Sheet post-processing apparatus

Abstract: A sheet post processing apparatus includes at least one sheet accommodating device for accommodating sheets; sheet discharging device for discharging sheets to the sheet accommodating device; transfer device for transferring a set of sheets on the sheet accommodating mean to a sheet take-out position; and manual control device for operating the transfer device.

Description: FIELD OF THE INVENTION AND RELATED ART The present invention relates to a sheet post processing apparatus, more particularly to a sheet post processing apparatus having a binding means for post processing sheets, such as copy sheets, after sorted and/or accommodated in bin trays after the sheets are discharged from a copying machine, printing machine, laser beam printer or another image forming apparatus. Document US 4,208,122 shows a reproduction apparatus including an electrostatic copying machine or the like which is operative to produce single copies of a plurality of documents using an automatic document feed device or a plurality of copies of a single document. The copies are discharged onto a sorting device for stacking the copies in either of two positions on a tray thereof. In the automatic feed mode the original documents, after being fed through the automatic feed device, are discharged into a discharge unit having a cover. If the cover is opened within a predetermined length of time to remove the documents after termination of the copying operation in the automatic feed mode the sorting device is actuated to shift the copies from one position to the other. The same operation is effected in the multiple copy mode if a next copying operation is initiated within the predetermined length of time. The sorting device preferably includes a fixed tray and a movable sheet engaging member which is toggled between two stable positions for shifting the copies to one or the other of the positions on the tray. In this manner, the copies are sorted in sets in the automatic feed mode and according to the original documents in the multiple copying mode. Document US 4,411,515 shows a copy set collecting and storage arrangement for a high speed copy reproduction system or duplicator machine having a finishing station. The arrangement includes an elevator for collecting finished copy sets in a stack and a conveyor for receiving one or more stacks from the elevator. The operator may unload the stacks from the sorter bins manually. Controls are devised for "limitless" finishing wherein the duplicator is placed in Standby, count holding condition when the full storage capacity has been reached and the programmed reproduction run has not been achieved. The controls will effect automatic start-up again when one or more of the stacks have been removed until once again the capacity has been reached and the reproduction run has not been completed. Furthermore, a conventional copying machine is provided with a sorter by which the discharged sheets can be sorted in the order of pages by moving the bins up and down. In such a sorter, a group of bins are moved during the sorting operation from a low position adjacent to the floor to a high position away from the floor and in the opposite direction. At the end of the sorting operation, the group of bins takes either low or high position, and in former case, the operativity of taking the sheets out is not good. Conventionally, therefore, the operativity is improved by automatically moving the group of bins to the high position after the end of the sorting operation if the group of bins does not take the high position. Generally, a stapling sorter which can staple the sorted sheet, is operable in a sorting mode, non-sorting mode, grouping mode, and in addition, sorting-stapling mode. However, sets of sheets sorted in the sorting mode can be automatically stapled by actuating a manual stapling key provided in the stapling sorter. If the group of bins is automatically moved to the high position, the following complicated and non-efficient operations are required. That is, if the operator attempts to staple the sorted sets of sheets, the group of bins moves to the bottom most position from the topmost position to permit stapling operations for each set of sheets, and then, the group of bins is moved to the topmost position to facilitate taking-out operation. Some apparatus is provided with a sheet set transferring means for moving the sheets to an easy- take-out position immediately after the sheets are sorted. In this case, the manual stapling operation is not possible. SUMMARY OF THE INVENTION Accordingly, it is a principal object of the present invention