BACKGROUND

[0001] A finisher is to perform a finishing operation on a sheet of printing medium, for example, on a sheet of paper. The finisher may be a stand-alone device. The finisher may be connected to a printing device to form an image forming device and may perform a finishing operation on a printed sheet by performing a process subsequent to a printing operation performed by the printing device.

[0002] The finishing operation may include a bookbinding process of binding multiple sheets of aligned paper, a folding process of folding a sheet of paper, a hole-punching process of hole-punching a sheet of paper, or the like.

BRIEF DESCRIPTION OF THE DRAWINGS

[0003] FIG. 1 illustrates an example of a finisher.

[0004] FIG. 2 is an exploded perspective view of a structure for circulating an ejector according to an example.

[0005] FIG. 3 illustrates a moving path of an ejector based on a movement of a circulation member according to an example.

[0006] FIGS. 4Ato 4F are perspective views showing movement of a guide member based on a circulation movement of an ejector according to an example. [0007] FIGS. 5A to 5F are perspective views showing movements of a guide member and a parallel holding member based on a circulation movement of an ejector according to an example.

[0008] FIGS. 6A and 6B are partial side views of an example of a finisher.

[0009] FIGS. 7A to 7C are partial side views of an example of a paper damage prevention structure.

[0010] FIG. 8 is a partial side view of an example of a finisher.

[0011] FIG. 9 is a partial perspective view of an example of a finisher. DETAILED DESCRIPTION

[0012] A finisher is to perform a finishing operation on a plurality of sheets of a printing medium, such as paper, arranged on an alignment tray (e.g., a paper alignment tray). After the finishing operation is completed, the plurality of sheets are discharged and stacked into a stacking tray by an ejector. The ejector, while moving along a circulation path, pushes ends of the plurality of sheets and discharges them to the stacking tray, and returns to an original position. The ejector may be held in a constant posture during the circulation movement. When the ejector's posture is unstable, a driving load may increase during the circulation movement, and the ejector may interfere with other members of the finisher adjacent to a circulation path and become unable to move.

[0013] In various examples as described herein, an ejector is slidably supported by a guide member and may move along a straight section, for example, a discharge section for discharging a plurality of sheets of a printing medium (e.g., paper) and a return section for returning to an original position. When the ejector moves along a rotation section, for example, a first connection section connecting the discharge section to the return section and a second connection section connecting the return section to the discharge section, the guide member moves in parallel to positions corresponding to the return section and the discharge section, respectively. According to this example, when the ejector moves along the straight section, the ejector is supported to be slidable by the guide member, so that the ejector may be maintained in a stable posture. In addition, when the ejector moves along the rotation section, the guide member moves in parallel, so that the ejector is not inclined and may be maintained in a stable posture. Accordingly, an increase in a driving load due to an unstable posture of the ejector and defective movement of the ejector may be avoided or prevented.

[0014] FIG. 1 illustrates an example of a finisher. FIG. 2 is an exploded perspective view of a structure for circulating an ejector according to an example. FIG. 3 illustrates a moving path of an ejector based on a movement of a circulation member according to an example. [0015] Referring to FIGS. 1 to 3, a finisher may include an alignment tray 30 (e.g., a paper alignment tray) in which a plurality of sheets of printing medium (e.g., paper) P to be finished are aligned, a stacking tray 40 in which the plurality of sheets of paper P discharged from the paper alignment tray 30 may be stacked, an ejector 50 for pushing the plurality of sheets of paper P on the paper alignment tray 30 and discharging them to the stacking tray 40, a circulation member 60 for circulating and moving the ejector 50, and a guide member 70 for supporting the ejector 50 to be slidable.

[0016] The ejector 50 may move along a discharge section 60a to discharge a plurality of sheets of paper P on the paper alignment tray 30 to the stacking tray 40, a return section 60c parallel to the discharge section 60a, a first connection section 60b connecting the discharge section 60a to the return section 60c, and a second connection section 60d connecting the return section 60c to the discharge section 60a. The discharge section 60a and the return section 60c may include straight sections, and the first connection section 60b and the second connection section 60d may include rotation sections. The ejector 50 is to move in a discharge direction D1 along the discharge section 60a, and move in a return direction D2, which is the opposite direction to the discharge direction D1 , along the return section 60c. The discharge direction D1 and the return direction D2 may be a longitudinal direction L of the paper P. The circulation member 60 may circulate the ejector 50 along the discharge section 60a, the first connection section 60b, the return section 60c, and the second connection section 60d. The guide member 70, when the ejector 50 moves along the discharge section 60a and the return section 60c, may be located in a discharge guide position and a return guide position, respectively, to support the ejector 50 to be slidable. The guide member 70, when the ejector 50 moves along the first connection section 60b and the second connection section 60d, is to move in parallel to a position (e.g., the return guide position) corresponding to the return section 60c and a position (e.g., the discharge guide position) corresponding to the discharge section 60a, respectively. The parallel movement means that the guide member 70 moves from the discharge guide position to the return guide position or vice versa while maintaining a state parallel to the discharge section 60a and the return section 60c.

