Perforation device and image forming system equipped therewith

Abstract

The present invention provides a perforation device capable of improving the efficiency of the perforation process, a sheet post-processing device equipped therewith, and an image forming system. [Solution] The system comprises a perforation processing unit and a collection tank. The perforation processing unit performs perforation on the conveyed sheet. The collection tank is located below the perforation processing unit and collects the perforation waste generated by the perforation process. The system further includes a detection unit that detects when the collection tank is full and when it is nearly full. The detection unit is composed of multiple light sensors arranged vertically, each consisting of a light-emitting element and a light-receiving element arranged opposite each other, and detects the perforation waste when it enters the optical path of the light sensor. Each light-emitting element is mounted on the same light-emitting substrate, and each light-receiving element is mounted on the same light-receiving substrate.

Description

Technical Field

[0006] , , ,

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[0001] The present invention relates to a punching device and an image forming system including the same.

Background Art

[0002] A conventional punching device includes a punching processing unit and a collection tank. The punching processing unit performs a punching process on a conveyed sheet. The collection tank is disposed below the punching processing unit and stores punching chips generated by the punching process. The punching device further includes a detection unit that detects a full state in which the punching chips are fully accumulated in the collection tank.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the configuration of Patent Document 1, when the detection unit detects the full state, the punching process is interrupted to prompt the disposal of the punching chips. For this reason, downtime may occur and the efficiency of the punching process may decrease.

[0005] In view of the above problems, an object of the present invention is to provide a punching device capable of improving the efficiency of the punching process and an image forming system including the same.

Means for Solving the Problems

[0006] <000L033>To achieve the above objective, the first configuration of the present invention comprises a perforation processing unit and a recovery tank. The perforation processing unit performs perforation on a sheet that has been transported. The recovery tank is located below the perforation processing unit and contains the perforation waste generated by the perforation process. The device further includes a detection unit that detects when the recovery tank is full and when it is nearly full. The detection unit is composed of multiple optical sensors arranged vertically, each consisting of an opposing light-emitting element and a light-receiving element, and detects the perforation waste when it enters the optical path of the optical sensor. Each light-emitting element is mounted on the same light-emitting substrate, and each light-receiving element is mounted on the same light-receiving substrate. [Effects of the Invention]

[0007] According to the first configuration of the present invention, it is possible to provide a perforation device capable of improving the efficiency of the perforation process and an image forming system equipped therewith. [Brief explanation of the drawing]

[0008] [Figure 1] A schematic diagram showing the configuration of an image forming system consisting of an image forming apparatus 200 according to one embodiment of the present invention. [Figure 2] A schematic side cross-sectional view showing the configuration of a sheet post-processing device 1 including a perforating device 20 according to one embodiment of the present invention. [Figure 3] Side cross-sectional view of a drilling device 20 according to one embodiment of the present invention. [Figure 4] Perspective view of a drilling device 20 according to one embodiment of the present invention [Figure 5] Perspective view of a drilling device 20 according to one embodiment of the present invention [Figure 6] Plan view of the light-emitting substrate 251 of a drilling device 20 according to one embodiment of the present invention. [Figure 7] Plan view of the light-receiving substrate 252 of the drilling device 20 according to one embodiment of the present invention. [Figure 8] Circuit diagram showing an example of a detection unit 25 of a drilling device 20 according to one embodiment of the present invention. [Figure 9]Circuit diagram showing an example of a detection unit 25 of a drilling device 20 according to one embodiment of the present invention. [Figure 10] A flowchart illustrating an example of the operation of an image forming apparatus 200 according to one embodiment of the present invention, which determines the near-full state of the recovery tank 24. [Modes for carrying out the invention]

[0009] Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. In this specification, when describing the sheet post-processing apparatus 1 according to the embodiment of this disclosure, the direction in which the rotation axis C of the shaft 233 shown in Figure 4 extends will be simply referred to as the "axial direction (A1-A2 direction)". The directions defined herein are merely names used for explanatory purposes and do not limit the actual positional relationships or directions.

[0010] Figure 1 is a schematic diagram showing the configuration of an image forming system 300, which consists of a sheet post-processing device 1 equipped with a perforating device 20 according to one embodiment of the present invention, and an image forming apparatus 200 to which the sheet post-processing device 1 is connected.

