JP2006062853A - Sheet post processing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet post processing device capable of improving the binding productivity by shortening waiting time until the next sheet bundle is released. <P>SOLUTION: The sheet post processing device of the present invention comprises a housing tray 130 for temporarily housing a sheet discharged from an image forming device, a binding means 150 for binding a housed sheet bundle 10, and a releasing means 160 for releasing the bound sheet bundle to a stack tray 180. The releasing means 160 comprises a conveyance belt 161 and a release pawl 162 provided for the conveyance belt 161. After pushing up the sheet bundle to a releasing position by the release pawl 162, the releasing means returns the release pawl 162 to the original position by reversing the conveyance belt 161. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sheet post-processing apparatus that performs a binding process on a sheet discharged by an image forming apparatus such as a copying machine.

  In Patent Document 1, in a sheet post-processing apparatus including a discharge unit that discharges a bound sheet bundle to a stack tray, the discharge claw is moved in advance from the standby position of the discharge claw to a position near the sheet bundle, and then the discharge claw A technique is disclosed in which the sheet bundle is pushed up to the discharge position to discharge the sheet bundle to the stack tray.

Japanese Patent Laid-Open No. 11-60038

  However, in the prior art described in Patent Document 1, the discharge claw discharges the sheet bundle to the stack tray and then returns to the standby position by driving the conveyance belt. However, the discharge claw may catch the rear end of the sheet bundle. Therefore, it is necessary to stop the driving of the conveying belt for a predetermined time at the discharge position. Therefore, there is a problem that it takes time until the discharge claw returns to the original standby position, the waiting time until the start of the next discharge operation becomes long, and the productivity of the binding process is inferior. In particular, in the case of a small number of sheet bundles (for example, two-sheet binding), there is a problem that the waiting time until the start of the discharge operation becomes long and the productivity of the binding process is inferior.

  It is an object of the present invention to obtain a sheet post-processing apparatus that can shorten the waiting time until the next sheet bundle is discharged and improve the productivity of the binding process.

  In order to solve the above-described problem, the invention described in claim 1 includes a storage tray that temporarily stores sheets discharged from the image forming apparatus, a binding unit that performs binding processing of the stored sheet bundle, A discharge unit that discharges the bound sheet bundle to the stack tray, and the discharge unit includes a conveyance belt and a discharge claw provided on the conveyance belt, and after the sheet bundle is pushed up to the discharge position by the discharge claw, the conveyance belt The release claw is returned to the original position by reversing.

  In the invention described in claim 2, when binding a small number of sheets in the invention described in claim 1, the sheet bundle is pushed up to the discharge position by the discharge claw, and then the conveyance belt is reversed to release the claw. When a large number of sheets are bound, the sheet bundle is pushed up to the discharge position by the discharge claw, and then the conveyance belt is rotated forward to return the discharge claw to the original position. It is characterized by that.

  According to the present invention, after the discharge claw pushes up the sheet bundle and discharges the sheet bundle to the stack tray, the discharge claw is returned to the original position by reversing the conveying belt. For example, after the sheet bundle is discharged to the stack tray The waiting time until the start of the next discharge operation is shortened and the productivity of the binding process is improved as compared with the case where the conveyor belt is rotated in the same direction as it is and the discharge claw is returned to the original position.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1 is a cross-sectional view schematically showing a sheet post-processing apparatus according to the present invention, FIG. 2 is an enlarged perspective view showing a driving mechanism of the discharging means in FIG. 1, and FIG. 3 is an enlarged drawing means in the conventional system. 4 is a timing chart showing the operation timing of the discharge claw in the conventional method, FIG. 5 is an enlarged cross-sectional view showing the discharge means in the new method, and FIG. 6 is a timing showing the operation timing of the discharge claw in the new method. FIG. 7 is a timing chart showing the operation timing of each mechanism in the case of two-sheet binding. FIG. 8 is a timing chart showing a comparison between the operation timing of the release claw before the change and the operation timing of the release claw after the change. 9 is a flowchart showing the binding processing operation according to the present embodiment.

