SHEET DISCHARGE DEVICE, DOCUMENT CONVEYING DEVICE, AND IMAGE FORMING APPARATUS EQUIPPED WITH SAME

Abstract

To provide a sheet discharge device capable of alternately arranging two stoppers at different regulation positions with a simple configuration and a document conveyance device and an image forming device equipped with the same.SOLUTION: A sheet discharge device includes a sheet discharge part, a sheet placement part, and a stopper mechanism. The stopper mechanism includes: a first stopper rotatably supported at a first retreat position and a first regulation position; a second stopper movable to a first position stored along a downstream edge of the sheet placement part and a second position away from the first position at the downstream side in a sheet ejection direction, and is rotatably supported at a second retreat position and a second regulation position; and a link mechanism connecting the first stopper and the second stopper. The first stopper is arranged at the first regulation position when the second stopper is arranged at the first position, and the first stopper is arranged at the first retreat position when the second stopper is arranged at the second position.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus such as a copier or printer, a sheet post-processing apparatus which performs a predetermined post-processing on sheets after image formation processing, a sheet discharge device which is mounted on a document transporting device which automatically transports sheet documents and discharges sheets, and a document transporting device and image forming apparatus equipped with the same. [Background technology]

[0002] Image forming devices such as copiers and laser printers are provided with a discharge tray for discharging paper on which a desired image has been formed by an electrophotographic process, or documents that have been transported by a document transport device to a document reading section and have had their document images read. Normally, a slope that slopes upward in the discharge direction is formed between the discharge outlet and the loading section of the discharge tray to ensure a certain stack amount. Paper or documents discharged from the discharge outlet slide down along the slope and are stacked with their rear ends aligned.

[0003] In recent years, image forming devices with high paper transport speeds have become mainstream as image formation processing speeds increase. When the transport speed of discharged paper increases, the discharged paper passes over the bent portion between the inclined surface and the paper stacking section and jumps out onto the paper stacking section. This can cause the paper to not slide down along the inclined surface, resulting in stacking problems.

[0004] Various methods have been proposed to improve the consistency of discharged paper. For example, Patent Document 1 discloses an image forming device that includes an original size detection sensor that can detect the size of the discharged paper, an original stopper that is freely attached to the front of the original output tray that receives the paper in the paper discharge direction in such a way that it can be freely inserted and removed, and a control means that controls the insertion and removal of the original stopper in response to the detected paper size. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2009-267589 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the configuration of Patent Document 1, the document stopper is a sliding type, and a dedicated motor and control means are required to move it to a predetermined regulating position. Also, since the document stopper is always standing up regardless of the placement position, the document stopper can get in the way when removing the discharged document. Furthermore, there is a risk that the document stopper standing up in an unnecessary position will cause the discharged document to fall or cause stacking problems.

[0007] In view of the above problems, the present invention has an object to provide a sheet ejection device capable of disposing two stoppers alternately at different regulating positions with a simple configuration, and a document transport device and an image forming apparatus including the same. [Means for solving the problem]

[0008] In order to achieve the above object, a first configuration of the present invention is a sheet discharge device including a sheet discharge section, a sheet stacking section, and a stopper mechanism. The sheet discharge section discharges sheets. The sheet stacking section is disposed downstream of the sheet discharge section in the sheet discharge direction, and has a sheet stacking surface on which sheets discharged from the sheet discharge section are stacked. The stopper mechanism is provided on the sheet stacking section, and abuts against and aligns the leading edge of the sheets discharged from the sheet discharge section. The stopper mechanism has a first stopper, a second stopper, and a link mechanism. The first stopper is supported rotatably at a first retracted position where it is laid down substantially horizontally along the sheet stacking surface, and a first restricting position where it stands up substantially perpendicular to the sheet stacking surface. The second stopper is disposed downstream of the first stopper in the sheet discharge direction, and is movable between a first position where the second stopper is stored along the downstream end of the sheet stacking section and a second position where the second stopper is moved from the first position downstream in the sheet discharge direction, and is supported rotatably at a second retracted position where the second stopper is retracted below the sheet stacking surface and a second restricting position where the second stopper protrudes above the sheet stacking surface. The link mechanism connects the first stopper and the second stopper. When the second stopper is disposed at the first position, the first stopper is disposed at the first restricting position, and when the second stopper is disposed at the second position, the first stopper is disposed at the first retracted position. Effect of the Invention

