JP2007091370A - Sheet processing device, and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet processing device capable of delaying the interruption of the work by the determination of the full condition by allowing a plurality of stack trays 18a, 18b to be in a full condition. <P>SOLUTION: When the full condition of a stack tray 18a on the upper stage is determined, the delivery destination is changed to a stack tray on the lower stage and the loading is continued without any other change. When the full condition of a stack tray 18b on the lower stage is determined, the full condition is firstly processed to prohibit the further delivery of the sheets. Since the stack tray 18a on the upper rank is preferentially filled, the lowering position of the stack tray 18b can be kept higher than that when the stack tray 18b on the lower rank is filled, and the interference with a saddle tray 106 arranged below a stack tray 18c or the book-bound sheet bundle stacked on the saddle tray 106 can be avoided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile machine, and a multifunction machine, a sheet processing apparatus that accepts and processes a sheet discharged from another office machine, and an image forming apparatus having a built-in / connected sheet processing apparatus. About.

  Sheet processing that accepts sheets discharged from image forming apparatuses such as copiers, printers, facsimiles, etc., and performs various processes such as alignment, sorting, stacking, folding, envelope filling, binding processing, bookbinding, punching, inspection, and processing The device has been put into practical use. Also, in an image forming apparatus such as a copying machine, such a sheet processing apparatus is built in or connected as a purchase option (so-called option).

  A sheet processing apparatus disclosed in Patent Document 1 includes upper, middle, and lower three-stage sheet stacking members (stack trays), and a stack tray is positioned below a discharge member (downstream discharge roller pair), and a downstream discharge roller. The sheet is discharged from the pair and loaded.

  The sheet processing apparatus disclosed in Patent Document 1 has a full load standard for each stage of a plurality of stack trays, and stops loading when a predetermined bundle discharge is completed when the full load standard is met in the stacking process. .

  The sheet processing apparatus disclosed in Patent Document 1 includes a distance measuring sensor above the stack tray and measures the distance to the uppermost sheet, that is, the stacking surface. As the stacking progresses, the stack tray is gradually lowered so that the height of the stacking surface measured by the distance measuring sensor is kept constant.

JP 11-322180 A

  In the sheet processing apparatus disclosed in Patent Document 1, an individual full load standard is set for each stage of the stack tray, and loading is judged to have stopped when the full standard is met in the stacking process. Even if there is room, loading and image formation are interrupted.

  Once the full load determination is made, an operation to take out the sheet bundle from the stack tray and reset the stack tray is necessary. At this time, if there is a half-loaded stack, the full load determined There is a possibility that the sheet bundle is taken out by mistake.

  Further, in the sheet processing apparatus shown in Patent Document 1, a full load standard with a margin is provided, and the stacking is continued until the bundle discharge is completed even after the full load determination, but with the full load standard with a margin, The number of sheets that can be stacked on the stack tray has decreased, and the time for full loading has been advanced, and conversely, full load judgment has been made frequently, and work has been interrupted.

  If the image formation is frequently stopped, the operation rate of the system is lowered. If the sheet bundle is frequently taken out from the stack tray, the number of work steps is increased and a work mistake is likely to occur.

  By the way, in the sheet processing apparatus disclosed in Patent Document 1, the lower the stack position of the lower stack tray, the lower the room for lowering the upper stack tray, and accordingly, the sheets stacked on the upper stack tray. You can increase the number.

  However, when the standby position of the lower stack tray is lowered, the lower stack tray is lowered toward the standby position, and the lower stack tray is placed on the saddle tray disposed below the stack tray and the sheet stack loaded on the saddle tray. There is a high possibility that the stack tray will interfere.

  When the interference actually occurs, an overload of the motor is detected, an error is stopped, a complicated return operation is required, and the sheet bundle stacked on the saddle tray may be damaged.

  Therefore, in order to avoid such interference, the standby position with a margin was set for the lower stack tray, but this margin reduces the lowering space of all the stack trays and reduces the number of stacked sheets. As a result, the time of full loading was accelerated.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet processing apparatus capable of delaying a work interruption due to a full load judgment by bringing all the sheet stacking members (stack trays) close to full load.