[0017] A plurality of sheets of paper P may be stacked on the paper alignment tray 30. Both ends of the plurality of sheets of paper P in a width direction W may be aligned by a pair of side guides 32. Ends of the plurality of sheets of paper P in a longitudinal direction L may be aligned by an end guide 33. The finisher may be provided with a transfer structure to transfer the paper P. As an example, the transfer structure may include transfer rollers 11 and 12 and an alignment member 13. Each of the transfer rollers 11 and 12 may include a pair of rollers rotated in engagement with each other to transfer paper P introduced through an inlet 91. The alignment member 13 may be located above the paper alignment tray 30. The alignment member 13 may include, for example, a paddle with an elastic arm. The paper P transferred by the transfer rollers 11 and 12 falls to the paper alignment tray 30. The alignment member 13 pushes the paper P on the paper alignment tray 30 toward the end guide 33 while being rotated. Both ends of the paper P in the width direction W may be aligned by the pair of side guides 32, and the ends of the paper P in the longitudinal direction L may be aligned by an end guide 33. In this example, the plurality of sheets of paper P may be aligned on the paper alignment tray 30.

[0018] A finishing operation may include a bookbinding process of binding multiple sheets of aligned paper, a folding process of folding a sheet of paper, a hole-punching process of hole-punching a sheet of paper, or the like. In an example, the finisher includes a binder 20 for applying a bookbinding staple to a plurality of sheets of paper P. The binder 20 may be aligned with one corner of the end of the paper alignment tray 30, so that a bookbinding staple may be applied into the corner of the plurality of sheets of paper P. As the binder 20 moves in a width direction W, one or more bookbinding staples may be applied into the edge of the plurality of sheets of paper P. The plurality of sheets of paper P on which a binding operation (i.e. , a finishing operation) has been completed may be discharged to the stacking tray 40 by the ejector 50.

[0019] The ejector 50 may be connected to the circulation member 60 and circulate as the circulation member 60 circulates. The circulation member 60 may be implemented by, for example, a flat belt, a timing belt, a wire, etc. The circulation member 60 may be supported by a first pulley 61 adjacent to the stacking tray 40 and a second pulley 62 away from the stacking tray 40 to circulate. A diameter of the first pulley 61 and the second pulley 62 may be the same. In an example, the circulation member 60 is a timing belt, and the first pulley 61 and the second pulley 62 are timing pulleys. A motor (not shown) may be connected to, for example, the first pulley 61 to rotate the first pulley 61. Accordingly, the circulation member 60 may be circulated.

[0020] The ejector 50 may be connected to the circulation member 60. For example, a clamp 63 may be connected to the circulation member 60. A connection hole 631 may be provided in the clamp 63. The ejector 50 may include a shaft 51 extending toward the clamp 63. The shaft 51 may be inserted into the connection hole 631. The shaft 51 and the connection hole 631 may be loosely fitted with each other. Accordingly, the ejector 50 may be rotated with respect to the connection hole 631 .

[0021] The ejector 50 may include a grip portion 52 in which ends of the plurality of sheets of paper P may be accommodated. The ejector 50 may include a lower support portion 53 to support the ends of the plurality of sheets of paper P at a bottom of the plurality of sheets of paper P and an extension portion 54 to extend upward from the lower support portion 53 so as to push the ends of the plurality of sheets of paper P. The ejector 50 may include an opening/closing member 55 rotatably supported by the extension portion 54. The opening/closing member 55 may include an opening/closing portion 551 facing the lower support portion 53 and an interference portion 552 located opposite the opening/closing portion 551 based on a rotation center. The lower support portion 53, the extension portion 54, and the opening/closing portion 551 may form the grip portion 52 in which the ends of the plurality of sheets of paper P may be accommodated. The opening/closing member 55 may open and close the grip portion 52. The opening/closing member 55 may be biased in a direction of closing the grip portion 52. For example, the opening/closing member 55 may be biased in a direction in which the grip portion 52 is closed by its own weight, that is, the opening/closing portion 551 may approach the lower support portion 53. Although not shown in the drawings, the opening/closing member 55 may be biased in a direction in which the grip portion 52 is closed by an elastic member. [0022] In the above described example, the plurality of sheets of paper P on the paper alignment tray 30 may be accommodated in the grip portion 52 of the ejector 50. As shown in FIG. 3, the ejector 50, while circulating around the discharge section 60a, the first connection section 60b, the return section 60c, and the second connection section 60d, may push the plurality of sheets of paper P on the paper alignment tray 30 to discharge them to the stacking tray 40 and return to the original position. The discharge section 60a and the return section 60c are sections between the first pulley 61 and the second pulley 62, and the first connection section 60b and the second connection section 60d are semicircular sections around the first pulley 61 and the second pulley 62, respectively. Because the diameter of the first pulley 61 and the diameter of the second pulley 62 are the same, the discharge section 60a and the return section 60c are parallel to each other.

