading platform 11, spaced apart in the Y-axis direction. Each side fence 12 is a wall section having a predetermined length in the X-axis direction and a predetermined height in the Z-axis direction, and has multiple openings 12a that penetrate in the Y-axis direction.

[0029] As shown in Figure 3, the side fence drive unit 15 comprises a guide shaft 37, a drive belt 38, and a side fence drive motor 39. A pair of guide shafts 37, spaced apart in the X-axis direction, extend in the Y-axis direction, and carriages 40 attached to the top of each of the pair of side fences 12 are supported so as to be movable in the Y-axis direction along the pair of guide shafts 37. The drive belt 38 is an endless belt stretched between a driving pulley (not shown) rotated via the output shaft of the side fence drive motor 39 and a driven pulley 41, extending in the Y-axis direction and connected to each carriage 40. When the side fence drive motor 39 is driven, force is transmitted to each carriage 40 via the drive belt 38, causing the pair of side fences 12 to move in the Y-axis direction. The pair of side fences 12 move symmetrically in the Y-axis direction, performing movements toward each other and movements toward each other. By controlling the side fence drive motor 39 to switch the direction of movement (circumferential direction) of the drive belt 38, the direction of movement of the pair of side fences 12 in the Y-axis direction can be switched.

[0030] The front end fence 13 is a wall portion located opposite the rear end fence 25 in the X-axis direction, situated above the loading platform 11, and positioned approximately at the same location as the central support portion 31 in the Y-axis direction. The front end fence 13 has a restricting surface 13a facing the return direction F2. The front end fence 13 functions as a restricting portion that restricts the position of the front end of the paper P discharged to the loading platform 11 in the discharge direction F1.

[0031] As shown in Figure 3, the front-end fence drive unit 16 comprises a guide shaft 42, a drive belt 43, and a front-end fence drive motor 44. A pair of guide shafts 42, spaced apart in the Y-axis direction, extend in the X-axis direction, and a carriage 45 attached to the upper part of the front-end fence 13 is supported so as to be movable in the X-axis direction along the guide shafts 42. The drive belt 43 is an endless belt stretched between a driving pulley (not shown) and a driven pulley 46, which are rotated via the output shaft of the front-end fence drive motor 44, and extends in the X-axis direction and connects to the carriage 45. When the front-end fence drive motor 44 is driven, force is transmitted to the carriage 45 via the drive belt 43, and the front-end fence 13 moves in the X-axis direction. By controlling the front-end fence drive motor 44 to switch the direction of movement (circumferential direction) of the drive belt 43, the direction of movement of the front-end fence 13 in the X-axis direction can be switched.

[0032] The memory unit of the control unit 4 stores media information about the paper P and discharge condition information that defines the discharge conditions based on the media information. The media information includes the size of the paper P (length in the X-axis direction, width in the Y-axis direction), the basis weight of the paper P, and the friction coefficient of the surface of the paper P (paper quality). The discharge condition information includes the position (spacing) of the pair of side fences 12 in the Y-axis direction, the position of the front-end fence 13 in the X-axis direction, the speed at which the paper P is discharged (rotation speed of the transport roller pair 20), and the discharge interval of the paper P. The control unit 4 reads the discharge condition information based on the input media information and drives the side fence drive unit 15 and the front-end fence drive unit 16 to position the pair of side fences 12 and the front-end fence 13, respectively, at positions suitable for the paper P to be discharged. Then, it rotates the transport roller pair 20 at the optimal speed to discharge the paper P from the paper discharge unit 10 to the stacking table 11.

[0033] Furthermore, the control unit 4 drives the loading platform drive unit 14 to adjust the height of the loading platform 11 according to the amount of paper P loaded on the loading surfaces 31a and 32a of the loading platform 11. As the number of paper P loaded on the loading platform 11 increases, the loading platform 11 is lowered to maintain a constant height position for the highest loaded paper P. This highest paper P height position is set as the reference upper limit position for the paper P.

[0034] When the loading platform 11, loaded with paper P, is lowered to a predetermined lower limit, it is placed on the trolley 17. Then, the trolley 17 loaded with paper P can be pulled out from the device housing 3.

[0035] When paper P is discharged from the paper discharge section 10 to the stacking platform 11, the mounting surfaces 31a and 32a on the stacking platform 11 are set to be lower than the discharge platform 21 of the paper discharge section 10. Paper P discharged from the paper discharge section 10 proceeds in the discharge direction F1 above the stacking platform 11 along a predetermined flight path (shown by dashed arrows in Figures 1, 5 to 8). The leading edge fence 13 is located on the extension of this flight path, and when the leading edge of paper P in the discharge direction F1 hits the restricting surface 13a of the leading edge fence 13, the further progress of paper P in the discharge direction F1 is restricted and paper P falls downward. Then, within the space enclosed by the leading edge fence 13, a pair of side fences 12, and the rear end fence 25, paper P is sequentially stacked on the mounting surfaces 31a and 32a of the stacking platform 11. At that time, the air pushed by the paper P falling toward the stacking platform 11 can easily escape to the side through the opening 12a, allowing the paper P to fall smoothly and be stacked stably.

[0036] In this manner, the media discharge device 1 restricts the leading edge position of the paper P with the leading edge fence 13 and restricts the position of both sides of the paper P in the width direction with the pair of side fences 12 while discharging the paper P. When a full load state is detected, where the amount of paper P stacked on the stacking platform 11 has reached a predetermined amount, the control unit 4 stops discharging any further paper P to the stacking platform 11.

[0037] In existing media discharge devices, a common problem with media discharge is that the end of the media may lean against a restricting part, such as the front-end fence (also called the end fence). The occurrence of this leaning condition will be explained using the configuration of media discharge device 1 as a reference example shown in Figure 5.