to provide a sheet post processing apparatus which is provided with a binding means and which is good in the operativity thereof. This object is achieved by a sheet post processing apparatus comprising at least one sheet accommodating means for accommodating sheets; sheet discharging means for discharging sheets to said sheet accommodating means; transfer means for transferring a set of sheets discharged onto said sheet accommodating means to a sheet take-out position to facilitate taking-out of the sheets; and manual control means for operating said transfer means, wherein said transfer means is operated in response to an actuation of said manual control means. The apparatus further comprises detecting means for detecting presence or absence of the sheet on said sheet accommodating means, wherein said manual control means is operable while presence of the sheet is detected by said detecting means. These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a front view of a copying machine provided with a sorter. Figure 2 is a top plan view of the sorter. Figure 3 is an enlarged top plan view of a major part in Figure 2. Figure 4 illustrates operation of the apparatus of Figure 2. Figure 5 illustrates operation of the apparatus of Figure 2. Figure 6 illustrates operation of the apparatus of Figure 2. Figure 7 is a perspective view of a major part of the sorter of Figure 1. Figure 8 is a flow chart of operation of the apparatus in accordance with a first embodiment. Figure 9 is a flow chart of operation of the apparatus in accordance with a third embodiment (Figure 8). Figure 10 is a flow chart of operation of the apparatus in accordance with a second embodiment. Figure 11 is is a flow chart of operation of the apparatus in accordance with a third embodiment (Figure 10). Figure 12 is a block diagram according to a first embodiment. Figure 13 is a block diagram according to a second embodiment. Figure 14 is a block diagram according to another embodiment. Figure 15 is a block diagram according to a further embodiment. DESCRIPTION OF THE PREFERRED EMBODIMENTS Figure 1 shows a general arrangement of a sheet post processing apparatus according to an embodiment of the present invention. As shown in Figure 1, an automatic document feeder 300 for automatically circulating the original documents, is provided on a top of the main assembly of the image forming apparatus. At a downstream side, there is provided a sorter 100 having 20 bin trays (b1, b2, ---b20). The image forming apparatus is a known electrophotographic type, and therefore, the description of the image forming process of the apparatus is omitted for simplicity. Briefly, an image of an original placed at a predetermined position an a platen glass 208 is formed on a photosensitive drum 201 through an unshown optical system, and the image is developed by a developing device disposed adjacent the photosensitive drum, and the developed image is transferred onto a sheet by a transfer electrode 203. The transferred image is fixed by a fixing device 205 into a permanent image. A sorter 100 is a bin-movable type sorter, and bin trays b arranged vertically are movable step by step up and down by one full-rotation of helical cams 4 supported on cam shafts 4' provided at opposite ends, wherein trunnion b'' are moved up and down along the helical grooves. The cams 4 movement is controlled by a motor M under the control of CPU, as disclosed in U.S. Patent No. 5,092,509. The sheet having an image formed by the main assembly 200 of the image forming apparatus, is fed to sorter 100 through a pair of discharging rollers 206, and is directed to either a sorting path or non-sorting path by a flapper 1. In the non-sorting mode, all the sheets are passed through the non-sorting path, and are discharged to a non-sorting tray 30. In the sorting mode, the sheets are passed through the sorting path, and the sheets are received by bin trays moving up or down synchronously with the sheet discharge by the discharging roller 3. A transmitting type photosensor constituted by elements 40a and 40b function to detect presence or absence of the sheet on the bin through a hole 41. The manual control means for operating the transfer means are operable while presence of sheets is detected by the sheet detecting means. In this embodiment, the position of the group of bins is a home position when the topmost bin b1 is opposed to the sheet discharging position. The main assembly of the sorter 100 is provided with a counter for counting which bin is opposed to the sheet discharging position, so that the position of the bin group can be known upon the end of the sheet discharge. Designated