JP4065506B2 - Sheet processing apparatus and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet processing apparatus and an image forming apparatus including the sheet processing apparatus, and more particularly to a positional relationship between a full load detection flag and a sheet rear end and a sheet stacking alignment property when a sheet is discharged.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, some image forming apparatuses such as copying machines and printers are provided with a sheet processing apparatus that performs a binding process on a sheet after image formation, for example. In these conventional apparatuses, when stacking a sheet bundle bound with a single sheet and staples on the same stacking tray, the stacking tray is fully loaded by a light transmission sensor (light emitting unit and light receiving unit). There were many products.
[0003]
When detecting with the full load detection flag, it is necessary to detect the stapled portion at the upstream end of the sheet bundle in the transport direction when stacking sheets bundled with staples. In the case of a single sheet having a large air resistance, the flight distance is greater than that of a bundle of sheets bound with staples, so it is necessary to detect at a position where the full load detection flag is extended to a position where the sheet does not jump over the full load detection flag. There are different parts to be detected in each loading mode. Therefore, in order to solve the latter problem, there is an apparatus that predicts the full load of the stapled sheet bundle at the point of detecting the full load of the single sheet. However, since the full load detection accuracy is poor, the light transmission sensor that detects the full load of the sheet by installing a light emitting unit and a light receiving unit in the upstream portion of the sheet outside in the sheet width direction and crossing the light in the sheet width direction is described above. It was often used because it was simple without worrying about the problem of jumping over the sheet.
[0004]
[Problems to be solved by the invention]
However, in the above-described conventional technology, in a device that uses a light transmission sensor for full load detection, the sensor member is expensive, leading to an increase in product cost. On the other hand, the device using the full load detection flag is cheaper than the device using the light transmission sensor, but the following problems have occurred in order to realize it.
[0005]
In recent years, the sheet discharge speed has increased due to the speedup of the image forming apparatus, so the speed at the time of discharging a single sheet has also increased, and the distance popping out from the discharge port has become considerably larger than before, so when discharging a single sheet, Frequently, the trailing edge of a single sheet falling onto the stacking tray jumps over the leading edge of the full load detection flag kicked up by the sheet while drawing a parabola through the discharge port. In particular, in order to reduce the cost, a single sheet and a bundle of sheets stapled with staples are discharged from the same discharge port and further stacked on the same stacking tray. The stapled portion (the portion where the sheet bundle expands due to the staple) can be detected. As a result, the single sheet stacked on the stacking tray is in a state in which the trailing end of the sheet leans on the leading end of the full load detection flag. Then, the preceding sheet placed on the leading edge of the full load detection flag when the subsequent sheet is discharged is kicked out by the subsequent sheet when the full load detection flag is rotated upward and falls outside the stacking tray, disturbing the stackability. I was sorry.
[0006]
SUMMARY An advantage of some aspects of the invention is that it provides a sheet processing apparatus that does not disturb stacking alignment and an image forming apparatus including the sheet processing apparatus.
[0008]
[Means for Solving the Problems]
  the aboveThe present invention for achieving the objectofThe configuration accepts and conveys a sheet discharged from the image forming apparatus main body, and discharges the sheet from a discharge port.SaidLocated below the outlet,SaidA sheet stacking means for stacking sheets discharged from the discharge port;SaidIt has a rotation fulcrum above the discharge port,SaidA pivotable detection member that hangs down to the bottom of the discharge port, depending on the first position before discharging the sheet and the sheet when discharging the sheet.SaidA second position between the first position and the third position that is flipped up above the discharge port; and the height of the sheet surface is detected at the second position, andSheetThe detection member for detecting the full load of the sheets stacked on the stacking means and the sheet trailing edgeSaidAfter passing through the outletSaidWhen the detection member rotates and drops from the third position toward the second and first positions,SaidDetection memberofDelay means for delaying the rotational drop of the detection member so that the positions of the leading edge and the trailing edge of the sheet do not reverse in the direction of gravity.
[0009]
According to the above configuration, it is possible to reliably detect the full sheet load of the sheet stacking means by using the cheapest detection means using a flag without using an expensive full load detection means such as a light transmission sensor. The sheet stackability of the stacking means is not disturbed. Also, the positional relationship between the sheet and the detection member can be maintained by controlling the rotational fall speed of the detection member.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in the following embodiments should be appropriately changed according to the configuration of the apparatus to which the present invention is applied and various conditions. As long as there is no specific description, it is not the meaning which limits the scope of the present invention only to them.
[0011]
[Reference example]
  FIG.SheetFIG. 15 is a schematic cross-sectional view illustrating an overall configuration of a laser beam printer that is an example of an image forming apparatus including a processing device.Sheet1 is an overall perspective view of a laser beam printer as an example of an image forming apparatus including a processing device.
[0012]
(Overall configuration of image forming apparatus)
1 and 15, reference numeral 100A denotes a laser beam printer as an image forming apparatus, and reference numeral 100 denotes a laser beam printer main body (hereinafter referred to as a printer main body) as an image forming apparatus main body. The laser beam printer 100A is a computer, Alternatively, connected to a network such as a LAN, an image is formed (printed) on a sheet by a predetermined image forming process based on image information or a print signal sent from the computer or the network, and the sheet is discharged.
