Post-processing apparatus and image forming apparatus

Abstract

This further reduces the decline in printing productivity compared to conventional methods when printing jobs with and without post-processing are performed consecutively. [Solution] The paper guide control unit moves the paper guide member on the intermediate tray to position Q1 (S1), and the control unit executes print job J1, which includes stapling. Next comes print job J2, which does not include stapling, but the paper guide control unit does not move the paper guide member, and the control unit executes print job J2, which does not include stapling. At this time, the printed paper is placed on the intermediate tray and then discharged into the output tray all at once after all printing is complete.

Description

Technical Field

[0005] , , , ,

[0001] The present invention relates to a post-processing device and an image forming apparatus including the post-processing device.

Background Art

[0002] [[ID=ll]] Some image forming apparatuses are provided with a post-processing device that performs post-processing such as stapling or punching holes in the paper after printing an image on the paper. Patent Document 1 discloses a method for reducing a decrease in productivity by providing a first conveyance path for post-processing the sheet and a second conveyance path for not performing post-processing, and when a plurality of print jobs including both a job for performing lamination processing and a job for not performing lamination processing are instructed, executing a print job that does not perform lamination processing at an arbitrary timing and conveying the paper through the second conveyance path.

[0003] Patent Document 2 discloses a method for reducing a decrease in productivity associated with switching the conveyance speed in a sheet post-processing device when the discharge speed to the sheet post-processing device is different between when the sheet is discharged in reverse and when it is discharged without being reversed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] s The technology described in Patent Document 1 reduces productivity loss by using separate transport paths for each job when there is a mix of print jobs that include processing and those that do not. However, since it requires switching transport paths, there are limits to how much productivity loss can be reduced. Furthermore, Patent Document 2 does not describe the case where there is a mix of print jobs that include post-processing such as stapling or perforation, when the printed paper is placed on an intermediate tray before discharge.

[0006] The present invention aims to further reduce the decline in printing productivity compared to conventional methods when printing jobs with and without post-processing are performed consecutively. [Means for solving the problem]

[0007] A post-processing device according to one aspect of the present invention is a post-processing device comprising: a device body having a transport path for transporting paper in a predetermined transport direction; an intermediate tray on which the paper transported via the transport path is placed; a paper guide member movably provided on the intermediate tray and aligning the paper position in the paper width direction perpendicular to the transport direction; a control unit that controls the operation of the post-processing device and controls the position of the paper guide member; a post-processing unit that performs post-processing on the paper placed on the intermediate tray; and a discharge transport unit that discharges the paper placed on the intermediate tray to a discharge tray, wherein the control unit When the job includes the post-processing described above, the paper guide member is moved to a first position that aligns the position of the paper; when the job does not include the post-processing described above, the paper guide member is moved to a second position that is outside the paper width in the paper width direction of the paper; if a job that does not include the post-processing described above follows a job that does not include the post-processing described above, and the width of the paper used in the job that does not include the post-processing described above is less than or equal to the width of the paper used in the job that includes the post-processing described above, the paper guide member is not moved from the first position to the second position after the job that includes the post-processing described above is completed.

[0008] Furthermore, the image forming apparatus of the present invention comprises an image forming unit for printing an image on paper, and the above-mentioned post-processing device relating to one aspect of the present invention. [Effects of the Invention]

[0009] According to the present invention, when printing jobs with and without post-processing are performed consecutively, the decrease in printing productivity can be reduced even further than in the conventional method. [Brief explanation of the drawing]

[0010] [Figure 1] This is a front cross-sectional view of an image forming apparatus. [Figure 2] This diagram shows the configuration of the intermediate tray. [Figure 3] This is a block diagram showing the internal configuration of an image forming apparatus. [Figure 4] This diagram illustrates the movement of the paper guide when a series of print jobs includes both print jobs with and without stapling. (A) shows the case where the paper guide member is moved for each print job using a control method not according to this embodiment, and (B) shows the case where the paper guide member is moved using the control method according to this embodiment. [Figure 5] This diagram illustrates the movement of the paper guide when three types of print jobs are mixed in a series of print jobs: print jobs that include stapling, print jobs that include shift sorting, and print jobs that do not include stapling or shift sorting. (A) shows the case where the paper guide member is moved for each print job using a control method other than that of this embodiment, and (B) shows the case where the paper guide member is moved using the control method of this embodiment. [Modes for carrying out the invention]

[0011] Hereinafter, a post-processing device and an image forming apparatus according to one embodiment of the present invention will be described with reference to the drawings. Figure 1 is a front cross-sectional view of the image forming apparatus 100. The image forming apparatus 100 of this embodiment prints images on paper from, for example, a copier and a printer. Alternatively, it may be a multifunction device equipped with multiple functions such as a copy function, a printer function and a facsimile function.