[0023] As described above, the ejector 50 may be rotated with respect to the clamp 63. When the posture of the ejector 50 becomes unstable during circulation movement, the driving load of a motor driving the circulation member 60 may increase, and the ejector 50 may be stuck between other members (e.g., adjacent members) of the finisher and thus cannot be moved. In order to stably maintain the posture of the ejector 50 during circulation movement, the finisher of this example includes the guide member 70. The ejector 50 may be supported to be slidable on the guide member 70. For example, a guide slot 71 may be provided in the guide member 70. The guide slot 71 extends linearly. A length of the guide slot 71 may be greater than or equal to a length of a straight section, that is, the discharge section 60a. The ejector 50 may be provided with a guide protrusion 56 that may be inserted into the guide slot 71 . In an example, the guide protrusion 56 may be supported, for example, by sliding, rolling, etc. in the guide slot 71. In an example, a pair of guide protrusions 56 are supported by the guide slot 71 . The guide member 70 is to support the ejector 50 to be slidable when the ejector 50 moves along the discharge section 60a and the return section 60c, which are straight sections. As a result, while moving along the straight section, the ejector 50 may be supported by the clamp 63 and the guide member 70 so that the ejector 50 is not inclined and may be maintained in a stable posture.

[0024] In order to maintain the ejector 50 in a stable posture (e.g., without inclining) while moving along the first connection section 60b and the second connection section 60d, which are rotation sections, the guide member 70 may be moved in parallel from a position corresponding to the discharge section 60a to a position corresponding to the return section 60c and from a position corresponding to the return section 60c to a position corresponding to the discharge section 60a. As illustrated in FIG. 2, an example of the finisher may include a first link 110 that is rotatable about a first axis AX1 adjacent to a central axis of the first pulley 61 and connected to an end of the guide member 70 adjacent to the first pulley 61 , and a second link 120 that is rotatable about a second axis AX2 adjacent to a central axis of the second pulley 62 and connected to an end of the guide member 70 adjacent to the second pulley 62.

[0025] For example, a first hole 210 and a second hole 220 forming the first axis AX1 and the second axis AX2 may be provided in a side frame 200. A distance between the first hole 210 and the second hole 220 may be the same as a distance between the central axis of the first pulley 61 and the central axis of the second pulley 62. A line connecting the first hole 210 to the second hole 220 may be parallel to a line connecting the central axis of the first pulley 61 to the central axis of the second pulley 62. The first link 110 may include a shaft 111 that is rotatably inserted into the first hole 210. The second link 120 may include a shaft 121 that is rotatably inserted into the second hole 220. Cylindrical support protrusions 72 and 73 may be provided at an end of the guide member 70 that is adjacent to the first pulley 61 and another end of the guide member 70 that is away from the first pulley 61 , respectively. A hole 112 into which the cylindrical support protrusion 72 may be inserted may be provided in the first link 110. A hole 122 into which the cylindrical support protrusion 73 may be inserted may be provided in the second link 120. The cylindrical support protrusion 72 and the hole 112 and the cylindrical support protrusion 73 and the hole 122 may be loosely fitted to each other, respectively. A distance between the shaft 111 and the hole 112 may be equal to the radius of rotation of the connection hole 631 of the clamp 63 with respect to the central axis of the first pulley 61 . The distance between the shaft 111 and the hole 112 and a distance between the shaft 121 and the hole 122 may be the same. In an example, the guide member 70 may be supported by the first link 110 and the second link 120 and may be rotated around the first axis AX1 and the second axis AX2 without inclining.

[0026] FIGS. 4Ato 4F are perspective views showing movement of a guide member based on a circulation movement of an ejector according to an example. [0027] Referring to FIG. 4A, the guide member 70 is located in a discharge guide position and may support the ejector 50 to be slidable along the discharge section 60a. While the ejector 50 is moved in the discharge direction D1 along the discharge section 60a, the guide member 70 may be maintained in the discharge guide position. The ejector 50 may be guided by the guide slot 71 and may be moved in the discharge direction D1 without being inclined.