[0013]
Reference numeral 300 denotes a sheet processing apparatus. The sheet processing apparatus 300 is arranged above the printer main body 100, and passes a sheet discharged from the printer main body 100 to the outside of the apparatus via a conveyance unit in the sheet processing apparatus. In the face-down state with the image side down, the first intermediate stacking unit 300B is loaded into and mounted on the second intermediate stacking unit 300C (slide guides 301 and 302 described later), and then the second intermediate stacking described later. Alignment is performed using the alignment function of the unit 300C, the sheets are bundled for each predetermined job, one or more of the sheets are stapled and discharged and stacked on the sheet stacking unit 325, or the sheet stacking unit is simply face down 325 is discharged and loaded.
[0014]
Here, the sheet processing apparatus 300 and the printer main body 100 are electrically connected by a cable connector (not shown). In addition, the sheet processing apparatus 300 includes a casing part 300 </ b> A that stores each part, and is detachable from the printer main body 100.
[0015]
(Printer configuration)
Next, the configuration of each unit of the printer main body 100 will be described along the conveyance path of the conveyed sheet S.
[0016]
In the printer main body 100, a plurality of sheets S are stacked in the feeding cassette 200, and the uppermost sheet S1 is sequentially separated and fed one by one by various rollers. The sheet S fed from the feeding cassette 200 by a predetermined print signal supplied from a computer or a network is first placed on the upper surface of the image forming unit 101 that forms a toner image by a so-called laser beam type image forming process. The toner image is transferred, and subsequently, heat and pressure are applied by the fixing device 120 on the downstream side, whereby the toner image is permanently fixed.
[0017]
Next, the sheet S on which the image has been fixed is folded back in a substantially U-shaped sheet conveyance path up to the discharge roller 130, so that the image surface is reversed, and the image surface is thus on the lower side. Then, the printer body 100 is discharged face down to the outside.
[0018]
Here, the sheet S is face-down provided on the upper portion of the printer main body 100 by, for example, a discharge roller 130 according to the position of the flapper 150 of the printer main body 100 that rotates based on a control signal from a control unit (not shown). (FD) Whether to be discharged to the discharge unit 125 or to the sheet stacking unit 325 of the sheet processing apparatus 300 is selected.
[0019]
(Configuration of sheet processing apparatus)
Next, the configuration of the sheet processing apparatus 300 and the movement of each part when the sheet S conveyed from the printer main body 100 goes to the sheet processing apparatus 300 will be described with reference to FIGS. 2 and 3.
[0020]
In FIG. 2, 330a is a discharge upper roller, 330b is a discharge lower roller, M is a jogger motor as a driving source, 322 is a paddle, 323 is a reference wall for abutting the rear end of the sheet (end in the conveyance direction) at the time of alignment. is there. Here, as shown in the figure, the discharge roller pair 330 as discharge means composed of the discharge upper roller 330a and the discharge lower roller 330b is disposed on the downstream side in the sheet conveyance direction of the flapper 150 described above and is not used. It is rotationally driven by the illustrated drive motor.
[0021]
  Further, the discharge upper roller 330 a is pivotally supported by an arm 330 c that can rotate around a paddle shaft 350. The jogger motor M (see FIG. 1) is a drive source for driving slide guides 301 and 302 described later.hereIn stepping motors are used.
[0022]
Further, the paddle 322 serving as an alignment means at the end portion in the sheet conveyance direction is made of a flexible material such as rubber, and a plurality of paddles 322 are fixed to the paddle shaft 350 in a direction perpendicular to the sheet conveyance direction. When the sheet is discharged from the printer main body 100, the paddle shaft 350 is driven to rotate in the clockwise direction, whereby the sheet S moves in the direction opposite to the sheet conveying direction, and the rear end ( The end portion in the transport direction abuts on the reference wall 323 and is aligned. By providing the paddle 322 in this way, the consistency can be further improved.
[0023]
  As shown in FIG.,In the sheet processing apparatus 300, a slide guide 301 and a slide guide 302, which will be described in detail later, are provided as the second intermediate stacking unit 300 </ b> C (alignment unit) having a function of performing alignment in the width direction orthogonal to the sheet conveyance direction. ing. In the figure, H is a stapler that is a binding unit that staples the sheet bundle and performs a binding process on the sheet bundle.The hereThen, the stapler H is fixedly arranged on the slide guide 301 side in order to staple each sheet at the upper left corner of the image surface of the image-formed sheet and bind each sheet.
[0024]
The sheet processing apparatus 300 configured as described above is configured to perform stapling processing based on a command output in advance from a computer or the like. Before S is discharged by the conveying roller 121 (see FIG. 1) provided in the printer main body 100, the flapper 150 is rotated counterclockwise by a solenoid (not shown) as shown in FIG. The conveyance path is switched to the sheet processing apparatus side.
[0025]
As a result, the sheet S is carried into the sheet processing apparatus 300 by the conveying roller 121. The sheet S thus carried into the sheet processing apparatus 300 is detected by rotating the flag 391 of the entrance sensor 390 in the clockwise direction, thereby causing the flag 391 to transmit the photosensor 392. Thereafter, the sheet S is conveyed upward by the entrance roller pair 363.
[0026]
(Discharge loading operation)
  by the way,The sheet processing apparatus 300 is capable of stapling and discharging and stacking the sheets on the sheet stacking unit 325 and simply discharging and stacking on the sheet stacking unit 325 by face-down. Hereinafter, each discharge stacking operation will be described.
[0027]
(Face-down discharge loading)
First, an operation for discharging and stacking sheets on the sheet stacking unit 325 in a face-down manner will be described.
[0028]
In this case, as shown in FIG. 4A, the bottom surfaces of the slide guide 301 on the right side and the slide guide 302 on the left side with respect to the sheet carry-in direction are not in contact with the sheet S that is carried in, that is, the sheet S. Is retracted to a position outside by a predetermined amount from the width direction.