  The sheet processing apparatus according to the present invention includes a plurality of sheet stacking members that are vertically arranged and can be moved up and down, a discharge member that can discharge the sheets to the plurality of sheet stacking members, and a sheet stacking member that is disposed below the discharge member. And a control means for discharging the sheet to the sheet processing apparatus, wherein the control means determines a stacking amount of the plurality of sheet stacking members before starting stacking, The stacking is started from the sheet stacking member.

  Then, the control unit stacks the sheets until the predetermined full load standard is satisfied with the upper sheet stacking member, and then continues stacking with the lower sheet stacking member, whereby the lower sheet stacking member is continued. A series of loading processes can be continued until the member meets a predetermined full load standard.

  In the sheet processing apparatus of the present invention, the stacking amount of the plurality of sheet stacking members is determined before starting stacking, and stacking is started from the upper stackable sheet stacking member. When left unattended, the lower sheet stacking member does not start stacking sheets, so that the upper sheet stacking member is halfway stacked and the lower sheet stacking member determines the full load. Loading is not interrupted. Accordingly, it is possible to undoubtedly take out a sheet bundle for which fullness is determined by taking out sheets in order from the upper level.

  Even if the full load standard is met with one sheet stacking member, the stacking is automatically transferred to another sheet stacking member and the stacking is continued. Not interrupted.

  In addition, since the upper sheet stacking member is fully loaded and moved upward, the sheets are stacked on the lower sheet stacking member, so that the lower sheet is loaded more than when the lower sheet stacking member is loaded first. The amount of descent required for the stacking member is small, in other words, the sheets stacked on the lower sheet stacking member do not interfere with the lowering space of the upper sheet stacking member. The standby position of the lower sheet stacking member can be set higher accordingly.

  In addition, the standby position of the lower sheet stacking member is set at a height that does not interfere with another sheet stacking member that is fixedly disposed below the sheet stacking member or a sheet bundle stacked on another sheet stacking member. Thus, it is possible to avoid an error stop, a complicated return operation, and damage to the sheet bundle without slightly increasing the full load time at each stage.

  Also, compared to the case where loading is judged for each level and loading is interrupted, stacking can be continued for a long time until multiple levels are full, reducing the number of sheet bundle removal and sheet stacking member resets. Thus, work errors can be reduced and the operating rate of the sheet processing apparatus can be improved.

  The sheet processing apparatus of this embodiment will be described with reference to the drawings. FIG. 1 is a front view of an image forming apparatus to which the sheet processing apparatus of the present embodiment is connected, FIG. 2 is a block diagram of a control system of the image forming apparatus, FIG. 3 is an explanatory diagram of the configuration of the finisher unit, and FIG. FIG. 5 is an explanatory diagram of the drive unit of the tray unit, FIG. 6 is an explanatory diagram of the swing guide, FIG. 7 is an explanatory diagram of the snoco shutter open state, and FIG. 8 is an explanatory diagram of the snoco shutter closed state. FIG. 9 is a plan view of the stapler, and FIG. 10 is a flowchart of sheet discharge control.

  The sheet processing apparatus B of the present embodiment includes, for example, stack trays 18a, 18b, and 18c that are sheet stacking members, a downstream discharge roller pair 17 that is a discharge member, and a finisher control unit 211 that is a control unit, for example. The image forming apparatus according to the present exemplary embodiment includes an image forming unit 3 that is an image forming unit and a sheet processing apparatus B that is a processing unit.

<About copier>
As shown in FIG. 1, the copying machine E is configured by connecting a sheet processing apparatus B to an apparatus main body A. The sheet processing apparatus B includes a finisher unit C that sorts the sheets P formed by the apparatus main body A for each number of copies, and a stitcher unit D that performs a bookbinding process for binding and folding a plurality of sheets P. The stitcher unit D is not necessarily provided.

  The apparatus main body A of the copying machine E optically reads a document automatically fed from the document feeding apparatus 1 provided on the upper portion of the apparatus main body A by the optical unit 2, converts the read signal into a digital signal, and converts the image data. The image is transmitted to the image forming unit 3, and the image of the original is copied onto a sheet P such as plain paper or overhead projector (OHP) paper.