[0028] When the ejector 50 enters the arc-shaped first connection section 60b, the ejector 50 descends along the periphery of the first pulley 61 . The ejector 50 pushes the guide member 70 in the discharge direction D1 and simultaneously presses the guide member 70 downward. The first link 110 and the second link 120 are rotated about the first axis AX1 and the second axis AX2, respectively. As shown in FIG. 4B, when the ejector 50 reaches a midway position of the first connection section 60b, the first link 110 and the second link 120 are rotated 90°. When the ejector 50 moves past the midway position of the first connection section 60b, the ejector 50 pushes the guide member 70 in the return direction D2 and simultaneously presses the guide member 70 downward. The first link 110 and the second link 120 are rotated about the first axis AX1 and the second axis AX2, respectively. As shown in FIG. 4C, when the ejector 50 reaches the end of the first connection section 60b, the first link 110 and the second link 120 have a rotational phase of 180°. The ejector 50 enters the return section 60c. The guide member 70 reaches a return guide position that supports the ejector 50 slidably moving along the return section 60c.

[0029] As shown in FIG. 4D, while the ejector 50 is moved in the return direction D2 along the return section 60c, the guide member 70 may be maintained in the return guide position, and the first link 110 and the second link 120 are not rotated. The ejector 50 may be guided by the guide slot 71 and may be moved in the return direction D2 without being inclined. When the ejector 50 enters the arc-shaped second connection section 60d, the ejector 50 rises along the periphery of the second pulley 62. The ejector 50 pushes the guide member 70 in the return direction D2 and simultaneously presses the guide member 70 upward. The first link 110 and the second link 120 are rotated about the first axis AX1 and the second axis AX2, respectively. As shown in FIG. 4E, when the ejector 50 reaches a midway position of the second connection section 60d, the first link 110 and the second link 120 have a rotational phase of 270°. When the ejector 50 moves past the midway position of the second connection section 60d, the ejector 50 pushes the guide member 70 in the discharge direction D1 and simultaneously presses the guide member 70 upward. As shown in FIG. 4F, when the ejector 50 passes through the second connection section 60d, the first link 110 and the second link 120 have a rotational phase of 360°. The ejector 50 reenters the discharge section 60a. The guide member 70 returns to a discharge guide position that supports the ejector 50 slidably moving along the discharge section 60a.

[0030] Because the first link 110 and the second link 120 have the same length, while the ejector 50 moves along the first connection section 60b and the second connection section 60d, the first link 110 and the second link 120 have the same amount of rotation about the first axis AX1 and the second axis AX2. Accordingly, the guide member 70 is not inclined and may move in parallel to the return guide position and the discharge guide position, and the ejector 50 may be supported by the guide member 70 and may move along the first connection section 60b and the second connection section 60d without inclining.

[0031] Referring again to FIG. 2, an example of the finisher may further include a parallel holding member 80. The parallel holding member 80 may move in parallel with the guide member 70. The parallel holding member 80 may have a rotational phase different from that of the guide member 70. A rotational phase difference between the parallel holding member 80 and the guide member 70 may be 90°. For example, the rotational phase of the parallel holding member 80 may lead 90° ahead of the rotational phase of the guide member 70.

[0032] An example of the finisher may include a third link 130 connected to the first link 110, to rotate about the first axis AX1 and to connect to an end of the parallel holding member 80 adjacent to the first pulley 61 , and a fourth link 140 connected to the second link 120, to rotate about the second axis AX2 and to connect to an end of the parallel holding member 80 adjacent to the second pulley 62. The third link 130 may have a rotational phase difference from the first link 110 and rotate together with the first link 110. The fourth link 140 may have a rotational phase difference from the first link 120 and rotate together with the second link 120. The rotational phase difference between the third link 130 and the first link 110 and the rotational phase difference between the fourth link 140 and the second link 120 may be the same. One end and the other end of the parallel holding member 80 may be connected to the third link 130 and the fourth link 140, respectively.

[0033] For example, the shaft 111 of the first link 110 may pass through the first hole 210 provided in the side frame 200 and protrude to the outside of the side frame 200. A D-cut portion 113 may be provided on the shaft 111. A D-hole 131 into which the D-cut portion 113 of the shaft 111 may be inserted may be provided in the third link 130. A hole 81 may be provided at an end of the parallel holding member 80 adjacent to the first pulley 61. The third link 130 may be provided with a shaft 132 that may be rotatably inserted into the hole 81. The shaft 121 of the second link 120 may pass through the second hole 220 provided in the side frame 200 and protrude to the outside of the side frame 200. A D-cut portion 123 may be provided on the shaft 121. A D-hole 141 into which the D-cut portion 123 of the shaft 121 may be inserted may be provided in the fourth link 140. A hole 82 may be provided at the end of the parallel holding member 80 adjacent to the second pulley 62. The fourth link 140 may be provided with a shaft 142 that may be rotatably inserted into the hole 82. A distance between the D- hole 131 and the shaft 132 of the third link 130 may be the same as a distance between the hole 112 and the shaft 111 of the first link 110. A distance between the D-hole 141 and the shaft 142 of the fourth link 140 may be the same as a distance between the hole 122 and the shaft 121 of the second link 120.