[0038] Figure 5(A) shows the state in which the leading edge of the paper P is facing upward and leaning against the leading edge fence 13 in the discharge direction F1. This state is called the upper lean at the leading edge leaning portion Pa of the paper P. When the paper P is discharged diagonally upward while being curved along the paper guides 23 on both edges of the discharge platform 21, the paper P may be in a state where the upper lean at the leading edge leaning portion Pa is likely to occur.

[0039] Figure 5(B) shows the state in which the leading edge of the paper P is facing downwards and leaning against the leading edge fence 13 in the discharge direction F1. This state is called downward leaning at the leading edge leaning portion Pa of the paper P. The leading edge fence 13 is suspended and supported above the loading platform 11, and there is a gap between the lower end of the leading edge fence 13 and the loading platform 11. As a result, downward leaning is likely to occur at the leading edge leaning portion Pa of the paper P when the leading edge of the paper P enters this gap.

[0040] Figure 5(C) shows the state in which the rear end of the paper P in the discharge direction F1 (the end on the return direction F2 side) is facing upward and leaning against the rear end fence 25. This state is called the upward lean of the rear end leaning portion Pb of the paper P. When the paper P hits the front end fence 13 and bounces strongly in the return direction F2, this upward lean of the rear end leaning portion Pb may occur.

[0041] Although not shown in Figure 5, a downward lean may occur at the rear end of the paper P, where it leans downward against the rear end fence 25.

[0042] If the edge of a sheet of paper P leans against a restricting part such as the front-end fence 13 or the rear-end fence 25, the sheet of paper P will not be stacked in the correct position on the stacking tray 11. Furthermore, not only the sheet of paper P that is leaning, but also the sheets of paper P discharged afterward may be stacked on the stacking tray 11 out of their correct positions. In particular, in a large-capacity media discharge device that can load a large number of sheets of paper P onto the stacking tray 11, correcting the misalignment of the sheets of paper P afterward is extremely time-consuming. For example, if misalignment occurs due to a sheet of paper P leaning, even if the side fence drive unit 15 or the front-end fence drive unit 16 is driven to adjust the position of the side fences 12 or the front-end fence 13 after a series of sheets of paper P have been discharged, the stacked sheets of paper P may not be aligned.

[0043] Therefore, it is necessary to detect if the paper P is leaning against the regulating unit during the discharge operation and to take appropriate countermeasures. One example of a countermeasure is to stop the discharge operation of the paper P from the paper discharge unit 10 to the stacking tray 11 and issue a notification when the leaning of the paper P is detected. With the discharge operation stopped, the user who received the notification checks the paper P on the stacking tray 11, and if there is any leaning or misalignment of the paper P, corrects it manually or by other means before resuming the discharge operation. This countermeasure method has the problem of reducing productivity in paper processing due to increased downtime caused by stopping the discharge operation, and it also has the problem of increasing the workload of the user.

[0044] Furthermore, if the amount of paper P leaning is small, the leaning of the paper P may resolve naturally over time, due to contact with the next sheet of paper to be ejected, or vibration of the stacking platform 11. In such cases, stopping the ejection operation or issuing a notification of a loading error would not only waste time but also affect the user's confidence in the device.

[0045] Another known method to eliminate the leaning of the paper P against the leading edge fence 13 is to retract the leading edge fence 13 in the discharge direction F1 and then return it to its restricted position. However, moving the leading edge fence 13 requires a pause, such as stopping the paper discharge operation, which limits the speed of paper discharge.

[0046] Another known countermeasure involves changing the ejection conditions in the paper output section 10 to prevent the recurrence of paper P leaning. However, this countermeasure cannot correct paper P leaning that has already occurred.

[0047] The media discharge device 1 of this embodiment solves the above-mentioned problems and prevents paper loading defects while avoiding a decrease in the paper discharge efficiency P, and its details are described below. The media discharge device 1 is equipped with a leading-end detection sensor 50, a leading-end detection sensor 51, a rear-end detection sensor 52, and a rear-end detection sensor 53 as means for detecting leaning of the paper P. Furthermore, when leaning of the paper P against the restricting section (leading-end fence 13 or rear-end fence 25) is detected by each of the detection sensors 50, 51, 52, and 53, the media discharge device 1 is equipped with a media position correction unit 60 and a media position correction unit 70 as means for eliminating the leaning.

[0048] The tip-side detection sensor 50 is a detection means for detecting the upward lean of the tip portion Pa of the paper P relative to the tip-side fence 13. The tip-side detection sensor 50 is a distance measuring sensor capable of measuring the presence or absence of an object and the distance to the object. The tip-side detection sensor 50 is positioned at a height corresponding to the height of the upward lean that occurs at the tip side of the paper P when an upward lean of a predetermined size or larger occurs.

[0049] As shown in Figure 6(A), when the paper P discharged onto the loading platform 11 experiences an upward lean at the leading edge of the leading edge fence 13, the leading edge detection sensor 50 detects the distance to the leading edge of the leading edge and outputs a signal. The control unit 4 receives the output signal from the leading edge detection sensor 50 and determines that an upward lean has occurred at the leading edge of the paper P.

[0050] The tip-side detection sensor 51 is a detection means for detecting the lower edge of the tip-end portion Pa of the paper P relative to the tip-side fence 13. The tip-side detection sensor 51 is a distance measuring sensor capable of measuring the presence or absence of an object and the distance to the object. The tip-side detection sensor 51 is positioned at a height corresponding to the height of the lower edge when a lower edge of a predetermined size or larger occurs at the tip side of the paper P.

[0051] As shown in Figure 7(A), when the paper P discharged onto the loading platform 11 experiences a downward lean at the leading edge of the leading edge fence 13, the leading edge detection sensor 51 detects the distance to the leading edge of the leading edge and outputs a signal. The control unit 4 receives the output signal from the leading edge detection sensor 50 and determines that a downward lean has occurred at the leading edge of the paper P.