  A plurality of sheet cassettes 4 that store sheets P of various sizes are provided in the lower part of the apparatus main body A. Note that only one sheet cassette 4 is shown and the others are omitted. The sheet P in the sheet cassette 4 is fed into the image forming unit 3 by the conveyance roller 5. A latent image is formed on the photosensitive drum 3b of the image forming unit 3 by the laser beam from the light irradiation unit 3a based on the image information read by the optical unit 2.

  The latent image on the photosensitive drum 3 b is developed with toner to become a toner image, and the toner image on the photosensitive drum 3 b is transferred to the sheet P sent to the image forming unit 3. Thereafter, the sheet P is conveyed to the fixing device 6, and heat and pressure are applied by the fixing device 6 so that the toner image is permanently fixed.

  In the single-sided recording mode in which an image is formed on only one side of the sheet P, the sheet P that has passed through the fixing device 6 is immediately sent from the apparatus main body A to the sheet processing apparatus B. However, in the double-sided recording mode in which images are formed on both sides of the sheet P, the sheet P on which an image has been recorded on one side according to the above processing operation passes through the retransmission pass 7 by switchback conveyance and is again sent to the image forming unit. 3 and an image is also formed on the other surface. The sheet P on which images are formed on both sides is finally sent from the apparatus main body A to the sheet processing apparatus B. The sheet P can be supplied not only from the sheet cassette 4 but also from the multi-tray 8.

  As shown in FIG. 2, the entire copying machine E is controlled by a CPU circuit unit 200. In the CPU circuit unit 200, there are provided a ROM 202 that stores the sequence of each unit, that is, a control procedure, and a RAM 203 that temporarily stores various information as necessary.

  The document feeder control unit 204 controls the document feeding operation of the document feeder 1. The image reader control unit 205 controls the optical unit 2 to control reading of a document. The image signal control unit 206 receives the reading information of the image reader control unit 205 or the image information sent from the external computer 207 via the external I / F 208, processes the image information, and controls the printer. A processing signal is sent to the unit 209.

  The printer control unit 209 controls the photosensitive drum 3 b based on the image processing signal from the image signal control unit 206 so that an image can be formed on the sheet P. The operation unit 210 can input sheet size information when the user uses the copier E, what kind of processing is performed on the sheet P, for example, information on stapling, and the like. Information on the operation state of the finisher unit C and the stitcher unit D of the apparatus main body A of the copying machine E and the sheet processing apparatus B can be displayed.

  The finisher control unit 211 performs bidirectional communication with the CPU circuit unit 200 to control operations in the finisher unit C and the stitcher unit D of the sheet processing apparatus B. The FAX control unit 212 controls the apparatus main body A so that the copying machine E can be used as a fax, and transmits and receives image signals to and from other faxes.

<About the sheet processing apparatus>
As shown in FIG. 3, the finisher unit C in the sheet processing apparatus B, when discharging the sheet P to the stack tray 18, in addition to the normal discharge mode (normal mode) in which the sheet P is discharged as it is, the offset mode, the staple Sheet processing corresponding to each mode such as a mode can be selected.

  In the normal mode, the conveyance roller pair 15, the upstream discharge roller pair 16, and the contacted downstream discharge roller pair 17 sequentially convey the sheet P discharged from the apparatus main body A to the finisher unit C. The paper is directly discharged and stacked on the stack tray 18a (18b and 18c are also acceptable).

  In the downstream discharge roller pair 17, the swing roller 17 b comes into contact with the stationary roller 17 a. The stationary roller 17a is rotated by driving from the sheet discharge driving motor 40 of FIG. The nip between the stationary roller 17a and the swing roller 17b is located at the sheet discharge port 36 in FIG. The conveyance roller pair 15 and the upstream discharge roller pair 16 are driven to rotate by the sheet conveyance drive motor 41 in FIG.

  As shown in FIG. 5, the three stack trays 18 a, 18 b, and 18 c are integrally moved up and down by the built-in drive unit 220. The three-tier stack trays 18a, 18b, 18c and the tray frame 57 are integrated to form a tray unit 58. For this reason, the three stack trays 18a, 18b, and 18c can be moved up and down integrally with respect to the finisher frame 59 of the finisher unit C. The tray unit 58 is moved up and down, that is, the stack tray 18 is moved up and down by transmitting the forward / reverse driving of the stacker motor 221 to the rack portion 58 a provided in a part of the tray unit 58 by the pinion gear 225.

