JP3842382B2 - Post-processing device for image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a post-processing apparatus that takes in an image-recorded sheet discharged from an image forming apparatus such as a printer, a copier, a facsimile machine, or a printing machine, and reverses and discharges at least the sheet inside.
[0002]
[Prior art]
  2. Description of the Related Art Conventionally, there is a post-processing device that takes in an image-recorded sheet discharged from an image forming apparatus such as a printer or a copying machine, and reverses and discharges the sheet inside.
[0003]
[Problems to be solved by the invention]
  Naturally, post-processing devices with a sheet reversing function can be reversed without damaging the sheet. On the premise of such basic performance, the post-processing device is compact and takes up little installation space, and at low cost. It is desirable to be.
[0004]
  The present invention has been made in view of the above, and an object of the present invention is to provide a compact post-processing apparatus that has a sheet reversing function, is compact, does not take an installation place, and is low in cost.
[0005]
[Means for Solving the Problems]
  In order to achieve the above-described object, the present invention is located in a passage path that accepts a sheet discharged from the image forming apparatus by the introduction section, passes the sheet as it is, and discharges it from the discharge section, and an area directly below the passage path. An inclined reversing tray that is inclined so that the end on the discharge side becomes higher and a sheet stopper is provided on the lower end, and a sheet conveying means that sends the sheet on the inclined reversing tray to the discharge unit, There is a branch path that sends a sheet from the middle of the passage path to the inclined inversion tray, and a switching gate that is at the intersection of the passage path and the branch path and switches the flow path alternatively between the passage path side and the branch path side. When the sheet fed from the branch path contacts the inclined reversing tray, the angle α formed between the sheet and the surface on the high side of the tilted reversing tray is set to be an acute angle. Is the leading edge of the sheet is guided by the inclination of the inclined inverting tray flows at low from high place, so as to stop against the sheet stopNone. Further, a punching device is provided in front of the switching gate so that the sheet can be punched between the introduction part of the passage path and the switching gate.A post-processing apparatus for an image forming apparatus is provided.
[0006]
  When the sheet discharged from the image forming apparatus is received by the introduction section when the switching gate is open on the passage path side, the post-processing apparatus passes the sheet as it is and discharges it from the discharge section. On the other hand, when the switching gate is open on the branch path side, when the sheet discharged from the image forming apparatus enters the introduction portion, the sheet flows from the passage path to the inclined inversion tray through the branch path. When the sheet sent from the branch path contacts the inclined reversing tray, the angle α between the sheet and the surface on the high side of the tilted reversing tray is set to be an acute angle. The entering sheet naturally flows from the high place to the low place along the inclination of the inclined inversion tray, and stops when it hits the sheet stopper. The sheet is reversed at this stage. Then, the sheet conveying unit is operated to push back and discharge the sheet on the inclined inversion tray.
  In addition, a punching device is provided in front of the switching gate so that the sheet can be punched between the introduction part of the passage path and the switching gate. Any of the sheets can be perforated.
[0007]
  Preferably, as described in claim 2, branching feeding means for forcibly feeding the sheet toward the inclined inversion tray is formed in the branching path, and the branch feeding means separates the trailing edge of the sheet. It is preferable that the front end of the sheet reaches the sheet stopper of the inclined inversion tray before. By doing so, since the leading edge of the sheet reaches the sheet stopper at high speed and reliably, the edges of the sheet can be neatly aligned. By the way, in the natural fall method, first, it takes time until the sheet reaches the sheet stop and stabilizes, and there is a possibility that the sheet stops in the middle and the edges of the sheet become uneven.
[0008]
  Preferably, an impeller is incorporated in a part of the branch feeding means according to claim 2, and the trailing edge of the sheet is kicked out toward the inclined inversion tray by the impeller. By doing so, high-speed processing can be performed without bringing the trailing edge of the preceding sheet into contact with the leading edge of the succeeding sheet.
[0009]
  Claims4As described above, a notch portion may be formed in a part of the inclined inversion tray, and a stapler may be provided corresponding to the notch portion. By doing so, it is possible to bind the sheets that are reversed on the inclined reversing tray and stacked in the page order with the stapler.