[0052] The rear end detection sensor 52 is a detection means for detecting the overhang of the rear end portion Pb of the paper P relative to the rear end fence 25. The rear end detection sensor 52 is a distance measuring sensor capable of measuring the presence or absence of an object and the distance to the object. The rear end detection sensor 52 is positioned at a height corresponding to the height of the overhang that occurs at the rear end of the paper P when an overhang of a predetermined size or larger occurs.

[0053] As shown in Figure 8(A), when the paper P discharged onto the loading platform 11 experiences an upward lean at the rear end portion Pb against the rear end fence 25, the rear end detection sensor 52 detects the distance to the rear end portion Pb and outputs a signal. The control unit 4 receives the output signal from the rear end detection sensor 52 and determines that an upward lean has occurred at the rear end of the paper P.

[0054] The rear end detection sensor 53 is a detection means for detecting the underhang (not shown in the figure) of the rear end of the paper P relative to the rear end fence 25. The rear end detection sensor 53 is a distance measuring sensor capable of measuring the presence or absence of an object and the distance to the object. The rear end detection sensor 53 is positioned at a height corresponding to the height of the underhang that occurs at the rear end of the paper P when an underhang of a predetermined size or larger occurs.

[0055] Although not shown in the diagram, if the paper P discharged onto the loading platform 11 experiences a downward lean at the rear end of the rear end fence 25, the rear end detection sensor 53 detects the distance to the rear end lean and outputs a signal. The control unit 4 receives the output signal from the rear end detection sensor 53 and determines that a downward lean has occurred at the rear end of the paper P.

[0056] As shown in Figures 3 and 4, a support plate 55 is provided located behind the front end fence 13 on the discharge direction F1 side, and the front end detection sensors 50 and 51 are attached to a sensor bracket 56 fixed to the support plate 55. Both the front end detection sensors 50 and 51 are positioned to detect the paper P without being obstructed by the front end fence 13.

[0057] As shown in Figure 4, the rear-end detection sensor 52 and the rear-end detection sensor 53 are attached to a sensor bracket 57 fixed to the rear of the partition wall 24 on the return direction F2 side. Both the rear-end detection sensor 52 and the rear-end detection sensor 53 are positioned to detect the paper P without being obstructed by the partition wall 24 and the rear-end fence 25.

[0058] The media position correction unit 60 comprises an upper pulley 61 and a lower pulley 62 arranged at a distance from each other in the vertical direction, and a loop-shaped (endless) belt 63 wrapped around the upper pulley 61 and the upper pulley 61. The upper pulley 61 and the lower pulley 62 are each rotatably supported around a rotation axis 61a and a rotation axis 62a extending in the Y-axis direction. The rotation axes 61a and 62a are provided on the sides of the front end fence 13.

[0059] The belt-driven motor 64 (Figure 2) can drive one of the upper pulleys 61 and the lower pulley 62 to rotate as the driving pulley. When the driving pulley rotates, the driving force is transmitted to the belt 63, causing the belt 63 to circulate between the upper pulley 61 and the lower pulley 62. The other of the upper pulley 61 and the lower pulley 62 is a driven pulley that rotates in conjunction with the circulating motion of the belt 63. Alternatively, both the upper pulley 61 and the lower pulley 62 may be driven as driving pulleys.

[0060] The belt 63 has a first lifting section 63a and a second lifting section 63b that extend vertically between the upper pulley 61 and the lower pulley 62. When the upper pulley 61 and the lower pulley 62 are rotated counterclockwise from Figure 6 to Figure 8, the first lifting section 63a moves downward from the upper pulley 61 toward the lower pulley 62, and the second lifting section 63b moves upward from the lower pulley 62 toward the upper pulley 61. This operation in the media position correction unit 60 is called the downward correction operation. When the upper pulley 61 and the lower pulley 62 are rotated clockwise from Figure 6 to Figure 8, the first lifting section 63a moves upward from the lower pulley 62 toward the upper pulley 61, and the second lifting section 63b moves downward from the upper pulley 61 toward the lower pulley 62. This operation in the media position correction unit 60 is called the upward correction operation.

[0061] As shown in Figures 3 and 4, the media position correction unit 60 is equipped with multiple belt drive units, each containing an upper pulley 61, a lower pulley 62, and a belt 63, positioned at different locations in the width direction (Y-axis direction) of the paper P. More specifically, one belt drive unit is provided on each side of the front-end fence 13. The belt drive motor 64 simultaneously operates the belts 63 of the belt drive units on both sides of the front-end fence 13. Alternatively, each belt drive unit may be equipped with its own belt drive motor 64, allowing the belts 63 on both sides of the front-end fence 13 to be operated separately.

[0062] In each belt drive unit on either side of the front-end fence 13, the first lifting section 63a is positioned to protrude slightly towards the return direction F2 from the restricting surface 13a of the front-end fence 13. Therefore, when the leading edge of the paper P being discharged in the discharge direction F1 comes into contact with the restricting surface 13a of the front-end fence 13, the leading edge of the paper P also comes into contact with the first lifting section 63a of the belt 63. The belt 63 is flexible, and when the leading edge of the paper P comes into contact with the first lifting section 63a, the first lifting section 63a can bend to absorb the impact. This makes it possible to suppress excessive bouncing in the return direction F2 when the paper P comes into contact with the front-end fence 13.

[0063] An anti-static brush is provided on the outer surface (the surface that contacts the paper P) of the loop-shaped belt 63. The belt 63 is made of a flexible material such as rubber as its base material, and the anti-static brush is attached to the base material by means of adhesive or welding. The anti-static brush is made of anti-static fibers and suppresses the generation of static electricity in the paper P that comes into contact with the first lifting section 63a.

[0064] By suppressing static electricity in the paper P with the belt 63 equipped with an anti-static brush, it becomes less likely for the paper P to lean against the leading edge fence 13 due to static electricity, and it is also effective in preventing multiple sheets of paper P stacked on the stacking platform 11 from sticking together due to static electricity.