  An encoder 226 is attached on the output shaft of the stacker motor 221. The number of pulses of the encoder 226 can be detected by the stacker motor clock sensor 227. The raising / lowering distance of the stack trays 18a, 18b, and 18c can be determined by how many pulses the tray unit 58 is raised and lowered from the home position that is the initial position. The home positions of the stack trays 18a, 18b, and 18c are detected when the tray home position sensor 228 detects the tray unit flag 57a provided at the lower portion of the tray frame 57.

  As shown in FIG. 6, the stack tray 18a is provided with a stack sensor 53 that detects the presence or absence of the sheet P on the stack tray 18a. A distance measuring sensor 54 for detecting the uppermost surface of the sheet P stacked on the stack tray 18a with infrared rays or the like is provided above the swing guide 20 that supports the swing roller 17b.

  As shown in FIG. 7, the downstream discharge roller pair 17 can contact / separate the non-moving roller 17a and the swing roller 17b by rotating the swing guide 20 about the shaft 31a.

  In front of the staple tray 12, a snow shutter 34 is provided so as to be movable up and down. When discharging the sheet P to the stack tray 18, the snooter shutter 34 moves below the swing roller 17b and does not prevent the discharge of the sheet P. However, the stack tray 18a stacks the sheet P and discharges the sheet P. When passing through 36, it rises and closes the hatched portion F, forms a guide surface that connects the upper and lower slat guides 27a and 27b on the same plane, and the sheet P falls to the sheet discharge port 36. To prevent.

  On the side wall surface of the finisher unit C, an upper slat guide 27a is fixed above the sheet discharge port 36, and a lower slat guide 27b is fixed below the sheet discharge port 36, and comes into contact with the rear end of the sheets P stacked on the stack tray 18. This prevents the upstream flow of the sheet P and the disturbance of the stacking state. Further, a stopper 30 that rotates about the rotation shaft 30a is provided above the snowboard shutter 34, and when the snowboard shutter 34 is lifted and the sheet discharge port 36 is closed, it is shown in FIG. As described above, the stopper 30 is fitted into the groove 34 a of the snooter shutter 34 to lock the snooter shutter 34. The stopper 30 is rotated in the Y direction in FIG. 7 when the sheet discharge port 36 is opened, and the lock of the snooter shutter 34 is released.

  As shown in FIG. 9, the stapler 13 is movable along a rail groove 14 a formed on the fixed base 14 and via a rotatable roller 13 a provided on the stapler 13. The fixed base 14 is provided with a staple position sensor 232 for detecting the home position of the stapler 13, and the home position of the stapler 13 is determined by forming a sensor flag 13 b in a part of the stapler 13. is doing. 9 (X) in FIG. 9 indicates the time when the stapler 13 is at the home position, and 13 (Y) indicates the time at which the stapler 13 is in the position where the double binding process is performed in the vicinity of the center of the sheet bundle in parallel with the sheet edge. Reference numeral 13 (Z) indicates a time when the sheet bundle corner portion is in a position for performing a binding process obliquely. The stapler 13 is moved to each position by a staple moving motor 39 shown in FIG.

  As shown in FIG. 3, in the offset mode and the staple mode, the finisher unit C of the sheet processing apparatus B performs the offset process or the staple process and discharges the sheets P to the stack tray 18a in a sorted state. Further, in the interruption mode, the sheet is discharged to the upper tray 19 without being discharged to the stack tray 18.

  Here, in the offset mode, the sheets P are sorted into a predetermined number of copies and discharged to the stack tray 18a. When the first sheet P of each portion is discharged, the side guide motor 42 in FIG. The guide 11 is moved so that only the first sheet P of each part is shifted in the width direction of the sheet P by a predetermined amount (direction orthogonal to the conveying direction of the sheet P), and the second and subsequent sheets P of each part are normally discharged. This is an operation mode. In this manner, the boundaries of the respective parts in the sheet P stacked on the stack tray 18 can be visually recognized.

