JP3887994B2 - Paper post-processing apparatus and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet post-processing apparatus for discharging an image-formed sheet discharged from an image forming apparatus main body such as an electrophotographic copying machine, a printer, and a facsimile machine by a sheet discharge unit and placing the sheet on a sheet discharge tray. Relates to the device.
[0002]
[Prior art]
2. Description of the Related Art A sheet post-processing device is used as a device that collates a plurality of image-recorded sheets discharged from an image forming apparatus main body for each number of copies and binds them by a binding unit. Some sheet post-processing devices have functions such as a shift sorting process, a collation process, a punching process, and a bookbinding process in addition to the above-described binding process.
[0003]
The sheet post-processing apparatus is connected to a main body of an image forming apparatus such as a copying machine, a printer, or a facsimile, and is driven in response to a sequence operation of a copy or print process.
[0004]
The paper post-processing device performs paper post-processing such as binding processing, shift sorting, and collation on the received paper, and then discharges the paper onto a paper discharge tray.
[0005]
Regarding the paper post-processing apparatus, JP-A-60-142359, JP-A-60-158463, JP-A-62-239169, JP-A-62-228802, JP-A-62-267667, JP-A-2-276661, Japanese Patent Publication No. 8-319054 and Japanese Patent Publication No. 5-41991 disclose a configuration in which various sheets are conveyed to a post-processing unit and brought into contact with a stopping unit.
[0006]
[Problems to be solved by the invention]
The image-formed processed paper transported into the paper post-processing apparatus is transported by the transporting means, then reversely transported and transported onto the intermediate stacker, and the rear end of the paper is brought into contact with the stopping means so that the predetermined position is reached. To be stopped. A plurality of sheets are sequentially conveyed and stacked at this stop position, and the trailing edge is aligned. After the post-processing such as binding processing is performed on the rear end-aligned paper bundle, the paper bundle is discharged to a discharge tray outside the apparatus by a discharge unit.
[0007]
The following mechanism is known for the paper discharge means of such a paper post-processing apparatus.
[0008]
(1) A sheet post-processing apparatus that conveys a sheet to a post-processing unit by a winding ring, contacts a stop unit, and lowers a sheet discharge roller to discharge a sheet bundle only at the time of sheet discharge.
[0009]
(2) The intermediate stacker is installed at a steep inclination angle, the paper is transported to the post-processing section by the free fall of the paper, is brought into contact with the stop means, and the paper discharge roller is moved up and down by using the engaging mechanism, and the paper bundle Paper discharge means for discharging the paper by applying a pressing force to the paper discharge roller using a solenoid.
[0010]
(3) A vertical force automatic variable device is provided in the paper discharge means, and a vertical force for obtaining a high gripping force is provided when discharging a bundle of sheets in which a plurality of sheets are bound, rather than when discharging a single sheet. Paper post-processing device to be added (Japanese Patent Laid-Open No. 8-217323).
[0011]
In any of the above-described sheet post-processing apparatuses, it is difficult to stabilize the sheet transportability with respect to sheets of all characteristics, and there is a risk of being affected by sheet curling, static electricity, and the like. There is also a problem that the mechanism is complicated and the manufacturing cost is high.
[0012]
The present invention provides a sheet post-processing apparatus and an image forming apparatus provided with a sheet discharge unit having a simple mechanism that improves the above-described problems in a conventional sheet post-processing apparatus, improves sheet alignment performance, and has a simple mechanism. It is the purpose.
[0013]
[Means for Solving the Problems]
In the paper post-processing apparatus that achieves the above object, after the image-formed paper is transported by the transport means of the paper post-processing apparatus, it is loaded on the intermediate stacker, post-processed by the post-processing means, and then discharged by the paper discharge means. In the paper post-processing apparatus placed on the paper discharge tray, the paper discharge means includes a paper discharge upper roller and a paper discharge lower roller that can be rotated forward and reverse to hold and convey the paper. A roller, a pressure-bonding means that swings the paper discharge upper roller so that it can be pressed against and separated from the paper discharge lower roller, and a drive motor that can rotate forward and reverse to drive the paper discharge upper roller, paper discharge lower roller, and pressure bonding means. It has a, a driving means for a driving source, after transporting the sheet on the intermediate stacker while rotating the discharge sheet roller in the forward direction, stops the paper by switching the rotation of the exhaust sheet roller in a reverse direction When aligning with the means Wherein the pressure of the exhaust sheet roller with respect to the paper on the intermediate stacker, and is characterized in that it has a constant regardless of the sheet stacking amount on the intermediate stacker (claim 1).