[0065] The media position correction unit 70 has the same structure as the media position correction unit 60. The media position correction unit 70 includes an upper pulley 71 and a lower pulley 72 arranged at a distance from each other in the vertical direction, and a loop-shaped (endless) belt 73 wrapped around the upper pulley 71 and the upper pulley 71. The upper pulley 71 and the lower pulley 72 are each supported so as to be rotatable about a rotation axis 71a and a rotation axis 72a extending in the Y-axis direction. The rotation axes 71a and 72a are attached to brackets (not shown) provided on the partition wall 24.

[0066] The belt drive motor 74 can drive one of the upper pulleys 71 and the lower pulley 72, which will rotate as the driving pulley. When the driving pulley rotates, the driving force is transmitted to the belt 73, causing the belt 73 to circulate between the upper pulley 71 and the lower pulley 72. The other of the upper pulley 71 and the lower pulley 72 is a driven pulley that rotates in conjunction with the circulating motion of the belt 73. Alternatively, both the upper pulley 71 and the lower pulley 72 may be driven as driving pulleys.

[0067] The belt 73 has a first lifting section 73a and a second lifting section 73b that extend vertically between the upper pulley 71 and the lower pulley 72. When the upper pulley 71 and the lower pulley 72 are rotated clockwise from Figure 6 to Figure 8, the first lifting section 73a moves downward from the upper pulley 71 toward the lower pulley 72, and the second lifting section 73b moves upward from the lower pulley 72 toward the upper pulley 71. This operation in the media position correction unit 70 is called the downward correction operation. When the upper pulley 71 and the lower pulley 72 are rotated counterclockwise from Figure 6 to Figure 8, the first lifting section 73a moves upward from the lower pulley 72 toward the upper pulley 71, and the second lifting section 73b moves downward from the upper pulley 71 toward the lower pulley 72. This operation in the media position correction unit 70 is called the upward correction operation.

[0068] As shown in Figures 3 and 4, the media position correction unit 70 is equipped with multiple belt drive units, each containing an upper pulley 71, a lower pulley 72, and a belt 73, positioned at different locations in the width direction (Y-axis direction) of the paper P. More specifically, one belt drive unit is provided on each side of the rear end fence 25. The belt drive motor 74 simultaneously operates the belts 73 of the belt drive units on both sides of the rear end fence 25. Alternatively, each belt drive unit may be equipped with its own belt drive motor 74, allowing the belts 73 on both sides of the rear end fence 25 to be operated independently.

[0069] In each belt drive unit on either side of the rear end fence 25, the first lifting section 73a is positioned to protrude slightly toward the discharge direction F1 than the restricting surface 25a of the rear end fence 25. Therefore, when the paper P discharged in the discharge direction F1 hits the front end fence 13 and bounces, and the rear end of the paper P comes into contact with the restricting surface 25a of the rear end fence 25, the rear end of the paper P also comes into contact with the first lifting section 73a of the belt 73. The belt 73 is flexible, and when the front end of the paper P hits the first lifting section 73a, the first lifting section 73a can bend and absorb the impact. This suppresses further bouncing of the paper P when it comes into contact with the rear end fence 25, thereby stabilizing the paper P.

[0070] An anti-static brush is provided on the outer surface (the surface that contacts the paper P) of the loop-shaped belt 73. Similar to the belt 63 described earlier, the belt 73 is made of a flexible material such as rubber as its base material, and the anti-static brush is attached to the base material by means of adhesive or welding. By providing the anti-static brush to the belt 73, the generation of static electricity in the paper P that the first lifting unit 73a contacts is suppressed.

[0071] By suppressing static electricity in the paper P with the belt 73 equipped with an anti-static brush, it becomes less likely for the paper P to lean against the rear end fence 25 due to static electricity, and it is also effective in preventing multiple sheets of paper P stacked on the stacking platform 11 from sticking together due to static electricity.

[0072] The first lifting section 63a of the belt 63 in the media position correction unit 60 is positioned at approximately the same height as the restricting surface 13a of the front end fence 13. The first lifting section 73a of the belt 73 in the media position correction unit 70 is positioned at approximately the same height as the restricting surface 25a of the rear end fence 25. The front end fence 13 extends to a higher position in the Z-axis direction than the rear end fence 25 in order to receive the paper P discharged from the paper discharge unit 10 in the discharge direction F1. On the other hand, the upper end of the rear end fence 25 is positioned lower than the upper end of the front end fence 13 so as not to obstruct the discharge of paper P from the paper discharge unit 10. Corresponding to this difference in height between the front end fence 13 and the rear end fence 25, the media position correction unit 60 is positioned higher than the media position correction unit 70 overall. More specifically, the rotation axis 61a of the upper pulley 61 of the media position correction unit 60 is located above the rotation axis 71a of the upper pulley 71 of the media position correction unit 70. Also, the rotation axis 62a of the lower pulley 62 of the media position correction unit 60 is located above the rotation axis 72a of the lower pulley 72 of the media position correction unit 70.

[0073] The operation and control for resolving paper sagging in the media discharge device 1 configured as described above will now be explained. Figure 6 shows the operation when upper sagging occurs at the leading edge sagging portion Pa of the paper P, Figure 7 shows the operation when lower sagging occurs at the leading edge sagging portion Pa of the paper P, and Figure 8 shows the operation when upper sagging occurs at the rear edge sagging portion Pb of the paper P. The case where lower sagging occurs at the rear end of the paper P is not shown in the illustration, but the operation to resolve sagging in this case will also be described later. The flowchart in Figure 9 shows the flow of processing content encompassing multiple sagging occurrence patterns, and each step described below is shown in Figure 9.

[0074] During the paper ejection operation, the control unit 4 controls the operation of the lifting motor 35 of the loading platform drive unit 14, lowering the loading platform 11 according to the amount of paper P loaded onto the loading platform 11. Specifically, the height of the loading platform 11 is changed so that the height position of the highest paper P to be ejected is maintained at a predetermined reference upper limit position.