[0011] As shown in Figure 1, the image forming apparatus 200 prints an image on a sheet (paper) based on image data input from an external source via a network communication unit (not shown) and image data read by an image reading unit 201 located at the top of the image forming apparatus 200.

[0012] The sheet post-processing device 1 is detachably connected to the side of the image forming apparatus 200. The sheet post-processing device 1 performs post-processing such as punch hole formation and binding on sheets that have been image-formed (printed) by the image forming apparatus 200. The sheet post-processing device 1 is not limited to performing post-processing on sheets automatically transported from the image forming apparatus 200, but may also transport sheets set in a tray (not shown) by the user to a position where post-processing can be performed and then perform post-processing on those sheets.

[0013] FIG. 2 is a side cross-sectional view schematically showing the configuration of the sheet post-processing apparatus 1 of the present embodiment. As shown in FIG. 2, the sheet post-processing apparatus 1 includes a sheet inlet 2, a first sheet conveyance path (conveyance path) 3, a first sheet discharge unit 4, a second sheet conveyance path 5, a second sheet discharge unit 6, a third sheet conveyance path 7, a third sheet discharge unit 8, a post-processing unit 9, and a post-processing control unit 10.

[0014] The sheet inlet 2 is an opening provided on a side surface of the sheet post-processing apparatus 1 facing the image forming apparatus 200. The sheet conveyed from the image forming apparatus 200 toward the sheet post-processing apparatus 1 passes through the sheet inlet 2 and is carried into the interior of the sheet post-processing apparatus 1.

[0015] The first sheet conveyance path 3 extends substantially horizontally in a direction away from the image forming apparatus 200 (left direction in FIG. 2) from the sheet inlet 2 to the first sheet discharge unit 4. The direction from the sheet inlet 2 toward the first sheet discharge unit 4 is referred to as the sheet conveyance direction B1 in the first sheet conveyance path 3. The sheet inlet 2 is located at the upstream end in the sheet conveyance direction of the first sheet conveyance path 3. The first sheet conveyance path 3 has a plurality of conveyance roller pairs 3r and conveys the sheet carried into the sheet post-processing apparatus 1 from the sheet inlet 2 toward the downstream side in the sheet conveyance direction.

[0016] The first sheet discharge unit 4 is provided on a side surface of the sheet post-processing apparatus 1 opposite to the side surface facing the image forming apparatus 200. The first sheet discharge unit 4 is disposed at the downstream end in the sheet conveyance direction of the first sheet conveyance path 3. The first sheet discharge unit 4 includes a first discharge port 41, a first discharge roller pair 42, and a first discharge tray 43.

[0017] The first row outlet 41 is located at the downstream end of the first sheet conveyance path 3 in the sheet conveyance direction. The first discharge roller pair 42 is disposed at the first row outlet 41. The first discharge tray 43 is located on the downstream side of the first row outlet 41 in the sheet conveyance direction. The sheet conveyed through the first sheet conveyance path 3 and reaching the first row outlet 41 is discharged onto the first discharge tray 43 through the first row outlet 41 by the first discharge roller pair 42. The first discharge tray 43 is one of the final discharge locations for the sheets post-processed by the sheet post-processing apparatus 1.

[0018] The second sheet conveyance path 5 branches from the first branch portion (branch portion) 31 on the first sheet conveyance path 3 and extends horizontally and upward in a direction away from the image forming apparatus 200 (left direction in FIG. 2) to the second sheet discharge portion 6. The first branch portion 31 is disposed on the downstream side of the punching device 20 with respect to the sheet conveyance direction in the first sheet conveyance path 3. Hereinafter, the direction from the first branch portion 31 toward the second sheet discharge portion 6 is referred to as the sheet conveyance direction in the second sheet conveyance path 5. The first branch portion 31 is located at the upstream end of the second sheet conveyance path 5 in the sheet conveyance direction. The second sheet conveyance path 5 has a plurality of conveyance roller pairs 5r and conveys the sheet conveyed through the first sheet conveyance path 3 by branching it at the first branch portion 31 toward the second sheet discharge portion 6.