by a reference numeral 9 is an electric stapler for stapling the sheets by an upper head driven by a motor and a lower anvil. It is disposed at a predetermined position (solid line) opposed to the bin tray b, and is movable to a stapling position indicated by broken lines. The movement is effected and controlled by an unshown motor (Figure 2), as described in detail in the above-mentioned U.S. patent. Figure 2 is a top plan view of the sheet post processing apparatus 100. The sheet 10 is discharged at a part of the image forming apparatus 200, and is received by the sorter 100, and is then discharged to a bin tray b by the rollers 3 in the apparatus. Referring to Figure 2-5, the description will be made as to alignment and movement of the sheet thereafter. When the sheet 10 is discharged to bin tray b, the sheet 10 is aligned to a reference rod 8 by reciprocal motion of an aligning rod 7 driven by a motor M2. Until all the sheets are discharged, the operation is repeated for each sheet (Figure 4). The aligning rod 7 is supported by shaft 7'. In this embodiment, the reference rod 8 is moved to a position (A) which is a reference position to provide a reference surface in Figure 3. When the sheet 10 is moved on the bin tray b to permit the operator to take the sheet 10 out from the operator side, the reference rod 8 is retracted from the inside of the bin tray b. At this time, the reference rod 8 is moved to a position (B) and is retracted to an outside of the bin tray b, so that all the discharged sheets are pushed toward the operator (Figure 5). After the end of the pushing to a predetermined extent, the aligning rod 7 stops, and thereafter, the reference rod 8 moves to raise a corner of the sheet, thus inclining the sheet relative to the bin tray. Then, the aligning rod 7 is moved again to move the sheet. Thus, the sheet is moved to an opening adjacent the operator, thus facilitating the operator's taking out action at the operator side of the apparatus (Figure 6). The reference rod 8 has dual functions, i.e., to provide a reference plane for the discharged sheets, and to push the sheets. Referring to Figure 7, the reference rod 8 will be described in detail. Opposed to the aligning rod 7, the reference rod 8 is disposed extending through cut-away portions of the bin trays b. The reference rod 8 extends in a sheet discharging direction, and is engaged with a guide rail 23 supported below a non-sorting tray 30, and one end thereof is fixed on a belt 24 stretched in parallel with the guide rail 23. The belt 24 is trained around a pulley 26 of a pulse motor 25 fixed below the non-sorting tray 30 and an idler pulley 27. Thus, by forward and backward rotations of the motor 25, the reference rod 8 is moved between a home position (B) where the reference rod 8 is retracted out of the bin tray area (behind the stopper b') and an operative position (A) for aligning the sheets and pushing them. The detection for position (B) is effected by a sensor S1, and position (A) is effected on the basis of the pulse input to the pulse motor 25. The description will be made as to the operation in each of the sheet discharging modes. Referring to Figure 8, in a sorting mode wherein the sheets are automatically stapled after the sorting, the bin trays b are moved up or down step by step sequentially, after the end of the discharge of the last sheet, and during the movement the stapler 9 staples the sheet set on each bin. After the stapling, the sets of sheets thus stapled are moved altogether to the opening 11. In detail, when the bin tray b moved by one step, the stapler 9 is entered and staples the sheets, and then, the stapler returns. Thereafter, the bin tray moved further by one step, the stapler 9 enters again to staple the next set of sheets, and the stapler 9 returns. This is repeated so that the sheets are stapled step by step. In the sorting mode, after the sheet discharge (S.D.), the sets of sheets are taken out, and the bin trays b are placed in the stand-by state until the sheet sensors 40a and 40b are reset. If the user wishes to staple during this period, a manual stapling switch on an operation panel of the sorter is actuated. Then, the bin trays move up or down step by step, and the stapler operates for each bin tray to sequentially staple the sets of sheets. After the end of stapling, the stapled sheet sets are transferred to the take-out opening 11 in the manner described above. When the operator wants to transfer the sheet to the take-out opening 11 without stapling during the stand-by state, a manual take-out switch is actuated by the operator, in response to which the aligning rod 7 