[0010]
  Also preferably, the claims5And a tray guide is formed above the inclined inversion tray, and4A bulging portion is formed on one or both of the inclined inversion tray and the tray guide with respect to a portion corresponding to the notch portion described in the above, and the gap between the two is narrowed by narrowing the point around the notch portion. Is good. By doing so, the thickness of the sheet bundle is reduced by being reduced at the bulging portion, so that binding with the stapler is facilitated. In addition, since the bulging portion is partial, the resistance acting on the sheet is reduced, so that the sheet can be smoothly inserted into and discharged from the bulging portion.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
  Embodiments of the present invention will be described below with reference to the drawings. 1 is a longitudinal cross-sectional view of the post-processing apparatus, FIG. 2 is a perspective view of the post-processing apparatus partially seen through, FIG. 3 is an enlarged cross-sectional view showing the main part of the passage path and the branch path, and FIG. 4 is the branch path. FIG. 5 is a perspective view of the sheet conveying means, FIG. 6 is a sectional view taken along the line XX of FIG. 4, FIG. 7 is a perspective view of the inclined inversion tray, and FIG. 9 is an exploded perspective view showing the guide and the feed roller, and FIG. 9 is an enlarged cross-sectional view of the main part of the introduction part showing another form of the play space.
[0012]
  The post-processing apparatus 1 has an appearance in which an upper tray 3a and a lower tray 3b are arranged side by side on a box-shaped body 2 as shown in FIG. 2, and is discharged from the image forming apparatus M as shown by a one-dot chain line in FIG. It is attached to the side of the side. A wheel 4 for movement is provided on the bottom surface of the post-processing apparatus 1 and is movable within a range that does not come off the rail member 5 of the image forming apparatus M. The post-processing apparatus 1 is moved by holding the handle 6 provided at the center of the front surface of the lower tray 3b when collecting punch scraps or removing the jammed sheet S described later. If the post-processing apparatus 1 is moved by holding the handle 6 provided on the tray in this way, even if the sheet S is placed on the tray and the center of gravity is biased toward the tray, the handle 6 You can balance with the applied force. Therefore, the moving operation of the post-processing apparatus 1 can be performed smoothly.
[0013]
  Further, as shown in FIG. 1, the post-processing apparatus 1 includes a safety switch 8 that is turned on by being pushed by the pin 7 of the image forming apparatus M, that is, a safety switch 8 that detects the connection between the post-processing apparatus 1 and the image forming apparatus M. When the post-processing apparatus 1 is separated from the image forming apparatus M, the safety switch 8 is activated and the power of the post-processing apparatus 1 is automatically turned off. Since the safety switch 8 is provided, there is no risk of electric shock when the post-processing apparatus 1 is separated from the image forming apparatus M and compared with a structure in which the power is turned on and off manually. There is no simple mistake to forget to turn on the power when connected to M.
[0014]
  The head of the post-processing apparatus 1 is provided with a lid member 1a that can be opened as shown by a two-dot chain line in FIG. Further, the post-processing apparatus 1 is provided with two discharge portions 9a and 9b corresponding to the upper tray 3a and the lower tray 3b, respectively.
[0015]
  Next, the internal structure of the post-processing apparatus 1 will be described. On the side surface of the post-processing apparatus 1 facing the image forming apparatus M, an introduction portion 10 for the sheet S is formed at substantially the same height as the discharge portion 9a of the upper tray 3a. An introduction guide 12 that is swingable around (see FIG. 1) is provided. This introduction guide 12 is adapted to be fitted into the discharge port M1 of the image forming apparatus M, and its own cam surface 12a is placed on the stepped portion M2 of the discharge port M1 to be stabilized, and the post-processing apparatus 1 is image-formed. When disconnected from the device M, it loses its support and lowers its tip due to its own balance.
[0016]
[Passage route]
  A passage path 13 extends from the introduction portion 10 to the upper discharge portion 9a. The passage 13 includes a pair of upper and lower sheet guides 14 following the introduction guide 12, first feed rollers 15 a and 15 b facing the middle of the sheet guide 14, and a second feed located near the discharge unit 9. It is roughly composed of rollers 16a and 16b.
[0017]
  Of the first feed rollers 15a and 15b, the upper roller 15a is a so-called idler roller that can freely rotate, and the lower roller 15b is a driving roller that rotates counterclockwise in FIG. . Then, the sheet S is conveyed at the same speed as the sheet feeding speed of the image forming apparatus M with the sheet S sandwiched between the both feeding rollers 15a and 15b. Although the rotary shaft 17 of the lower feed roller 15b has a known clutch mechanism (not shown), the power from a power source (not shown) is interrupted by the action of the clutch mechanism, and the feed roller 15b is rotated and stopped. Switch between bidirectional states. The clutch mechanism has a so-called one-way structure that transmits power only in a certain direction. When a reverse phenomenon occurs in which the conveying speed of the sheet S overtakes the feeding speed of the feeding roller 15b, the feeding roller 15b moves the sheet S. Switch to follow and follow. As such a one-way clutch mechanism, for example, a ball silent ratchet adopted between a bicycle sprocket and a shaft can be applied.