[0012] As shown in Figure 1, the image forming apparatus 100 comprises an image reading unit 14, a paper feeding unit 12, a first transport path 13, an image forming unit 14, a second transport path 15, a fixing unit 16, an operation panel 17, and a post-processing device 9.

[0013] An operation panel 17, which includes a display panel and various keys, is located on the front of the main unit 10 of the device. The display panel is equipped with either a liquid crystal display (LCD) or an organic light-emitting diode (OLED) display. The various keys include a menu key for calling up menus, a confirmation key for confirming various operations and settings, and a start key.

[0014] When the image forming apparatus 100 performs an image reading operation, the image reading unit 14 reads the document placed on the document placement table 19 and acquires the document image, under the control of the control unit 111 of the control unit 11, which will be described later.

[0015] When the image forming apparatus 100 performs an image forming operation, the image forming unit 14 forms a toner image on the paper P fed from the paper feeding unit 12 through the first transport path 13, based on the original image acquired by the image reading unit 14. The image forming unit 14 includes a photosensitive drum, a charging device, an exposure device, an original device, a transfer roller, and a cleaning device, and forms a toner image on the paper P using an electrophotographic method. However, the image forming unit 14 may also use a method other than electrophotographic, such as an inkjet method.

[0016] The paper P on which the toner image has been formed by the image forming unit 14 passes through the second transport path 15, where the fixing unit 16 heats and pressurizes the toner image to fix it to the paper P. The discharge port 21, which is the exit of the second transport path 15, is connected to the third transport path 93 of the post-processing device 9, and the fixed paper P exits the discharge port 21 and is sent to the third transport path 93.

[0017] The post-processing device 9 includes a discharge tray 92, a third conveyance path 93, a stapling unit 95, an intermediate tray 96, etc. The intermediate tray 96 is provided in the middle of the conveyance path that continues to the discharge tray 92 via the third conveyance path (immediately upstream of the discharge tray 92). Note that the first conveyance path 13, the second conveyance path 15, and the third conveyance path 93 correspond to the paper conveyance unit in the claims.

[0018] The intermediate tray 96 is arranged so as to incline obliquely downward from one end side (the discharge tray 92 side) toward the other end side. A roller pair 98 (discharge conveyance unit) for discharging the stack of papers placed on the intermediate tray 96 to the discharge tray 92 is provided at one end side of the intermediate tray 96. The stapling unit 95 is arranged at the other end side of the intermediate tray 96 and performs stapling on the stack of papers placed on the intermediate tray 96. The stapled stack of papers is discharged to the discharge tray 92 by the roller pair 98 sandwiching and rotating the stack of papers.

[0019] FIG. 2 is a diagram showing an example of the configuration of the intermediate tray 96. The intermediate tray 96 is a plate-shaped member having a paper placement surface 50 on the upper surface. The paper P is placed at the position indicated by the dashed line. The paper guide members 51A and 51B (paper guide member 51) are L-shaped members composed of a surface in contact with the placement surface 50 and a wall member that stands up from the outside in the paper width direction W of that surface. Further, guide grooves 52A and 52B extending in the paper width direction W are formed in the placement surface 50. The guide grooves 52A and 52B are formed from near the center in the placement surface 50 toward the outside in the paper width direction W.

[0020] The paper guide member 51 is provided so as to be movable in the paper width direction W on the placement surface 50 along the guide grooves 52A and 52B, and is controlled to move by a paper guide drive unit 911 described later. The paper guide drive unit 911 has a motor (not shown), etc., receives a control signal from the control unit 111 (FIG. 3), drives the motor, and moves the paper guide member 51.

[0021] When the printing job includes staple processing as post-processing, the control unit 111 moves the paper guide member 51 to a predetermined staple alignment position of the paper P (for example, the position Q1 of the solid line in FIG. 2). Similarly, in the case of shift sorting (changing the discharge position on the discharge tray 92 for each part) as post-processing, the control unit 111 moves the paper guide member 51 to a predetermined shift sorting alignment position (a position different from the staple alignment position in the paper width direction W).

[0022] When the printing job does not include post-processing such as staple processing or shift sorting, the control unit 111 moves the paper guide member 51 to a position where it does not interfere with paper conveyance (for example, the position Q2 of the dotted line in FIG. 2, outside the paper width direction of the paper P).