[0009] According to the first configuration of the present invention, the first stopper rotates from the first restricting position to the first retracted position as the second stopper moves from the first position to the second position, and the first stopper rotates from the first retracted position to the first restricting position as the second stopper moves from the second position to the first position. That is, the arrangements of both the first stopper and the second stopper can be changed with a single operation. Therefore, it is no longer necessary to change the arrangements of the first stopper and the second stopper individually, improving the operability of the stopper mechanism. [Brief description of the drawings]

[0010] [Figure 1]FIG. 1 is a schematic diagram showing an internal configuration of an image forming apparatus 100 equipped with a document transport device 3 having a sheet discharge device according to the present invention; [Diagram 2] FIG. 1 is a side cross-sectional view showing the internal structure of the document transport device 3. [Diagram 3] 3 is a partial side view of the document ejection tray 32 and its surroundings in the document transport device 3 in FIG. 2. [Figure 4] An enlarged view of the stopper mechanism 60 in FIG. [Diagram 5] FIG. 1 is a perspective view of a first stopper 61, showing a state in which the first stopper 61 is disposed at a retracted position. [Figure 6] FIG. 1 is a perspective view of a first stopper 61. FIG. 2 is a view showing a state in which the first stopper 61 is disposed at a regulating position. [Figure 7] FIG. 1 is a partial perspective view of the stopper mounting portion 90 and its surroundings on the document stacking surface 32a of the document discharge tray 32. [Figure 8] FIG. 1 is a side cross-sectional view of the first stopper 61, showing a state in which the first stopper 61 is placed in a restricted position. [Figure 9] FIG. 1 is a side cross-sectional view of the first stopper 61, showing a state in which the first stopper 61 is disposed at a retracted position. [Figure 10] FIG. 3 is a partial side view of the document discharge tray 32 and its surroundings of the document transport device 3 in FIG. 2, showing the arrangement of the stopper mechanism 60 when discharging a large-sized document; [Figure 11] FIG. 13 is a perspective view of a connecting portion between a second stopper 71 and a first link member 81, showing a state in which the second stopper 71 is disposed at a retracted position. [Figure 12] FIG. 13 is a perspective view of a connecting portion between a second stopper 71 and a first link member 81, illustrating a state in which the second stopper 71 is disposed in a restricted position. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Fig. 1 is a schematic diagram showing the internal configuration of an image forming apparatus 100 equipped with a document transport device 3 having a sheet discharge device of the present invention. As shown in Fig. 1, the image forming apparatus 100 is a so-called internal paper discharge type digital multifunction machine, and is roughly composed of a main housing 20 and an upper housing 21 disposed on the upper part thereof.

[0012] The main housing 20 is composed of a lower housing 20a and a connecting housing 20b located above the lower housing 20a along the right side of FIG. 1 and connected to the upper housing 21. Inside the lower housing 20a, there are provided a paper feed section 4 arranged at the bottom, a paper transport section 5 arranged on the side and above the paper feed section 4, an image forming section 6 arranged above the paper feed section 4, and a fixing section 7 arranged downstream in the paper transport direction of the image forming section 6 (right side of FIG. 1). The connecting housing 20b is provided with a paper discharge section for transporting the paper S after fixing and discharging it from the main housing 20. In addition, on the left side of the connecting housing 20b directly below the upper housing 21, there is formed an internal discharge space 22 that is widely open toward the left side and the front.

[0013] The image forming unit 6 forms a predetermined toner image on the paper S by an electrophotographic process, and includes a photosensitive drum 10 which is a rotatably supported image carrier, and a charging device 11, an exposure device 12, a developing device 13, a transfer device 14, a cleaning device 15, and a charger (not shown) which are arranged around the photosensitive drum 10 in the direction of rotation.

[0014] An image reading unit 8 is provided within the upper housing 21. The image reading unit 8 reads image information of an original D (an example of a sheet), and when the original is to be read one by one, the original transport device 3 is opened and the original is placed on a contact glass provided on the upper surface of the upper housing 21. When a stack of originals is to be automatically read, the original is placed on a paper feed tray of the closed original transport device 3, and the originals are automatically fed one by one from the stack onto the contact glass.