[0018]
  Of the second feed rollers 16a and 16b, the upper roller 16a is a rotatable idle roller, and the lower roller 16b is a driving roller that rotates counterclockwise in FIG. . Then, the sheet S is conveyed at the same speed as the sheet feeding speed of the image forming apparatus M with the sheet S sandwiched between both the feeding rollers 16a and 16b. The upper feed roller 16 a is attached to a movable sheet guide 20 that can swing around a hinge 19 via an elastic arm 21. Accordingly, the upper feed roller 16a can be integrally opened with the sheet guide 20 when a sheet jam occurs in the passage path 13. The sheet guide 20 has a knob 20a protruding at the tip, and the tip of the knob 20a protrudes from the bottom of the lid member 1a. Therefore, if the end of the sheet guide 20 is lifted with the knob 20a, the lid member 1a can be opened together.
[0019]
[Inclined tray]
  An inclined inversion tray 23 is provided in a region directly below the passage path 13 via a branch path 22 described later. The inclined inversion tray 23 is inclined so that the end portion on the discharge portion 9b side becomes higher, and a sheet stopper 24 is provided at the lower end portion, that is, the end portion on the introduction portion 10 side. The inclination of the inclined reversing tray 23 is determined by an angle α (see FIG. 1) between the sheet S and the surface on the higher side of the inclined reversing tray 23 when the sheet S sent from a branch path 22 described later contacts the inclined reversing tray 23. (Hereinafter simply referred to as the approach angle α) is set to an acute angle.
[0020]
  The inclined inversion tray 23 receives the sheet S on its upper surface and slides it downstream, and a plurality of ribs 25 project from the upper surface for the purpose of reducing friction with the sheet S. Further, a tray guide 26 is provided above the inclined inversion tray 23, and a plurality of sheets S can be stored between the tray guide 26. The tray guide 26 is also provided with a plurality of ribs 27 on its surface for the purpose of reducing friction with the sheet S.
[0021]
  The inclined inversion tray 23 is provided with an alignment unit 29 that aligns one side of the stored sheet S against a fixed reference wall 28 on one side. The alignment unit 29 includes an L-shaped sliding member 29a provided at the opposite end of the fixed reference wall 28, and a swing arm 29b that moves the sliding member 29a. The sliding member 29 a can be linearly slid in a direction perpendicular to the feeding direction of the sheet S by fitting in the slit 23 a formed in the inclined inversion tray 23. On the other hand, the swing arm 29b reciprocally swings within a certain range by a drive source such as a motor or a solenoid (not shown), and the sliding member 29a is interlocked with the swing arm 29b as shown in FIG. A reciprocating linear motion is performed between the solid line and the two-dot chain line. A leaf spring-like cushion member 29c is provided at the contact point between the sliding member 29a and the swing arm 29b as shown by the broken line in FIG. 6, and when a large resistance is applied to the sliding member 29a, The cushion member 29c is bent to prevent excessive movement of the sliding member 29a.
[0022]
  In addition, a sheet conveying means 30 as shown in FIG. The sheet conveying means 30 includes an endless timing belt 31 that circulates along the bottom surface of the inclined reversing tray 23, and a T-shaped feeding claw 32 that protrudes from the timing belt 31. The feed claw 32 is protruded from the established travel line 33, and only the feed claw 32 is projected from the upper surface of the inclined inversion tray 23 by the rotation of the timing belt 31. Two sets of the timing belt 31 and the running line 33 are provided at an interval, and the sheet S on the upper surface of the inclined inversion tray 23 is evenly pushed by the two feeding claws 32.
[0023]
  Two feeding claws 32 are provided for each timing belt 31 so that they are alternately projected on the upper surface of the inclined inversion tray 23, thereby eliminating unnecessary movement of the timing belt 31 and improving efficiency. It is trying to raise. Further, the feeding claw 32 performs an operation of abutting and pushing the end of the sheet S. Therefore, in order to fulfill its function, it is sufficient that the key portion is opposed to the sheet S in an inverted L shape. The reason why the feeding claw 32 is formed in a T shape is to improve the workability by being attached in either direction and to prevent generation of defective products due to work mistakes. Further, the timing belt 31 of the sheet conveying unit 30 is merely an example, and other than that, a chain or a string may be used, or the feeding claw 32 may be driven by a linear motor.