[0029]
Accordingly, after the sheet conveyed by the inlet roller pair 363 passes through the staple roller pair 320, the sheet S is conveyed at the position received from the printer main body 100 shown in FIG. Then, the sheet is conveyed by the discharge roller pair 330 without being offset in the sheet width direction by the slide guide, and drops toward the sheet stacking unit 325 as shown by the arrow in FIG. 4B and FIG. 2B. . At this time, the full load detection flag 600 as the detection member in FIG. 2A is pushed up by the sheet S around the rotation center 601 and rotates as shown in FIG.
[0030]
(Discharge loading after stapling)
Next, an operation of stapling sheets and discharging and stacking them on the sheet stacking unit 325 will be described.
[0031]
Here, as shown in FIG. 4A, the bottom surfaces of the slide guide 301 on the right side and the slide guide 302 on the left side with respect to the sheet loading direction do not come into contact with the sheet S being loaded, that is, the width of the sheet S. As shown in FIG. 3A, the reference pins 303 and 304 provided on the wall surfaces of the slide guides 301 and 302 are prevented from interfering with the loaded sheet S from a position outside the direction by a predetermined amount. The sheet S moves to a position more than a predetermined amount outside the width direction. Before this movement, the full load detection flag 600 rotates the arm 330c used as a drive means for the full load detection flag upward, and the cam surface of the flag 600 is pushed up by the cam surface of the arm 330c. Retreat to the position shown in FIG. In this state, the slide guides 301 and 302 are moved to the state shown in FIG. 4A, the full load detection flag 600 is inserted into the slide guides 301 and 302, and the arm 330c is lowered again to a position where the discharge roller pair 330 nips. Prepare for sheet loading. This is an initial operation at the time of staple stacking.
[0032]
At this time, the distance between the end surfaces of the bottom surfaces of the two slide guides 301 and 302 is smaller than the width of the sheet S, and the two slide guides 301 and 302 are in such a position (first position). The second intermediate stacking unit 300C that supports the sheet S entering can be configured.
[0033]
Accordingly, the sheet conveyed by the inlet roller pair 363 passes through the staple roller pair 320 and then passes through the gap between the staplers H and is then conveyed by the discharge roller pair 330 to be the second configured by the slide guides 301 and 302. Are conveyed onto the guide surface of the intermediate stacking unit 300C.
[0034]
  In addition,hereHowever, the arm 330c is used as the driving means for the full load detection flag 600, but the present invention is not limited to this. For example, a dedicated driving means may be provided separately.
[0035]
Here, as shown in FIG. 5A, the guide surface of the second intermediate stacking unit 300C is inclined at a predetermined angle with respect to the horizontal direction, and is mutually on the upstream side and the downstream side in the sheet carry-in direction. Specifically, a bent portion 300D that bends at an inclination angle α is formed between a predetermined section on the upstream side and a predetermined section on the downstream side. In addition, by having such a bent portion 300D, bending of the central portion of the sheet S that is not guided by the slide guides 301 and 302 forming the second intermediate stacking portion 300C is prevented.
[0036]
On the other hand, immediately after the first sheet is thus conveyed on the surface formed by the slide guides 301 and 302, the arm 330c rotates counterclockwise as shown in FIG. As a result, the discharge upper roller 330a pivotally supported by the arm 330c is retracted upward, and the discharge roller pair 330 is separated.
[0037]
(Configuration of slide guide)
Here, the configuration of the slide guides 301 and 302 will be described in detail.
[0038]
As shown in FIG. 3, each of the slide guides 301 and 302 is guided by a total of four guide pins 313a provided on the mold frame F and guide pins 313b provided on the sheet metal frame F ′. It can be reciprocated in the left-right direction, that is, the direction (width direction) perpendicular to the sheet conveying direction, and moved by the driving force from the jogger motor M.
[0039]
Further, when viewed from the downstream side in the sheet conveyance direction, the slide guides 301 and 302 are each a wall portion that guides both sides of the sheet S and a support portion that supports the upper and lower surfaces of the sheet S, as shown in FIG. And has a substantially U-shaped cross section, and the lower surface of the U-shape supports each sheet discharged onto the first intermediate stacking unit 300B and carried into the second intermediate stacking unit 300C. In addition, the central portion of the sheet S in the width direction is not guided.
[0040]
Further, the slide guide 302 is provided with a slide rack 310 having a flat gear that meshes with the step gear 317. A slide rack 312 having a flat gear that meshes with the step gear 317 is also attached to the slide guide 301.
[0041]
Here, the slide rack 312 is provided to be movable relative to the slide guide 301 via a coiled spring 314. The spring 314 has one end abutting on the slide guide 302 and the other end abutting on the slide rack 312 and urges the slide guide 301 and the slide rack 312 to expand. The slide rack 312 has an embossed portion 312a that moves the square hole portion 301a on the slide guide 301 side.
[0042]
Further, two reference pins 303 made of metal having excellent wear resistance are provided on the side wall of the slide guide 301, and two reference pins 304 are provided on the side wall of the slide guide 302, respectively. When doing so, the slide guide 302 moves as described above, and the reference pin 304 and the pin 303 come into contact with the both side end faces 305 and 306 of the sheet.
[0043]
The slide guide 301 and the slide guide 302 are supported in the height direction by a step gear 317 and a jog sheet metal frame F ′.
[0044]
(Slide guide operation)
Next, the operation of each slide guide 301, 302 will be described.
[0045]
When the sheet processing apparatus 300 is turned on, the staple roller pair 320 starts rotating, and then the jogger motor M rotates and the step gear 317 rotates, so that the rack 310 of the slide guide 302 is driven to the outside. evacuate.