  In the staple mode, the sheets P are sorted into a predetermined number of copies and discharged to the stack tray 18. However, the sheets P are temporarily stacked and aligned on the staple tray 12, and a sheet bundle is formed to form an edge. This is an operation mode in which staple binding is performed by the stapler 13 and the staple-bound sheet bundle is stacked on the staple tray 12.

  The sheet processing apparatus B can select a bookbinding mode in addition to the normal mode, the offset mode, and the staple mode described above. As shown in FIG. 1, the stitcher unit D guides the sheet P discharged from the apparatus main body A through the vertical path 60 and aligns the sheet bundle by the number of copies, and further staples the sheet bundle by the staple unit 61. The sheets are bound and folded in half by a folding unit 63 to form a booklet.

  Briefly explaining the operation of the stitcher unit D, the vertical path 60 guides the sheet P discharged from the apparatus main body A, and the stopper 62 receives the lower end of the sheet P and aligns it in units of the number of sheets in the sheet bundle. . Thereafter, the staple unit 61 staples the sheet bundle on the stopper 62 at, for example, two points at the center position in the sheet length direction (sheet conveyance direction). The binding location is not limited to two locations. Any number of locations may be used.

  Next, the stopper 62 is lowered to move the sheet bundle until the binding position of the sheet bundle reaches the nip position of the folding roller 78. Thereafter, the pushing plate 79 pushes the sheet bundle in the thickness direction and pushes the sheet bundle into the nip of the folding roller 78. The folding roller 78 sandwiches and conveys the sheet bundle at the nip and folds it in half. The sheet bundle that has been folded into a booklet is discharged to the stacking tray 106.

  As shown in FIG. 4, the sheet processing apparatus B is controlled by a finisher control unit (central processing unit) 211. The finisher control unit 211 stores therein a program corresponding to an explanation of the operation of each unit, which will be described later, and executes this program to control each driving unit (movable member and its driving system) of the sheet processing apparatus B. Control is performed and communication with the CPU circuit unit 200 (FIG. 2) of the apparatus main body A is performed.

  The finisher control unit 211 includes a distance measuring sensor 54, a stack sensor 53, a side guide motor 42, a sheet conveyance drive motor 41, a sheet discharge drive motor 40, and a drive motor rotation detection sensor 55 that detects the rotation speed of the sheet discharge drive motor 40. , Stacker motor 221, stacker motor clock sensor 227 for detecting the pulse amount of encoder 226 provided on the output shaft of stacker motor 221, tray home position sensor 228 for detecting the home position of tray unit 58 (stack tray 18), stapler 13 is connected to a staple moving motor 39, a staple position sensor 232, and the like.

<Loading height detection method>
Next, a load amount detection method and a full load detection method based on height detection will be described.

  The level detection of the uppermost surface of the sheets P (or sheet bundles) stacked on the stack tray 18 a is performed by a distance measuring sensor 54 provided above the swing guide 20. The distance measuring sensor 54 includes a light emitting unit that irradiates the sheet bundle with light rays such as infrared rays, and a light receiving unit that receives the light rays irregularly reflected by the sheet bundle, and measures the angle of the reflected light to reach the stacking surface. It is designed to detect distance.

  When the sheet P is discharged to the stack tray 18a, the rear end of the sheet P may be caught by the finisher unit C and may not settle down. If level detection is performed in such a state, accurate distance detection may not be performed. Therefore, when the sheet P is discharged, the stack tray 18 a once descends downward and then rises again, so that the sheet P is settled on the stack tray 18.

  The level detection is performed when the stack tray 18 is lowered because the stack P is blocked by the next sheet P to be discharged. However, since the sheet P may not be settled at the time of lowering, the finisher control unit 211 performs the level detection operation twice or more at predetermined intervals by the distance measuring sensor 54 and continuously within the error range. When a value is acquired, the value is acquired as a detection result.

  Further, the position after the lowering / raising of the stack tray 18a is controlled so that the height of the stacking surface is always constant based on the data obtained by the level detection.

  Thus, the stack height of the sheets P stacked on the stack tray 18a is detected by detecting the position and level of the stack tray 18a.