[0024]
  As shown in FIGS. 6 and 7, the inclined reversing tray 23 is formed with a notch 34 at one corner of the sheet stopper 24, and an electric stapler 35 attached to the body 2 side is provided with the notch 34. It faces. The stapler 35 is set so that the binding point is optimized by slightly moving the stationary sheet S against the sheet stopper 24. Therefore, when the stapler 35 is operated, the bundle of sheets S is moved by the sheet conveying unit 30 to a point where the stapler 35 is bound, and the sheets S are temporarily stopped there. By doing so, the stapler 35 can be disposed closer to the center of the body 2, which is effective for making the post-processing apparatus 1 compact.
[0025]
  Further, as shown in FIG. 7, the inclined reversing tray 23 is formed with a bulging portion 23b around the notch 34, and the tray guide 26 is also inclined and reversed as shown in FIG. A bulging portion 26a is formed at a position opposite to the bulging portion 23b of the tray 23, and the gap between the inclined inversion tray 23 and the tray guide 26 is narrowed by the two bulging portions 23b and 26a. It should be noted that the bulging portions 23b and 26a may be provided only on either one of the inclined reversing tray 23 and the tray guide 26 without being provided on both.
[0026]
  6 and 7, reference numeral 36 denotes a sheet sensor provided on the fixed reference wall 28, which detects the presence or absence of the sheet S based on the signal, thereby preventing the stapler 35 from being idle. Reference numerals 37 and 38 denote two sheet sensors provided on the sheet stopper 24, and the size of the sheet S (represented by the two-dot chain line in FIG. 6 in the embodiment) by combining the signals of both the sheet sensors 37 and 38. A4 size (see symbol S-A) and letter size (see symbol S-L) indicated by a one-dot chain line in FIG. Reference numeral 39 denotes a home position sensor for the feed claw 32, which detects a protruding piece 32a projecting from the feed claw 32, and controls the timing belt 31 with the signal to stop the feed claw 32 at the home position. As described above, the sensors 36 to 38 are optical ones in the embodiment, but a micro switch or a reed switch may be used. Furthermore, in FIG. 5, reference numeral 40 is a support base of the sheet conveying means 30, reference numeral 41 is a pulley for the timing belt 31 attached to the shaft 42, reference numeral 43 is a tension member of the timing belt 31, and reference numeral 44 is the timing belt 31. Drive motor.
[0027]
[Branch route]
  As shown in FIGS. 1, 3, and 4, a branch path 22 is provided between the passage path 13 and the inclined inversion tray 23. The branch path 22 includes an upper half portion of the tray guide 26 and a branch feeding unit straddling the tray guide 26 and the body 2. The branch feed means are third feed rollers 45a and 45b attached to the tray guide 26 and the body 2, respectively. Of the third feed rollers 45a and 45b, the roller 45a of the tray guide 26 is a free idle roller, and the other roller 45b is a drive roller that rotates clockwise in FIG. . Then, the sheet S is sandwiched between both the feed rollers 45a and 45b, and is faster than the sheet feed speed of the first feed rollers 15a and 15b (= the sheet feed speed of the image forming apparatus M) (in the embodiment, about twice). The sheet S is conveyed in the above-described manner. The feed roller 45a on the tray guide 26 side is attached via an elastic arm similar to the second feed roller 16a (not shown), and is in contact with the feed roller 45b with a predetermined pressure.
[0028]
  The attachment positions of the third feed rollers 45a and 45b on the branch path 22 are set so that the distance from the contact point of the feed rollers 45a and 45b to the sheet stopper 24 of the inclined reverse tray 23 is shorter than the sheet length. Accordingly, even if the leading edge of the sheet S reaches the sheet stopper 24, the trailing edge of the sheet S still remains on the feeding rollers 45a and 45b, so that the feeding rollers 45a and 45b push the trailing edge while the sheet S is bent thereafter. Further, since the blade is pushed by the blades of the impeller 47 described later, the leading edge of the sheet S surely hits the sheet stopper 24.