[0046]
In addition, when the jogger motor M rotates and the step gear 317 rotates, the slide guide 301 first moves the slide rack 312 relatively, and the embossed portion 312a of the slide rack 312 moves to the right side of the square hole portion 301a of the slide guide 301 in FIG. After coming into contact with the end face, it is retracted to the outside by being pressed by the embossed portion 312a.
[0047]
The slide guide 301 is provided with a slit portion 301S, and when the slit portion 301S moves to a predetermined retraction distance, the photosensor 316 transmits light as shown in FIG. Stops. Hereinafter, this position is referred to as a home position.
[0048]
On the other hand, when a signal that the sheet S enters the sheet processing apparatus 300 is input from the printer main body 100, the jogger motor M rotates, the slide guides 301 and 302 move inward, and the sheet that enters as shown in FIG. Stop at a position wider than the width of S by a predetermined amount d. At this position, the slide guide 301 is in a state where the stopper 301b abuts against the guide pin 313a and cannot move further inward. Hereinafter, this position is referred to as a standby position. In this standby position, the side surface of the slide guide 301 becomes the reference position for the alignment operation.
[0049]
  hereThe standby positions of the slide guides 301 and 302 are set so that the gaps on both sides are equal to or larger than the predetermined amount d when the size (width) of the sheet S is the maximum size that can be passed.
[0050]
When aligning a narrower sheet than this, the slide guide 302 moves to the right by an amount corresponding thereto, so that the left gap at the standby position shown in FIG. . On the other hand, in this case, the gap between the sheet and the slide guide 302 widens by half the amount that is narrower than the predetermined amount d.
[0051]
On the other hand, as shown in FIG. 6, after the alignment in the width direction is performed by the slide guides 301 and 302, both the slide guides 301 and 302 are retracted to the outside by a small amount, thereby restricting the alignment direction of the sheet S to a rough state. The sheet S is brought into a movable state in the sheet conveyance direction. Thereafter, as shown in FIG. 5 (b), the paddle 322 rotates once while contacting the upper surface of the sheet S in the clockwise direction around the paddle shaft 350, whereby the sheet S is abutted against the reference wall 323. Align.
[0052]
These operations enable alignment in the sheet conveying direction and the width direction. In order to maintain such an aligned state, a lever 400b provided with a friction member 400a as shown in FIG. 7 described later is provided in the vertical direction in the vicinity of the right end surface of the aligned sheet as shown in FIG. A stamp means 400 is provided for pressing the aligned sheet S after moving to.
[0053]
Then, after the aligning operation is completed by the stamp unit 400, the sheet in the aligned state is moved by pressing the upper surface of the sheet before the next entering sheet contacts the aligned sheet. Therefore, the alignment is prevented from being disturbed.
[0054]
Note that after the alignment of the first sheet is completed in this way, the second sheet is conveyed. In this case, the discharge roller pair 330 is separated when the second and subsequent sheets are conveyed. Therefore, when the trailing edge of the sheet S completely passes through the staple roller pair 320, the sheet returns to the direction opposite to the conveyance direction by its own weight and moves toward the reference wall 323. Since the alignment operation from here is exactly the same as that of the first sheet, description thereof is omitted.
[0055]
Then, such an operation is repeated to perform an operation of aligning the last (nth) sheet (Sn) of one job, and each reference pin 304 provided on the slide guide 302 moves the left side surface of the sheet along the slide guide 301. 6 in a state where the movement of the slide guide 302 is stopped, the position on the right side of the rear end is stapled by a small stapler H located on the right side of the rear end of the sheet bundle.
[0056]
Here, according to this configuration and operation, during the alignment operation of each sheet, the slide guide 301 stops and does not move at the reference position, and only the slide guide 302 moves and the left end portion of each sheet moves to the reference position. Thus, the binding process by the stapler H fixedly arranged on the slide guide 301 side is performed accurately and reliably.
[0057]
Furthermore, even when the width of each sheet carried in one job varies or when the sheet size changes within one job, for example, from LTR to A4, the position of the left end of each sheet is made uniform. Therefore, the finish of the binding process by the stapler H becomes accurate and beautiful, and an excellent effect is obtained.
[0058]
On the other hand, when the stapling operation is completed in this way, as shown in FIG. 5C, the arm 330c rotates in the clockwise direction, so that the discharge upper roller 330a supported on the arm 330c is moved downward. As a result, the discharge roller pair 330 is formed, and at the same time, the discharge roller pair 330 is driven to start the rotation of the discharge upper roller 330a and the discharge lower roller 330b. As a result, the sheet bundle S is sandwiched between the discharge roller pair 330 and conveyed onto the second intermediate stacking unit 300 </ b> C formed by the slide guides 301 and 302.
[0059]
After that, when the sheet bundle S is completely discharged from the discharge roller pair 330, the jogger motor M is rotationally driven to move the slide guide 302 from the state shown in FIG. When the slide guide 302 starts to move, the slide rack 312 moves to the right in FIG. 6 on the slide guide 301 side, and the slide guide 301 itself does not move immediately.
[0060]
When the position of the slide guide 302 passes the standby position shown in FIG. 3, the embossed portion 312a of the slide rack 312 comes into contact with the end surface of the square hole portion 301a of the slide guide 301, and the slide guide 301 is moved to the right side in FIG. The movement starts and both slide guides 301 and 302 move.