[0015] The basic operation of the image forming apparatus 100 configured as above will be described. First, the surface of the photoconductor drum 10, which rotates in the counterclockwise direction in Fig. 1, is uniformly charged by the charging device 11. Then, based on the image information read by the image reading unit 8, a beam of light from the exposure device 12 is irradiated onto the circumferential surface of the photoconductor drum 10, thereby forming an electrostatic latent image on the surface of the photoconductor drum 10. Toner is supplied as a developer from the developing device 13 to this electrostatic latent image, thereby forming a toner image.

[0016] In parallel with the formation of the toner image, paper S is sent from paper feed unit 4 to paper transport path 5 and is stopped temporarily at registration roller pair 9. Then, paper S stopped at registration roller pair 9 is transported toward photoconductor drum 10 on which the toner image has been formed at a predetermined timing, where the toner image on the surface of photoconductor drum 10 is transferred to paper S by transfer device 14 consisting of a transfer roller or the like. Then, paper S with the toner image transferred thereto is separated from photoconductor drum 10 and transported toward fixing unit 7, where it passes through fixing unit 7 and is heated and pressurized to fix the toner image.

[0017] After the transfer process of the toner image onto the paper S is completed, the photosensitive drum 10 has any residual toner remaining on its peripheral surface removed by a cleaning device 15, and then undergoes a discharge process to remove any residual charge by a discharge device (not shown). Thereafter, the peripheral surface is again charged by a charging device 11, and image formation is performed in the same manner.

[0018] The paper S that has passed through the fixing unit 7 is transported into the connecting housing 20b along the vertical transport path 16 that faces vertically upward. The upper part of the vertical transport path 16 branches into two transport paths, one above the other, toward the left inside the connecting housing 20b, and the paper S guided to the lower transport path by the switching guide 17 arranged at the branching point is discharged to the left from the first discharge roller pair 18 and is stocked on the paper discharge tray 24 formed on the bottom surface of the internal discharge space 22. On the other hand, the paper S guided to the upper transport path by the switching guide 17 is discharged to the left from the second discharge roller pair 19 and is discharged onto the auxiliary discharge tray 25.

[0019] 2 is a side cross-sectional view showing the internal structure of the document transport device 3. A contact glass consisting of an automatic reading glass 27a and a manual document placement glass 27b is disposed on the upper surface of the image reading unit 8. The document transport device 3 is supported by a hinge portion (not shown) on the rear side of the image reading unit 8 (the rear side of the paper in FIG. 2) so as to be vertically openable and closable with respect to the image reading unit 8.

[0020] Within the cover member 31 of the document transport device 3, a document transport path d is formed from the document feed tray 29 to the document discharge tray (sheet stacking section) 32, and along the document transport path d, there are provided document transport members consisting of a pickup roller 33, a paper feed belt 34 and a separation roller 35, a pair of registration rollers 36, a pair of transport rollers 37, etc., a pair of discharge rollers (sheet discharge section) 43 that discharges the document D, and a back-side reading module 50 that reads the image on the back side of the document D.

[0021] The document transport path d is curved so as to reverse between the pair of registration rollers 36 and the automatic reading glass 27a. In addition, the document transport path d is provided with a plurality of paper detection sensors (not shown) including a paper feed sensor and a discharge sensor at appropriate positions for detecting the presence or absence of a document D or the passage of the document D.

[0022] A front side reading module 51 is disposed inside the image reading unit 8. The front side reading module 51 reads an image of a document placed on the manual document glass 27b while moving in the sub-scanning direction (the left-right direction in FIG. 2). The front side reading module 51 also reads an image on the front side of the document D transported by the document transport device 3 while stopped directly under the automatic reading glass 27a.

[0023] Next, a sheet-through document transport operation using the document transport device 3 will be described. In the sheet-through method, multiple documents D are set in the document feed tray 29 with the image surface facing upward. Of the documents D set in the document feed tray 29, the uppermost multiple documents are usually sent by the pickup roller 33 to a nip between the feed belt 34 and the separation roller 35. Then, only the topmost document D is separated by the separation roller 35 and transported a predetermined distance toward the pair of registration rollers 36, after which the rotational drive of the pickup roller 33 and the feed belt 34 is stopped and the primary feeding is completed.