[0029]
  As shown in FIGS. 4 and 8, a plurality of impellers 47 are fixedly attached to the rotation shaft 46 of the third feed roller 45b. The blades of the impeller 47 are elastic, and as shown by a broken line in FIG. The impeller 47 is always rotated integrally with the rotary shaft 46, and at the moment when the trailing edge of the sheet S is separated from the third feeding rollers 45a and 45b, the trailing edge of the sheet S is turned to the upper end of the inclined reversing tray 23. Kick out.
[0030]
[Switching gate]
  A swing type switching gate 48 is provided in the middle of the passage path 13 and between the first feed rollers 15a and 15b and the second feed rollers 16a and 16b. This switching gate 48 is connected to a solenoid (not shown) via a drive shaft 49, and when the solenoid is excited, the end is lowered as shown by the solid line in FIG. In a state where the solenoid is demagnetized, the flow path of the branch path 22 is opened by raising the end as shown by a two-dot chain line in FIG. The switching of the flow path by the switching gate 48 is alternative, and the branch path 22 is closed with the passage path 13 opened, and conversely, the passage path 13 is closed with the branch path 22 opened.
[0031]
[Punching device]
  A punching device 50 is provided in the passage path 13 before the switching gate 48. The punching device 50 is a known device that moves the drilling blade 54 integral with the cam follower 53 up and down by an eccentric cam 52 integral with the rotary shaft 51. In connection with the punching device 50, the first feed rollers 15a and 15b serve as gate means for stopping the leading edge of the sheet S. That is, while the punching device 50 is operating, the rotation of the first feed rollers 15a and 15b is stopped to stop the feeding of the sheet S. Instead of using the first feed rollers 15a and 15b as the gate means, for example, a shutter-like component for opening and closing the passage path 13 may be provided in the middle of the passage path 13. However, in this case, a gate means is separately provided, which causes a cost increase. In other words, the punching device 50 is installed in association with the feeding rollers 15a and 15b, the sheet S is stopped by stopping the feeding rollers 15a and 15b, and the punching device 50 is operated in this state to punch the sheet S. In this case, it is not necessary to separately provide a sheet stopper for the punching device 50, so that the cost can be reduced.
[0032]
  Further, in association with the punching device 50, a play space 55 that allows the sheet S to bend is provided in front of the punching device 50, that is, between the punching device 50 and the discharge port M <b> 1 of the image forming apparatus M. For example, as shown in FIG. 3, the play space 55 is provided between the sheet guide 14 and the introduction guide 12, and the play space 55 is not shown in the figure when provided between the introduction guide 12 and the discharge port M1 as shown in FIG. However, FIG. 3 and FIG. 9 may be combined. As will be described later, the minimum required play space 55 is the number of sheets S from the image forming apparatus M within the time when the leading edge of the sheet S is stopped in connection with the operation of the punching device 50. It depends on whether it is sent. Note that an elastic synthetic resin plate 56 is provided in the play space 55 so that when the sheet S is bent in a large loop, it is pushed to elastically deform the synthetic resin plate 56 like a bow. It has become. By doing so, there is an effect that the bent sheet S is less likely to be wrinkled. Corresponding to the punching device 50, a box 57 for attaching punch scraps to the side of the tray guide 26 below the passage path 13 is attached.
[0033]
[Upper tray, Lower tray]
  As described above, the discharge sections 9a and 9b are provided with the upper tray 3a and the lower tray 3b that receive the sheet S. Of these, the upper tray 3a can be attached to and detached from the body 2, but in the attached state, it is in a fixed position and does not move. On the other hand, the lower tray 3b can be attached to and detached from the body 2, and the position is changed up and down in accordance with the sheet amount. That is, as shown in FIG. 2, the lower tray 3b is connected to an elevating device 58 including a motor 58a, a gear group 58b, a screw shaft 58c, an elevating arm 58d, and the sheet S placed on the lower tray 3b. Is detected by a sensor (not shown), and the motor 58a is controlled by the signal to move up and down so that the level of the sheet S is kept constant. The lifting device 58 is provided with sensors 58e and 58f to detect the upper and lower limit positions of the lifting arm 58d.
[0034]
[Explanation of operation of post-processing equipment]
  Next, the operation of the post-processing apparatus 1 of the present invention will be described. As described above, the post-processing apparatus 1 is attached to the side surface on the discharge side of the image forming apparatus M, and is pushed by the pin 7 of the image forming apparatus M so that the safety switch 8 is turned on and is energized.