[0034] In an example, the third link 130 and the fourth link 140 may be connected to the first link 110 and the second link 120, respectively, and rotate together. In addition, the third and fourth links 130 and 140 may have different rotational phases from the first and second links 110 and 120 with respect to the first and second axes AXI and AX2, respectively. Accordingly, the parallel holding member 80 may have a rotational phase different from that of the guide member 70. In this example, the rotational phases of the third and fourth links 130 and 140 lead 90° ahead of those of the first and second links 110 and 120, and the rotational phase of the parallel holding member 80 leads 90° ahead of the rotational phase of the guide member 70.

[0035] FIGS. 5A to 5F are perspective views showing movements of a guide member and a parallel holding member based on a circulation movement of an ejector according to an example.

[0036] Referring to FIG. 5A, the guide member 70 may be located in a discharge guide position. The parallel holding member 80 may be located in a rotational position that leads 90° ahead of the position of the guide member 70. As shown in FIG. 5B, while the ejector 50 moves along the discharge section 60a, the guide member 70 may be maintained in the discharge guide position, and the parallel holding member 80 also does not move.

[0037] When the ejector 50 enters the arc-shaped first connection section 60b, the ejector 50 pushes the guide member 70 in the discharge direction D1 and simultaneously presses the guide member 70 downward. The first link 110 and the second link 120 are rotated about the first axis AX1 and the second axis AX2 together with the third link 130 and the fourth link 140, respectively. The third link 130 and the fourth link 140 push the parallel holding member 80 in the return direction D2 and simultaneously press the parallel holding member 80 downward. As shown in FIG. 5C, when the ejector 50 reaches the midway position of the first connection section 60b, the first to fourth links 110, 120, 130, and 140 are each rotated 90°.

[0038] When the ejector 50 reaches the midway position of the first connection section 60b, the first link 110, the guide member 70, and the second link 120 are placed on a straight line. When the ejector 50 moves past the midway position of the first connection section 60b, the first link 110 is pushed in the return direction D2 and pressed downward at the same time, so that the first link 110 rotates. At this time, the same force may be applied to the second link 120, and the first link 110 and the second link 120 may rotate in the same direction. However, due to a dimensional tolerance of the first link 110 and the second link 120, a dimensional tolerance of a portion connecting the first link 110 and the second link 120 to the guide member 70, and the like, the second link 120 may be pushed in the return direction D2 and lifted upward at the same time. In addition, when the ejector 50 reaches the midway position of the first connection section 60b, the second link 120 may not reach a position in a straight line with the guide member 70. In this case, the second link 120 may be pushed in the return direction D2 and lifted upward at the same time. Then, as shown by dashed lines in FIG. 5C, the second link 120 may rotate in a direction opposite to the first link 110 and the guide member 70 may be inclined so that the ejector 50 may become in a non-movable state.

[0039] According to an example, the parallel holding member 80 having a rotational phase different from that of the guide member 70, for example, a rotational phase that leads 90° ahead of the rotational phase of the guide member 70 may be employed. When the first link 110, the guide member 70, and the second link 120 are placed on a straight line, the third link 130, the parallel holding member 80, and the fourth link 140 are not on a straight line. Therefore, when the ejector 50 moves past the midway position of the first connection section 60b, the first link 110 and the third link 130 rotate in the same direction, and the fourth link 140 also rotates in the same direction as the first link 110. Because the second link 120 and the fourth link 140 rotate together, the second link 120 also rotates in the same direction as the first link 110. Accordingly, the guide member 70 may be stably moved in parallel to the position shown in FIG. 5D without inclining. The ejector 50 enters the return section 60c. The guide member 70 reaches a return guide position. As shown in FIG. 5E, while the ejector 50 moves along the return section 60c, the guide member 70 and the parallel holding member 80 do not move.