<Full load detection method by height detection>
When the finisher control unit 211 detects that the uppermost surface of the sheet P on the stack tray 18a has a height equal to or higher than a predetermined level, the finisher control unit 211 determines that the stacking height of the sheets P is full. Specifically, when the stack tray 18a is moved up and down, the sheet stacking height of the stack tray 18a is detected at the time of each operation or after the operation is completed, and when it is detected that the predetermined amount is continuously exceeded a plurality of times, it is full. Judge.

  In this embodiment, the full sheet P determination is performed every time a predetermined number (for example, five) of sheets P is discharged onto the stack tray 18a.

<About sheet discharge control>
Next, sheet discharge control according to the present invention will be described based on the flowchart of FIG.

  When the user selects a sheet processing mode required for using the copying machine E through the operation unit 210 provided in the apparatus main body A, the CPU circuit section 200 of the apparatus main body A processes the set information. Then, the processing information is transmitted to the finisher control unit 211 of the sheet processing apparatus B.

  In step S400, the finisher control unit 211 of the sheet processing apparatus B receives designated processing information including sheet information, and starts sheet discharge control. Based on the received processing information, the finisher control unit 211 controls the sheet transport driving motor 41 to transport the sheet P so as to transport the sheet.

  The finisher control unit 211 determines a discharge destination by determining the number of stacked sheets on the stack trays 18a and 18b up to now and the current stack amount. In step S401, it is determined whether 1 bin (stack tray 18a) is fully loaded. If it is fully loaded, it is determined whether 2 bins (stack tray 18b) are fully loaded.

  If there is room for loading in one bin (stack tray 18a) in step S401, the process proceeds to step S405 to start loading in one bin and continue loading until one bin is full. When one bin is fully loaded, the process proceeds from step S402 to step S406 to start loading on two bins (stack tray 18b), and loading to two bins is performed until it is determined in step S402 that two bins are full. Let it continue.

  When it is determined that two bins (stack tray 18b) are fully loaded, the process proceeds from step S402 to step S403, and a full signal is transmitted to the CPU circuit unit 200 of the apparatus main body A to prohibit further sheet discharge. However, if the sheet discharge is completed before it is determined that two bins (stack tray 18b) are fully loaded, the process proceeds to step S404 and the sheet discharge control is ended.

  Thereafter, when new sheet processing information is received, since 1 bin (stack tray 18a) is full, stacking starts from 2 bins (stack tray 18b), and when 2 bins (stack tray 18b) are full, A full load signal is transmitted to the CPU circuit unit 200.

  In the sheet processing apparatus B of this embodiment, sheets are stacked with priority over one bin (stack tray 18a), and even if one bin (stack tray 18a) is full, stacking is not interrupted there and two bins (stack) Since the stacking destination is changed to the tray 18b) and the stacking is continued, it is possible to stack a larger number of sheets P by delaying the full load time than when the full load is determined by only one bin.

  In step S402, after it is determined that 2 bins (stack tray 18b) are fully loaded, the stacking destination is changed to 3 bins (stack tray 18c) to continue loading, and 3 bins (stack tray 18c) are determined to be fully loaded. Control may be performed so that the full load signal is transmitted to the CPU circuit unit 200 for the first time. In this case, it is possible to stack more sheets P by delaying the full load time.

<Another embodiment>
The stack trays 18a, 18b, and 18c shown in FIG. 1 may be configured so as to be individually provided with a motor and an elevating mechanism so that they can be moved up and down independently and stopped at an arbitrary height position. In the sheet stacking process, the stacking surface 18a is gradually lowered so that the stacking surface is detected by the distance measuring sensor 54 and the height of the stacking surface is kept substantially constant. In this case, the smaller the stack amount of the lower stack tray 18c, the larger the room for lowering the upper stack trays 18a and 18b, and the larger number of sheets can be stacked. Further, the smaller the stack amount of the middle stack tray 18b, the larger the room for lowering the upper stack tray 18a, and the larger number of sheets can be stacked. This is because if there is a stack, the lower stack tray 18c cannot be lowered to the same height unless the lower stack tray 18c is lowered, so that the same amount of sheets cannot be stacked.