[0035]
  First, a case where the sheet S discharged from the image forming apparatus M is passed as it is will be described. Normally, the switching gate 48 is raised as shown by the two-dot chain line in FIG. 3 to close the passage of the passage path 13, so that the solenoid is excited to lower the tip of the switching gate 48 as shown by the solid line in FIG. The flow path of the path 13 is opened. Then, the sheet S discharged from the image forming apparatus M is discharged from the first feed rollers 15a and 15b to the upper tray 3a through the second feed rollers 16a and 16b as shown by an arrow y in FIG. When punching the sheet S, the first feeding roller 15b is stopped first, and the leading edge of the sheet S discharged from the image forming apparatus M is stopped. In this state, if the eccentric cam 52 is rotated once to move the punching blade 54 up and down, a hole is formed in the edge of the sheet S. On the other hand, the second half of the sheet S is continuously sent out from the image forming apparatus M while the punching device 50 is operated and the leading edge of the sheet S is stopped in this way, but as shown in FIG. The center of the sheet S is bent as much as possible and escapes to the play space 55. Then, the punching operation is completed before the play space 55 is filled with the sheet S, and the first feeding roller 15b rotates to feed the sheet S to the second feeding rollers 16a and 16b.
[0036]
  It should be noted that punch scraps generated by the punching are dropped and stored in a box 57 under the punching device 50. Therefore, it is necessary to periodically collect and discard punch scraps. In that case, the post-processing apparatus 1 may be pulled by holding the handle 6 of the lower tray 3b, the post-processing apparatus 1 may be separated from the image forming apparatus M, and the box 57 may be attached or detached.
[0037]
  Next, a case where one sheet S is reversed and discharged will be described. Normally, the switching gate 48 has its tip raised as shown by a two-dot chain line in FIG. 3 to open the flow path of the branch path 22. Accordingly, the sheet S discharged from the image forming apparatus M is sent from the first feed rollers 15a and 15b to the third feed rollers 45a and 45b through the switching gate 48 as shown by an arrow z in FIG. As described above, the third feeding rollers 45a and 45b are set at a higher speed than the sheet feeding speed of the first feeding rollers 15a and 15b, and the leading edge of the sheet S is held by the third feeding rollers 45a and 45b. It is drawn in at high speed immediately. At this time, the rear end of the sheet S is sandwiched between the first feed rollers 15a and 15b. As described above, the first feed roller 15b is interposed between the power source and the one-way clutch mechanism. Therefore, the sheet S is automatically switched to the idle roller that follows the movement of the sheet S from the moment when a reverse phenomenon occurs in which the conveyance speed of the sheet S overtakes its own feeding speed.
[0038]
  In this manner, the first feeding rollers 15a and 15b draw the sheet S at the same speed as the feeding speed of the image forming apparatus M, and the third feeding rollers 45a and 45b provided behind the feeding rollers 15a and 15b. If the sheet conveying speed is set higher than that, and the clutch mechanism having the one-way structure is incorporated in the first feeding roller 15b, the sheet S introduced at a low speed in synchronization with the image forming apparatus M is post-processed. 1 can be processed at high speed. Of course, the second feed rollers 16a and 16b in the passage path 13 may be faster than the first feed rollers 15a and 15b. In this case, the loss resulting from the drilling operation can be recovered by carrying at high speed.
[0039]
  Next, when the leading edge of the sheet S reaches the tilted reversing tray 23, the entry angle α of the sheet S to the tilted reversing tray 23 is an acute angle. It flows naturally in the direction of the sheet stopper 24. At this stage, the sheet S is turned upside down. Then, the leading edge of the sheet S reaches the sheet stopper 24 immediately after being fed by the third feeding rollers 45 a and 45 b. As described above, the attachment positions of the third feed rollers 45a and 45b are set so that the distance from the contact point (release point) of the feed rollers 45a and 45b to the sheet stopper 24 of the inclined reversing tray 23 is shorter than the sheet length. Therefore, even if the leading edge of the sheet S reaches the sheet stopper 24, the trailing edge of the sheet S still remains on the feed rollers 45a and 45b. Therefore, thereafter, the sheet S is gently bent as shown in FIG. 4 and separated from the feed rollers 45a and 45b. Further, since the rotation shaft 46 of the third feeding roller 45b has an impeller 47 and rotates together with the feeding roller 45b, the moment when the trailing edge of the sheet S is separated from the feeding rollers 45a and 45b, FIG. As shown by the broken line, the rear end of the sheet S is kicked out toward the inclined inversion tray 23 side.