[0061]
  After this, when the distance between the slide guides 301 and 302 becomes near or wider than the width of the sheet, the stapled sheet bundle supported by the slide guides 301 and 302 is as shown in FIG. The sheet falls downward and is stacked on the sheet stacking unit 325. More than,2 shows a configuration and a series of operations of a printer main body and a sheet processing apparatus.
[0062]
  By the way, as already mentionedhereIn this case, the sheet processing apparatus 300 is mounted on the upper portion of the printer main body 100, and the conveyance path of the sheet discharged from the printer main body 100 is switched by the flapper 150 so that the sheets can be reversed and stacked. .
[0063]
Here, the sheet processing apparatus 300 is mounted on the upper portion of the printer main body 100 in this way, and the sheets are reversed and discharged and stacked, whereby the sheets on which images have been formed are discharged in the order of pages without providing a switchback mechanism. Can be loaded. Further, there is no inconvenience that the sheet interval has to be widened for switchback.
[0064]
As described above, in the printer main body 100 that discharges the sheet to the upper surface of the apparatus, the sheet processing apparatus 300 is provided above the discharge unit on the upper surface of the apparatus main body, and the sheet is reversed or in a reversed state. By selectively performing an operation of discharging the sheet stacking unit 325 after processing the sheet, the configuration of the sheet processing apparatus 300 can be simplified, and the sheet processing apparatus 300 and the sheet processing apparatus 300 are provided. In addition, the installation area and cost of the printer main body 100 can be reduced.
[0065]
In the above description, only the slide guide 302 operates and the slide guide 301 does not operate during the sheet alignment operation. However, the slide guide 301 may operate during the sheet alignment operation. In this case, for example, the slide guide 301 can be realized by using the same configuration as the slide guide 302.
[0066]
Furthermore, although the two slide guides 301 and 302 are configured to operate when the sheet after the alignment operation is dropped downward, only one of the slide guides 301 and 302 may be configured to operate when the sheet S is dropped downward.
[0067]
In the description so far, the case where the binding process is performed as the process for the sheet has been described, but according to this configuration, the puncher for punching the sheet or the sheet for performing the process of creating a sheet bundle by gluing the sheet. The same effect can be obtained with the processing apparatus.
[0068]
Incidentally, FIG. 7 is a view showing the structure of the stamp means 400 described above which is an alignment deviation prevention means. As shown in FIG. 7, the stamp means 400 is provided with a friction member 400a at the tip and a shaft 400c. An arm lever 400b that is a pivotable pressing member as a fulcrum, a solenoid 401 that is a releasing means for rotating the arm lever 400b to release the pressing operation of the arm lever 400b, and an arm lever 400b in the direction of an arrow 402, that is, A torsion coil spring (not shown) that urges the sheet S in a direction to press the sheet S in the direction of the slide guide 301 is provided.
[0069]
Here, during the discharging operation, the arm lever 400b of the stamp unit 400 is positioned outside the sheet conveyance path through which the succeeding sheet Sb passes the aligned preceding sheet Sa as shown in FIG. 7 by the force of the torsion coil spring. In other words, the pressing is performed at a position outside the sheet passing range.
[0070]
As a result, the arm lever 400b can be prevented from coming into contact with the succeeding sheet Sb to be discharged next, and the preceding sheet Sa that is already held in alignment with the second intermediate stacking unit 300C is the succeeding sheet. It is possible to prevent extrusion by Sb.
[0071]
On the other hand, when the succeeding sheet Sb is completely discharged, the succeeding sheet Sb moves in the direction of the arrow 403 shown in FIG. And while the succeeding sheet Sb moves in this way, the solenoid 401 is turned on. As a result, the arm lever 400b rotates in the direction of the arrow 404 shown in FIG. 8B, and as a result, the succeeding sheet Sb enters under the arm lever 400b.
[0072]
  After this, after the alignment in the sheet conveyance direction by the paddle 322 is performed, the slide guide 302 returns to the standby position.hereThe solenoid 401 is turned off before the slide guide 302 returns to the standby position and the preparation for carrying in the succeeding sheet is completed. As a result, the arm lever 400b presses the preceding sheet Sa again, and as a result, the preceding sheet Sa can be prevented from being pushed out by the subsequent sheet Sb that is subsequently conveyed.
[0073]
(Full load detection flag and discharge speed)
  Next, the full load detection flag and the sheet discharge speed setting will be described. FIG.Reference exampleFIG. 6 is a diagram comparing the position 901 of the full load detection flag in FIG.
[0074]
  As shown in FIG.Reference exampleCompared with the conventional full load detection flag position 900, the full load detection flag position 901 has a detection surface (the front end of the flag) in the vicinity of the standing wall 902 of the stacking tray 325 as the sheet stacking means. Note that the one-dot chain line arc drawn at the tip of each flag is the tip trajectory when each flag rotates about its fulcrum. This stacks a single sheet and a sheet bundle bound with the stapler H on the same tray 325, and the staple bundle sheet is a staple binding portion located on the upstream side in the sheet conveying direction, that is, near the standing wall 902. However, unlike the substantially linear stacking upper surface 903 that follows the tray surface as seen in single sheet stacking, the upper surface 904 swells due to the stacking, so that it corresponds to this.
[0075]
  Also,Although the printer main body 100 that feeds sheets to the sheet processing apparatus 300 is small, the number of sheets conveyed per minute is large, and the interval between the preceding sheet and the succeeding sheet (hereinafter referred to as sheet interval) is very narrow. For this reason, when sheets are successively carried into the sheet processing apparatus 300 in a state where the sheet interval is narrow, and when the preceding sheet is discharged from the discharge port of the sheet processing apparatus 300, the full load detection flag 600 bounced up by the preceding sheet. Is detected by the succeeding sheet before the full load on the sheet stacking tray 325 is detected, and the full load detection flag 600 has no time to detect the full load, and the full load detection flag 600 remains always full. May be misdetected.