[0024] After a predetermined time has elapsed since the primary paper feed is completed, the pair of registration rollers 36 are rotated by the operation of a secondary paper feed drive motor (not shown). The document D is transported toward the automatic reading glass 27a by the pair of registration rollers 36. The document D transported to the automatic reading glass 27a comes into contact with a document pressing member 53 arranged opposite the automatic reading glass 27a, and is pressed against the automatic reading glass 27a from above. Then, an image on the front side of the document D (the side of the automatic reading glass 27a) is read by the front side reading module 51 through the automatic reading glass 27a.

[0025] The document D that has passed through the automatic reading glass 27 a is transported toward the transport roller pair 37 and the discharge roller pair 43 , and is finally discharged onto the document discharge tray 32 by the discharge roller pair 43 .

[0026] When reading a double-sided document, the image on the back side of the document is read by the back side reading module 50 provided upstream of the automatic reading glass 27a, and then the image on the front side of the document is read by the front side reading module 51.

[0027] An original pressing member 45 is supported to be swingable along the original discharge direction on the lower surface of the original feed tray 29. The original pressing member 45 presses down the original D discharged onto the original discharge tray 32 by the discharge roller pair 43 to prevent the original D from curling or floating up.

[0028] A stopper mechanism 60 is disposed in the document discharge tray 32 for aligning the leading edge of the document D discharged by the discharge roller pair 43 by abutting against it. The stopper mechanism 60 includes a first stopper 61, a second stopper 71, and a link mechanism 80. A detailed configuration of the stopper mechanism 60 will be described later.

[0029] Fig. 3 is a partial side view of the periphery of document discharge tray 32 of document transport device 3 in Fig. 2, and Fig. 4 is an enlarged view of stopper mechanism 60 in Fig. 3. Figs. 5 and 6 are perspective views of first stopper 61. Fig. 7 is a partial perspective view of the periphery of stopper mounting portion 90 on document stacking surface 32a of document discharge tray 32. The configuration of stopper mechanism 60 will be described with reference to Figs. 3 to 7. Stopper mechanism 60 has first stopper 61, second stopper 71, and link mechanism 80.

[0030] The first stopper 61 is supported so as to be swingable along the document discharge direction with a first support shaft 63 provided on the base portion 62 as a swing fulcrum. The first stopper 61 is swingable between a retracted position (first retracted position, see FIG. 5) where it is laid down along the document placement surface 32a (sheet stacking surface) and a restricting position (first restricting position, see FIG. 6) where it stands up from the document placement surface 32a of the document discharge tray 32. When the first stopper 61 is placed at the retracted position, it is stored below the document placement surface 32a. The base portion 62 is mounted in a concave stopper mounting portion 90 formed on the document placement surface 32a of the document discharge tray 32 shown in FIG. 7.

[0031] An engaged portion 64 is formed on a regulating surface 61a, which is the surface on the upstream side of the first stopper 61 in the document discharge direction (arrow A direction). A pair of engaged portions 64 are formed on both sides in the width direction (arrow BB' direction) of the base end side (near the first support shaft 63) of the regulating surface 61a. An engaging portion 83 of a first link member 81 engages with the engaged portion 64. A pair of first fulcrum bosses 65a protruding outward in the width direction are formed on both side ends in the width direction of the first stopper 61.

[0032] 8 and 9 are side cross-sectional views of the first stopper 61, showing the state in which the first stopper 61 is disposed in the restricting position and the retracted position, respectively. A coil spring 70 is disposed inside the first stopper 61. The coil spring 70 extends in a direction perpendicular to the first support shaft 63, and one end of the coil spring 70 (the side farther from the first support shaft 63, the upper end in FIG. 8) is fixed to the spring receiving portion 61b. The other end of the coil spring 70 (the side closer to the first support shaft 63, the lower end in FIG. 8) is a free end, to which a pressing member 66 is attached. The pressing member 66 is urged in a direction approaching the first support shaft 63 by the urging force of the coil spring 70. A pressed portion 62a to which the pressing member 66 is pressed is formed on the base portion 62. The coil spring 70, the pressing member 66, and the pressed portion 62a constitute a first urging mechanism that imparts a rotation load to the first stopper 61.