[0075] Furthermore, during the paper ejection operation, in step S100, the control unit 4 detects whether or not the paper P is leaning against the front-end fence 13 or the rear-end fence 25, based on the output signals from the front-end detection sensor 50, the front-end detection sensor 51, the rear-end detection sensor 52, and the rear-end detection sensor 53. If leaning of the paper P is detected, the determination in step S100 becomes YES, and the process proceeds to step S101.

[0076] In step S101, the control unit 4 confirms whether the leaning of the paper P occurred at the leading edge (leading edge leaning portion Pa) or the trailing edge (trailing edge leaning portion Pb). Next, the process proceeds to step S102. In step S102, the control unit 4 confirms the direction of the leaning of the paper P. That is, it confirms whether the leaning occurred upwards or downwards. Depending on which of the leading edge detection sensor 50, leading edge detection sensor 51, trailing edge detection sensor 52, or trailing edge detection sensor 53 detects the leaning of the paper P, the confirmations in steps S101 and S102 can be performed. Therefore, it is also possible to process steps S101 and S102 together.

[0077] For example, Figure 6(A) shows a state where the leading edge of the paper P discharged from the paper discharge section 10 toward the stacking table 11 is curved upward and leaning against the leading edge fence 13 (upper leading edge lean). The upper lean that occurs in the leading edge of the paper Pa can be detected by distance measurement using the leading edge detection sensor 50. Figure 7(A) shows a state where the leading edge of the paper P discharged from the paper discharge section 10 toward the stacking table 11 is curved downward and leaning against the leading edge fence 13 (lower leading edge lean). The lower lean that occurs in the leading edge of the paper Pa can be detected by distance measurement using the leading edge detection sensor 51. Figure 8(A) shows a state where the rear end of the paper P discharged from the paper discharge section 10 toward the stacking table 11 is curved upward and leaning against the rear end fence 25 (upper rear end lean). The upward lean that occurs at the rear end lean portion Pb can be detected by distance measurement using the rear end detection sensor 52. Although not shown in the figure, the state in which the rear end lean portion Pb of the paper P discharged from the paper discharge section 10 toward the stacking table 11 is curved downward and leans against the rear end fence 25 (rear end downward lean) can be detected by distance measurement using the rear end detection sensor 53.

[0078] Based on the position and direction of the paper P being tilted as confirmed in steps S101 and S102, the control unit 4 drives the media position correction unit 60 or the media position correction unit 70 in step S103 to eliminate the tilt.

[0079] As shown in Figure 6(A), when an upward lean occurs at the leading edge of the paper P, the control unit 4 sends a drive signal to the belt drive motor 64 to perform a downward correction operation in the media position correction unit 60, as shown in Figure 6(B). When an upward lean occurs at the leading edge of the paper P, the leading edge of the paper P leans not only against the leading edge fence 13 but also against the first lifting sections 63a of the belts 63 on both sides. Therefore, when the belt drive motor 64 is driven based on the instruction from the control unit 4, and the first lifting section 63a against which the leading edge of the paper P leans moves from the upper pulley 61 to the lower pulley 62 (performing a downward correction operation), as shown in Figure 6(C), the force of movement of the first lifting section 63a is transmitted to the paper P by friction, causing the leading edge of the paper P to move downward.

[0080] As shown in Figure 7(A), if a downward lean occurs at the leading edge of the paper P, the control unit 4 sends a drive signal to the belt drive motor 64 to perform an upward correction operation in the media position correction unit 60, as shown in Figure 7(B). When a downward lean occurs at the leading edge of the paper P, the leading edge of the paper P leans not only against the leading edge fence 13 but also against the first lifting sections 63a of the belts 63 on both sides. Therefore, when the belt drive motor 64 is driven based on the instruction from the control unit 4, and the first lifting section 63a against which the leading edge of the paper P leans moves from the lower pulley 62 to the upper pulley 61 (performing an upward correction operation), as shown in Figure 7(C), the moving force of the first lifting section 63a is transmitted to the paper P by friction, causing the leading edge of the paper P to move upward.

[0081] As shown in Figure 8(A), when an upward lean occurs at the rear end lean portion Pb of the paper P, the control unit 4 sends a drive signal to the belt drive motor 74 to perform a downward correction operation in the media position correction unit 70, as shown in Figure 8(B). When an upward lean occurs at the rear end lean portion Pb, the rear end lean portion Pb leans not only against the rear end fence 25 but also against the first lifting portions 73a of the belts 73 on both sides. Therefore, when the belt drive motor 74 is driven based on the instruction from the control unit 4, and the first lifting portion 73a against which the rear end lean portion Pb is leaning moves from the upper pulley 71 to the lower pulley 72 (performing a downward correction operation), as shown in Figure 8(C), the moving force of the first lifting portion 73a is transmitted to the paper P by friction, causing the rear end lean portion Pb to move downward.

[0082] Although not shown in the diagram, if downward lean occurs at the rear end of the paper P, the control unit 4 sends a drive signal to the belt drive motor 74 to cause the media position correction unit 70 to perform an upward correction operation. When downward lean occurs at the rear end of the paper P, the rear end lean is also leaning against the first lifting section 73a of the belts 73 on both sides of the rear end fence 25. Therefore, when the belt drive motor 74 is driven based on the instruction from the control unit 4, and the first lifting section 73a, against which the rear end lean is leaning, moves from the lower pulley 72 to the upper pulley 71 (performing an upward correction operation), the force of movement of the first lifting section 73a is transmitted to the paper P by friction, causing the rear end lean to move upward.