  Therefore, if the upper stack tray is preferentially guided to the full load, such as the stack tray 18a over the stack tray 18b and the stack tray 18b over the stack tray 18c, the height of the lower stack trays 18b, 18c is higher than the case where it does not. The same stacking can be completed while maintaining the position high, that is, without causing interference with the saddle tray 106 or the bookbinding-processed sheet bundle stacked on the saddle tray 106.

  Conversely, when the processing information is transmitted from the CPU circuit unit 200 and the sheet processing apparatus B starts accepting the sheet P, the state of the saddle tray 106 and the bookbinding processing that has been stacked on the saddle tray 106 have been completed. If the number of sheet bundles is detected and there is no concern about interference, the standby position of the lower stack tray 18c is lowered by that amount, and the loading amount of the middle stack tray 18b and the upper stack tray 18a is increased ( That is, the full load standard may be loosened) and the full load time may be delayed.

<Another embodiment>
In the above-described embodiment, stacking processing is started in order from one bin, and when one bin is fully detected, the discharge destination tray of the sheet processing apparatus B is changed, and the stacking is performed on a plurality of stack trays. However, for example, in the case of a sheet processing apparatus including a two-stage stack tray that can be moved up and down and a fixed saddle tray, if the lower limit position of the lower stack tray interferes with the saddle tray, the saddle tray is already In the state where the sheet bundle is discharged, there is a case where it is impossible to retract the lower stack tray to the lower limit position.

  In such a case, the finisher control unit 211 that determines the stacking condition in this embodiment grasps the amount of each sheet stacked on the upper and lower stack trays, and the lower stack tray comes before the upper stack tray. When full, the stack of sheets stacked on the saddle tray gets in the way and the lower stack tray cannot be retracted to the lower limit position. The discharged sheet bundle and the upper stack tray interfere with each other, making it impossible to load the full stack onto the upper stack tray.

  Therefore, after performing the full stacking process on the upper stack tray in advance, the paper is discharged to the lower stack tray to prevent interference, and while checking the stacking status of other stack trays and saddle trays, The stack tray may be automatically switched by determining the stacking order by the sheet discharge control of the sheet processing apparatus so that the stack tray can be fully loaded.

  In this embodiment, the copying machine E 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 printer or a facsimile. The same effect can be obtained by applying the present invention to a sheet processing apparatus used in a forming apparatus.

  In the present exemplary embodiment, the sheet processing apparatus that is detachable from the image forming apparatus is illustrated. However, the present invention may be a sheet processing apparatus that is integrally included in the image forming apparatus. The same effect can be obtained by applying the invention.

  In this embodiment, the electrophotographic method is exemplified as the recording method. However, the present invention is not limited to this, and other recording methods such as an ink jet method may be used.

  In the present exemplary embodiment, the finisher control unit 211 serving as a control unit is placed in the sheet processing apparatus. However, the present invention is not limited to this. For example, the control unit may be configured in an image forming apparatus. The image forming apparatus may be controlled integrally.

  Further, in the present embodiment, the stapler 13 is illustrated for creating a sheet bundle inside the finisher C of the sheet processing apparatus B. However, the present invention is not limited to this. For example, a sheet such as a glue binding mechanism is provided. It may be a bundle creation device.

  In the present embodiment, the stacking height of the stack trays 18a, 18b, and 18c when the stacking surface height is maintained constant is measured to detect the stacking height of the sheets, and this is compared with a predetermined full load height. However, the full load determination is not limited to this, and the stacking height of the sheets P, the stacking weight of the sheets P (such as a load of a motor that raises and lowers the stack tray), the stack trays 18a, 18b, and 18c. It is possible to make a full load determination using various parameters and full load standards such as the number of sheets P stacked for each stage.

  In this embodiment, a constant full load standard is applied to the stack trays 18a and 18b irrespective of the load amount on the saddle tray 106. However, if there is no load on the saddle tray 106, the stack tray 18a is loaded. There is no concern that the stack trays 18a and 18b interfere with the sheets, and the room for the physical lowering of the stack trays 18a and 18b increases. Therefore, it is determined whether or not the saddle tray 106 is loaded at the start of loading. When the sheets P are not stacked, the fullness standard of the stack trays 18a and 18b may be relaxed so that more sheets P can be stacked.