Further, after the image-formed paper is transported by the transport means of the paper post-processing device, it is loaded on the intermediate stacker, post-processed by the post-processing means, discharged by the paper discharge means, and placed on the paper discharge tray. In the paper post-processing apparatus, the paper discharge means swings the paper discharge roller including a paper discharge upper roller and a paper discharge lower roller that can rotate forward and backward to sandwich and convey and discharge the paper, and the paper discharge upper roller. A pressure-bonding means that moves and press-contacts and separates from the paper discharge lower roller; and a drive means that uses a drive motor that can rotate forward and reverse to drive the paper discharge upper roller, paper discharge lower roller, and pressure-bonding means; And the sheet discharge lower roller is driven and rotated by the drive unit only when the sheet bundle post-processed by the post-processing unit is discharged by the sheet discharge unit. (Claim 4).
Further, after the image-formed paper is transported by the transport means of the paper post-processing device, it is loaded on the intermediate stacker, post-processed by the post-processing means, discharged by the paper discharge means, and placed on the paper discharge tray. In the paper post-processing apparatus, the paper discharge means swings the paper discharge roller including a paper discharge upper roller and a paper discharge lower roller that can rotate forward and backward to sandwich and convey and discharge the paper, and the paper discharge upper roller. A pressure-bonding means that moves and press-contacts and separates from the paper discharge lower roller; and a drive means that uses a drive motor that can rotate forward and reverse to drive the paper discharge upper roller, paper discharge lower roller, and pressure-bonding means; And a pressing force adjusting means is provided on the paper discharge upper roller, and the pressure of the paper discharge upper roller when the paper bundle post-processed by the post-processing means is discharged by the paper discharge means is determined by the thickness of the paper bundle. With the feature that it was made variable corresponding to That is a sheet post-processing apparatus (claim 5).
[0014]
Furthermore , an image forming apparatus that achieves the above object includes an image forming apparatus main body that forms an image on a sheet, and a sheet post-processing apparatus that post-processes the sheet on which the image is formed by the image forming apparatus main body. It is a characteristic (claim 6 ).
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of an image forming apparatus having a sheet post-processing apparatus provided with a paper discharge unit according to the present invention will be described with reference to the accompanying drawings.
[0016]
FIG. 1 is an overall configuration diagram of an image forming apparatus 1 equipped with a sheet post-processing device FS, an automatic document feeder DF, and an image reading device (scanner) SC.
[0017]
The illustrated image forming apparatus main body 1A includes an image processing unit 2, an image writing unit 3, an image forming unit 4, a high voltage power supply unit 5, a cassette paper feeding unit 6, a fixing device 7, a paper discharge unit 8, an automatic double-sided copy transport unit ( ADU) 9.
[0018]
An image reading device SC and an automatic document feeder DF are mounted on the upper portion of the image forming apparatus main body 1A. A sheet post-processing device FS is connected to the paper discharge unit 8 at the upper left of the image forming apparatus main body 1A.
[0019]
The document d placed on the document table of the automatic document feeder DF is conveyed in the direction of the arrow, and an image on one or both sides of the document is read by the optical system of the image reading device SC and read by the CCD image sensor C1.
[0020]
The analog signal photoelectrically converted by the CCD image sensor C1 is subjected to analog processing, A / D conversion, shading correction, image compression processing, and the like in the image processing unit 2 and then sent to the image writing unit 3.
[0021]
In the image writing unit 3, output light from the semiconductor laser is irradiated onto the photosensitive drum 4 </ b> A of the image forming unit 4 to form a latent image. In the image forming unit 4, processing such as charging, exposure, development, transfer, separation, and cleaning is performed, and the image is transferred to the sheet S conveyed from the cassette sheet feeding unit 6. The paper S carrying the image is fixed by the fixing device 7 and sent from the paper discharge unit 8 to the paper post-processing device FS. Alternatively, the single-sided image processed paper S sent to the automatic double-sided copy transport unit 9 by the transport path switching plate 8A is again subjected to double-sided image processing in the image forming unit 4, and then from the paper discharge unit 8 to the paper post-processing device FS. It is sent.