[0019] The first branch portion 31 has a first switching guide 311. The first switching guide 311 rotates between a position that guides the sheet conveyed on the first sheet conveyance path 3 from the sheet inlet 2 side along the first sheet conveyance path 3 to the first row outlet 41 and a position that branches from the first sheet conveyance path 3 and guides it to the second sheet conveyance path 5. Further, the first switching guide 311 rotates to a position that guides the sheet that has undergone folding processing and passed through the second folding conveyance path 106 described later to the second sheet conveyance path 5. The first switching guide 311 is connected to a drive mechanism (not shown), and its operation is controlled by the post-processing control unit 10.

[0020] The second sheet discharge section 6 is located on the side of the sheet post-processing device 1 opposite to the side facing the image forming apparatus 200, and is situated above the first sheet discharge section 4. The second sheet discharge section 6 is positioned at the downstream end of the second sheet transport path 5 in the sheet transport direction. The second sheet discharge section 6 includes a second discharge port 61, a second discharge roller pair 62, and a second discharge tray 63.

[0021] The second discharge port 61 is located at the downstream end of the second sheet transport path 5 in the sheet transport direction. The second discharge roller pair 62 is positioned at the second discharge port 61. The second discharge tray 63 is located downstream of the second discharge port 61 in the sheet transport direction. Sheets transported along the second sheet transport path 5 and reaching the second discharge port 61 are passed through the second discharge port 61 by the second discharge roller pair 62 and discharged onto the second discharge tray 63. The second discharge tray 63 is one of the final discharge locations for sheets that have undergone post-processing by the sheet post-processing device 1. Sheets that have not undergone post-processing and small-sized sheets are also discharged to the second discharge tray 63.

[0022] The third sheet transport path 7 branches off from the second branch 32 on the first sheet transport path 3 and extends downward to the third sheet discharge section 8. The direction from the second branch 32 towards the third sheet discharge section 8 is referred to as the sheet transport direction in the third sheet transport path 7. The second branch 32 is located downstream of the first branch 31 with respect to the sheet transport direction of the first sheet transport path 3 and is located at the upstream end of the sheet transport direction of the third sheet transport path 7. The third sheet transport path 7 has multiple transport roller pairs 7r and transports the sheets being transported on the first sheet transport path 3 by branching them off at the second branch 32 and transporting them toward the third sheet discharge section 8.

[0023] The second branching section 32 has a second switching guide 321. The second switching guide 321 rotates to a position that guides sheets being transported on the first sheet transport path 3 from the sheet inlet 2 side to the first discharge port 41 along the first sheet transport path 3, and to a position that guides sheets that have been transported on the first sheet transport path 3 from the sheet inlet 2 side, passed through the second branching section 32, and then switched back, to the third sheet transport path 7. The second switching guide 321 is connected to a drive mechanism (not shown) and its operation is controlled by the post-processing control unit 10. In this embodiment, sheets being transported on the first sheet transport path 3 are switched back and branched at the second branching section 32, but the sheets may be transported on the first sheet transport path 3 toward the third sheet discharge section 8 without being switched back. For example, sheets being transported may be directly branched from the downstream side of the sheet folding unit 100 (described later) and transported toward the third sheet discharge section 8.

[0024] The third sheet discharge section 8 is located on the side of the sheet post-processing device 1 opposite to the side facing the image forming apparatus 200, and is situated below the first sheet discharge section 4 (near the lower end of the sheet post-processing device 1). The third sheet discharge section 8 includes a third discharge port 81, a third discharge roller pair 82, and a third discharge tray 83.

[0025] The third discharge port 81 is located at the downstream end of the third sheet transport path 7 in the sheet transport direction. The third discharge roller pair 82 is positioned at the third discharge port 81. The third discharge tray 83 is located downstream of the third discharge port 81 in the sheet transport direction. Sheets transported along the third sheet transport path 7 and reaching the third discharge port 81 are discharged onto the third discharge tray 83 by the third discharge roller pair 82, passing through the third discharge port 81. The third discharge tray 83 is one of the final discharge locations for sheets that have been post-processed by the sheet post-processing device 1.

[0026] The post-processing unit 9 performs predetermined post-processing on the sheets that have been image-formed by the image forming apparatus 200 and transported into the sheet post-processing device 1. The post-processing unit 9 includes a perforating device 20, a sheet binding unit 92, a sheet folding unit 100, and a binding unit 94.