[0040]
  Next, the timing belt 31 of the sheet conveying unit 30 is operated, and the feeding claw 32 pushes out the sheet S through the travel line 33 of the inclined inversion tray 23. Then, when the timing belt 31 makes a half turn, the sheet S is discharged to the lower tray 3b, and stops at a position where the feeding claw 32 wraps under the inclined inversion tray 23. At this time, the other feed claw 32 stands by at the home position. Even when the sheet S is reversed, holes can be formed in the edge of the sheet S by the punching device 50 as described above. Further, when the sheet S is jammed in the branch path 22 or the inclined reversing tray 23, first, the post-processing apparatus 1 is separated from the image forming apparatus M by holding the handle portion 6 of the lower tray 3b, and the punch waste box 57 is removed. Then, the finger guide 26b of the tray guide 26 may be held and pulled forward. Then, since the tray guide 26 is rotated around the upper hinge portion 26c (see FIGS. 1 and 8) and opened, the jammed sheet S can be easily taken out.
[0041]
  Next, a case where a plurality of sheets S are bound together will be described. First, the sheets S are sent to the inclined inversion tray 23 one by one from the top page in the manner described above. In this case, the sheet S is fed in a substantially continuous state for high-speed processing. However, as described above, the trailing edge of the sheet S from the third feeding rollers 45a and 45b is the impeller 47, and the inclined inversion tray 23. As a result, the trailing edge of the preceding sheet S and the leading edge of the succeeding sheet S do not come into contact with each other.
[0042]
  Each time the sheet S is fed to the inclined reversing tray 23, the aligning unit 29 is operated once, and the sheet S is laterally fed by one reciprocating motion of the sliding member 29a so that one end is brought into contact with the fixed reference wall 28. Align. When the number of sheets increases to some extent, the gap between the bulging portions 23b and 26a becomes narrow and the feeding of the sheet S becomes tight. However, since the bulging portions 23b and 26a are partially small in area, their resistance is relatively small. Then, when the set number of sheets has been prepared, the feeding claw 32 of the sheet conveying unit 30 is operated, and the bundle of sheets S is moved to the binding point of the stapler 35 and stopped. Subsequently, the stapler 35 operates to bind the bundle of sheets S with a metal needle. At this time, the bundle of sheets S is easily bound since it is pressed by the bulging portions 23b and 26a.
[0043]
  Next, the feeding claw 32 of the sheet conveying unit 30 is actuated again, and the bundle of bound sheets S is discharged to the lower tray 3b. At this time, the feeding claw 32 is set so as to reduce the speed before the sheet S is conveyed at a high speed and discharged to the lower tray 3b. By doing so, there is no possibility of jumping out from the lower tray 3b even if the sheet S is conveyed at high speed. The lower tray 3b can be moved up and down as described above, and descends in accordance with the sheet amount, and automatically rises when the sheet S is removed.
[0044]
  Needless to say, even when a plurality of sheets S are reversed and bound together, the punching device 50 can make a hole in the edge of the sheet S. Further, the work of replenishing the metal needles of the stapler 35 is performed by separating the post-processing apparatus 1 from the image forming apparatus M.
[0045]
【The invention's effect】
  As described above, the post-processing apparatus of the present invention guides the sheet from the middle of the passage path to the inclined inversion tray via the branch path, and sets the entrance angle α of the sheet to the inclined inversion tray to an acute angle, thereby inclining the inversion tray. Since the front and back are reversed above, the sheet can be smoothly reversed without damaging the sheet, and further, the inclined reversing tray can be made compact because it is disposed in the region directly below the passage path.
  In addition, a punching device is provided in front of the switching gate so that the sheet can be punched between the introduction part of the passage path and the switching gate. Any of the sheets can be perforated. The technical idea of providing a punching device in front of the switching gate is applicable to all of “a post-processing device having a plurality of sheet paths and switching the plurality of paths with the switching gate”. By doing so, it is possible to obtain an excellent effect that drilling can be performed with one punching device regardless of which route is selected.
[0046]
  According to a second aspect of the present invention, a branch feeding means for forcibly feeding the sheet toward the inclined inversion tray is formed on the branch path, and the branch feeding means releases the sheet before the trailing edge of the sheet is released. It is preferable that the leading edge of the sheet reaches the sheet stopper of the inclined inversion tray. By doing so, since the leading edge of the sheet reaches the sheet stopper at high speed and reliably, the edges of the sheet can be neatly aligned.