[0033] As shown in Fig. 8, the pressing surface 66a of the pressing member 66 is inclined when viewed from the axial direction of the first support shaft 63. More specifically, when the first stopper 61 is disposed in the regulating position, it is inclined upward in the movement direction to the retracted position (to the right in Fig. 8). The upper surface of the pressed portion 62a of the base portion 62 is inclined more with respect to the horizontal plane than the pressing surface 66a, and the pressed portion 62a and the pressing surface 66a are in point contact at a contact point P1. The contact point P1 is located downstream (to the right in Fig. 8) of a perpendicular line L1 passing through the first support shaft 63 in the movement direction of the first stopper 61 from the regulating position to the retracted position.

[0034] As a result, the reaction force F1 acting from the pressed portion 62a to the pressing surface 66a at the contact point P1 generates a counterclockwise moment about the first support shaft 63, and urges the first stopper 61 in a direction toward the restriction position (counterclockwise direction in FIG. 8). As a result, the first stopper 61 arranged in the restriction position does not easily move to the retracted position, and therefore it is possible to suppress a malfunction in which the first stopper 61 moves to the retracted position due to an impact or the like when removing a document discharged to the document discharge tray 32.

[0035] On the other hand, when the first stopper 61 is disposed in the retracted position, as shown in Fig. 9, the side surface of the pressed portion 62a of the base portion 62 is inclined more with respect to the horizontal plane than the pressing surface 66a, and the pressed portion 62a and the pressing surface 66a are in point contact at a contact point P2. The contact point P2 is located upstream of the horizontal line L2 passing through the first support shaft 63 in the moving direction of the first stopper 61 from the restricting position to the retracted position (upper side in Fig. 9).

[0036] As a result, the reaction force F2 acting from the pressed portion 62a to the pressing surface 66a at the contact point P2 generates a clockwise moment about the first support shaft 63, and urges the first stopper 61 in a direction toward the retracted position (clockwise direction in FIG. 9). As a result, the first stopper 61 disposed in the retracted position does not easily move to the regulated position, so that when the document transport device 3 is opened and closed relative to the image reading unit 8 to read a manually placed document, the first stopper 61 disposed in the retracted position can be prevented from moving to the regulated position.

[0037] 3 and 4, the second stopper 71 is supported by an end portion on the downstream side in the document discharge direction (the right side in FIG. 4) of the first link member 81. The second stopper 71 is movable between a first position (see FIG. 3) stored along the edge 32b (see FIG. 7) on the downstream side in the document discharge direction of the document discharge tray 32, and a second position (see FIG. 10) spaced away from the edge 32b of the document discharge tray 32 downstream in the document discharge direction (moved from the first position downstream in the document discharge direction).

[0038] The link mechanism 80 has a first link member 81 and a second link member 82. The first link member 81 is disposed between the base portion 62 and the stopper mounting portion 90, and is supported so as to be capable of reciprocating in parallel with the document discharge direction. A pair of second fulcrum bosses 65b that protrude outward in the width direction are formed on the downstream side of the first link member 81 in the document discharge direction. The second stopper 71 is supported so as to be rotatable in the vertical direction on the end portion of the first link member 81 on the downstream side in the document discharge direction (the right side in FIG. 3). An engagement portion 83 that is L-shaped in side view and engages with the engaged portion 64 of the first stopper 61 is formed on the end portion of the first link member 81 on the upstream side in the document discharge direction (the left side in FIG. 3).

[0039] A pair of second link members 82 are disposed on both sides in the width direction of the base portion 62. A first end portion (upper end portion) 82a on the upstream side of the second link member 82 in the document discharge direction is rotatably connected to a first fulcrum boss 65a formed on the first stopper 61. A second end portion (lower end portion) 82b on the downstream side of the second link member 82 is rotatably connected to a second fulcrum boss 65b formed on the end portion of the first link member 81 on the downstream side in the document discharge direction.