[0027] The perforating device 20 is located immediately downstream of the sheet loading entrance 2 and includes the first sheet transport path 3. The perforating device 20 performs a perforating process on the sheets being transported along the first sheet transport path 3 to form punch holes. The configuration of the perforating device 20 will be described in detail later.

[0028] The sheet stapling unit 92 is positioned immediately upstream of the first sheet discharge section 4 with respect to the sheet transport direction of the first sheet transport path 3. The sheet stapling unit 92 performs a stapling process (binding process) on a sheet bundle formed by stacking multiple sheets, thereby binding the sheet bundle. The detailed configuration of the sheet stapling unit 92 will be described later.

[0029] The sheet folding unit 100 is positioned downstream of the punching device 20 and upstream of the sheet binding unit 92 with respect to the sheet transport direction of the first sheet transport path 3. The sheet folding unit 100 performs a folding process on a single sheet to form a crease. The sheet folding unit 100 can perform folding processes on a single sheet, such as a bi-fold, Z-fold, outer tri-fold, or inner tri-fold.

[0030] The binding unit 94 is positioned immediately upstream of the third sheet discharge unit 8 with respect to the sheet transport direction of the third sheet transport path 7. The binding unit 94 has a center folding unit 941 and a center stitching unit 942. The binding unit 94 performs a center folding process and a center stitching process on a sheet bundle formed by stacking multiple sheets, folding and stitching the sheet approximately in the center in the sheet transport direction, to form a booklet.

[0031] The post-processing control unit 10 includes a CPU, a memory unit, and other electronic circuits and electronic components (none of which are shown). The post-processing control unit 10 is communicatively connected to the main control unit of the image forming apparatus 200 (see Figure 1). The post-processing control unit 10 receives commands from the main control unit and, using the CPU, controls the operation of each component provided in the sheet post-processing device 1 based on control programs and data stored in the memory unit, thereby performing processing related to the functions of the sheet post-processing device 1. The first sheet transport path 3, the first sheet discharge unit 4, the second sheet transport path 5, the second sheet discharge unit 6, the third sheet transport path 7, the third sheet discharge unit 8, and the post-processing unit 9 each receive individual commands from the post-processing control unit 10 and perform post-processing on the sheets in conjunction. The functions of the post-processing control unit (control unit) 10 may also be performed by the main control unit of the image forming apparatus 200.

[0032] Next, the configuration of the perforating device 20 will be described. Figure 3 is a side cross-sectional view of the perforating device 20 mounted on the sheet post-processing device 1. Figures 4 and 5 are perspective views of the perforating device 20.

[0033] The drilling device 20 includes a loading guide 22, a drilling processing unit 23, a recovery tank 24, and a detection unit 25.

[0034] The loading guide 22 consists of an upper guide section 221 and a lower guide section 222. The upper guide section 221 and the lower guide section 222 face each other in the vertical direction with a predetermined width of space between them. The upper guide section 221 constitutes the upper surface of the first sheet transport path 3 near the sheet loading entrance (inlet) 2. The lower guide section 222 constitutes the lower surface of the first sheet transport path 3 near the sheet loading entrance (inlet) 2.

[0035] The lower guide portion 222 is supported so as to be rotatable in the vertical direction, with its rear end in the sheet width direction (one axial side A2) as a pivot point relative to the upper guide portion 221.

[0036] The perforation processing unit 23 is located on the downstream side B1 of the loading guide 22 in the sheet transport direction, and performs perforation on the sheet transported from the loading guide 22. In this embodiment, the perforation processing unit 23 includes an eccentric cam 231, a plurality of perforation blades 232, a shaft 233, and a housing 234.

[0037] The housing 234 is positioned on the downstream side B1 of the upper guide section 221 in the sheet transport direction and is formed integrally with the upper guide section 221. The housing 234 houses the eccentric cam 231, the drilling blade 232, and the shaft 233. A first sheet transport path 3 is also formed inside the housing 234 and communicates with the first sheet transport path 3 of the loading guide 22.

[0038] Multiple perforating blades 232 are arranged along the axis of the shaft 233 to make holes in the sheet. The perforating blades 232 reciprocate vertically in accordance with the rotation of the eccentric cam 231. In this embodiment, four perforating blades 232 are provided (corresponding to a four-hole system). However, the number of perforating blades 232 is not limited to four. The wall surface of the first sheet conveying path 3 has through holes 3a and 3b at positions corresponding to the perforating blades 232 (see Figure 3). Through hole 3a penetrates the upper wall surface of the first sheet conveying path 3 in the vertical direction. Through hole 3b penetrates the lower wall surface of the first sheet conveying path 3 in the vertical direction.