[0022]
The sheet post-processing device FS is detachably attached to the upper left portion of the image forming apparatus main body 1A. The sheet post-processing device FS includes a sheet transport unit 10, a sheet discharge unit 20, a sheet post-processing unit 30, and a lift sheet discharge unit 40.
[0023]
In FIG. 1, on the right side in the image forming apparatus main body 1 </ b> A, a cassette paper feeding unit 6 is located at the lower side in the height direction of the main body of the image forming unit 4, and a fixing device 7 and a paper discharging unit 8 are located above. Is provided. With this vertical arrangement configuration, a substantially vertical sheet conveyance path (1) is formed. The paper S sent out from the cassette paper supply unit 6 is transported along the vertically upward paper transport path (1) and discharged out of the apparatus main body.
[0024]
A sheet conveyance path (2) by the automatic duplex copying / conveying section 9 is formed substantially parallel to the vertical sheet conveyance path (1).
[0025]
By forming the above-described vertical sheet conveyance paths (1) and (2), a sheet conveyance path of the shortest distance from the cassette sheet feeding unit 6 to the sheet discharge unit 8 is configured.
[0026]
The sheet conveying means 10 of the sheet post-processing apparatus FS is accommodated in the space above the image forming apparatus main body 1A. The paper inlet portion 11 of the paper transport unit 10 is connected to the paper discharge roller 8B of the paper discharge portion 8 of the image forming apparatus main body 1A. In this mounted state, the paper discharge unit 20 and the paper post-processing unit 30 of the paper post-processing device FS are accommodated in the upper left space of the image forming apparatus main body. The lifting / lowering discharge means 40 comprising a plurality of discharge trays 41 and the lifting / lowering drive means 42 is located on the side surface side of the apparatus main body.
[0027]
FIG. 2 is a sectional view of the sheet post-processing apparatus FS.
[0028]
In FIG. 2, the sheet post-processing device FS includes a sheet transport unit 10, a sheet discharge unit 20, a sheet post-processing unit 30, and a lift sheet discharge unit 40, and is unitized and detachable from the apparatus main body. The moving means such as a rail can be pulled out toward the front side of the drawing.
[0029]
The paper transport means 10 is connected to a paper inlet 11 facing the paper discharge roller 8B of the paper discharge section 8, and is a paper transport guide plate (hereinafter referred to as a guide plate) that guides the discharged paper S to the paper discharge means 20. ) 12, 13 and conveying rollers 14, 15, and 16 including a driving roller and a driven roller for nipping and conveying the paper S. The sheet path composed of the guide plates 12 and 13 and the conveying rollers 14, 15, and 16 forms a substantially horizontal conveying path. The drive rollers 14, 15 and 16 are rotated forward by a drive motor (not shown).
[0030]
The paper discharge unit 20 includes a paper discharge upper roller 21, a paper discharge lower roller 22, and a pressure bonding unit 23 that are connected to a driving source and rotate forward and backward. The paper discharge upper roller 21 moves up and down by a torque limiter, and presses the paper discharge lower roller 22 by the crimping means 23.
[0031]
The sheet post-processing unit 30 includes an intermediate stacker 31 that stacks a plurality of sheets S conveyed by the sheet conveying unit 10, a width aligning unit 32 that aligns and regulates the width direction of the sheets S stacked on the intermediate stacker 31, Stop means 33 for positioning in the transport direction by abutting the leading end of the sheet S loaded on the intermediate stacker 31, binding means (stapler) 34 for driving the staples SP into the sheet bundle, and the binding means 34 are predetermined. It is comprised from the moving means 35 which moves to the position and rotates.
[0032]
The lifting / lowering discharge means 40 includes a plurality of inclined discharge trays (also referred to as bins) 41, and a lifting / lowering drive means 42 for raising and lowering the discharge tray 41 in the vertical direction.
[0033]
Although the illustrated sheet post-processing device FS has four discharge trays 41, there is a margin space below and above the elevating / discharging unit 40, and therefore a sheet post-processing device (with an additional number of bins) ( For example, a 10-20 bin paper post-processing device) FS can be mounted. Further, the sheet post-processing device FS can also serve as a function for sorting sheets such as a mail box.
[0034]
FIG. 3 is a schematic diagram showing a process of conveying and discharging the paper S in the paper post-processing device FS.