and reference rod 8 are operated to push or transfer the sheet sets to the take-out opening 11. In the grouping mode, the sheet sets are transferred to the take-out opening 11 automatically through the above-described manner after the end of the sheet discharge. With such a structure, any mode of operations can be carried out speedily. The block diagram of the operation is shown in Figure 12. Referring to Figure 10, a second embodiment will be described. In the second embodiment, the bins are shifted up to further enhance the sheet taking-out operativity. In the staple-sort mode, the stapler 9 sequentially staples the sheets after the end of the sheet discharge, and automatically transfer the sheet sets to the take-out opening 11 through the above-described manner. Using the bin position counter, the discrimination is made as to whether or not the group of bins takes the topmost position. If not, the lead cams 4 are operated to rotate to shift the bin group to the topmost position. In the sorting mode, the stand-by state is established after the discharge of the sheets. When the operator wants to staple sheets, the stapling switch is actuated to operate the stapler 9. After the stapling, the set of sheets is automatically transferred to take-out opening 11 through the above-discussed manner. When the bin position counter (or sensor S2) detects that the bin group is not at the topmost position, the lead cam 4 rotates to shift the bin group up to the topmost position. When the operator want to transfer the sheets to the take-out opening 11 without stapling and to shift the bins up, the operator actuates the sheet take-out switch, the sheets sets are transferred in the manner described above, and thereafter, the bins are shifted up to the topmost position. In addition, in the grouping mode, the above-described operation is carried out automatically, after the sheet discharge. With the above-described structure, any mode of operations can be effected as desired by the operator without conventional wasteful and cumbersome operations. So, the operativity of the sheet set taking-out operation is significantly improved. The block diagram operations are shown in Figure 13. Referring to Figures 9 and 11, a third embodiment will be described. This embodiment is advantageous in that the size of the apparatus can be reduced. In this embodiment, the size of the sheet transferred to the take-out opening 11 is limited to a relatively small size, such as A4, letter size or the like, and the transfer of the large size sheet is prevented although the shifting-up of the bins is permitted. When the large size sheets are transferred to permit them to be taken out at the operators side, the width of the take-out opening 11 is required to be quite large. By limiting to the small size, the width of the take-out opening 11 can be one half for example so that the downsizing of the apparatus is possible. The operations of various parts of the apparatus of this embodiment are the same as described in the foregoing embodiment, and therefore, the detailed description is omitted for simplicity. As means for inputting the size information, manual size input means, automatic size detector in cassettes K1 and K2, or the like are usable. In the foregoing the description has been made with respect to the sorter, but the present invention is applicable to a finisher having one tray. In this case, sheet set transfer means and stapling means are provided, and sheet set transfer means stand-by control means is also provided to prevent automatic operation of the sheet set transfer means. After the manual stapling, the sheet sets are manually transferred to an easy take-out position. When the sheet sets are taken out, a sensor detects the event, the stand-by state is reset. The block diagram of the system of this embodiment is shown in Figure 14. After the sheet sorting, the sheets are stapled manually, the bins are moved up manually. The block diagram of the system of this embodiment is shown in Figure 15. In the case of embodiment having both of transfer means and the bin moving means, the bin may be moved up after the sheet set is transferred by the transfer means, or the sheet set may be moved to the easy take-out position after the bin is moved up. In case of a sorter, the bin moving means is not inevitable, and the bins may be fixed. In this case, the stapling means is moved up and down along the bin trays. In the case of a sorter, the sheet set take-out position is not necessarily the bin topmost position, but may be a slightly higher position than usual. This position is called a predetermined position for taking the sheet out.