  As shown in FIG. 1, the sheet post-processing apparatus 100 includes a storage tray 130 that temporarily stores sheets discharged from the image forming apparatus, a sheet transport unit 120 that transports sheets toward the storage tray 130, Alignment means 140 that aligns both sides, binding means 150 that performs binding processing on the stored sheet bundle, stack tray 180 that stacks the bundle of sheets for which binding processing has been completed, and discharge for scooping up the sheet bundle for which binding processing has been completed Means 160 and a discharge roller 170 for discharging the sheet bundle picked up by the discharge means 160 to the stack tray 180 are provided.

  As shown in FIG. 2, the discharge means 160 includes a discharge belt 161 provided in a substantially triangular shape so as to surround the storage tray 130, and a discharge claw 162 for scooping up and scooping the rear end of the sheet bundle 110. Is provided. The discharge belt (conveyance belt) 161 is connected to a discharge drive motor 164 via a drive shaft 163, and the discharge belt 161 is driven by the drive of the discharge drive motor 164 so that the discharge claw 162 moves. A sensor detection unit 165 is provided at a lower position on the back side of the storage tray 130, and a position detected by the sensor detection unit 165 is a standby position of the discharge claw 162.

  Next, drive control of the discharge means will be described. There are two control methods for the discharge means 160 used in the present embodiment. After the discharge claw 162 is transported to the discharge position, the transport belt 161 is rotated in the same direction as it is to return the discharge claw 162 to the standby position. (Conventional method) and a method (new method) in which the discharge claw 162 is transported to the discharge position and then the transport belt 161 is rotated in the direction opposite to the discharge direction to return the discharge claw 162 to the standby position. The former is a control method used when binding a large number of sheets as described later, and the latter is a method used when binding a small number of sheets.

  In the conventional method, as shown in FIGS. 3 and 4, the discharge claw 162 is in the standby position where the sensor detection unit 165 is provided before the sheet binding process, and the binding processing unit 150 starts the binding process operation of the sheet bundle. At the same time, the discharge drive motor 164 is driven, the discharge claw 162 moves from the standby position to a position in the vicinity of the sheet bundle (discharge operation start position), and the discharge drive motor 164 temporarily stops (hereinafter referred to as a preliminary operation, indicated by a in the figure). ). At the same time when the binding process of the sheet bundle by the binding processing unit 150 is completed, the discharge drive motor 164 is driven again, the sheet bundle is scooped up by the discharge claw 162, and the sheet bundle is discharged to the stack tray 180 at the discharge position (b in the drawing). ). The discharge drive motor 164 temporarily stops at this discharge position for a predetermined time. Thus, the reason why the discharge claw 162 is temporarily stopped at the discharge position is to prevent the discharge claw 162 from catching the sheet bundle when the discharge claw 162 is turned to the back side of the storage tray 130 with the vicinity of the discharge position as a vertex. . In this way, the discharge claw 162 is temporarily stopped at the discharge position, and after the sheet bundle is sent to the discharge roller 170, the discharge drive motor 164 is driven again, and the discharge claw 162 returns to the standby position (in FIG. Show). Thereafter, the discharge claw 162 waits at the standby position until the next sheet bundle binding process is started.

  In the new method, as shown in FIGS. 5 and 6, the discharge claw 162 is in the standby position where the sensor detection unit 165 is provided before the sheet binding process, and the preliminary operation moves from this standby position to a position near the sheet bundle. (Indicated by a in the figure). At the same time when the binding process of the sheet bundle by the binding means 150 is completed, the discharge drive motor 164 of the conveying belt 161 is driven, the sheet bundle is scooped up by the discharge claw 162, and the sheet bundle is discharged to the stack tray 180 at the discharge position (FIG. Middle b). Thereafter, the discharge drive motor 164 reverses and the discharge claw 162 returns from the discharge position to the discharge operation start position (return operation, indicated by d in the figure). When the second and subsequent discharge operations are performed, the preliminary operation is not performed, and the discharge operation and the return operation are repeated to sequentially discharge the sheet bundle to the stack tray 180. In the case of the final part, after the discharge operation is completed, as described in the conventional method, the discharge drive motor 164 does not reverse, and the discharge claw 162 moves and returns to the standby position (indicated by c in the figure). .