[0035]
(1) Paper discharge (paper conveyance path (3), see FIG. 3 (a))
The image-formed paper S discharged from the paper discharge roller 8B of the paper discharge unit 8 of the image forming apparatus 1 is introduced into the paper inlet portion 11 of the paper transport unit 10 of the paper post-processing device FS, and is stored in the guide plate 12. It passes through the transport path, is sandwiched and transported by transport rollers 14 and 15 that rotate forward, and is transported while being transported by transport roller 16 that rotates forward.
[0036]
The leading edge of the sheet S passes through the paper discharge upper roller 21 and the paper discharge lower roller 22 that are rotated in the forward direction on the downstream side of the conveyance, being pressed and sandwiched, and along the inclined surface of the paper discharge tray 41 of the lift paper discharge means 40. It rises. When the rear end portion of the sheet S passes through the holding position of the conveyance roller 16, the rear end portion of the sheet S is lowered by its own weight and comes into contact with the inclined surface of the intermediate stacker 31.
[0037]
(2) Reverse feed before paper post-processing (paper transport path (4), see FIG. 3B)
After the sensor PS1 provided in the vicinity of the transport roller 15 detects the passage of the trailing edge of the paper S, the timer measures the predetermined time, and then the paper discharge upper roller 21 is driven to rotate backward and descends to press the paper. . The paper discharge lower roller 22 driven by the same drive source is stopped by the clutch and is driven to rotate by the paper discharge upper roller 21. The paper discharge upper roller 21 is made of a flexible foam such as a sponge roller, and is in light pressure contact with the paper S on the paper discharge lower roller 22.
[0038]
By switching the reverse rotation of the discharge upper roller 21, the sheet S lightly pressed against the reverse discharge upper roller 21 and the discharge lower roller 22 stopped at the nipping position is conveyed obliquely downward on the intermediate stacker 31. Then, the trailing edge of the sheet S hits the stopping means 33 and the conveyance is stopped.
[0039]
A pair of width aligning means 32 movably provided on both side surfaces of the intermediate stacker 31 is movable in a direction orthogonal to the paper transport direction, and when receiving a paper sheet S being transported on the intermediate stacker 31, the paper width When the sheet is opened more widely and is transported on the intermediate stacker 31 and stopped by coming into contact with the stop means 33, the width of the sheet bundle is aligned by tapping the side edge in the width direction of the sheet S.
[0040]
Similarly, the succeeding sheets S are sequentially stacked on the upper surface of the preceding sheet S on the intermediate stacker 31 through the sheet transport paths {circle over (3)} and (4). Stops in contact.
[0041]
After the trailing edge of all the sheets S for one book is in contact with the stopping means 33, the staple means SP is driven into the sheet bundle by the binding means 34 to form a booklet.
[0042]
(3) Paper discharge after paper post-processing (paper transport path (5), see FIG. 3C)
When the binding process is completed, the stopped paper discharge upper roller 21 is switched to the normal rotation, and the sheet bundle sandwiched between the paper discharge lower roller 22 and the paper discharge upper roller 21 switched to the strong pressure contact by the pressure-bonding means 23 is obtained. Then, it is conveyed obliquely upward and accommodated in the paper discharge tray 41.
[0043]
4 is a plan view of the main part of the paper discharge means 20, and FIG. 5 is a front view of the paper discharge means.
[0044]
The drive motor M1 capable of rotating in the forward and reverse directions swings and rotates the rotary shaft 231 of the pressure-bonding means 23 via the timing belt TB1. The swing member 232 fixed to the rotating shaft 231 is held so as to be swingable about the rotating shaft 231. Reference numeral 233 denotes a torque limiter provided on the rotary shaft 231, and reference numeral 234 denotes a pressing force adjusting spring that adjusts the pressing force of the swing member 232.
[0045]
A groove portion 232 </ b> A is formed at the distal end portion of the swing member 232. The rotary shaft 211 of the paper discharge upper roller 21 is loosely fitted in the groove portion 232A and is supported so as to be movable.
[0046]
Two hard rollers 212 are supported on the rotating shaft 211 so as to be driven to rotate, and a sponge roller 213 is fixed thereto.