[0039] The shaft 233 extends above the drilling blades 232 along the direction of arrangement of the drilling blades 232. The shaft 233 is rotatably supported in the housing 234.

[0040] The eccentric cams 231 are attached to four locations in the axial direction of the shaft 233, each corresponding to a drilling blade 232. The shaft 233 is connected to the rotating shaft of a motor (not shown) via gears, and the eccentric cams 231 rotate as the motor rotates the shaft 233.

[0041] The perforation process by the perforation processing unit 23 first uses a non-contact sensor (not shown), such as an optical sensor, to detect whether the sheet conveyed by the conveyor roller pair 3r has been transported to a predetermined position. If it is determined that the sheet has been transported to the predetermined position, the drive of the conveyor roller pair 3r is stopped, and the sheet stops at the predetermined position.

[0042] At this time, the eccentric cam 231 is stopped at a predetermined angle (hereinafter referred to as the retraction angle) to position the drilling blade 232 in a position that does not obstruct the transport of the sheet (hereinafter referred to as the retraction position), and the sheet is stopped in the state where it has been transported into the first sheet transport path 3.

[0043] Next, the eccentric cam 231 is rotated from its retracted angle to a predetermined direction. This causes the punching blade 232 to descend from the retracted position through the through hole 3a towards the sheet. The punching blade 232 descends to the punching position (below the through hole 3b) where it makes a hole in the sheet. By further rotating the eccentric cam 231, the punching blade 232 rises from the punching position and returns to the retracted position.

[0044] The recovery tank 24 is located below the perforation processing unit 23 and contains the perforation waste generated by the perforation process. The recovery tank 24 is positioned across the perforation processing unit 23 and the loading guide 22 in the sheet transport direction (B1-B2 direction). The recovery tank 24 has a storage section 241 and a mounting section 242. The storage section 241 and the mounting section 242 are in communication within the internal space of the recovery tank 24. The storage section 241 is located below the mounting section 242 and contains the perforation waste.

[0045] The mounting section 242 protrudes upward from the downstream side B1 in the sheet transport direction of the storage section 241 and is mounted on the perforation processing section 23. An opening 242a is provided on the upper surface of the mounting section 242 (see Figure 5). Perforation debris is generated when the sheet is punched out by the perforation processing section 23 and falls downward through the through-hole 3b. The fallen perforation debris is collected inside the storage section 241 of the recovery tank 24 through the opening 242a.

[0046] The recovery tank 24 is detachably attached to the lower surface of the housing 234 of the perforation section 23. As an example of the mounting structure, a guide rail (not shown) is provided on the lower surface of the housing 234. In addition, a slide rail (not shown) is provided on the upper surface of the mounting section 242 of the recovery tank 24.

[0047] The guide rail and slide rail extend parallel to the sheet width direction (axial direction A1-A2). The rear end of the slide rail in the sheet width direction (one axial side A2) and the front end of the guide rail in the sheet width direction (the other axial side A1) are engaged, pushing the recovery tank 24 towards the rear in the sheet width direction (one axial side A2). As a result, the slide rail slides along the guide rail, and the recovery tank 24 slides in the sheet width direction (axial direction A1-A2) and is attached to the housing 234 (see Figures 4 and 5). In this way, the recovery tank 24 is supported in the perforation section 23 so as to be detachable by sliding in the sheet width direction (axial direction A1-A2).

[0048] On the other hand, by pulling the recovery tank 24 forward in the sheet width direction (the other axial side A1), the slide rail slides along the guide rail, and the recovery tank 24 is removed from the perforation processing unit 23. When the recovery tank 24 has accumulated perforation debris inside, it is removed from the perforation processing unit 23 and the perforation debris is discarded.

[0049] The detection unit 25 is composed of multiple light sensors 250a and 250b arranged vertically (see Figure 3). Light sensor 250a consists of a light-emitting element 251a and a light-receiving element 252a arranged opposite each other in the sheet transport direction (B1-B2 direction). Light sensor 250b consists of a light-emitting element 251b and a light-receiving element 252b arranged opposite each other in the sheet transport direction (B1-B2 direction).