[0083] As described above, in step S103, the leaning of the paper P is resolved by having the media position correction unit 60 and the media position correction unit 70 perform a leaning relief operation according to the position and direction of the leaning of the paper P (step S104). The control unit 4 continuously performs the leaning determination in step S100 during the paper ejection operation, and if it detects that the paper P is leaning, it executes the leaning relief process from steps S101 to S104. When ejecting multiple sheets of paper P in succession, the leaning relief process is executed without stopping the ejection operation of the next sheet of paper P.

[0084] In step S103, the control unit 4 may adjust the operation of the media position correction unit 60 or media position correction unit 70 according to the paper ejection conditions of the paper P. For example, as the ejection speed of the paper P increases, the time until the next ejected paper P overlaps with the previously ejected paper P becomes shorter, and the time available for resolving the paper P tangling decreases. To address this, the control unit 4 refers to the ejection condition information stored in the memory unit and, as the ejection speed of the paper P increases, increases the rotation speed of the belt drive motor 64 and belt drive motor 74 during the tangling resolution operation, thereby speeding up the operation of belts 63 and 73. In other words, the rotation speed of belts 63 and 73 is changed in proportion to the ejection speed of the paper P. This makes it possible to eject multiple sheets of paper P at high speed while resolving the paper P tangling without delay.

[0085] The likelihood and amount of paper P sagging vary depending on various conditions such as the size of the paper P, the friction coefficient of the paper surface, and the basis weight of the paper P. When processing in step S103, the control unit 4 may refer to these conditions regarding the paper P and control the rotation speed of the belt drive motors 64 and 74. For example, under discharge conditions where the amount of paper P sagging onto the front end fence 13 and the rear end fence 25 tends to be large, the control unit 4 may increase the rotation speed of the belt drive motors 64 and 74 to quickly eliminate the paper P sagging through high-speed operation of the belts 63 and 73.

[0086] If no leaning of the paper P occurs (including cases where the leaning is resolved after steps S101 to S104), the determination in step S100 is NO, and the process proceeds to step S105. In step S105, it is determined that the ejection of the paper P is complete. This includes cases where a series of image forming jobs in the image forming apparatus 2 is completed and the final sheet of paper P is ejected onto the stacking tray 11, or when a full stack state is detected where the amount of paper P stacked on the stacking tray 11 has reached a predetermined amount, and paper ejection is stopped. In these cases, the determination in step S105 is YES, and the process proceeds to step S106. If the determination in step S105 is NO, the process returns to step S100.

[0087] In step S106, the control unit 4 drives the side fence drive unit 15 and the front end fence drive unit 16 based on the discharge condition information stored in the memory unit to adjust the distance between the pair of side fences 12 in the Y-axis direction and the position of the front end fence 13 in the X-axis direction, thereby aligning the positions of the multiple sheets of paper P loaded on the loading platform 11. If leaning of the paper P is detected during the discharge operation, the leaning condition is resolved by the processing from steps S101 to S104 to prevent the paper P from being unbalanced, so that the paper alignment in step S106 can be performed easily and reliably. Once the paper alignment in step S106 is complete, the discharge process shown in Figure 9 is exited.

[0088] As described above, the media discharge device 1 of this embodiment includes a loading platform 11 on which the paper P, which is the medium, is loaded; a leading edge fence 13 and a trailing edge fence 25, which are regulating parts that regulate the positions of the leading edge and trailing edge of the paper P discharged to the loading platform 11 in the discharge direction; and media position correction parts 60 and 70 that, when they detect that the paper P is leaning against the leading edge fence 13 or the trailing edge fence 25, apply a force to move the leaning portion of the paper P (leading edge leaning portion Pa, trailing edge leaning portion Pb) along the leading edge fence 13 or the trailing edge fence 25 in the vertical direction (Z-axis direction) to eliminate the leaning of the paper P.

[0089] According to the media discharge device 1 of this embodiment, while continuously discharging paper P onto the stacking platform 11, the media position correction units 60 and 70 automatically resolve any leaning of the paper P. Therefore, there is no need to stop the discharge of paper P and perform maintenance by the user each time leaning of paper P is detected. Even if the leaning of paper P resolves itself naturally, the media position correction units 60 and 70 perform only minimal operations within the device without stopping the discharge operation, thus improving the reliability of the device without imposing unnecessary waiting times or maintenance effort.

[0090] Furthermore, when resolving the paper P from sticking, the parts necessary for the basic ejection operation of the paper P (such as the transport roller pair 20 of the paper ejection unit 10, the side fence 12, and the leading edge fence 13) are not made to perform any extra operations, and only the media position correction units 60 and 70 are operated. As a result, the paper sticking resolution operation can be performed quickly and simultaneously with the ejection operation of the paper P.

[0091] The media discharge device 1 of this embodiment is equipped with a media position correction unit 60 and a media position correction unit 70 on both the leading edge and the trailing edge sides in the discharge direction of the paper P, making it possible to eliminate leaning of the leading edge of the paper P against the leading edge fence 13 and to eliminate leaning of the trailing edge of the paper P against the trailing edge fence 25.

[0092] However, in the media discharge device of this disclosure, it is not essential to provide media position correction units on both the leading and trailing ends in the discharge direction of the media; it is sufficient to provide a media position correction unit on at least one of the leading and trailing ends in the discharge direction. In particular, in media discharge devices, the media often leans against the regulating unit on the leading end in the discharge direction, so it is preferable to provide a media position correction unit (corresponding to the media position correction unit 60 in this embodiment) on at least the leading end.

[0093] When the control unit 4 detects that the paper P is leaning upward against the front fence 13 or the rear fence 25, it moves the leaning portion of the paper P (front leaning portion Pa or rear leaning portion Pb) downward via the media position correction unit 60 or the media position correction unit 70. Also, when the control unit 4 detects that the paper P is leaning downward against the front fence 13 or the rear fence 25, it moves the leaning portion of the paper P (front leaning portion Pa or rear leaning portion Pb) upward via the media position correction unit 60 or the media position correction unit 70. In this way, since the media position correction unit 60 or the media position correction unit 70 directly moves the leaning portion of the paper P in the opposite direction to the leaning direction, it is possible to reliably eliminate the leaning compared to forms that rely on the weight of the paper P to eliminate the leaning.