[0047]
A timing belt TB2 is installed between a pulley fixed to one end of the rotating shaft 211 and a pulley fixed to the rotating shaft 231. Due to the forward / reverse rotation of the rotation shaft 231, the rotation shaft 211 rotates forward / reversely via the timing belt TB <b> 2.
[0048]
The tip portions of the two pressing springs 214 fixed to the rotating shaft 231 are pressed against the rotating shaft 211 and urged downward.
[0049]
The swing member 232 swings up and down by driving the torque limiter 233 by forward and reverse rotation driving of the rotating shaft 211.
[0050]
Above the swinging member 232, a rotary shaft 236 that can be fitted to the bearing 235 of the crimping apparatus main body and rotatable is horizontally supported. The rotation shaft 236 is rotated by driving transmitted from the drive motor M2 via the gears G1, G2, G3, G4, and G5.
[0051]
A pressing cam 237 is fixed to the rotating shaft 236 and can be rotated integrally. As the pressing cam 237 rotates, the swing member 232 is pressure-bonded via the leaf spring 214.
[0052]
The gear G6 fixed to the shaft end of the rotating shaft 231 is connected to the gear G7 via the mechanical clutch K1. A pulley coaxial with the gear G7 rotates the rotation shaft 221 of the sheet discharge lower roller 22 via the timing belt TB3.
[0053]
Two lower rollers 222 having a rubber coating layer on the outer peripheral surface are fixed to the rotating shaft 221. The elastic roller 212 of the paper discharge upper roller 21 is pressed against and separated from the lower roller 222. The hard roller 223 disposed at the center between the two lower rollers 222 is formed of a hard resin and can be freely rotated by being fitted to the rotation shaft 221. The sponge roller 213 of the paper discharge upper roller 21 is pressed against and separated from the hard roller 223.
[0054]
In FIG. 5, a sheet holding member 36 is swingably supported above the intermediate stacker 31. The front end portion of the paper holding member 36 is self-weighted or spring-biased, and makes slight contact with the upper surface side of the paper placed on the intermediate stacker 31, thereby preventing the paper warping from proceeding to the stopping means 33. Align.
[0055]
6 and 7 are front views showing the paper transport and paper discharge process by the paper discharge means. Hereinafter, sheet conveyance and sheet discharge during sheet post-processing will be described.
[0056]
(1) See FIG. 6 (a):
The first sheet S1 conveyed on the sheet conveyance guide plate 13 is sandwiched between a drive roller 16A driven by a conveyance drive motor (not shown) and a driven roller 16B that is driven to rotate while being in pressure contact with the drive roller 16A. Be transported. The leading edge of the sheet S1 enters the paper discharge opening 24 in a state where the paper discharge upper roller 21 is separated from the paper discharge lower roller 22.
[0057]
At this time, the upper discharge roller 21 and the lower discharge roller 22 are rotated forward by the drive motor M1, and the swing member 232 is swung by a predetermined torque of the torque limiter 233 and retracted to an upper position and stopped.
[0058]
(2) See FIG. 6 (b):
After the sensor PS1 detects the passage of the rear end portion of the first sheet S1, the timer for measuring a predetermined time is used to drive the discharge upper roller 21 in the reverse rotation by the reverse rotation of the drive motor M1. At the same time, the lower discharge roller 22 is stopped by the mechanical clutch K1 by the reverse rotation of the drive motor M1.
[0059]
In addition, the torque of the torque limiter 233 provided on the rotating shaft 231 by the reverse rotation driving of the drive motor M1 causes the swinging member 232 to swing and the discharge upper roller 21 to move down, and a predetermined pressing of about 50 g · f. Apply pressure. The first sheet S <b> 1 is conveyed by the conveying force that is lightly pressed against the sponge roller 213 of the sheet discharge upper roller 21 that is driven and rotated, and is slid on the surface of the intermediate stacker 31 and conveyed toward the stop unit 33.
[0060]
(3) See FIG. 6 (c):
After the trailing edge of the first sheet S1 comes into contact with the stopping means 33, the drive motor M1 is switched to normal rotation, the paper discharge upper roller 21 and paper discharge lower roller 22 rotate forward, and the swing member 232 It is swung by the predetermined torque of the torque limiter 233, retracts to an upper position and stops, and returns to the same state as FIG. 6 (a). In this state, similarly to the first sheet S1, the second sheet S2 is nipped and conveyed by the driving roller 16A and the driven roller 16B and enters the paper discharge opening 24.