[0076]
  For that reason,hereIn the sheet processing apparatus, the first, second, and third conveying speeds are appropriately selected using the inlet roller pair 363, the staple roller pair 320, and the discharge roller pair 330, which constitute a conveying unit that conveys the sheet. I am trying to transport it. The first transport speed is a transport speed for receiving a sheet from the printer main body 100, the second transport speed is a transport speed for transporting the inside of the sheet processing apparatus 300, and the third transport speed is a discharge port of the sheet processing apparatus 300. This is the conveyance speed when discharging the trailing edge of the sheet. When a sheet is conveyed using these three types of conveyance speeds, the time during which a single sheet is held in the sheet processing apparatus passes through the sheet processing apparatus at a constant speed while maintaining the first conveyance speed. It is set to be the same as or less than the time to be performed. This will be described in detail below.
[0077]
First, the sheet conveyance speed in the sheet processing apparatus 300 is detected based on the sheet size after the leading edge position of the sheet is detected by the inlet sensor 390 disposed near the inlet roller pair 363 of the sheet processing apparatus 300 shown in FIG. At a different predetermined timing, the speed is increased to a second transport speed that is faster than the first transport speed when the sheet is received in the sheet processing apparatus 300 (for example, the staple roller pair 320 and the discharge roller pair 330 are not illustrated). The conveyance motor is increased by about 1.6 times) to increase the sheet interval with the succeeding sheet. However, the predetermined timing that varies depending on the sheet size is the timing at which the trailing edge of the sheet received in the sheet processing apparatus 300 passes through the fixing device 120 of the printer main body 100, and this timing is measured from the detection of the leading edge of the sheet. Measured in advance for each sheet size and set on the software.
[0078]
By performing this speed increase, the sheet interval is opened several times as compared to before the speed increase, so that the full load detection flag 600 can be detected, and only the printer main body 100 can be detected without reducing the productivity on the printer main body 100 side. It can be maintained according to the specifications when used in
[0079]
However, as an adverse effect of the speed increase, when the sheet is discharged at the speed increasing speed, the rear end of the sheet S jumps over the front end of the full load detection flag 600 as shown in FIG. In FIG. 10A, the positional relationship between the full load detection flag 600 and the sheet S is not reversed in the direction of gravity, but the sheet S having a larger air resistance than the full load detection flag 600 is as shown in FIG. Then, the trailing end draws a parabolic locus 906, and jumps over the leading end locus 905 of the full load detection flag 600 during the fall. The time until the sheet S reaches the stacking tray 325 is longer than the time until the full load detection flag 600 returns to the home position (first position) before the sheet is discharged. The vertical relationship in the direction of gravity of the full load detection flag 600 is reversed as shown in FIG. 10C, and the rear end of the sheet S is landed on the front end of the full load detection flag 600. Thereafter, when the full load detection flag 600 is flipped up by the subsequent sheet, the preceding sheet S is repelled by the full load detection flag 600 and falls from the stacking tray 325.
[0080]
The full load detection flag 600 is a rotatable detection member that has a rotation fulcrum above the discharge port and hangs down to the lower side of the discharge port. And a second position (full load detection position) between the first and third positions, and the height of the seat surface at the second position. And the full load of the sheets stacked on the stacking tray 325 is detected.
[0081]
  As a countermeasure to the above problem,hereThen, before the predetermined timing when the trailing edge of the sheet passes through the discharge port of the sheet processing apparatus 300, the sheet discharge speed is decelerated to the predetermined speed obtained by measurement, as shown in FIGS. The sheet S is landed on the stacking surface at a position where the trailing edge locus 906 of the sheet S does not jump over the leading edge locus 905 of the full load detection flag 600 at all positions where the sheet S is falling. That is, the conveyance speed for discharging the trailing edge of the sheet from the discharge port is reduced to a third conveyance speed (sheet discharge speed) that is slower than the second conveyance speed increased as described above. It should be noted that the predetermined speed (sheet discharge speed) obtained by the above-described measurement is that the trailing edge trajectory 906 of the sheet S is the full load detection flag at all positions where it is falling, as shown in FIGS. This is the speed at which the sheet S is landed on the stacking surface at a position that does not jump over the leading end locus 905 of 600.
[0082]
  Also,hereIn order to reduce costs, the conveyance system of the sheet processing apparatus 300 is driven by a single conveyance motor (stepping motor). Therefore, it is difficult to make a sufficient sheet interval due to the fact that all the conveyance rollers have a short conveyance section that can be accelerated for further downsizing, and further there is an upper limit of the acceleration of the conveyance motor. . When the trailing edge of the preceding sheet passes through the discharge port of the sheet processing apparatus 300, the leading edge of the succeeding sheet is reduced by reducing the discharging speed to a speed at which the trailing edge of the sheet does not jump over the leading edge of the full load detection flag 600. It will rush into the inlet roller pair 363. Therefore, the conveyance speed of the sheet processing apparatus 300 is reduced by lowering the deceleration speed (third conveyance speed) of the discharge speed to the fixing speed of the printer body and pulling the sheet between at least the sheet processing apparatus 300 and the printer body 100. This prevents the occurrence of step-out.
[0083]
In addition, in the case of staple alignment, as in the case of single sheet conveyance control, the speed is increased in the middle to widen the sheet interval and create the time required for sheet alignment. I try not to drop it.