[0023] FIG. 3 is a block diagram showing the internal configuration of the image forming apparatus 100. The image forming apparatus 100 includes a control unit 11, an image reading unit 18, an image forming unit 14, an operation panel 17, a storage unit 31, a post-processing device 9, and the like. The same elements as those described using FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

[0024] The image reading unit 18 reads the image of the document and acquires image data. The image forming unit 14 prints the image acquired by the image reading unit 18 on paper. The storage unit 31 is a large-capacity storage device including an SSD (Solid State Drive) or an HDD (Hard Disk Drive) that stores image data, various programs, data tables, and the like.

[0025] The control unit 11 is composed of a processor, a RAM (Random Access Memory), a ROM (Read Only Memory), and the like. The processor is a CPU (Central Processing Unit), an MPU, or an ASIC, etc. This control unit 11 functions as the control unit 111 by the processor executing a control program stored in the ROM or the like. Note that the control unit 111 of the control unit 11 may be composed of a hard circuit without depending on the operation based on the control program.

[0026] The control unit 111 is responsible for the overall operation control of the image forming apparatus 100. The control unit 111 also controls the operation of the post-processing device 9, and controls the paper guide drive unit 911 to move the position of the paper guide member 51 on the intermediate tray 96. The control unit 111 is an example of a control unit as described in the claims. In this embodiment, the control unit 111 is shown as being located within the image forming apparatus 100, but the control unit 111 may be located in the post-processing device 9.

[0027] The paper guide member 51 will now be described. The following operations are controlled by the control unit 111. In the case of a print job that involves stapling or shift sorting, the control unit 111 moves the paper guide member 51 to position Q1 to align the paper P. After printing is done on the paper by the image forming unit 14, the paper is transported and placed on the intermediate tray 96. When, for example, one copy of a multi-copy printout is loaded onto the intermediate tray 96, the stapling unit 95 staples the stack of paper making up that one copy of the printout, and the roller pair 98 discharges the stack of paper to the discharge tray 92 (paper stack discharge).

[0028] On the other hand, in the case of a print job that does not include stapling or shift sorting, the control unit 111 moves the paper guide member 51 to a predetermined position Q2 that does not interfere with paper transport. The predetermined position Q2 is a position that is outside in the paper width direction W of the position where the edge of the largest standard-sized paper that can be placed on the intermediate tray 96 is located. The paper width direction W is perpendicular to the transport direction of the paper P. The image forming unit 14 prints on the paper, and the paper is sent from the second transport path 15 to the third transport path 93, passes over the intermediate tray 96, and is discharged to the discharge tray 92 by the roller pair 98. In other words, the paper does not remain on the intermediate tray 96, but passes over the intermediate tray 96 and is discharged directly to the discharge tray 92 (straight discharge).

[0029] In other words, the control unit 111 switches the position of the paper guide member 51 to Q1 or Q2 depending on whether or not the print job includes stapling or shift sorting. Switching the position of the paper guide member 51 takes a certain amount of time, for example, about 20 seconds. Therefore, for example, if there are multiple print jobs running consecutively, and some print jobs include stapling or shift sorting while others do not, changing the position of the paper guide member 51 for each print job would require switching time each time, leading to a decrease in printing productivity.

[0030] Therefore, when print jobs are running consecutively, and there is a mix of print jobs that include stapling or shift sorting and those that do not, the movement of the paper guide member 51 is minimized to suppress a decrease in productivity.

[0031] Figure 4 illustrates the movement of the paper guide member 51 when a series of print jobs include both print jobs with and without stapling as an example of post-processing. Figure 4(A) shows the case where the paper guide member 51 is moved for each print job using a control method other than that of this embodiment, while Figure 4(B) shows the case where the paper guide member 51 is moved using the control method of this embodiment.

[0032] First, control methods other than those described in this embodiment will be explained using Figure 4(A).

[0033] The control unit moves the paper guide member 51 to position Q1 (staple alignment position) in Figure 2 (S1), and the control unit executes the print job J1 which includes stapling. Once the image forming unit 14 has formed the image, the stapling unit 95 performs stapling on the paper loaded in the intermediate tray 96 under the control of the control unit, and the roller pair 98 discharges the paper into the output tray 92.

[0034] Next, the control unit moves the paper guide member 51 to position Q2 (S2) and executes a print job J2 that does not include stapling. The printed paper passes through without being placed on the intermediate tray 96, and the roller pair 98 ejects it one sheet at a time into the output tray 92.