[0040] When the ejector 50 enters the arc-shaped second connection section 60d, the ejector 50 pushes the guide member 70 in the return direction D2 and simultaneously lifts the guide member 70 upward. The first link 110 and the second link 120 are rotated about the first axis AX1 and the second axis AX2 together with the third link 130 and the fourth link 140, respectively. The third link 130 and the fourth link 140 push the parallel holding member 80 in the discharge direction D1 and simultaneously lift the parallel holding member 80 upward. When the ejector 50 reaches the midway position of the second connection section 60d as shown in FIG. 5F, the first link 110, the guide member 70, and the second link 120 are again placed on a straight line. The third link 130, the parallel holding member 80, and the fourth link 140 are not in a straight line. Therefore, when the ejector 50 moves past the midway position of the second connection section 60d, the first link 110 and the third link 130 rotate in the same direction, and the fourth link 140 also rotates in the same direction as the first link 110. Because the second link 120 and the fourth link 140 rotate together, the second link 120 also rotates in the same direction as the first link 110. Accordingly, the guide member 70 may be stably moved in parallel to the position shown in FIG. 5A without inclining. The ejector 50 enters the discharge section 60a. The guide member 70 reaches a discharge guide position.

[0041] As such, by employing the parallel holding member 80 having a rotational phase different from the rotational phase of the guide member 70, while the ejector 50 moves along a rotation section, the guide member 70 may be stably moved in parallel. In addition, the ejector 50 may be guided by the guide member 70 to stably circulate. The rotational phase of the parallel holding member 80 need not necessarily be faster than the rotational phase of the guide member 70. Further, the rotational phase difference between the parallel holding member 80 and the guide member 70 need not necessarily be 90°. When the rotational phase difference between the parallel holding member 80 and the guide member 70 is 90°, while the ejector 50 moves along the rotation section, the guide member 70 is not inclined and may move more stably in parallel.

[0042] As described above, the opening/closing member 55 may be biased to rotate to a position where the grip portion 52 is closed. In order to discharge a plurality of sheets of paper P on the paper alignment tray 30, it is necessary to open the grip portion 52 such that ends of the plurality of sheets of paper P may be accommodated in the grip portion 52. [0043] FIGS. 6A and 6B are partial side views of an example of a finisher.

[0044] Referring to FIGS. 6A and 6B, a finisher may include a first cam portion 230. When the ejector 50 moves along the second connection section 60d, the first cam portion 230 may interfere with the opening/closing member 55 to switch the opening/closing member 55 to an open position to open the grip portion 52. That is, the first cam portion 230 may allow the ejector 50 to enter the discharge section 60a with the grip portion 52 open. For example, the first cam portion 230 may be provided on the side frame 200.

[0045] As shown in FIG. 6A, as the ejector 50 moves along the second connection section 60d, the interference portion 552 of the opening/closing member 55 contacts the first cam portion 230, and the opening/closing member 55 rotates in a direction to open the grip portion 52. The opening/closing portion 551 is apart from the lower support portion 53. When the ejector 50 reaches a start end of the discharge section 60a, the opening/closing member 55 reaches an open position and the grip portion 52 is opened as shown in FIG. 6B. At the start end of the discharge section 60a, the opening/closing member 55 may interfere with the first cam portion 230 to be maintained in the open position. When the ejector 50 moves away from the start end of the discharge section 60a and moves in the discharge direction D1 , the contact between the first cam portion 230 and the interference portion 552 may end, and the opening/closing member 55 may rotate in a direction of closing the grip portion 52 by its own weight or by the elastic force of an elastic member. When ends of the plurality of sheets of paper P are accommodated in the grip portion 52, the opening/closing portion 551 of the opening/closing member 55 presses the plurality of sheets of paper P toward the lower support portion 53. Accordingly, while the ejector 50 moves along the discharge section 60a, the ends of the plurality of sheets of paper P may be stably maintained in a state accommodated in the grip portion 52.

[0046] When the ejector 50 moves along the first connection section 60b, the ends of the plurality of sheets of paper P fall out of the grip portion 52 and fall into the stacking tray 40. At this time, when the opening/closing member 55 is located in a closed position and the opening/closing portion 551 is pressing the ends of the plurality of sheets of paper P toward the lower support portion 53, it may be difficult for the ends of the plurality of sheets of paper P to be separated from the grip portion 52, and thus the ends of the plurality of sheets of paper P may be damaged. Accordingly, to avoid damage to the paper P, the grip portion 52 may be opened when the ejector 50 moves along the first connection section 60b.

[0047] FIGS. 7A to 7C are partial side views of an example of a paper damage prevention structure.

[0048] Referring to FIG. 2 and FIGS. 7A to 7C, a finisher may include a second cam portion 310 such that, when the ejector 50 moves along the first connection section 60b, the second cam portion 310 may interfere with the opening/closing member 55, for example, the interference portion 552, to switch the opening/closing member 55 to an open position to open the grip portion 52. The second cam portion 310 may be provided on, for example, a side cover 300 (of FIG. 2) that may cover a side portion of the circulation member 60. When the ejector 50 moves along the first connection section 60b, the second cam portion 310 may interfere with the interference portion 552 of the opening/closing member 55 to rotate the opening/closing member 55 to an open position.