[0061]
(4) See FIG. 7 (a):
As in the case of transporting the first sheet S1, the sensor PS1 (see FIG. 3A) detects the passage of the rear end of the second sheet S2, and then counts a predetermined time with a timer, The paper discharge upper roller 21 is reversely driven by the reverse rotation drive of the drive motor M1, and the swing member 232 is swinged downward by the torque limiter 233, and is held in the same state as in FIG.
[0062]
The second sheet S2 is transported in the same manner as when transporting the first sheet S1, is placed on the first sheet S1, and stops with the trailing edge contacting the stop means 33. .
[0063]
The third and subsequent sheets are stacked on the intermediate stacker 31 by repeating the operations of FIGS. 6A to 6C in the same manner as the first sheet S1 and the second sheet S2. Even if the thickness of the paper stacked on the intermediate stacker 31 increases, the paper discharge upper roller 21 presses the paper with a constant force of the urging force of the torque limiter.
[0064]
(5) See FIG. 7B:
After the binding process to the sheet bundle, the pressing cam 237 is rotated by the driving rotation of the driving motor M2, and the receiving surface 232B of the swinging member 232 is pressed to make a strong pressure contact. Since the paper discharge upper roller 21 is biased by the pressing spring 214, the pressing force of the paper discharge upper roller 21 changes according to the thickness of the sheet bundle. The paper discharge upper roller 21 is strongly pressed by the lowered swinging member 232 and the pressing spring 214, and strongly presses the sheet bundle sandwiched between the paper discharge lower rollers 22.
[0065]
In this sheet bundle pressing state, the sponge roller 213 of the paper discharge upper roller 21 is pressed and deformed by the hard roller 223 of the paper discharge lower roller 22. Further, in this paper pressing state, the two hard rollers 212 of the paper discharge upper roller 21 are in strong pressure contact with the two lower rollers 222 of the paper discharge lower roller 22, respectively, and securely hold the paper bundle.
[0066]
By the forward rotation driving of the drive motor M1, the paper discharge upper roller 21 rotates forward. At the same time, the mechanical clutch K1 is engaged, and the paper discharge lower roller 22 rotates forward. The bound sheet bundle is nipped and transported between the upper paper discharge roller 21 and the lower paper discharge roller 22 that rotate forward, and is discharged to the paper discharge tray 41.
[0067]
In the embodiment of the present invention, the paper post-processing apparatus connected to the copying machine is shown. However, the present invention is also applicable to an image forming apparatus such as a printer and a facsimile, and a paper post-processing apparatus used in connection with a light printing machine. Is possible. For example, the automatic document feeder DF and the image reading device SC that are detachably provided on the image forming apparatus main body 1A may be removed and applied to a printer specification.
[0068]
【The invention's effect】
An image forming apparatus including a sheet post-processing apparatus and a sheet post-processing apparatus according to the present invention sandwiches a sheet conveyed by a conveying unit between a discharge upper roller and a discharge lower roller that can be pressed, separated, and rotated forward and backward. By conveying the sheet bundle to the post-processing means and discharging the sheet bundle after the post-processing, the sheet conveyance performance and the sheet alignment performance can be improved without being affected by the sheet curl or static electricity.
[0069]
In addition, by using a single drive motor that rotates normally and reversely and a torque limiter, the forward and reverse rotation of the paper discharge upper roller and paper discharge lower roller and the drive of raising and lowering the paper discharge upper roller are simplified. It is effective for reducing the manufacturing cost.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of an image forming apparatus equipped with a sheet post-processing apparatus, an automatic document feeder, and an image reading apparatus.
FIG. 2 is a cross-sectional view of a sheet post-processing apparatus.
FIG. 3 is a schematic diagram illustrating a process of conveying and discharging a sheet in a sheet post-processing apparatus.
FIG. 4 is a plan view of a main part of a paper discharge unit.
FIG. 5 is a front view of a paper discharge unit.
FIG. 6 is a front view showing a paper conveyance and paper discharge process by a paper discharge unit.