  Next, operations and effects of the sheet post-processing apparatus according to the present embodiment will be described with reference to timing charts of FIGS. 7 and 8 and a flowchart of FIG. The timing chart shown in FIG. 7 explains a case where two sheets are bound. In the flowchart of FIG. 9, a case where two or more sheets are bound is also described. As shown in FIG. 7, when the first sheet passes through the paper discharge sensor 125, the motors of the aligning unit and the pressing unit are driven to perform the alignment process of the first sheet in the storage tray 130. Similarly, when the second sheet passes the paper discharge sensor 125, the motor of the pressing means is driven to perform the alignment process for the second sheet in the storage tray 130.

  When the alignment processing of the first sheet and the second sheet is completed, the binding processing unit 150 starts the binding process operation of the sheet bundle, and at the same time, the discharge drive motor 164 is driven, and the discharge claw 162 moves to the discharge operation start position. A preliminary operation is performed (step S11). Next, the binding process is performed on the first and second sheets. When the binding process is completed, the discharge driving motor 164 is driven again, and the sheet bundle is scooped up to the discharge position by the discharge claw 162 (step S12). , S13). Next, it is determined whether or not the number of sheets to be processed is a small number (two in this embodiment) (step S14). In the case of two sheets, the discharge claw 162 waits for 50 ms at the discharge position (step S17), then returns to the discharge operation start position by the return operation by reverse rotation of the discharge drive motor 164 (step S18), and waits for the next discharge operation. To do. If the number of sheets to be bound is a large number (three or more), the discharge claw 162 waits for 250 ms at the discharge position (step S15), and then returns to the standby position by a return operation (step S16).

  According to the present embodiment, after the discharge claw 162 is conveyed to the discharge position, the discharge belt 161 is rotated in the direction opposite to the discharge direction to return the discharge claw 162 to the discharge operation start position. After discharging the bundle to the stack tray 180, the standby time at the discharge position can be shortened compared to the case where the discharge belt 161 is rotated in the same direction and the discharge claw 162 is returned to the standby position. The waiting time is shortened, and the productivity of the binding process is improved.

  Further, only in the case of a small number of sheet bundles, after the discharge claw 162 is conveyed to the discharge position, the discharge belt 161 is rotated in the direction opposite to the discharge direction to return the discharge claw 162 to the discharge operation start position. Therefore, the processing time can be shortened particularly in the case of a small number of sheet bundles.

  When the discharge claw 162 is transported to the discharge position and then the discharge belt 161 is rotated in the direction opposite to the discharge direction, the distance to the discharge operation start position is shortened compared to the case where the discharge belt 161 is rotated in the normal direction. The time can be shortened by the distance difference.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. In the above-described embodiment, when the number of sheets to be bound is two, the discharge drive motor 164 is reversely rotated to return to the discharge operation start position. However, the set number is not limited to two, and 3 It may be more than one.

It is sectional drawing which shows schematically the sheet | seat post-processing apparatus which concerns on this invention. It is a perspective view which expands and shows the drive mechanism of the discharge | release means of FIG. It is sectional drawing which expands and shows the discharge | release means in a conventional system. It is a timing chart which shows the operation timing of the discharge claw in a conventional system. It is sectional drawing which expands and shows the discharge | release means in a novel system. It is a timing chart which shows the operation timing of the discharge claw in a new system. It is a timing chart which shows the operation timing of each mechanism in the case of 2 sheets binding. It is a timing chart which compares and shows the operation timing of the discharge claw before a change, and the operation timing of the discharge claw after a change. It is a flowchart which shows the binding process operation | movement which concerns on this Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Sheet post-processing apparatus 110 Sheet bundle 130 Storage tray 150 Binding means 160 Ejecting means 161 Conveying belt 162 Ejecting claw

Claims (2)

  A storage tray that temporarily stores sheets discharged from the image forming apparatus; a binding unit that performs binding processing of the stored sheet bundle; and a discharge unit that discharges the bound sheet bundle to the stack tray. The means comprises a conveyance belt and a discharge claw provided on the conveyance belt, and after the sheet bundle is pushed up to the discharge position by the discharge claw, the conveyance belt is reversed to return the discharge claw to the original position. Post-processing device. When binding a small number of sheets, after pushing up the sheet bundle to the discharge position by the discharge claw, the transport belt is reversed to return the discharge claw to the original position, and when binding a large number of sheets, 2. The sheet post-processing apparatus according to claim 1, wherein after the sheet bundle is pushed up to the discharge position by the discharge claw, the conveyance belt is rotated forward as it is to return the discharge claw to the original position.

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