[0084]
  As mentioned above,Reference exampleAccording to the present invention, a sheet stacking tray capable of stacking both a single sheet and a stapled sheet can be used by using the detection means based on the cheapest full load detection flag without using a light transmission type expensive full load detection means. Full load can be detected reliably, and the stackability of sheets is not disturbed. Furthermore, when the sheet is being conveyed through the sheet processing apparatus, the sheet is discharged from the printer body at a speed higher than the conveyance speed of the sheet. In discharging the sheets, the sheets can be stacked without adversely affecting the productivity on the printer main body side.
[0085]
[No.1Embodiment)
  The following is the first in the present invention.1Embodiments will be described. However, the outline description of the image forming apparatus and the sheet processing apparatus is as follows.Reference exampleIs the same as the contents explained in, so the explanation will be excluded below.Reference exampleOnly the differences will be explained.
[0086]
  This embodiment is the aboveReference exampleThe difference is that, as shown in the perspective view of FIG. 12, a one-way type friction pad 910 is provided as a delay means at the rotation fulcrum of the full load detection flag.
[0087]
Since the friction pad 910 is a one-way type, the friction pad 910 does not act when the full load detection flag 600 is bounced by the front end of the sheet, and is smoothly raised. After that, the full load detection flag 600 that has been bounced has a first pivotal fulcrum that follows the sheet when the trailing edge of the sheet passes through the discharge port and the sheet is dropped and stacked on the stacking tray by its own weight. , It begins to rotate and drop toward the second full load detection flag position. At this time, as shown in FIGS. 13A to 13D, the full load detection flag 600 is affected by the friction pad 910 only at the time of rotating and dropping, and slowly starts to rotate and drop downward. The friction coefficient of the friction pad 910 is lower than the speed at which the sheet drops, and before the leading edge of the succeeding sheet jumps up the full load detection flag, the drop has been completed to the first and second positions, and The frictional force is set in advance so that the sensor is dropped within a time period in which the full state on the stacking tray 325 can be confirmed by a sensor (not shown).
[0088]
  As a result, the positional relationship between the full load detection flag 600 and the sheet S does not need to be reversed in the direction of gravity, and it is possible to prevent the sheets from being kicked out by the full load detection flag 600 and ejected out of the stacking tray 325. Can do. In this embodiment, as shown in FIG.Reference exampleSince the drop speed of the full load detection flag 600 is set to be slower than that, it is possible to widen the setting range of the sheet discharge speed (third conveyance speed).
[0089]
[No.2Embodiment)
The following is the first in the present invention.2Embodiments will be described. However, the outline description of the image forming apparatus and the sheet processing apparatus is as follows.Reference exampleIs the same as the contents explained in, so the explanation will be excluded below.Reference examples andFirst1Only portions different from the embodiment will be described.
[0090]
In the present embodiment, when the full load detection flag 600 is bounced at the leading end of the sheet and moves to the third position, as shown in FIG. A stopper member 920 for stopping is provided.
[0091]
FIG. 14A is a diagram illustrating a state in which the full load detection flag 600 is flipped up to the third position by the seat. At that time, the stopper member 920 is at the position shown in FIG. Thereafter, before the trailing edge of the sheet S passes through the discharge port, the stopper member 920 is rotated by a solenoid (not shown) as shown in FIG. 14B, and the full load detection flag 600 is rotated by its own weight even after passing the sheet. In order not to fall, the stopper 921 near the rotation fulcrum of the full load detection flag 600 is hooked, and the full load detection flag 600 is stopped at the third position shown in FIG.
[0092]
As shown in FIGS. 14C to 14D, the stopper member 920 releases the stopper member 920 as shown in FIG. 14D when the sheet S falls on the stacking tray 325. The full load detection flag 600 is rotated and dropped. However, before the succeeding sheet jumps up the full load detection flag 600, the full load detection flag 600 is released to the first and second positions, and the stopper member 920 is released within a range that allows sufficient time for full load detection. The amount of increase in the conveyance speed of the sheet being conveyed is also set accordingly. The drop timing of the full load detection flag 600 can be set to an appropriate drop timing of the full load detection flag 600 for each sheet size based on the sheet size information received from the printer main body 100.
[0093]
  Thus, the positional relationship between the full load detection flag 600 and the sheet S does not need to be reversed in the direction of gravity, and it is possible to prevent the sheets from being kicked out by the full load detection flag 600 and ejected out of the stacking tray 325. it can. In this embodiment, as shown in FIG.Reference exampleUnlike the full load detection flag 600, the drop timing of the full load detection flag 600 is controlled, so that the setting range of the sheet discharge speed (third conveyance speed) can be widened.
[0094]
[Other Embodiments]
  Mentioned aboveReference examples andIn the embodiment, the printer is exemplified as the image forming apparatus. However, the present invention is not limited to this. For example, the image forming apparatus may be another image forming apparatus such as a copying machine or a facsimile machine, or a multi-function machine combining these functions. The same effect can be obtained by applying the present invention to a sheet processing apparatus used in the image forming apparatus.
[0095]
  Also mentioned aboveReference examples andIn the embodiment, the sheet processing apparatus that is detachable from the main body of the image forming apparatus is illustrated, but the present invention is not limited to this. For example, the sheet processing apparatus that the image forming apparatus integrally has may be used. The same effect can be obtained by applying the present invention to the sheet processing apparatus.
[0096]
  Also mentioned aboveReference examples andIn the embodiment, the electrophotographic method is exemplified as the recording method. However, the recording method is not limited to this, and other recording methods such as an ink jet method may be used.