[0040] Next, a method for adjusting the positions of the first stopper 61 and the second stopper 63 of the stopper mechanism 60 according to the size of the document D discharged to the document discharge tray 32 will be described. When a small-sized document D (A4 size or smaller) is discharged, the rotating end of the first stopper 61 is grasped and rotated from the retracted position (see FIG. 5) to the regulating position (see FIG. 6). At the regulating position where the first stopper 61 stands up from the document placement surface 32a as shown in FIG. 3, the leading edge of the small-sized document D (e.g., A4 size) is abutted against the first stopper 61 to align it.

[0041] Furthermore, as the first stopper 61 rotates from the retracted position to the regulating position, the first end 82a of the second link member 82 is lifted upward, and the second end 82b moves upstream in the document discharge direction. As a result, the first link member 81 connected to the second end 82b of the second link member 82 also moves upstream in the document discharge direction. This causes the second stopper 71 to be stored in a stopper storage portion 91 (see FIG. 7) formed on the downstream edge 32b of the document discharge tray 32 in the document discharge direction.

[0042] Fig. 10 is a partial side view of the vicinity of the document discharge tray 32 of the document transport device 3 in Fig. 2, and shows the arrangement of the stopper mechanism 60 when discharging a large-sized document. When discharging a large-sized (A3 size) document D, the second stopper 71 stored in the stopper storage section 91 is pulled out from the state in Fig. 3 to the downstream side in the document discharge direction (the left side in Fig. 3).

[0043] As the second stopper 71 is pulled out, the first link member 81 to which the second stopper 71 is connected also moves downstream in the document discharge direction. As a result, the second end 82b of the second link member 82 connected to the first link member 81 also moves downstream in the document discharge direction, and the first end 82a of the second link member 82 is pulled down. As a result, as shown in Fig. 10, the first stopper 61 connected to the first end 82a of the second link member 82 rotates from the restricted position to the retracted position against the biasing force of the coil spring 70.

[0044] Furthermore, as the first link member 81 moves downstream in the document discharge direction, the engaging portion 83 of the first link member 81 engages with the engaged portion 64 of the first stopper 61. This causes the first stopper 61 to be held in the retracted position.

[0045] Furthermore, by grasping the rotating end of the second stopper 71 rotatably connected to the first link member 81 and rotating it upward, the second stopper 71 is held in a state in which it stands up substantially perpendicular to the first link member 81. The second stopper 71 abuts against and aligns the leading edge of a large-size (A3 size) document D at a regulating position protruding above the document placement surface 32a of the document discharge tray 32 as shown in FIG.

[0046] 11 and 12 are perspective views of a connecting portion between the second stopper 71 and the first link member 81. Fig. 11 is a view showing a state in which the second stopper 71 is arranged in a retracted position (second retracted position) retracted below the document placement surface 32a. Fig. 12 is a view showing a state in which the second stopper 71 is arranged in a restricted position (second restricted position) protruding above the document placement surface 32a.

[0047] The second stopper 71 has second support shafts 73 protruding from both widthwise edges thereof, which are rotatably supported by the first link member 81. A tension spring 75 is connected between the first link member 81 and the second stopper 71. One end of the tension spring 75 is fixed to a spring fixing portion (not shown) of the first link member 81, and the other end engages with a spring mounting portion 77 of the second stopper 71. The tension spring 75 and the spring mounting portion 77 constitute a second biasing mechanism that applies a rotational load to the second stopper 71.

[0048] 11, when the second stopper 71 is disposed in the retracted position, the spring attachment portion 77 is located below the support shaft 73 (downstream in the moving direction of the second stopper 71 from the restricting position to the retracted position). As a result, the biasing force of the tension spring 75 generates a moment in the clockwise direction in FIG. 10 about the second support shaft 73, and biases the second stopper 71 in the direction toward the retracted position. As a result, the second stopper 71 disposed in the retracted position does not easily move to the restricting position, and therefore, when the document transport device 3 is opened and closed relative to the image reading unit 8 to read a manually placed document, a problem that the first stopper 61 disposed in the retracted position moves to the restricting position can be suppressed.

[0049] When a predetermined force is applied to the second stopper 71 to rotate it toward the restricted position from the state shown in Fig. 11, the spring attachment portion 77 moves away from the spring fixing portion, thereby pulling the tension spring 75, and the second stopper 61 is positioned at the restricted position as shown in Fig. 12. When the second stopper 61 is positioned at the restricted position, the spring attachment portion 77 is positioned above the support shaft 73 (downstream in the moving direction of the second stopper 71 from the retracted position to the restricted position).