[0094] Each media position correction unit 60 and 70 comprises upper pulleys 61 and 71 and lower pulleys 62 and 72 arranged at a distance from each other in the vertical direction, and belts 63 and 73 that are wrapped around 61 and 71 and the lower pulleys 62 and 72 and are movable in the vertical direction. When the paper P leans against the front end fence 13, the front end leaning portion Pa of the paper P comes into contact with the belt 63 (first lifting portion 63a), and the upper pulleys 61 and 62 are rotated to move the belt 63 in the vertical direction, thereby eliminating the leaning of the paper P. When the paper P leans against the rear end fence 25, the rear end leaning portion Pb of the paper P comes into contact with the belt 73 (first lifting portion 73a), and the upper pulleys 71 and 72 are rotated to move the belt 73 in the vertical direction, thereby eliminating the leaning of the paper P.

[0095] In the media position correction units 60 and 70, the parts that contact the leading edge lean Pa and the trailing edge lean Pb of the paper P are belts 63 and 73 that extend in the vertical direction. Therefore, they can contact the paper P regardless of the degree of leaning, and can reliably move the paper P to a position where the leaning is eliminated. In other words, the media position correction units 60 and 70 have excellent performance in eliminating the leaning of the paper P.

[0096] As a variation different from this embodiment, the media position correction unit may be equipped with multiple rollers arranged vertically instead of a belt. When the leaning portion of the paper P is in contact with one of the multiple rollers, the corresponding roller is rotated to apply a force that moves the leaning portion vertically, thereby eliminating the leaning.

[0097] Compared to this modified example, the media position correction unit 60, 70 of this embodiment has the advantage of simplifying the power transmission mechanism and control content for driving, as it only requires rotational driving of at least one of the upper pulleys 61, 71 and the lower pulleys 62, 72. Furthermore, since the first lifting portions 63a, 73a of the belts 63, 73 that contact the leading edge support portion Pa and the rear edge support portion Pb of the paper P are flat and extend uniformly in the vertical direction, there is an advantage that movement force can be efficiently and stably applied to the support portion of the paper P regardless of which part of the first lifting portion 63a, 73a contacts it.

[0098] The media position correction unit 60 is equipped with belts 63 on both sides of the front end fence 13 in the width direction (Y-axis direction) of the paper P. The media position correction unit 70 is equipped with belts 73 on both sides of the rear end fence 25 in the width direction (Y-axis direction) of the paper P. By arranging belts 63 and 73 on both sides of the regulating front end fence 13 and rear end fence 25 in this way, leaning can be eliminated for paper P of various widths. In addition, by arranging belts 63 and 73 on both sides of the front end fence 13 and rear end fence 25, when eliminating leaning of the paper P, the bias in the movement force in the width direction of the paper P is eliminated, and the paper P can be returned to the stacking platform 11 without tilting.

[0099] The number of belts in the media position correction unit is not limited to two; it may be one or three or more. For example, as a different modification from this embodiment, a structure may be created in which a portion of the width of the front end fence 13 and the rear end fence 25 in the Y-axis direction is omitted, and one belt may be placed within the width range of the front end fence 13 and the rear end fence 25. As another different modification, two or more belts (a total of four or more belts in each media position correction unit) may be placed on each of the Y-axis sides of the front end fence 13 and the rear end fence 25.

[0100] The belts 63 and 73 of the media position correction units 60 and 70 in this embodiment are equipped with static elimination brushes on the surfaces that contact the paper P. By providing static elimination functionality to the belts 63 and 73, the effect of suppressing the paper P from sticking or sagging due to static electricity can be obtained. Even when the belts 63 and 73 are not in operation, the static elimination effect can be obtained by the static elimination brushes, so they can serve the same role as static elimination brushes provided in the discharge path of existing media discharge devices.

[0101] Furthermore, by configuring the outer surfaces of the belts 63 and 73 with static-eliminating brushes, the friction coefficient of the first lifting sections 63a and 73a with respect to the paper P is not excessive, and the appropriate force, neither too much nor too little, can be applied to the paper P when the belts 63 and 73 are driven. As a result, leaning on the paper P can be eliminated without damaging it.

[0102] As a variation different from this embodiment, it is also possible to use a belt with a configuration in which the base material is exposed on the outer surface without the static elimination brush. However, if the base material of the belt is made of a material with a high coefficient of friction such as rubber, excessive force may be applied to the paper when the belt is driven, potentially damaging the paper. In contrast, the belts 63 and 73 of this embodiment, as described above, can eliminate sagging while applying appropriate force to the paper P through contact via the static elimination brush.

[0103] The media discharge device 1 of this embodiment is equipped with four detection sensors 50, 51, 52, and 53, each of which is a distance measuring sensor, in order to individually detect the upper and lower folds on the leading edge side of the paper P and the upper and lower folds on the trailing edge side of the paper P. This makes it possible to detect the location and direction of the folds on the paper P with high precision.

[0104] The type and arrangement of sensors for detecting the leaning are not limited to those described above. For example, with regard to detecting the upper leaning of the paper P, a distance measuring sensor may be placed only on one side in the X-axis direction. In other words, only one of the front-end detection sensor 50 and the rear-end detection sensor 52 may be provided. Since both the front-end detection sensor 50 and the rear-end detection sensor 52, which are distance measuring sensors, can distinguish and detect the difference between the distance to the front-end leaning portion Pa causing the upper leaning and the distance to the rear-end leaning portion Pb causing the upper leaning, if there are no obstacles in between that obstruct the measurement of distance, the front-end leaning portion Pa and the rear-end leaning portion Pb can be distinguished and detected by a single detection sensor.