[0049] While the ejector 50 moves along the discharge section 60a, the ends of the plurality of sheets of paper P may be accommodated in the grip portion 52 of the ejector 50. As an example, the ends of the plurality of sheets of paper P may be placed on the lower support portion 53, and the opening/closing portion 551 of the opening/closing member 55 may be biased in a direction of closing the grip portion 52 by its own weight or by the elastic force of an elastic member. When the ejector 50 moves along the discharge section 60a, the extension portion 54 pushes the ends of the plurality of sheets of paper P in the discharge direction D1. Accordingly, the plurality of sheets of paper P may move in the discharge direction D1 together with the ejector 50. When the ejector 50 enters the first connection section 60b, the ejector 50 descends. As shown in FIG. 7A, the ejector 50 moves in the discharge direction D1 until the ejector 50 reaches the midway position of the first connection section 60b, and the opening/closing member 55 is located in a closed position.

[0050] When the ejector 50 moves past the midway position of the first connection section 60b, the ejector 50 moves toward the return direction D2. Because the ends of the plurality of sheets of paper P are in contact with an end of a frame having a structure that drives the ejector 50, for example, an end 201 close to the stacking tray 40 of the side frame 200, the ends of the plurality of sheets of paper P do not move in the return direction D2. Accordingly, the ends of the plurality of sheets of paper P are separated from the grip portion 52 of the ejector 50 and fall to the stacking tray 40. At this time, when the opening/closing member 55 is located in a position to close the grip portion 52, as the plurality of sheets of paper P are pulled in the return direction D2, the ends of the plurality of sheets of paper P are pressed against the end 201 of the side frame 200 to cause damage such as stabbing, bending, etc. In an example, the smaller the number of sheets of paper P accommodated in the grip portion 52, the more likely the sheets of paper P are damaged.

[0051] According to this example, as shown in FIG. 7B, while the ejector 50 moves along the first connection section 60b, the opening/closing member 55 rotates to the open position while the interference portion 552 of the opening/closing member 55 interferes with the second cam portion 310. The force by which the opening/closing portion 551 presses the plurality of sheets of paper P is released. When the ejector 50 moves past the midway position of the first connection section 60b, the ejector 50 moves toward the return direction D2. The ends of the plurality of sheets of paper P are in contact with the end 201 of the side frame 200 close to the stacking tray 40. Because the grip portion 52 is in an open state, the plurality of sheets of paper P are not pulled in the return direction D2. Thus, damage to the ends of the plurality of sheets of paper P may be avoided or prevented. As shown in FIG. 7C, the ends of the plurality of sheets of paper P may be separated from the grip portion 52 and may fall to the stacking tray 40.

[0052] The ejector 50 circulates from a home position along the discharge section 60a, the first connection section 60b, the return section 60c, and the second connection section 60d to return to the home position.

[0053] FIG. 8 is a partial side view of an example of a finisher.

[0054] Referring to FIG. 8, a finisher may include a position detection sensor 400 that detects a position of the ejector 50. For example, the position detection sensor 400 may include a rotating arm 410 that rotates by contacting the ejector 50, and a sensor unit 420 that generates different electrical signals depending on whether the rotating arm 410 rotates. The sensor unit 420 may include an optical sensor having a light-emitting unit and a light-receiving unit. For example, in a state in which the ejector 50 is not in contact, the rotating arm 410 may be located in a position deviated from between the light-emitting unit and the light-receiving unit as shown by dashed lines in FIG. 8. The rotating arm 410 may rotate when it contacts the ejector 50 and may be located between the lightemitting unit and the light-receiving unit. When the rotating arm 410 is located away from between the light-emitting unit and the light-receiving unit, light may be detected in the light-receiving unit, and when the rotating arm 410 is located between the light-emitting unit and the light-receiving unit, light may not be detected in the light-receiving unit. For example, when light is detected, the sensor unit 420 may generate a signal HIGH, and when light is not detected, the sensor unit 420 may generate a signal LOW. Accordingly, it may be detected whether the ejector 50 is located in a position in contact with the rotating arm 410 according to a signal generated by the sensor unit 420. The sensor unit 420 may include a micro switch that is turned on/off according to whether the rotating arm 410 rotates.

[0055] For example, as shown in FIG. 8, the ejector 50 may be in contact with the rotating arm 410 near an end of the return section 60c, that is, at a position adjacent to the second connection section 60d to rotate the rotating arm 410. A controller (not shown) may detect the position of the ejector 50 and may drive a drive motor for circulating the circulation member 60 for a certain time or for a certain step to locate the ejector 50 at a home position.