FIG. 7 is a front view showing a paper conveyance and paper discharge process by a paper discharge unit.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Image forming apparatus 1A Image forming apparatus main body 10 Paper conveyance means 12, 13 Paper conveyance guide plates 14, 15, 16 Conveyance roller 20 Paper discharge means 21 Paper discharge upper roller 211, 221, 231, 236 Rotating shaft 212 Elastic roller 213 Sponge roller 214 Pressing spring 22 Discharging lower roller 222 Lower roller 223 Hard roller 23 Pressing means 232 Oscillating member 233 Torque limiter 234 Pressing force adjusting spring 237 Pressing cam 24 Discharging opening 30 Paper post-processing means 31 Intermediate stacker 33 Stopping means 34 Binding Means (stapler)
40 Lifting / discharging means 41 Output tray (bin)
42 Lifting drive means FS Paper post-processing device K1 Mechanical clutch K2 One-way clutch M1, M2 Drive motor PS1 Sensors S, S1, S2, Paper

Claims (6)

The paper on which the image is formed is transported by the transport means of the paper post-processing device, then loaded on the intermediate stacker, post-processed by the post-processing means, and then discharged by the paper discharge means and placed on the paper discharge tray. In the aftertreatment device
The paper discharge means includes a paper discharge roller composed of a forward and reverse rotatable paper discharge roller and a paper discharge lower roller that conveys and discharges the paper while sandwiching the paper, and the paper discharge lower roller by swinging the paper discharge upper roller. pressure, a pressing means for the separable, driving means for said exhaust sheet roller and the discharge lower roller and the pressure means and the driving source forward and reverse rotatable drive motor for driving a, was closed in,
When the paper is transported onto the intermediate stacker while rotating the paper discharge upper roller in the forward direction, the rotation of the paper discharge upper roller is switched to the reverse direction, and the paper is brought into contact with the stopping means for alignment. The sheet post-processing apparatus is characterized in that the pressing force of the sheet discharge upper roller on the sheet is constant regardless of the sheet stacking amount on the intermediate stacker . The sheet post-processing apparatus according to claim 1 , wherein the paper discharge upper roller is provided on a swinging member swingable about a rotation shaft, and a torque limiter is provided on the rotation shaft . There is provided a pressing means for allowing the upper discharge roller to be pressed, and when the paper bundle post-processed by the post-processing means is discharged by the discharge means, the pressing means is driven by the pressing force of the upper discharge roller. , sheet post-processing apparatus according to claim 1 or 2, characterized in that discharging by sandwiching the sheet bundle already aftertreatment pressurizes the sheet discharging lower roller. The paper on which the image is formed is transported by the transport means of the paper post-processing device, then loaded on the intermediate stacker, post-processed by the post-processing means, and then discharged by the paper discharge means and placed on the paper discharge tray. In the aftertreatment device
The paper discharge means includes a paper discharge roller composed of a forward and reverse rotatable paper discharge roller and a paper discharge lower roller that conveys and discharges the paper while sandwiching the paper, and the paper discharge lower roller by swinging the paper discharge upper roller. A pressure-bonding means that enables pressure contact and separation, and a drive means that uses a drive motor that can rotate forward and reverse to drive the paper discharge upper roller, the paper discharge lower roller, and the pressure-bonding means.
The sheet post-processing apparatus , wherein the sheet discharge lower roller is driven and rotated by the driving unit only when the sheet bundle post-processed by the post-processing unit is discharged by the sheet discharge unit. The paper on which the image is formed is transported by the transport means of the paper post-processing device, then loaded on the intermediate stacker, post-processed by the post-processing means, and then discharged by the paper discharge means and placed on the paper discharge tray. In the aftertreatment device
The paper discharge means includes a paper discharge roller composed of a forward and reverse rotatable paper discharge roller and a paper discharge lower roller that conveys and discharges the paper while sandwiching the paper, and the paper discharge lower roller by swinging the paper discharge upper roller. A pressure-bonding means that enables pressure contact and separation, and a drive means that uses a drive motor that can rotate forward and reverse to drive the paper discharge upper roller, the paper discharge lower roller, and the pressure-bonding means.
The discharge upper roller is provided with a pressing force adjusting means, and the pressing force of the discharge upper roller when the paper bundle post-processed by the post-processing means is discharged by the paper discharge means corresponds to the thickness of the paper bundle. A sheet post-processing apparatus characterized in that it is variable . An image forming apparatus main body that forms an image on a sheet, and the sheet post-processing apparatus according to any one of claims 1 to 5 that post-processes a sheet on which an image is formed by the image forming apparatus main body. A featured image forming apparatus.

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