[0047]
  In addition, as described in claim 3, an impeller is incorporated in a part of the branch feeding means according to claim 2, and the trailing edge of the sheet is kicked out to the inclined inversion tray side by the impeller. Good. By doing so, high-speed processing can be performed without bringing the trailing edge of the preceding sheet into contact with the leading edge of the succeeding sheet.
[0048]
  Claims4As described above, a notch portion may be formed in a part of the inclined inversion tray, and a stapler may be provided corresponding to the notch portion. By doing so, it is possible to bind the sheets that are reversed on the inclined reversing tray and stacked in the page order with the stapler.
[0049]
  Claims5And a tray guide is formed above the inclined inversion tray, and4If the bulging part is formed in one or both of the inclined inversion tray and the tray guide with respect to a part corresponding to the notch part described in the above, the gap between the two is narrowed by narrowing the point around the notch part. Since the thickness of the sheet bundle is reduced, binding with the stapler is facilitated, and since the bulging part is partial, resistance acting on the sheet is reduced, so that the sheet can be inserted into the bulging part. There is an effect that can be discharged smoothly.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of an aftertreatment device.
FIG. 2 is a perspective view of the post-processing apparatus seen through a part thereof.
FIG. 3 is an enlarged cross-sectional view showing a main part of a passage route and a branch route.
FIG. 4 is an enlarged cross-sectional view showing a main part of a branch path and an inclined inversion tray.
FIG. 5 is a perspective view of a sheet conveying unit.
6 is a cross-sectional view taken along line XX of FIG.
FIG. 7 is a perspective view of an inclined inversion tray.
FIG. 8 is an exploded perspective view showing a tray guide and a feed roller.
FIG. 9 is an enlarged cross-sectional view of the main part of the introduction part showing another form of the play space.
[Explanation of symbols]
  M: Image forming apparatus
  S ... Sheet
  1 ... Post-processing device
  9a, 9b ... discharge part
  10 ... introduction part
  13 ... Passing route
  22… Branch route
  23 ... Inclined tray
  23b, 26a ... bulging part
  24 ... Seat stop
  26 ... Tray guide
  30. Sheet conveying means
  34 ... Notch
  35 ... Stapler
  45a, 45b ... Third feed roller (branch feed means)
  47 ... impeller
  48… Switching gate
  50 ... punching device

Claims (5)

A passage route for accepting a sheet discharged from the image forming apparatus at the introduction unit, passing the sheet as it is, and discharging it from the discharge unit;
An inclined inversion tray that is located in a region directly below the passage path, is inclined so that the end on the discharge unit side is high, and is provided with a sheet stopper at the low end.
A sheet conveying means for feeding the sheet on the inclined inversion tray to the discharge unit side;
A branch path that sends the sheet to the inclined inversion tray starting from the middle of the passing path;
A switching gate that is at the intersection of the passage route and the branch route, and selectively switches the flow path between the passage route side and the branch route side,
When the sheet fed from the branch path contacts the inclined reversing tray, the angle α formed between the sheet and the surface on the high side of the tilted reversing tray is set to be an acute angle, so that the leading edge of the sheet sent from the branch path Is guided by the inclination of the inclined reversing tray, flows from a high place to a low place, and stops when it hits the sheet stopper .
Further, the post-processing apparatus of the image forming apparatus , wherein a punching device is provided in front of the switching gate so that the sheet can be punched between the introduction portion of the passage path and the switching gate .   A branch feeding means for forcibly feeding the sheet toward the inclined inversion tray is formed in the branch path, and the leading edge of the sheet reaches the sheet stopper of the inclined inversion tray before the branch feeding means releases the trailing edge of the sheet. The post-processing apparatus according to claim 1, wherein the post-processing apparatus is an image forming apparatus.   A post-processing apparatus according to claim 2, wherein an impeller is incorporated in a part of the branch feeding means according to claim 2, and the trailing edge of the sheet is kicked out toward the inclined inversion tray by the impeller. The inclined notches formed on a part of the inverted tray, the post-processing device of an image forming apparatus according to claim 1, 2 or 3, wherein the provision of the stapler so as to correspond to the notch. A tray guide is formed above the inclined inversion tray, and a bulging portion is formed in one or both of the inclined inversion tray and the tray guide with respect to a portion corresponding to the cutout portion according to claim 4. A post-processing apparatus for an image forming apparatus, wherein the gap between the two is narrowed by narrowing the point around the notch.

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