  According to the sheet processing apparatus of this embodiment, in the conventional sheet discharge control, if discharge control is performed by specifying the discharge destination from the apparatus main body, all discharge trays may not be fully loaded depending on the discharge order. It was. However, compared to such a sheet processing apparatus, in the sheet processing apparatus using the present invention, the sheet processing apparatus determines the paper discharge destination tray, thereby reducing the load on the processing of the apparatus main body A. By determining the discharge order with priority on the full load processing, it is possible to load the full load on all the discharge destination trays in the sheet post-processing apparatus.

1 is a front view of an image forming apparatus to which a sheet processing apparatus according to an exemplary embodiment is connected. 2 is a block diagram of a control system of the image forming apparatus. FIG. It is explanatory drawing of a structure of a finisher unit. It is a block diagram of a control system of the sheet processing apparatus. It is explanatory drawing of the drive means of a tray unit. It is explanatory drawing of a rocking | fluctuation guide. It is explanatory drawing of a snowboard shutter open state. It is explanatory drawing of a snook shutter closed state. It is a top view of a stapler. 6 is a flowchart of sheet discharge control.

Explanation of symbols

A Main unit (image forming device)
B Sheet processing device 15 Conveying roller pair 16 Upstream discharge roller pair 17 Downstream discharge roller pair (discharge member)
18a, 18b, 18c Stack tray (sheet stacking member)
12 Staple tray 40 Sheet discharge drive motor (control means)
211 Finisher control section (control means)
221 Stacker motor (control means)

Claims (10)

A plurality of sheet stacking members that are vertically arranged and can be moved up and down;
A discharge member capable of discharging the sheet to the plurality of sheet stacking members;
A control means for discharging the sheet by moving the sheet stacking member below the discharge member,
The sheet processing apparatus, wherein the control unit determines a stacking amount of the plurality of sheet stacking members before starting stacking, and starts stacking from the upper stackable sheet stacking member.   2. The sheet according to claim 1, wherein the control unit continues the stacking with the lower sheet stacking member after stacking the sheet until the upper sheet stacking member meets a predetermined full load standard. Processing equipment.   The sheet processing apparatus according to claim 2, wherein the control unit interrupts stacking when the lower-level sheet stacking member meets a predetermined full load standard. Another sheet stacking member arranged fixedly below the sheet stacking member,
2. The control unit according to claim 1, wherein when the sheet is not stacked on the other sheet stacking member, the full load standard is relaxed so that more sheets can be stacked on the sheet stacking member. The sheet processing apparatus according to 2 or 3.   The predetermined full load standard is characterized by detecting a stacking height of the sheets stacked on the sheet stacking member, and determining that the sheet is full when the height matches a predetermined full load height. The sheet processing apparatus according to claim 2 or 3.   4. The predetermined full load standard is obtained by counting the number of sheets stacked on the sheet stacking member, and determining that the load is full when the counted value matches a predetermined full load number. Sheet processing device.   3. The predetermined full load standard, wherein the weight of the sheets stacked on the sheet stacking member is detected, and it is determined that the full load is satisfied when the weight matches the predetermined full load weight. 3. The sheet processing apparatus according to 3. Image forming means for forming an image on the sheet;
An image forming apparatus comprising: a processing unit that receives and processes the sheet image-formed by the image forming unit;
8. An image forming apparatus according to claim 1, wherein the processing unit is the sheet processing apparatus according to claim 1.   9. The image forming apparatus according to claim 8, wherein the processing unit is commonly controlled by a control unit that controls the image forming unit. Image forming means for forming an image on a sheet;
A plurality of sheet stacking members which are arranged above and below to stack the sheets imaged by the image forming means and can be moved up and down;
A discharge member capable of discharging the sheet to the plurality of sheet stacking members;
A control unit that moves the sheet stacking member below the discharge member to discharge the sheet;
The image forming apparatus according to claim 1, wherein the control unit determines a stacking amount of the plurality of sheet stacking members before starting stacking, and starts stacking from the upper stackable sheet stacking member.

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