[0035] Subsequently, before print jobs J3 and J5 which include stapling, the control unit moves the paper guide member 51 to position Q1 (S3, S5). Then, before print job J4 which does not include stapling, the control unit moves the paper guide member 51 to position Q2 (S4).

[0036] Next, the control according to this embodiment will be explained with reference to Figure 4(B).

[0037] First, the control unit 111 moves the paper guide member 51 to position Q1 (S1), and the control unit 111 executes print job J1, which includes stapling. Next, print job J2, which does not include stapling, follows. However, the control unit 111 does not move the paper guide member 51, provided that the width of the paper used in print job J2 (which does not include post-processing) (the paper size in the paper width direction perpendicular to the paper transport direction) is less than or equal to the width of the paper used in print job J1, which includes post-processing. In this case, the printed paper is placed on the intermediate tray 96, and after all printing is complete, the roller pairs 98 are discharged together into the discharge tray 92 without post-processing (simple bundle discharge). For example, the control unit 111 determines the width of the paper used for printing by (i) in the case of a print job from the paper size information included in each print job, or (ii) in the case of a copy job from a size detection signal from a known size detection sensor that detects the size of the original placed on the original placement table 19 or the automatic document feeder (ADF) (not shown). Note that a print job includes both print jobs and copy jobs. Furthermore, if the above conditions are not met, the control unit 111 moves the paper guide member 51 to position Q2 before executing a print job that does not include subsequent post-processing, and executes the print job that does not include subsequent post-processing with straight ejection.

[0038] Subsequently, print jobs including stapling and print jobs without stapling are executed consecutively (J3, J4, and J5). However, the control unit 111, as described above, does not move the paper guide member 51 from position Q1, provided that the width of the paper used in the later-executed print jobs without post-processing is less than or equal to the width of the paper used in the earlier-executed print jobs including post-processing. In this way, when print jobs with and without post-processing are executed consecutively, the time required to move the paper guide member 51 can be eliminated by not changing the position of the paper guide member 51 for each print job, thereby avoiding a decrease in productivity. Furthermore, when print jobs J1 to J5 shown in Figure 4(B) are executed consecutively, the control unit 111 controls the paper guide member 51 not to move from its previous position, provided that the width of the paper used in the later-executed print jobs is less than or equal to the width of the paper used in the earlier-executed print jobs.

[0039] Figure 5 illustrates the movement of the paper guide member 51 when three types of print jobs are mixed in a continuous print job: a print job that includes stapling, a print job that includes shift sorting, and a print job that does not include stapling or shift sorting. Figure 5(A) shows the movement of the paper guide member 51 using a control method other than that of this embodiment, while Figure 5(B) shows the movement of the paper guide member 51 using the control method of this embodiment.

[0040] First, control methods other than those described in this embodiment will be explained using Figure 5(A).

[0041] As shown in Figure 5(A), the control unit moves the paper guide member 51 to position Q1 in Figure 2 (S11), and the control unit executes a print job J11 that includes stapling. After printing by the image forming apparatus 14, the stapling unit 95 staples the paper loaded in the intermediate tray 96, and the roller pair 98 discharges the paper into the output tray 92.

[0042] Next, the control unit moves the paper guide member 51 to a predetermined position (alignment position for shift sort) for shift sorting (S12), and executes the print job J12 which includes shift sorting. The printed paper is aligned to the shift sort position by the paper guide member 51 on the intermediate tray 96, and the roller pair 98 discharges the paper together into the output tray 92.

[0043] The control unit then moves the paper guide member 51 to position Q2 (S13) and executes a print job J13 that does not include stapling. The printed paper passes through without being placed in the intermediate tray 96, and the roller pair 98 ejects it one sheet at a time into the output tray 92.

[0044] Before print job J14, which includes stapling, the control unit moves the paper guide member 51 to position Q1 (S14). Then, before print job J15, which does not include stapling, the control unit moves the paper guide member 51 to position Q2 (S15).

[0045] Next, the control according to this embodiment will be explained using Figure 5(B).

[0046] First, the control unit 111 moves the paper guide member 51 to position Q1 (alignment position for stapling) (S11), and the control unit 111 executes print job J11 which includes stapling. Next, before print job J12 which includes shift sorting, the control unit 111 moves the paper guide member 51 to a predetermined position for shift sorting (alignment position for shift sorting) (S12).