[0050] 10 about the second support shaft 73, the biasing force of the tension spring 75 biases the second stopper 71 in the direction toward the restricted position. As a result, the second stopper 71 disposed in the restricted position does not easily move to the restricted position, and it is possible to suppress the second stopper 71 from moving to the retracted position due to an impact or the like when removing a document discharged to the document discharge tray 32. When a predetermined force is applied to the second stopper 71 from the state in FIG. 12 to rotate it toward the retracted position, it returns to the state in FIG. 11 again, and the second stopper 71 is held in the retracted position by the restoring force of the tension spring 75.

[0051] When a small-sized document D is discharged from the state shown in FIG. 10, the second stopper 71 is rotated to the retracted position, and then moved to the upstream side in the document discharge direction (the left side in FIG. 10) to be stored in the stopper storage section 91. In addition, as the second stopper 71 moves, the engaging section 83 also moves to the upstream side in the document discharge direction, and thus the engagement with the engaged section 64 of the first stopper 61 is released. Furthermore, the second end 82b of the second link member 82 also moves to the upstream side in the document discharge direction, and thus the first end 82a of the second link member 82 is lifted. As a result, the first stopper 61 connected to the first end 82a of the second link member 82 rotates from the retracted position to the restricted position against the biasing force of the coil spring 70.

[0052] According to the configuration of this embodiment, the first stopper 61 rotates from the restricting position to the retracted position as the second stopper 71 moves from the first position to the second position, and the first stopper 61 rotates from the retracted position to the restricting position as the second stopper 71 moves from the second position to the first position. That is, the positions of both the first stopper 61 and the second stopper 71 can be changed with one operation. Therefore, it is no longer necessary to change the positions of the first stopper 61 and the second stopper 71 individually, and the operability of the stopper mechanism 60 is improved.

[0053] Furthermore, when the second stopper 71 is moved to the second position, the engaging portion 83 of the first link member engages with the engaged portion 64 of the first stopper 61 to hold the first stopper 61 in the retracted position, so that the first stopper 61 disposed in the retracted position does not easily move to the restricted position. Therefore, when the document transport device 3 is opened and closed relative to the image reading unit 8 to read a manually placed document, it is possible to reliably prevent the first stopper 61 disposed in the retracted position from moving to the restricted position.

[0054] Furthermore, when the first stopper 61 and the second stopper 71 are disposed in the restricted position, they are urged in the direction toward the restricted position by the coil spring 70 and the tension spring 75. Furthermore, when the first stopper 61 and the second stopper 71 are disposed in the retracted position, they are urged in the direction toward the retracted position by the coil spring 70 and the tension spring 75. Therefore, there is no risk of the first stopper 61 and the second stopper 71 moving inadvertently due to vibration or impact, and usability of the first stopper 61 can be improved.

[0055] The present invention is not limited to the above embodiment, and various modifications are possible within the scope of the present invention. For example, in the above embodiment, the sheet discharge device having the discharge roller pair 43 for discharging the document and the document discharge tray 32 for stacking the discharged document, and the document transport device 3 including the pickup roller 33, the paper feed belt 34 and the separation roller 35, the registration roller pair 36, the transport roller pair 37, and other document transport members are described as examples, but the present invention can be applied in exactly the same way to a sheet discharge device including the first discharge roller pair 18 mounted on the image forming device 100 and the paper discharge tray 24 for stacking the paper discharged from the first discharge roller pair 18, and a sheet discharge device mounted on a paper post-processing device that performs post-processing such as punch hole formation, stapling, and sorting on the paper on which an image has been formed. [Industrial Applicability]

[0056] The present invention can be used in a sheet ejection device that includes a sheet stacking section for stacking ejected sheets and a stopper that aligns the leading edge of the sheet ejected to the sheet stacking section by abutting it against the sheet. By using the present invention, it is possible to provide a sheet ejection device that has a simple configuration, in which stoppers are arranged at positions corresponding to sheets of multiple sizes and that can also regulate unnecessary movement of the stopper. [Explanation of symbols]