[0050] The detection unit 25 detects drilling debris when it enters the optical paths of the light sensors 250a and 250b. Each light-emitting element 251a and 251b is mounted on the same light-emitting substrate 251, and each light-receiving element 252a and 252b is mounted on the same light-receiving substrate 252. The light-emitting substrate 251 and the light-receiving substrate 252 are arranged in the mounting section 242 of the recovery tank 24 and face each other in the sheet transport direction (B1-B2 direction) (see Figure 3).

[0051] Figure 4 is a plan view of the light-emitting substrate 251, and Figure 5 is a plan view of the light-receiving substrate 252. The light-emitting substrate 251 has four light-emitting elements 251a and four light-emitting elements 251b mounted on it. The four light-emitting elements 251a and the four light-emitting elements 251b are arranged in a single row along the axial direction (axial direction A1-A2) of the shaft 233. The four light-emitting elements 251a are positioned above the four light-emitting elements 251b.

[0052] Furthermore, the light-receiving substrate 252 has four light-receiving elements 252a and four light-receiving elements 252b mounted on it. The four light-receiving elements 252a and the four light-receiving elements 252b are arranged in a single row along the axial direction (axial direction A1-A2) of the shaft 233. The four light-receiving elements 252a are positioned above the four light-receiving elements 252b.

[0053] Each light-emitting element 251a faces each light-receiving element 252a in the sheet transport direction (B1-B2 direction) and constitutes each light sensor 250a. Similarly, each light-emitting element 251b faces each light-receiving element 252b in the sheet transport direction (B1-B2 direction) and constitutes each light sensor 250b. Light sensor 250a detects when the collection tank 24 is full of punctured waste. Light sensor 250b detects when the collection tank 24 is nearly full.

[0054] The four light-emitting elements 251a and 4 light-emitting elements 251b are arranged facing each other vertically with respect to the four drilling blades 232. Similarly, the four light-receiving elements 252a and 4 light-receiving elements 252b are arranged facing each other vertically with respect to the four drilling blades 232. In other words, the light sensors 250a and 250b are arranged in a row at predetermined intervals in the axial direction (A1-A2 direction) of the shaft 233, corresponding to each drilling blade 232. As a result, the light sensors 250a and 250b can detect the accumulation position of drilling debris accumulated directly below the four drilling blades 232. Therefore, even if the drilling debris accumulates unevenly in the axial direction (A1-A2 direction) of the shaft 233, the light sensors 250a and 250b can accurately detect whether the recovery tank 24 is full or near full.

[0055] The detection position for the full state or the near-full state can be changed by changing the mounting position of the light-emitting element 251a or light-emitting element 251b on the light-emitting substrate 251 and the mounting position of the light-receiving element 252a or light-receiving element 252b on the light-receiving substrate 252 in the vertical direction.

[0056] Specifically, by shifting the mounting position of the light-emitting element 251b on the light-emitting substrate 251 to the mounting hole 251c, and shifting the mounting position of the light-receiving element 252b on the light-receiving substrate 252 to the mounting hole 252c, the detection position of the near-full state can be changed upward. Also, by shifting the mounting position of the light-emitting element 251a on the light-emitting substrate 251 to the mounting hole 251c, and shifting the mounting position of the light-receiving element 252a on the light-receiving substrate 252 to the mounting hole 252c, the detection position of the full state can be changed downward. This makes it possible to easily change the detection position of the full state or the near-full state while suppressing an increase in manufacturing costs.

[0057] Figures 8 and 9 are circuit diagrams showing an example of the detection unit 25. The four photodetectors (photodiodes) 252a and the four photodetectors (photodiodes) 252b are all connected in parallel, and current flows when any of the photodetectors 252a or 252b receive light emitted from the opposing light-emitting elements 251a or 251b. As a result, in this embodiment, the detection circuit using the photodetectors 252a and 252b is shared between the circuit for detecting the full state and the circuit for detecting the near-full state. This makes it possible to easily change the detection position for the full state or the near-full state while further suppressing the increase in manufacturing costs.

[0058] More specifically, the negative (-) terminal of comparator 26 is connected to photodiodes 252a and 252b, which are connected in parallel via resistor R3. Additionally, a grounded capacitor C1 is connected to the negative (-) terminal of comparator 26. The connection point of resistors R5 and R6 is also connected to the negative (-) terminal of comparator 26. Resistors R5 and R6 are voltage divider resistors connected in series between the power supply Vcc and ground.

[0059] The positive (+) terminal of comparator 26 is connected to the power supply Vcc via resistors R1 and R2 connected in series. Additionally, the connection point of resistors R4 and R7 is connected to the positive (+) terminal of comparator 26. Resistors R4 and R7 are voltage divider resistors connected in series between the power supply Vcc and ground. Capacitor C2 is connected in parallel with resistor R7.

[0060] The comparator 26 compares a threshold value obtained from the positive (+) terminal with the voltage values ​​supplied from the photodetectors 252a and 252b. If the voltage values ​​from the photodetectors 252a and 252b are higher than the threshold value, the comparator 26 outputs a High signal. If the voltage values ​​from the photodetectors 252a and 252b are lower than the threshold value, the comparator 26 outputs a Low signal.

[0061] Therefore, if all optical paths of the photodetectors 252a and 252b are not obstructed by the drilling debris, and the voltage values ​​from the photodetectors 252a and 252b are higher than the threshold, the comparator 26 outputs a High signal. On the other hand, if either optical path of the photodetectors 252a or 252b is obstructed by the drilling debris, and the voltage values ​​from the photodetectors 252a and 252b are lower than the threshold, the comparator 26 outputs a Low signal.

[0062] The post-processing control unit 10 determines whether the recovery tank 24 is full or near full based on the High signal or Low signal output from the comparator 26.

[0063] Figure 10 is a flowchart showing an example of the operation performed by the post-processing control unit 10 to determine whether the recovery tank 24 is near full. In this embodiment, while the sheet post-processing device 1 is running, the post-processing control unit 10 determines whether the recovery tank 24 is full or near full with perforated debris based on information from the detection unit 25.

[0064] Specifically, LED light is emitted sequentially from the four light-emitting elements 251b, and it is determined whether or not the optical path of any of the light-receiving elements 252b is blocked by the drilled debris (step S1). If the optical paths of all light-receiving elements 252b are not blocked (NO in step S1), a High signal is input to the post-processing control unit 10. As a result, the post-processing control unit 10 determines that the drilled debris has not reached a near-full state in the recovery tank 24.

[0065] On the other hand, if any of the optical paths of the light-receiving elements 252b are blocked (YES in step S1), a Low signal is input to the post-processing control unit 10. As a result, the post-processing control unit 10 determines that the drilled debris is in a near-full state in the recovery tank 24.

[0066] In step S2, the post-processing control unit 10 prompts the user to dispose of the perforated debris by, for example, displaying on the display unit (not shown) that the recovery tank 24 is near full. At this time, the user does not need to dispose of the perforated debris immediately, but can dispose of it when the ongoing post-processing is finished, in preparation for subsequent post-processing executions.

[0067] In step S3, LED light is emitted sequentially from the four light-emitting elements 251a, and it is determined whether or not the optical path of any of the light-receiving elements 252a is blocked by the drilling debris. If the optical paths of all light-receiving elements 252a are not blocked (NO in step S3), a High signal is input to the post-processing control unit 10. As a result, the post-processing control unit 10 determines that the drilling debris in the recovery tank 24 is in a near-full state and has not yet reached a full state.

[0068] On the other hand, if any of the optical paths of the light-receiving elements 252a are blocked (YES in step S3), a Low signal is input to the post-processing control unit 10. As a result, the post-processing control unit 10 determines that the puncture debris is full in the recovery tank 24.

[0069] In step S4, the display unit (not shown) indicates that the recovery tank 24 is full, prompting the user to dispose of the drilled debris. In step S5, the ongoing post-processing is stopped. The user can dispose of the drilled debris and resume post-processing. At this point, the post-processing control unit 10 returns to step S1 and resumes monitoring the recovery tank 24.

[0070] In this embodiment, it is possible to detect a near-full state in the collection tank 24 before the perforation debris reaches a full state. This allows the user to discard the perforation debris before it reaches a full state, according to the near-full state indication. Therefore, by discarding the perforation debris before it reaches a full state during the execution of the perforation process, it is possible to prevent the perforation process from being stopped and downtime from occurring. Thus, the efficiency of the perforation process can be improved.

[0071] Furthermore, each light-emitting element 251a and 251b is mounted on the same light-emitting substrate 251, and each light-receiving element 252a and 252b is mounted on the same light-receiving substrate 252. This allows the light sensor 250a, which detects the full state, and the light sensor 250b, which detects the near-full state, to be configured on a common substrate, thereby suppressing an increase in manufacturing costs.

[0072] Although embodiments of the present invention have been described above, the scope of the present invention is not limited thereto, and various modifications can be made without departing from the spirit of the invention. For example, two or more rows of mounting holes 251c and mounting holes 252c may be provided in the vertical direction. This makes it possible to change the detection position of the full state or the near-full state in multiple steps in the vertical direction. In addition, in this embodiment, the light-emitting substrate 251 and the light-receiving substrate 252 are arranged in the mounting section 242 of the recovery tank 24, but they may be arranged in the storage section 241. [Industrial applicability]

[0073] The present invention can be used in a sheet post-processing device that applies predetermined post-processing to multiple sheets. [Explanation of Symbols]

[0074] 1 Sheet Post-processing Device 2 Sheet loading entrance 3. First sheet transport path 3a, 3b through hole 3r transport roller pair 4. First sheet discharge section 5. Second sheet transport path 5r transport roller pair 6. Second sheet discharge section 7. Third sheet transport path 7r Conveyor Roller Pair 8. Third sheet discharge section 9. Post-processing 10 Post-processing control unit 20 Drilling device 22. Delivery Guide 23 Perforation Processing Unit 24 Recovery Tanks 25 Detection unit 26 Comparators 31. First branching point 32 Second branch 41 1st outlet 42 First discharge roller pair 43 First discharge tray 61 2nd outlet 62. Second discharge roller pair 63 Second discharge tray 81 3rd outlet 82 Third discharge roller pair 83 Third Ejection Tray 92 units 94 Manufacturing Division 100-sheet folding unit 106 Second folding transport path 200 Image forming apparatus 201 Image Reading Unit 231 Eccentric cam 232 Perforating blade 233 Shaft 234 Housing 241 Storage Unit 242 Mounting part 242a opening 243a Regulatory aspects 250a, 250b light sensor 251 Light-emitting substrate 251a, 251b Light-emitting element 251c, 252c mounting holes 252 Photodetector substrate 252a, 252b Photodetector 300 Image Forming Systems 311 First Switching Guide 321 Second Switching Guide 941 Center fold 942 Saddle-stitched section A1 Axial side (other side) A2 One side in the axial direction B1 Downstream side in the sheet transport direction C Rotation axis C1 Capacitor C2 Capacitor R1-R7 resistor Vcc power supply

Claims

1. A perforation processing unit that performs perforation on the transported sheets, A sheet post-processing device comprising a recovery tank located below the perforation processing unit for containing perforation waste generated by the perforation process, The system further includes a detection unit that detects when the collection tank is full of the drilling debris and when it is nearly full. The detection unit is configured by arranging a plurality of light sensors, each composed of a light-emitting element and a light-receiving element arranged opposite each other, in a vertical direction, and detects the drilled debris when it enters the optical path of the light sensor. A drilling device in which each of the light-emitting elements is mounted on the same light-emitting substrate, and each of the light-receiving elements is mounted on the same light-receiving substrate.

2. The drilling device according to claim 1, wherein the detection circuit using the light-receiving element is shared by the circuit for detecting the full state and the circuit for detecting the near-full state.

3. The drilling device according to claim 1 or claim 2, wherein the detection position for the full state or the detection position for the near-full state can be changed by changing the mounting position of the light-emitting element on the light-emitting substrate and the mounting position of the light-receiving element on the light-receiving substrate in the vertical direction.

4. The aforementioned perforation processing unit is The shaft and The system comprises a plurality of perforating blades arranged along the axis of the shaft for making holes in the sheet, The aforementioned optical sensors are arranged in a plurality in the axial direction of the shaft, corresponding to each of the drilling blades, in a drilling device.

5. A sheet post-processing device including the perforation device according to claim 1 or claim 2, An image forming system comprising an image forming apparatus that forms an image on the sheet and sends it to the transport path.

Images