[0047] Furthermore, before print job J13, which does not include stapling or shift sorting, the control unit 111 moves the paper guide member 51 from position Q2 to position Q1 (S13). The reason for moving the paper guide member 51 to position Q1 in S13 is that print job J14, which includes stapling, follows print job J13. To eliminate the time required to move the paper guide member 51 from position Q2 to position Q1 before print job J14, the control unit 111 moves the paper guide member 51 to position Q1 in advance before print job J13. The paper printed by print job J13 is then placed on the intermediate tray 96, and after all printing is complete, it is discharged together into the output tray 92.

[0048] Subsequently, print jobs including stapling and print jobs without stapling are mixed and run consecutively (J14 and J15). However, the control unit 111 does not move the paper guide member 51 from position Q1, provided that the width of the paper used in the later print job is less than or equal to the width of the paper used in the earlier print job. In this way, when print jobs with and without post-processing are run consecutively, the position of the paper guide member 51 is not changed for each print job, eliminating the time required to move the paper guide member 51 and avoiding a decrease in productivity.

[0049] Furthermore, if a series of print jobs include both print jobs with and without post-processing, and a print job without post-processing is paused during execution, the control unit 111 may move the paper guide member 51 from position Q1 to position Q2 during the pause. When the paper guide member moves to position Q2, the roller pair 98 ejects the paper straight. This makes it possible to move the paper guide member 51 from position Q1 to position Q2 without reducing productivity by effectively utilizing the interruption period during the pause.

[0050] The present invention is not limited to the configuration of the above embodiments and various modifications are possible. Furthermore, the configuration and processing shown in the above embodiments using Figures 1 to 5 are merely one embodiment of the present invention and are not intended to limit the present invention to such configuration and processing. [Explanation of symbols]

[0051] 100 Image forming apparatus 11 Control Unit 111 Control Unit 9. Post-processing 13 Image reading unit 51 Paper guide member 95 Staple section 96 Intermediate Tray

Claims

1. A post-processing device, A device body having a transport path for transporting paper in a predetermined transport direction, An intermediate tray on which paper transported via the aforementioned transport path is placed, A paper guide member is provided movably on the intermediate tray and aligns the paper position in the paper width direction perpendicular to the transport direction, A control unit that controls the operation of the post-processing device and controls the position of the paper guide member, A post-processing unit that performs post-processing on the paper placed on the intermediate tray, The system includes an discharge transport unit that discharges the paper placed on the intermediate tray to the discharge tray, The control unit, When the job includes the post-processing described above, the paper guide member is moved to a first position that aligns the position of the paper; when the job does not include the post-processing described above, the paper guide member is moved to a second position that is outside the paper width in the paper width direction of the paper. If a job that does not include the post-processing is performed consecutively after a job that includes the post-processing, and the width of the paper used in the job that does not include the post-processing is less than or equal to the width of the paper used in the job that includes the post-processing, the post-processing device does not move the paper guide member from the first position to the second position after the job that includes the post-processing is completed.

2. The control unit, In the case of a job that includes the post-processing described above, the discharge transport unit is instructed to discharge a bundle of paper from the intermediate tray to the discharge tray after the post-processing has been performed on the paper on the intermediate tray. In the case of a job that does not include the aforementioned post-processing, the discharge conveying unit is instructed to perform straight discharge, discharging the paper that has been conveyed toward the intermediate tray one sheet at a time to the discharge tray without stacking it on the intermediate tray. The post-processing apparatus according to claim 1, wherein, if a job including the post-processing is followed immediately by a job not including the post-processing, and the width of the paper used in the job not including the post-processing is less than or equal to the width of the paper used in the job including the post-processing, the paper guide member is not moved from the first position to the second position after the job including the post-processing is completed, and the discharge conveying unit is made to discharge the paper bundle without the post-processing when the job not including the post-processing is performed.

3. The post-processing apparatus according to claim 1, wherein the control unit moves the paper guide member to the second position during the pause when a job without post-processing is performed consecutively after a job including post-processing, and the job without post-processing is paused during its execution.

4. The post-processing apparatus according to claim 3, wherein, when a job including the post-processing is followed by a job without the post-processing, and the job without the post-processing is temporarily suspended during execution, the paper guide control unit moves the paper guide member to the second position during the temporary suspension, and then, for the job without post-processing that follows the currently running job without post-processing, the control unit causes the paper discharge unit to perform the straight discharge on the paper that has been transported toward the intermediate tray.

5. An image forming unit that prints an image onto paper, A post-processing device according to any one of claims 1 to 4, An image forming apparatus equipped with [a specific feature].

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