[0057] 3 Document Feeder 6 Image forming section 8 Image reading unit 32 Document ejection tray (sheet stacking area) 32a Document loading surface (sheet loading surface) 43 Discharge roller pair (sheet discharge section) 60 Stopper mechanism 61 First Stopper 62 Base 62a: Pressed portion (first biasing mechanism) 63 1st spindle 64 Engaged part 66 Pressing member (first biasing mechanism) 70 Coil spring (first biasing mechanism) 71 Second Stopper 73 2nd support shaft 75 Tension spring (secondary biasing mechanism) 77 Spring mounting part (second biasing mechanism) 80 Link mechanism 81 First link member 82 Second link member 82a First end 82b Second end 83 Engagement part 90 Stopper attachment part 91 Stopper storage area 100 Image forming device

Claims

1. a sheet discharge unit that discharges a sheet; a sheet stacking section disposed downstream of the sheet discharge section in a sheet discharge direction and having a sheet stacking surface on which the sheets discharged from the sheet discharge section are stacked; a stopper mechanism provided in the sheet stacking section and configured to abut against and align a leading edge of the sheet discharged from the sheet discharge section; In a sheet ejection device comprising: The stopper mechanism includes: a first stopper supported rotatably at a first retracted position where the first stopper is laid down substantially horizontally along the sheet stacking surface and at a first regulating position where the first stopper is erected substantially perpendicularly to the sheet stacking surface; a second stopper that is disposed downstream of the first stopper in the sheet discharge direction, that is movable between a first position stored along the downstream end of the sheet stacking section and a second position moved from the first position downstream in the sheet discharge direction, and that is rotatably supported at a second retracted position retracted below the sheet stacking surface and a second regulating position protruding above the sheet stacking surface; a link mechanism connecting the first stopper and the second stopper; having A sheet discharging device characterized in that when the second stopper is positioned at the first position, the first stopper is positioned at the regulating position, and when the second stopper is positioned at the second position, the first stopper is positioned at the retracted position.

2. The link mechanism includes: a first link member supported on the sheet stacking portion so as to be reciprocally movable in parallel with the sheet discharge direction, the first link member having a downstream end in the sheet discharge direction to which the second stopper is connected; a second link member having a first end portion on an upstream side with respect to the sheet discharge direction rotatably connected to the first stopper and a second end portion on a downstream side with respect to the sheet discharge direction rotatably connected to the first link member; having By moving the second stopper from the first position to the second position, the first link member moves downstream in the sheet discharge direction, and the first end of the second link member pulls down the first stopper in accordance with the movement of the first link member, and moves from the first restricting position to the first retracted position; The sheet ejection device according to claim 1, characterized in that by moving the second stopper from the second position to the first position, the first link member moves upstream in the sheet ejection direction, and as the first link member moves, the first end of the second link member lifts the first stopper and moves from the first retracted position to the first regulating position.

3. The sheet ejection device according to claim 2, characterized in that the first link member has an engagement portion that engages with an engaged portion of the first stopper to hold the first stopper in the first retracted position when the second stopper is moved to the second position.

4. a first biasing mechanism that applies a rotation load to the first stopper, A sheet ejection device as described in any one of claims 1 to 3, characterized in that the first biasing mechanism biases the first stopper positioned at the first retracted position in a direction from the first regulating position toward the first retracted position, and biases the first stopper positioned at the first regulating position in a direction from the first retracted position toward the first regulating position.

5. 5. The sheet ejection device according to claim 1, wherein the first stopper is stored below the sheet stacking surface when the first stopper is disposed at the first retracted position.

6. a second biasing mechanism that applies a rotation load to the second stopper, A sheet ejection device as described in any one of claims 1 to 5, characterized in that the second biasing mechanism biases the second stopper positioned at the second retracted position in a direction from the second regulating position toward the second retracted position, and biases the second stopper positioned at the second regulating position in a direction from the second retracted position toward the second regulating position.

7. A sheet ejection device according to any one of claims 1 to 6, a document transport member that transports a sheet-shaped document to the sheet discharge device; A document transport device comprising:

8. an image forming unit that forms an image on a sheet-shaped recording medium; 7. The sheet ejection device according to claim 1, which ejects the recording medium on which an image has been formed by the image forming unit; An image forming apparatus comprising:

Images