Claims: A sheet post processing apparatus comprising: at least one sheet accommodating means ( b ) for accommodating sheets; sheet discharging means ( 3 ) for discharging sheets to said sheet accommodating means; detecting means for detecting presence or absence of sheets on said sheet accommodating means; transfer means ( 7 , 8 ) for transferring a set of sheets discharged onto said sheet accommodating means to a sheet take-out position ( 11 ) to facilitate taking-out of the sheets; and manual control means for operating said transfer means, wherein said transfer means is operated in response to an actuation of said manual control means being operable while presence of sheets is detected by said detecting means. An apparatus according to claim 1, wherein said sheet accommodating means includes a plurality of sheet accommodating trays arranged above each other in a direction, and said sheet accommodating means is movable in the direction or in the reverse direction by moving means. An apparatus according to claim 2, wherein the direction is an upward direction and an upward movement of said sheet accommodating means by said moving means can be effected by said manual control means. An apparatus according to claim 1 to 3, further comprising binding means for binding sheets. An apparatus according to claim 4, wherein said manual control means is arranged for operating said transfer means after operating said binding means. An apparatus according to claim 4 or 5, wherein the upward movement of said sheet accommodating means by said moving means is effected to move upwardly a set of sheets bound by said binding means. An apparatus according to claim 4 or 5, further comprising automatic control means for operating, in an automatic binding mode, said transfer means after operating said binding means. An apparatus according to claim 4 or 5, further comprising automatic control means for sequentially operating, in an automatic binding mode, said sheet discharging means, said binding means, said transfer means and said sheet accommodating means by said moving means in the order named. An apparatus according to claim 4 or 5, further comprising automatic control means for sequentially operating, in an automatic binding mode, said sheet discharging means, said binding means, said sheet accommodating means by said moving means for upward movement and said transfer means in the order named. An apparatus according to any one of the preceding claims 3 to 9, wherein said manual control means effects upward movement of said sheet accommodating means by said moving means before or after operating said transfer means. An apparatus according to any one of the preceding claims 4 to 9, wherein said manual control means sequentially operates said binding means, said transfer means and said sheet accommodating means by said moving means in the order named. An apparatus according to any one of the preceding claims 4 to 9, wherein said manual control means sequentially operates said binding means, said sheet accommodating means by said moving means and said transfer means in the order named. An apparatus according to any one of preceding claims 2 to 12, wherein when said sheet accommodating means is not at a predetermined position for permitting the sheet to be taken out, said moving means operates for upward movement of said sheet accommodating means. An apparatus according to claim 13, further comprising a position sensor for detecting the position of said sheet accommodating means. An apparatus according to any one of preceding claims, further comprising: sheet size information means; and selecting means for selectively operating said transfer means in response to an output of said sheet size information means. An apparatus according to claim 15, wherein said moving means is operated for upward movement with operation of said transfer means when said selecting means is operated or not. An apparatus according to claim 15 or 16, wherein said selecting means is arranged for selectively operating said transfer means by said manual control means in response to an output of said sheet size information means. An apparatus according to claim 4, further comprising: automatic control means for operating, in an automatic binding mode, said transfer means after operating said binding means, said manual control means being arranged for operating, in a non-automatic binding mode, said binding means and for operating said transfer means after operation of said binding means. An apparatus according to claim 18, further comprising automatic control means for operating said transfer means. An apparatus according to any one of the preceding claims, wherein said transfer means further includes a transfer device for transferring the set of sheets accommodated on said sheet accommodating means in a direction crossing with a sheet discharging direction and pushing means for pushing a downstream end portion of the set to incline it, wherein the inclined sheet is discharged in the inclined direction. An apparatus according to claim 20, wherein said transfer device also effects the discharge in the inclined direction. An apparatus according to any one of the preceding claims, wherein said sheet accommodating means includes only one sheet accommodating tray. An apparatus according to any one of claims 4 to 8 or 18 or 19, wherein said binding means is movable in the direction by moving means. An image forming apparatus comprising image forming means for forming an image on a sheet and a sheet post processing apparatus as defined in any one of the preceding claims.

Inventors: KATO KATSUHITO, TAKEHARA YOSHIFUMI, KATO, KATSUHITO, TAKEHARA, YOSHIFUMI, KATO, KATSUHITO, C/O CANON KABUSHIKI KAISHA, TAKEHARA, YOSHIFUMI, C/O CANON KABUSHIKI KAISHA
Applicants: CANON KK, CANON KABUSHIKI KAISHA
Application year: 1995
Main classification: G03G15
IPC codes: G03G15