[0105] Alternatively, a light-transmitting sensor may be used as the sensor for detecting leaning. For example, the light-emitting and light-receiving parts of a light-transmitting sensor can be placed at positions corresponding to the front-end detection sensor 50 and the rear-end detection sensor 52 in this embodiment, so that when no leaning occurs in the paper P, the light emitted from the light-emitting part is not blocked and is received by the light-receiving part. When leaning occurs in the front-end leaning part Pa or the rear-end leaning part Pb, the light emitted from the light-emitting part is blocked and is not received by the light-receiving part. With this configuration, it is possible to detect the leaning of the paper P using a light-transmitting sensor.

[0106] Furthermore, if the light-transmitting sensor of this modified form cannot be used to determine whether the position of the upward tilt is at the leading edge or the trailing edge of the paper P, the control unit 4 may, in response to the detection of the upward tilt, perform control to cause both the media position correction unit 60 and the media position correction unit 70 to execute a downward correction operation of the belts 63 and 73.

[0107] The media discharge device 1 of this embodiment is connected to an image forming apparatus 2 and is used to discharge paper P on which an image has been formed in the image forming apparatus 2 to the media discharge device 1. However, the applications of the media discharge device of this disclosure are not limited to this. For example, in the technical field of bookbinding, the media discharge device of this disclosure may be used as the destination for the sorted paper in a paper sorting device that sorts and transports multiple types of paper.

[0108] It should be noted that the present invention is not limited to the embodiments described above, and the components can be modified and implemented in practice without departing from the spirit of the invention. Furthermore, various inventions can be formed by appropriately combining the multiple components disclosed in the embodiments described above. For example, all the components shown in the embodiments may be combined as appropriate. It goes without saying that various modifications and applications are possible without departing from the spirit of the invention. Some of the inventions described in the specification of this application are listed below.

[0109] [Note 1] A loading platform on which the media is loaded, A restricting unit that restricts the position of at least one of the leading edge and trailing edge in the discharge direction of the medium discharged to the loading platform, A media position correction unit, which detects that the media is leaning against the regulating unit, applies a force to the leaning portion of the media to move it vertically along the regulating unit to eliminate the leaning of the media, A media discharge device characterized by comprising the following:

[0110] [Note 2] The system includes a control unit that controls the operation of the media position correction unit, and the control unit is: When an upward leaning of the medium is detected with respect to the regulating unit, the leaning portion of the medium is moved downward via the medium position correction unit. The media discharge device according to Appendix 1, characterized in that when a downward leaning of the media against the regulating unit is detected, the leaning portion of the media is moved upward via the media position correction unit.

[0111] [Note 3] The media position correction unit comprises an upper pulley and a lower pulley arranged at a distance from each other in the vertical direction, and a belt wrapped around the upper pulley and the lower pulley and movable in the vertical direction. The media discharge device according to Appendix 1 or 2, characterized in that when the media leans against the regulating part, the leaning portion of the media comes into contact with the belt, causing the upper pulley and the lower pulley to rotate and move the belt upward or downward, thereby eliminating the leaning of the media.

[0112] [Note 4] The media discharge device according to Appendix 3, characterized in that the media position correction unit is provided with the belts on both sides of the regulating unit in the width direction of the media.

[0113] [Note 5] The media discharge device according to Appendix 3, characterized in that the belt has an antistatic member on the surface that contacts the media. [Explanation of symbols]

[0114] 1 :Media discharge device 2: Image forming apparatus 3: Device housing 4: Control Unit 10: Paper output section 11: Loading platform 12: Side fence 12a:Aperture 13: End-side fence (regulating section) 13a: Regulatory aspects 14: Loading platform drive unit 15: Side fence drive unit 16: Front-side fence drive unit 21: Discharge table 24: Bulkhead 25: Rear end fence (regulating section) 25a: Regulatory aspects 30: Bottom plate 31: Central support part 32: Inclined support part 50, 51: Tip-side detection sensor 52, 54: Rear end detection sensor 60: Medium position correction section 61: Upper pulley 62: Lower pulley 63: Belt 63a: First elevator section 63b: Second elevator section 64: Belt-driven motor 70: Medium position correction section 71: Upper pulley 72: Lower pulley 73: Belt 73a: First elevator section 73b: Second elevator section 74: Belt-driven motor F1: Discharge direction F2: Return direction P:Paper (medium) Pa: Tip support part (support portion of the medium) Pb: Rear support portion (support portion of the medium)

Claims

1. A loading platform on which the media is loaded, A restricting unit that restricts the position of at least one of the leading edge and trailing edge in the discharge direction of the medium discharged to the loading platform, A media position correction unit, which detects that the media is leaning against the regulating unit, applies a force to the leaning portion of the media to move it vertically along the regulating unit to eliminate the leaning of the media, A media discharge device characterized by comprising the following:

2. The system includes a control unit that controls the operation of the media position correction unit, and the control unit is: When an upward leaning of the medium is detected with respect to the regulating unit, the leaning portion of the medium is moved downward via the medium position correction unit. The media discharge device according to claim 1, characterized in that when a downward leaning of the media against the regulating unit is detected, the leaning portion of the media is moved upward via the media position correction unit.

3. The media position correction unit comprises an upper pulley and a lower pulley arranged at a distance from each other in the vertical direction, and a belt wrapped around the upper pulley and the lower pulley and movable in the vertical direction. The media discharge device according to claim 1 or 2, characterized in that when the media leans against the regulating part, the leaning portion of the media comes into contact with the belt, causing the upper pulley and the lower pulley to rotate and move the belt upward or downward, thereby eliminating the leaning of the media.

4. The media discharge device according to claim 3, characterized in that the media position correction unit is provided with the belts on both sides of the regulating unit in the width direction of the media.

5. The media discharge device according to claim 3, characterized in that the belt is provided with an antistatic member on the surface that contacts the medium.

Images