[0097]
【The invention's effect】
  As described above, according to the present invention, it is possible to reliably detect the full load of sheets in the sheet stacking means using the cheapest detection member without using an expensive full load detection means of the light transmission type. Does not disturb the stackability of sheets in the sheet stacking means.
[0098]
Also, the positional relationship between the sheet and the detection member can be maintained by controlling the rotational fall speed of the detection member. In addition, the sheet conveyance speed can be controlled by controlling the rotation and dropping speed of the detection member together to widen the setting range of the sheet conveyance speed.
[Brief description of the drawings]
[Figure 1]SheetSchematic sectional view showing the overall configuration of a laser beam printer as an example of an image forming apparatus provided with a processing device
FIG. 2 is a diagram illustrating the configuration of the sheet processing apparatus and the movement of each unit when a sheet conveyed from the printer main body is directed to the sheet processing apparatus.
FIG. 3 is a plan view and a side view of main parts of the sheet processing apparatus.
FIG. 4 is a diagram illustrating a state where a sheet bundle is dropped when a slide guide provided in the sheet processing apparatus is located at a home position.
FIG. 5 is a diagram for explaining the movement of each part in the processing operation of the sheet processing apparatus.
FIG. 6 is a diagram illustrating a state in which sheets are aligned by the slide guide.
FIG. 7 is a diagram illustrating a configuration of stamp means provided in the sheet processing apparatus.
FIG. 8 is a diagram illustrating a state of the stamp portion when the sheet is aligned.
FIG. 9Reference exampleFigure comparing the position of the full load detection flag with the position of the conventional full load detection flag
FIG. 10Reference exampleThe figure explaining the full load detection flag at the time of not performing the speed control which concerns on, and the fall locus | trajectory of a sheet | seat
FIG. 11Reference exampleIs a diagram for explaining a full load detection flag and a sheet fall locus when speed control is performed
FIG. 121The figure explaining the position of the friction pad which adjusts the rotation fall speed of the full load detection flag concerning an embodiment
FIG. 131The perspective view explaining the full load detection flag and the fall locus of a sheet concerning an embodiment
FIG. 142The figure explaining the movement of the stopper member of the full load detection flag and sheet fall locus, and the full load detection flag according to the embodiment
FIG. 15SheetOverall perspective view of a laser beam printer as an example of an image forming apparatus provided with a processing device
[Explanation of symbols]
F ... Mold frame
F '... Sheet metal frame
H ... Stapler
M: Jogger motor
S, S1, Sa, Sb ... sheet
100: Printer body
100A ... Laser beam printer
101 Image forming unit
120: Fixing device
121 ... Conveying roller
125 ... Face-down (FD) discharge section
130 ... discharge roller
150 ... Flapper
200 ... Feed cassette
300 ... Sheet processing apparatus
300A ... casing part
300B ... 1st intermediate loading part
300C second intermediate loading section
300D ... Bent part
301, 302 ... slide guide (second intermediate stacking portion)
301S ... slit part
301a ... Square hole
301b ... stopper
303, 304 ... reference pin
305, 306 ... end face
310 ... slide rack
312 ... slide rack
312a ... Embossed part
313a, 313b ... guide pins
314: Spring
317 ... Step gear
320 ... Staple roller pair
322 ... Paddle
323 ... Reference wall
325 ... Sheet stacking unit (tray)
330 ... discharge roller pair
330a ... discharge upper roller
330b ... discharge lower roller
330c ... arm
350 ... Paddle shaft
363: Inlet roller pair
390 ... Entrance sensor
391 ... Flag
392 Photosensor
400… Stamp means
400a ... friction member
400b ... lever
400c ... axis
401 ... Solenoid
600 ... Full load detection flag
900, 901 ... position
902 ... Standing wall
903, 904 ... Loading surface
905 ... Flag tip locus
906 ... Seat rear end locus
910 ... friction pad
920 ... stopper member
921 ... Stopper part

Claims (5)

A sheet conveying means for receiving and conveying the sheet discharged from the image forming apparatus main body, and discharging it from the discharge port;
Is arranged below the outlet, a sheet stacking means for stacking the sheets discharged from the discharge port,
Has a rotation fulcrum on the outlet upward, a rotatable sensing member hung down to the lower of the discharge port, a first position before the sheet discharge, said discharge port upward by the sheet during the sheet ejection There is a third position that is flipped up and a second position between the first and third positions, and the height of the sheet surface is detected at the second position and stacked on the sheet stacking means. A detection member for detecting the full load of the sheet,
Said detecting member after the sheet trailing edge passes the outlet first from the third position 2, when the rotation falls in the first position direction, the position gravity direction of the distal end and the sheet trailing edge of the detecting member A delay means for delaying the rotational drop of the detection member so as not to reverse in
A sheet processing apparatus comprising: It said delay means, the sheet processing apparatus according to claim 1, wherein the braked in rotation dropping direction of the detecting member is a friction pad of the one-way type which slow down. Said delay means, the sheet processing apparatus according to claim 1, characterized in that the rotation of the detecting member in the third position is a stopper member for stopping a predetermined time. The sheet processing apparatus according to claim 3, wherein the timing at which the stopper member releases the rotation stop of the detection member is set differently depending on a sheet size. An image forming apparatus comprising: an image forming apparatus main body having an image forming unit that forms an image on a sheet; and a sheet processing apparatus that selectively processes a sheet discharged from the image forming apparatus main body.
Examples sheet processing apparatus, an image forming apparatus characterized by comprising a sheet processing device according to any one of claims 1 to 4.

Images