[0056] The home position of the ejector 50 may be determined according to a structure of the finisher. For example, the finisher may have a structure in which the binder 20 is fixedly located in a position aligned with one corner of the paper P. In this case, the home position of the ejector 50 may be a position accommodating ends of the plurality of sheets of paper P on the paper alignment tray 30. In this case, the home position of the ejector 50 may be the start end of the discharge section 60a as shown in FIG. 6B. When the ejector 50 is located in the home position, the opening/closing member 55 may be located in an open position to open the grip portion 52 by the first cam portion 230. In this state, a plurality of sheets of paper P to be finished may be aligned on the paper alignment tray 30, and the ends of the plurality of sheets of paper P may be accommodated in the grip portion 52. When the end guide 33 (of FIG. 1 ) is not employed, the ends of the plurality of sheets of paper P may be aligned by the extension portion 54 of the ejector 50. When the end guide 33 is employed, the ejector 50 located in the home position may align the ends of the plurality of sheets of paper P together with the end guide 33. Even when the end guide 33 is employed, the ejector 50 located in the home position may be slightly apart from the end guide 33 in a direction opposite to the discharging direction D1 and may not contact the ends of the plurality of sheets of paper P aligned by the end guide 33.

[0057] The home position of the ejector 50 may be a position that does not interfere with the plurality of sheets of paper P arranged on the paper alignment tray 30 by the end guide 33 (of FIG. 1 ). For example, the home position of the ejector 50 may be an end portion of the return section 60c after passing through the position detection sensor 400, a middle portion of the second connection section 60d, and the like as shown in FIG. 6A. In this case, after completing the finishing operation on the plurality of sheets of paper P, the ejector 50 enters the discharge section 60a from the home position through the second connection section 60d. The opening/closing member 55 rotates to an open position to open the grip portion 52 by interfering with the first cam portion 230. Thus, the ends of the plurality of sheets of paper P may be accommodated in the grip portion 52.

[0058] The end guide 33 may function as an initial ejector that pushes the plurality of sheets of paper P in the discharge direction D1 .

[0059] FIG. 9 is a partial perspective view of an example of a finisher.

[0060] Referring to FIG. 9, the end guide 33 may be supported by a guide shaft 510 extending in the discharge direction D1. A belt 520 may be connected to the end guide 33, and move the end guide 33 to an alignment position (i.e., a position shown by solid lines in FIG. 9) to align the ends of a plurality of sheets of paper P and an initial discharge position (a position shown by dashed lines in FIG. 9) to initially discharge the plurality of sheets of paper P. An initial position of the ejector 50 may be a position that does not interfere with the plurality of sheets of paper P arranged on the paper alignment tray 30 by the end guide 33. For example, the home position of the ejector 50 may be the end portion of the return section 60c after passing through the position detection sensor 400, the middle portion of the second connection section 60d, and the like as shown in FIG. 6A. In this way, a structure in which the end guide 33 functions as an initial ejector may be applied to a finisher having a structure in which the binder 20 (of FIG. 1 ) moves in the width direction W along the end of paper P.

[0061] With the end guide 33 located in an alignment position and the ejector 50 located in a home position, a plurality of sheets of paper P may be aligned on the paper alignment tray 30. When the plurality of sheets of paper P are finished, the end guide 33 may slightly move the plurality of sheets of paper P in the discharge direction D1 while moving from the alignment position to the initial discharge position. The initial discharge position of the end guide 33 may be a position exceeding a start end of the discharge section 60a. The ejector 50 may enter the discharge section 60a through the second connection section 60d. At this time, as shown in FIGS. 6A and 6B, as the opening/closing member 55 interferes with the first cam portion 230, the opening/closing member 55 rotates to the open position, and the grip portion 52 is opened. The ends of the plurality of sheets of paper P discharged to the initial discharge position may be accommodated in the grip portion 52 of the ejector 50. The contact between the first cam portion 230 and the interference portion 552 ends, and the opening/closing member 55 rotates in a direction of closing the grip portion 52 by its own weight or by the elastic force of an elastic member. The opening/closing portion 551 of the opening/closing member 55 presses the plurality of sheets of paper P toward the lower support portion 53. Accordingly, while the ejector 50 moves along the discharge section 60a, the ends of the plurality of sheets of paper P may be stably maintained in a state accommodated in the grip portion 52. After the ends of the plurality of sheets of paper P are received in the grip portion 52 of the ejector 50, the end guide 33 returns to the alignment position.

[0062] It should be understood that examples described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each example should typically be considered as available for other similar features or aspects in other examples. While one or more examples have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims.