Punching device, post-processing device, and image formation system

Abstract

To suppress the occurrence of dew condensation on a conveyance guide surface of a conveyance guide member.SOLUTION: A punching unit 70 performing punching to a sheet P is provided with a conveyance guide member 180 for guiding the sheet P. A detection sensor 161 capable of detecting an end part of the sheet P in a width direction is included in a positional deviation detection mechanism 150 for detecting a positional deviation amount of the sheet P in the width direction by moving the detection sensor 161 in the width direction. Further, a movement mechanism 190 for moving the punching unit 70 in the width direction so as to cancel the positional deviation amount on the basis of the positional deviation amount detected by the positional deviation detection mechanism 150 is provided. The positional deviation detection mechanism 150 is provided with a dew condensation removal part 165 for returning the part on which dew condensation is formed in conveyance guide surfaces 181a, 182a of the conveyance guide member 180 to a state before dew condensation or a state close thereto interlocking with the movement of the detection sensor 161.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a punching device that punches holes in sheets, a post-processing device including the punching device, and an image forming system including an image forming device. [Background technology]

[0002] BACKGROUND ART Conventionally, there has been known a post-processing device connected to an image forming apparatus such as a copying machine or a printer, which is provided with a punching device that performs a perforation process (punching process) on sheets (see, for example, Patent Document 1).

[0003] On the other hand, Patent Document 1 discloses a technology for pressing a sheet against the sheet guide surface (conveying guide surface) of a conveying guide plate in a punch unit (perforation device) in order to prevent problems such as condensation on metal parts such as the conveying guide plate, which can cause sheet jams (poor conveyance). Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional punching devices, condensation occurs on the conveying guide surface of the conveying guide member, causing sheet conveyance problems such as jams. Such problems could not be sufficiently solved even with the technology disclosed in Patent Document 1.

[0005] The present invention has been made to solve the above-mentioned problems, and aims to provide a punching device, a post-processing device, and an image forming system in which condensation is less likely to occur on the transport guide surface of the transport guide member. [Means for solving the problem]

[0006] The perforation device of this invention comprises a perforation unit that has a transport guide member that guides a sheet transported in a predetermined transport direction and performs a perforation process on the sheet, a positional deviation detection mechanism that has a detection sensor that can detect the widthwise end of the sheet perpendicular to the transport direction and moves the detection sensor in the widthwise direction to detect the amount of positional deviation of the sheet in the widthwise direction, and a movement mechanism that moves the perforation unit in the widthwise direction based on the amount of positional deviation detected by the positional deviation detection mechanism so as to offset the amount of positional deviation, and the positional deviation detection mechanism has a condensation removal section that returns condensed portions on the transport guide surface of the transport guide member to a state before condensation or a state close to that in conjunction with the movement of the detection sensor. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a punching device, a post-processing device, and an image forming system in which condensation is less likely to occur on the transport guide surface of the transport guide member. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is an overall configuration diagram showing an image forming system according to an embodiment of the present invention; [Figure 2] FIG. 2 is a top view showing the main parts of the punching device. [Figure 3] FIG. 10 is a front view showing the operation of the punching device during punching processing. [Figure 4] (A) A front view showing the positional deviation detection mechanism when the sensor unit is positioned in a retracted position at one end of the width direction, and (B) a front view showing the positional deviation detection mechanism when the sensor unit is positioned at the other end of the width direction. [Figure 5] FIG. 2 is a side view showing the punching device and the moving mechanism. [Figure 6] 1A is a front view showing the drilling device when the condensation removal unit is positioned in the sliding contact position, and FIG. 1B is a front view showing the drilling device when the condensation removal unit is positioned in the storage position. [Figure 7]10A is a front view showing the punching device when the condensation removing member starts to move to the sliding contact position, and FIG. 10B is a side view showing the positional deviation detection mechanism. [Figure 8] 10A is a front view showing the punching device when the condensation removing member starts to separate from the sliding contact position, and FIG. 10B is a side view showing the positional deviation detection mechanism. [Figure 9] 10 is a flowchart illustrating an example of control when a condensation removal mode is executed in the punching device. [Figure 10] FIG. 2 is a block diagram showing the configuration of a control system of the post-processing device. [Figure 11] FIG. 10 is a front view showing a positional deviation detection mechanism as a first modified example. [Figure 12] FIG. 10 is a diagram showing the overall configuration of an image forming system according to a second modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each drawing, the same or corresponding parts are designated by the same reference numerals, and redundant explanations will be appropriately simplified or omitted.

[0010] First, the overall configuration and operation of an image forming system 200 will be described with reference to FIG. In this embodiment, the image forming apparatus 1 is provided with a detachable post-processing device 50, and together with the post-processing device 50, constitutes one image forming system 200. Image forming apparatus 1 is a multifunction machine equipped with a copy function, a printer function, and a scanner function. A personal computer is connected to image forming apparatus 1 via a network as a remote input device. A user can use the personal computer to issue various commands to image forming apparatus 1 via communication to perform desired printing (image forming operation), or manually operate operation buttons and operation keys displayed on the screen of operation display panel 95 to issue various commands to perform desired printing (image forming operation).

[0011] As shown in FIG. 1, a scanner 13 (document reader) that optically reads image information of a document is installed on the top of the image forming apparatus 1. An intermediate transfer belt 8 is also installed above the center of the image forming apparatus 1. Photosensitive drums 2Y, 2M, 2C, and 2K (imaging units) corresponding to the respective colors (yellow, magenta, cyan, and black) are arranged side by side facing the intermediate transfer belt 8. Furthermore, the intermediate transfer belt 8 is pressed against a secondary transfer roller 15 (secondary transfer belt 16) below it, forming a secondary transfer nip as an image forming unit.

[0012] 1, a charging unit 3, a developing unit 4, a cleaning unit 5, a discharging unit, etc. are arranged around the photosensitive drum 2K corresponding to black. Then, an image creation process (charging process, exposure process, developing process, transfer process, cleaning process, discharging process) is carried out on the photosensitive drum 2K, and a black image is formed on the surface of the photosensitive drum 2K.

[0013] The other three photosensitive drums 2Y, 2M, and 2C have substantially the same configuration around them, and images corresponding to the respective toner colors are formed on the surfaces of the photosensitive drums 2Y, 2M, and 2C. Below, we will omit the description of the image formation process on the other three photosensitive drums 2Y, 2M, and 2C as appropriate, and will only describe the image formation process corresponding to black.

[0014] The photosensitive drum 2K is rotated by a main motor in the counterclockwise direction in Fig. 1. Then, at the position of the charging unit 3, the surface of the photosensitive drum 2K is uniformly charged (charging process). Thereafter, the surface of the photosensitive drum 2K reaches the irradiation position of the laser light emitted from the exposure unit 7, and an electrostatic latent image corresponding to black is formed by exposure scanning in the width direction (the direction perpendicular to the paper surface of Figure 1, which is the main scanning direction) at this position (this is the exposure process).

[0015] When the image forming apparatus 1 is used as a copy machine, a latent image is formed on the photosensitive drum 2K by irradiation with laser light from the exposure unit 7 based on image information of an original document read by the scanner 13. On the other hand, when the image forming apparatus 1 is used as a printer, a latent image is formed on the photosensitive drum 2K by irradiation with laser light from the exposure unit 7 based on image information sent from a personal computer.

[0016] Thereafter, the surface of the photosensitive drum 2K reaches a position facing the developing unit 4, where the electrostatic latent image is developed to form a black toner image (developing step). Thereafter, the surface of the photosensitive drum 2K reaches the position (primary transfer nip) where the intermediate transfer belt 8 and primary transfer roller 6 face each other, and at this position the toner image formed on the surface of the photosensitive drum 2K is primarily transferred onto the surface of the intermediate transfer belt 8 (primary transfer process). At this time, a small amount of untransferred toner remains on the photosensitive drum 2K.

[0017] Thereafter, the surface of the photosensitive drum 2K reaches a position facing the cleaning unit 5, and at this position, the untransferred toner remaining on the photosensitive drum 2K is collected into the cleaning unit 5 by a cleaning blade (cleaning process). Finally, the surface of the photosensitive drum 2K reaches a position between the cleaning unit 5 and the charging unit 3, facing a charge removal unit (not shown), where the residual potential on the photosensitive drum 2K is removed. Thus, the series of image forming processes performed on the photosensitive drum 2K is completed.

[0018] The above-described image forming process is performed on the surfaces of the other photosensitive drums 2Y, 2M, and 2C in the same manner as on the black photosensitive drum 2K. Then, the toner images of each color formed on the surface of each photosensitive drum 2Y, 2M, 2C, and 2K are primarily transferred onto the intermediate transfer belt 8 in a superimposed manner. In this way, a color image is formed on the intermediate transfer belt 8.

[0019] Thereafter, the intermediate transfer belt 8, onto which the toner images of each color have been primarily transferred in a superimposed state, reaches a position facing a secondary transfer roller 15 (secondary transfer belt 16). At this position, a secondary transfer nip (image forming portion) is formed between the secondary transfer opposing roller 9 and the secondary transfer roller 15, sandwiching the intermediate transfer belt 8 and the secondary transfer belt 16. The four-color toner images formed on the intermediate transfer belt 8 are then secondarily transferred onto a sheet P, such as paper, that has been transported to the position of this secondary transfer nip (secondary transfer process). At this time, untransferred toner that has not been transferred to the sheet P remains on the intermediate transfer belt 8.

[0020] Thereafter, the intermediate transfer belt 8 reaches the position of an intermediate transfer cleaning unit (not shown) between the secondary transfer nip and the primary transfer nip for yellow (primary transfer roller 6). At this position, untransferred toner and other deposits adhering to the surface of the intermediate transfer belt 8 are removed. Thus, the series of transfer processes performed on the intermediate transfer belt 8 is completed.

[0021] Referring to Figure 1, the sheet P transported to the position of the secondary transfer nip (image forming section) is transported from a paper feed section 10 arranged below the image forming apparatus 1 via a transport path K1 on which a paper feed roller 11, a registration roller 12, etc. are arranged. More specifically, a plurality of sheets P such as paper are stacked and stored in the paper feed unit 10. When the paper feed roller 11 is rotated counterclockwise in FIG. 1, the topmost sheet P is fed toward between the registration rollers 12 via a conveying path K1.

[0022] The sheet P conveyed to the registration rollers 12 is temporarily stopped at the roller nip of the registration rollers 12, which have stopped rotating. Then, the registration rollers 12 are rotated in synchronization with the color image on the intermediate transfer belt 8, and the sheet P is conveyed toward the secondary transfer nip (image forming unit). In this way, the desired color image is transferred onto the sheet P.

[0023] Thereafter, the sheet P onto which the color image has been transferred at the secondary transfer nip position is conveyed by the secondary transfer belt 16, and after being separated from the secondary transfer belt 16, is conveyed by the conveying belt 18 to the position of the fixing unit 19. Then, at this position, the color image transferred onto the surface is fixed onto the sheet P by the heat and pressure of the fixing belt and pressure roller (the fixing process). Thereafter, the sheet P is discharged to the outside of the image forming apparatus 1 by the paper discharge rollers 25 via the discharge conveyance path K2. Furthermore, the sheets P discharged from the image forming apparatus 1 are transported inside the post-processing device 50, where they are subjected to processes (post-processing) such as perforation (punching) and binding. The sheets P (sheet stack PT) that have been subjected to post-processing are then discharged onto a discharge tray 59. The configuration and operation of the post-processing device 50 will be described in detail later. In this way, a series of image forming processes (image forming operations) in the image forming apparatus 1 is completed.

[0024] The post-processing device 50 will be described in detail below. First, the sheet P discharged from the image forming apparatus 1 is fed (conveyed) into the post-processing apparatus 50 by the inlet rollers 51. When the user has previously selected the "normal processing mode" on the operation display panel 95, the conveying path is switched by the switching claw 57, and the sheet P is discharged directly onto the discharge tray 59 by the discharge roller 58 via the linear conveying path K11. At this time, if the user has additionally selected "perforation processing (punch processing)" in advance on the operation display panel 95, the perforation processing is performed on the sheet P by the perforation device 69 when the sheet P passes through the perforation device 69. Note that the perforation device 69 in this embodiment is made up of a perforation unit 70, a positional deviation detection mechanism 150 (horizontal registration detection mechanism), etc., which will be described in detail later. Furthermore, if the user has additionally selected "sorting process" on the operation display panel 95 in advance, when the sheet P is discharged onto the discharge tray 59 by the discharge rollers 58, the discharge rollers 58, which function as a sorting processing section, move in the width direction in accordance with the timing for sorting the sheet P, and the sorting process is performed on the sheet P discharged onto the discharge tray 59.

[0025] On the other hand, when the user has previously selected the "binding processing mode" on the operation display panel 95 of the image forming apparatus 1, the sheet P is conveyed toward the internal tray 61 via the binding processing conveyance path K12 by switching the conveyance path using the switching claw 57. Then, the sheet aligning unit 60 aligns the sheets P (sheet stack PT) stacked on the internal tray 61 in the conveyance direction and the width direction.

[0026] More specifically, each time a sheet P (sheet stack PT) is placed on the tray surface of the internal tray 61, the tapping roller 56 disposed above it rotates about its rotation axis from a retracted position to a position where it abuts against the uppermost sheet P, and the tapping roller 56 is driven to rotate counterclockwise in Fig. 1, thereby transporting (moving) the sheet P toward the end fence 62. As a result, the trailing ends of the multiple sheets P (sheet stack PT) abut against the end fence 62, and the positions of the multiple sheets P (sheet stack PT) in the transport direction are aligned. In the present embodiment, each time a sheet P (sheet stack PT) is placed on the tray surface of the internal tray 61, the stopper portion 64 held on the belt surface of the conveyor belt 65 moves to push the leading edge of the sheet P as the conveyor belt 65 travels clockwise in FIG. 1, and the sheet P is conveyed (moved) toward the end fence 62. As a result, the trailing edges of the multiple sheets P (sheet stack PT) hit the end fence 62, and the positions of the multiple sheets P (sheet stack PT) in the conveying direction are aligned. Furthermore, when the sheet stack PT is aligned in the conveying direction in this manner, at least one of a pair of side fences (jogger fences) (not shown) installed at both widthwise ends of the internal tray 61 moves in the widthwise direction (a direction perpendicular to the conveying direction, that is, a direction perpendicular to the plane of the paper in Figure 1) so as to sandwich the sheets P (sheet stack PT) each time a sheet P is placed on the internal tray 61 (or after the desired number of sheets P have been stacked), thereby aligning the widthwise position of the sheets P (sheet stack PT).

[0027] Then, the stapler 80, which is movable in the width direction, moves in the width direction to bind the rear end of the sheets P (sheet stack PT), whose conveying direction and width direction have been aligned by the sheet alignment device 60, at a predetermined position. Thereafter, the bound sheets P (sheet stack PT) move diagonally upward along the inclination of the tray surface due to the movement of the stopper portion 64, which also functions as a discharge claw, in the discharge direction, and after passing through the discharge conveying path K13, are discharged onto the discharge tray 59 by conveyance by the discharge rollers 58. Furthermore, even in the binding processing mode, if the user has additionally selected "perforation processing" in advance on the operation display panel 95, the perforation processing is performed on the sheet P by the perforation device 69 when the sheet P passes through the perforation device 69.

[0028] The following will describe in detail the characteristic configuration and operation of the punching device 69 installed in the post-processing device 50 (image forming system 200) in this embodiment. 1, 5, etc., a punching device 69 in this embodiment is provided with a punching unit 70, a positional deviation detection mechanism 150, a moving mechanism 190, and the like.

[0029] 2, 3, etc., the punching unit 70 performs a punching process on the trailing end of the sheet P in the conveying direction (the right end in FIG. 2). 5, the punching unit 70 is provided with a transport guide member 180 that guides the sheet P transported in a predetermined transport direction (+x direction), and performs a punching process on the sheet P guided by the transport guide member 180. The punching process by the punching unit 70 may be performed while the sheet P is being transported, or may be performed by temporarily stopping the transport of the sheet P. The transport guide member 180 is configured such that two transport guide plates (an upper transport guide plate 181 and a lower transport guide plate 182) made of metal face each other. The sheet P is transported along the transport path sandwiched between the lower surface (transport guide surface 181a) of the upper transport guide plate 181 and the upper surface (transport guide surface 182a) of the lower transport guide plate 182.

[0030] As shown in FIG. 3, the punching unit 70 is provided with a first frame 71 and a second frame 72. The first frame 71 holds a substantially rod-shaped blade 71a (punch portion) so that it can move in a predetermined direction, and is disposed above the conveyance path of the sheet P. More specifically, the first frame 71 holds a movable plate 71c, to which multiple blades 71a (three blades 71a in this embodiment) are fixed, via bearings so that it can move up and down. The movable plate 71c is biased upward by a tension spring 71d, and a cam 71b abuts against its upper portion. The control unit 300 controls the motor 91 to rotate the cam 71b to the position shown in FIG. 3A or 3B, thereby moving the blade 71a up and down together with the movable plate 71c relative to the first frame 71, whose position in the vertical direction (±z direction) is fixed. The first frame 71 also functions as a part of the upper conveyance guide plate 181. The second frame 72 is disposed opposite the first frame 71 with a gap in a predetermined direction (the vertical direction, which is the direction in which the blade portion 71a moves). The first frame 71 and the second frame 72 are fixed and held by studs 73. The second frame 72 is formed with holes 72a into which the tips of the blade portions 71a, which penetrate the sheet P conveyed into the gap between the first and second frames 71 and 72 during punching processing, are inserted. The second frame 72 also functions as a part of the conveying lower guide plate 182. Although not shown in the figure, a punch scrap collection container is detachably installed below the second frame 72 to collect punch scraps generated when the blade portion 71a penetrates the sheet P after they fall under their own weight through the hole portion 72a.

[0031] In the punching device 69 configured in this manner, when punching is not being performed (when not performing punching), the blade portion 71a (movable plate 71c) is positioned in an upper standby position due to the force of the tension spring 71d, as shown in Figure 3(A). 3(B), with a sheet P (which is in a temporarily transported state) interposed between the first frame 71 and the second frame 72, the cam 71b rotates under the control of the control unit 300 and pushes the movable plate 71c downward against the bias of the tension spring 71d. Then, the blade portion 71a of the movable plate 71c enters the hole portion 72a of the second frame 72 through the sheet P, thereby forming a punched hole in the sheet P. The punching device 69 is not limited to one that uses such a cam mechanism, but may also use, for example, a link mechanism.

[0032] 4 to 8, the misalignment detection mechanism 150 is provided with a detection sensor 161 that can detect the edge of the sheet P in the width direction (the ±y direction, which is a direction perpendicular to the conveying direction). The misalignment detection mechanism 150 moves the detection sensor 161 in the width direction (±y direction) to detect the amount of misalignment of the sheet P in the width direction (horizontal registration).

[0033] 4, the positional deviation detection mechanism 150 is provided with a drive mechanism including a forward / reverse rotating motor 151, a drive pulley 153 mounted on the motor shaft of the motor 151, a driven pulley 154 that tensions the timing belt 152 together with the drive pulley 153, and the timing belt 152. A sensor unit 160 that holds a detection sensor 161 (e.g., a reflective photosensor) is held by a part of the timing belt 152, and moves in the ±y directions (width direction) when the timing belt 152 rotates due to the drive of the motor 151. The positional deviation detection mechanism 150 also includes a guide member 155 that guides the movement of the sensor unit 160 in the ±y directions (width direction), and a home position sensor 158 that detects when the sensor unit 160 (detection sensor 161) is located at the home position (the position shown in FIG. 4A, which is the retracted position).

[0034] 2 and 4, when the sheet P is conveyed toward the punching unit 70, the detection sensor 161 (sensor unit 160) located at the home position (retracted position) shown in Fig. 4(A) is moved in the +y direction toward the other end side (the position shown in Fig. 4(B)), and the detection sensor 161 optically detects the position of the widthwise end (edge) of the sheet P before the punching process. The widthwise end of the sheet P is detected in this way before the punching process because if the sheet P is conveyed with a shift in the width direction and the punching process is performed on the sheet P, the punch holes in the sheet P will be shifted from the desired positions. The sensor unit 160 is provided with a condensation removal section 165 for preventing sheet transport failure due to condensation on the transport guide surfaces 181a and 182a of the transport guide member 180, which will be described in detail later.

[0035] Referring to Figure 5, the moving mechanism 190 moves the punching unit 70 in the width direction (±y direction) based on the amount of positional misalignment detected by the positional misalignment detection mechanism 150 (detection sensor 161) so as to offset the amount of positional misalignment. More specifically, the movement mechanism 190 is composed of a forward / reverse rotating motor 191, a drive gear 192 mounted on the motor shaft of the motor 191, a pinion gear-equipped driven gear 193 that tensions a timing belt 194 together with the drive gear 192, and the timing belt 194. The pinion gear of the pinion gear-equipped driven gear 193 is engaged with a rack gear 78 mounted on the punching unit 70. With this configuration, when the motor 191 of the movement mechanism 190 is driven, the punching unit 70 moves in the width direction (±y direction). Then, referring to Figure 2, when the detection sensor 161 (positional misalignment detection mechanism 150) detects that the sheet P has shifted from the position shown by the dashed line to the position shown by the solid line, the movement mechanism 190 moves the punching unit 70 by the amount of the positional misalignment (from the position shown by the dashed line to the position shown by the solid line). As a result, even if the sheet P is conveyed with a deviation in the width direction, the sheet P can be punched at a desired position.

[0036] 6 to 8, etc., in the punching device 69 of this embodiment, the misalignment detection mechanism 150 is provided with a condensation removal unit 165 that returns condensed portions (hereinafter referred to as "condensation portions") on the transport guide surfaces 181a, 182a of the transport guide member 180 to a state before condensation or a state close to that (a state in which the condensation state has been improved) in conjunction with the movement of the detection sensor 161 (sensor unit 160). That is, the misalignment detection mechanism 150 is provided with a condensation removal unit 165 that can remove the condensation portions on the transport guide surfaces 181a, 182a. More specifically, sensor unit 160 holds detection sensor 161 and link mechanism 166 that holds condensation removal unit 165. Link mechanism 166 is held by sensor unit 160 via base portion 167, and condensation removal unit 165 is installed at the tip of link mechanism 166. Then, as the sensor unit 160 moves from one end side in the width direction (the retracted position shown in Figure 4(A)) to the other end side (the position shown in Figure 4(B)), the link mechanism 166 is pushed by the first pushing portion 171 (see Figure 7(B)) which serves as the pushing portion of the positional misalignment detection mechanism 150, and the condensation removal portion 165 moves from a storage position (the position shown in Figure 6(B)) which does not interfere with the transport of the sheet P to a sliding contact position (the position shown in Figure 6(A)) where it slides against the transport guide surfaces 181a, 182a. That is, the condensation removal section 165 (and the link mechanism 166) moves from the storage position shown in FIG. 6(B) through the first pushing position by the first pushing section 171 (which is formed in a tapered shape) shown in FIGS. 7(A) and (B) to the sliding contact position shown in FIG. 6(A).

[0037] The condensation removing portion 165 slides in contact with the transport guide surfaces 181a and 182a of the transport guide member 180 in the ±x direction to remove condensation. The condensation removal section 165 can be an elastic member (e.g., made of a rubber material) that scrapes off water droplets adhering to the transport guide surfaces 181a and 182a, or a moisture-absorbing member (e.g., made of a sponge material) that absorbs water droplets adhering to the transport guide surfaces 181a and 182a.

[0038] As described above, the punching device 69 in this embodiment is provided with a condensation removal section 165 that can remove condensation on the transport guide surfaces 181a and 182a of the transport guide member 180, making it less likely for condensation to form on the transport guide surfaces 181a and 182a, and also reducing problems such as jamming and other sheet transport problems caused by condensation on the transport guide surfaces 181a and 182a. In particular, the punching device 69 in this embodiment receives the sheet P immediately after it is discharged from the image forming apparatus 1. The image forming apparatus 1 is provided with a fixing section 19 (fixing device) that heats and pressurizes the sheet P to fix an unfixed toner image carried on the sheet P. The sheet P is heated to approximately 200°C by the fixing section 19, causing the moisture contained in the sheet P to evaporate, which is likely to condense and turn into droplets on the conveyance guide surfaces 181a and 182a of the punching device 69. If the sheet P is conveyed with condensation on the conveyance guide surfaces 181a and 182a in this state, the condensed portions will act as a conveyance load, resulting in conveyance problems such as jamming of the sheet P. In contrast, the punching device 69 of this embodiment is provided with the condensation removal section 165 that makes it difficult for condensation to form on the conveyance guide surfaces 181a and 182a, so that such a problem is unlikely to occur. Furthermore, such condensation removal section 165 is installed in the positional deviation detection mechanism 150 and operates to remove condensation from the transport guide surfaces 181a and 182a in conjunction with the widthwise movement of the detection sensor 161 (sensor unit 160). This results in lower costs and a smaller overall device compared to when a separate device for removing condensation from the transport guide surfaces 181a and 182a is provided.

[0039] In this embodiment, after the condensation removal operation is completed, the condensation removal section 165 (and the link mechanism 166) moves from the sliding position shown in Figure 6(A) to the second pushing position by the second pushing section 172 shown in Figures 8(A) and (B), and then to the storage position shown in Figure 6(B). Specifically, in the process of the sensor unit 160 moving from the other end side in the width direction (the position shown in Figure 4(B)) to the one end side (the position shown in Figure 4(A)), the link mechanism 166 is pushed by the second pushing portion 172 (which is formed in a tapered shape) of the positional deviation detection mechanism 150, and the condensation removal portion 165 moves from the sliding position shown in Figure 6(A) to the storage position shown in Figure 6(B).

[0040] In this embodiment, the detection sensor 161 detects the amount of misalignment of the sheet P while the sensor unit 160 moves from the retracted position on one end side in the width direction shown in FIG. 4A to the central detection end position (a position with a margin in the +y direction from the position of the edge face of one end of the sheet when the positional misalignment can be maximized in the +y direction). This is because the misalignment of the sheet P can be grasped by detecting the edge face position on one end side of the sheet P with the detection sensor 161, and it is not necessary for the detection sensor 161 to perform detection over the entire area from one end side to the other end side (because it is not necessary to detect the edge face position on the other end side). In this case, the width size of the sheet P is grasped based on the sheet information, etc., input by the user to the operation display panel 95. Then, as the sensor unit 160 moves from its detection end position to the other end in the width direction shown in Figure 4(B), the condensation removal section 165 moves from the storage position (see Figure 6(B)) to the sliding position (see Figure 6(A)). By configuring in this manner, the condensation removal operation by the condensation removal unit 165 and the positional deviation detection operation by the detection sensor 161 are performed at different times, preventing the two operations from interfering with each other.

[0041] Here, in this embodiment, the condensation removal mode in which the condensation removal unit 165 is moved from the storage position shown in Figure 6(B) to the sliding position shown in Figure 6(A) can be executed before the first punching process is started after the power is turned on. 9, when punching is selected as a job in image forming system 200, it is determined whether the job is the first one since image forming system 200 is turned on (step S1). If it is determined that the job is the first one since power is turned on, the condensation removal mode is executed (step S2), and then the punching process is executed (step S3). On the other hand, if it is determined that the job is not the first one since power is turned on, the condensation removal mode is not executed, and the punching process is executed directly (step S3). This type of control is useful because condensation often occurs on the transport guide surfaces 181a and 182a of the punching device 69 in jobs performed first thing in the morning in winter. When moisture contained in the sheet P is heated and evaporated in the fixing unit 19 of the image forming apparatus 1 in a low-temperature environment, it is cooled by the transport guide surfaces 181a and 182a made of a metal material in the punching device 69, condensing into droplets. Therefore, if the condensation removal mode is executed only for the first job after the power is turned on, the sheet P will wipe off the moisture before it forms droplets, making it less likely that the sheet P will jam due to condensation. In other words, it is possible to efficiently prevent condensation on the transport guide surfaces 181a and 182a while reducing unnecessary power consumption. In the example of FIG. 9, the condensation removal mode is executed for the first job when the power is turned on, but the condensation removal mode can also be executed at any timing, such as when returning from the energy saving mode.

[0042] The adjustment mode in which the movement mechanism 190 moves the punching unit 70 in the width direction (±y direction) based on the amount of positional deviation detected by the detection sensor 161 can be executed every time punching processing is performed. In this case, when the condensation removal mode is not executed, the movement of the sensor unit 160 can be limited to from the retracted position on one end side in the width direction to the detection end position in the center, as described above.

[0043] The post-processing device 50 configured in this manner is controlled by the control unit 300 shown in FIG. 10 (and FIG. 1). 10, the control unit 300 of the post-processing device 50 is connected to the control unit of the image forming apparatus 1 via an interface. The control unit of the image forming apparatus 1 is also connected to the operation display panel 95, the various driving members and various sensors of the image forming apparatus 1 via the interface. The control unit 300 of the post-processing device 50 is also connected to the conveyance system motors, conveyance system sensors, drive system motors, drive system sensors, etc. via the interface. The control unit 300 of the post-processing device 50 is also connected to the detection sensor 161 of the punching device 69, the various motors 91, 151, 191, the various home position sensors 158, 198, etc. via the interface. The overall control system of the image forming system 200 configured in this manner executes the various operations in the image forming system 200 described above.

[0044] <Variation 1> As shown in FIG. 11, in a punching device 69 in the first modification, a positional deviation detection mechanism 150 is provided with a plurality of condensation removal units 165A, 165B. More specifically, the first condensation removal unit 165A is made of an elastic member such as rubber that scrapes off water droplets adhering to the transport guide surfaces 181a and 182a, while the second condensation removal unit 165B is made of a moisture-absorbing member such as sponge that absorbs water droplets adhering to the transport guide surfaces 181a and 182a. 4 and the like, these condensation removal units 165A and 165B are held by the sensor unit 160 via a link mechanism 166, and perform the condensation removal operation in the same manner. By using a plurality of condensation removal sections 165A and 165B in this manner, the condensation removal performance on the transport guide surfaces 181a and 182a of the transport guide member 180 is further improved.

[0045] <Variation 2> As shown in Fig. 12, in the image forming system 200 of the second modification, a post-processing device 50 (sheet processing device) having a punching function and a binding function is detachably installed in the internal space W of the image forming apparatus 1 (the space provided between the document reading device 14 and the image forming unit 115). The internal space W is a space into which sheets P (printed sheets P) discharged from the image forming apparatus 1 can be discharged, and is also a space into which the discharged sheets P can be removed. In other words, when the post-processing device 50 is not installed, the internal space W functions as a space (discharge unit) in which sheets P discharged from the image forming apparatus 1 are stacked. In addition, a portion of the internal space W is open, and the user operates the operation display panel 95, views the display, and operates the post-processing device 50 from a direction directly facing the operation display panel 95. In addition, the image forming apparatus 1 (image forming system 200) in variant example 2 is provided with a second discharge roller 26 and a second discharge tray 159 for discharging the sheet P printed by the image forming apparatus 1 without passing through the post-processing apparatus 50 when the post-processing apparatus 50 is attached.

[0046] As described above, the punching device 69 in this embodiment includes a transport guide member 180 that guides the sheet P transported in a predetermined transport direction, and a punching unit 70 that performs a punching process on the sheet P. The punching device 69 also includes a detection sensor 161 that can detect the edge of the sheet P in the width direction perpendicular to the transport direction, and a misalignment detection mechanism 150 that moves the detection sensor 161 in the width direction to detect the amount of misalignment of the sheet P in the width direction. The punching device 69 also includes a movement mechanism 190 that moves the punching unit 70 in the width direction based on the amount of misalignment detected by the misalignment detection mechanism 150 so as to offset the amount of misalignment. The misalignment detection mechanism 150 also includes a condensation removal unit 165 that, in conjunction with the movement of the detection sensor 161, returns condensed portions on the transport guide surfaces 181 a, 182 a of the transport guide member 180 to a state before condensation or a state close to that. This makes it difficult for condensation to form on the transport guide surfaces 181a and 182a of the transport guide member 180.

[0047] In this embodiment, the present invention is applied to an image forming system 200 in which a color image forming apparatus 1 is installed, but the present invention can naturally also be applied to an image forming system in which a monochrome image forming apparatus is installed. Furthermore, in this embodiment, the present invention is applied to a post-processing device 50 connected to an electrophotographic image forming apparatus 1, but the application of the present invention is not limited to this, and the present invention can also be applied to a sheet processing device connected to other types of image forming apparatus (for example, an inkjet type image forming apparatus, a stencil printing apparatus, etc.). Furthermore, in this embodiment, the present invention is applied to the image forming system 200 in which the post-processing device 50 and the image forming device 1 are installed, but the present invention can also be applied to a punching device (or post-processing device) that is an independent sheet processing device and is not connected to the image forming device 1. In such a case, it is assumed that the sheet P that contacts the transport guide member 180 has not been subjected to the fixing process in the image forming device 1 and therefore has not reached a high temperature, but the present invention is useful when the environment in which the device is used is prone to condensation. Furthermore, in this embodiment, the present invention is applied to a post-processing device 50 that performs binding and sorting processes in addition to punching processes, but the present invention can naturally also be applied to a post-processing device that performs only punching processes. Even in such cases, the same effects as those of this embodiment can be obtained.

[0048] It is to be noted that the present invention is not limited to the present embodiment, and it is clear that the present embodiment can be appropriately modified within the scope of the technical concept of the present invention in addition to the modifications suggested in the present embodiment. Furthermore, the number, position, shape, etc. of the components are not limited to the present embodiment, and the number, position, shape, etc. of the components can be any number, position, shape, etc. that is suitable for implementing the present invention.

[0049] In this specification, the term "sheet" is defined to include not only paper but also all sheets that are the subject of punching processing. [Explanation of symbols]

[0050] 1. Image forming device, 50 post-processing device (sheet processing device, 69 drilling equipment, 70 drilling units, 150 Position deviation detection mechanism (horizontal registration detection mechanism), 160 sensor units, 161 detection sensor (horizontal registration detection sensor), 165, 165A, 165B Condensation removal section, 166 link mechanism, 167 base part, 171 first pushing portion (pushing portion), 172 second pushing portion, 180 conveying guide member, 181 upper conveying guide plate (conveying guide member), 181a conveying guide surface, 182 conveying lower guide plate (conveying guide member), 182a conveying guide surface, 190 Moving mechanism; 200 Image forming system, P seat.

[0051] The present invention can also be embodied in a combination of Supplementary Notes 1 to 11, for example, as follows. (Appendix 1) a punching unit including a conveying guide member for guiding a sheet conveyed in a predetermined conveying direction, the punching unit performing a punching process on the sheet; a positional deviation detection mechanism including a detection sensor capable of detecting an edge of the sheet in a width direction perpendicular to the conveying direction, and configured to move the detection sensor in the width direction to detect a positional deviation amount of the sheet in the width direction; a movement mechanism that moves the punching unit in the width direction based on the amount of positional misalignment detected by the positional misalignment detection mechanism so as to offset the amount of positional misalignment; Equipped with The positional deviation detection mechanism is characterized in that it is equipped with a condensation removal section that returns condensed portions on the transport guide surface of the transport guide member to their pre-condensation state or a state close to it in conjunction with the movement of the detection sensor. (Appendix 2) the positional deviation detection mechanism includes a sensor unit that holds the detection sensor and a link mechanism that holds the condensation removal unit and is movable in the width direction; The punching device described in Appendix 1 is characterized in that, during the process of the sensor unit moving from one end to the other end in the width direction, the link mechanism is pushed by the pushing portion of the positional deviation detection mechanism, and the condensation removal portion moves from a storage position that does not interfere with the transport of the sheet to a sliding contact position in which it slides against the transport guide surface. (Appendix 3) The drilling device described in Appendix 2 is characterized in that during the process of the sensor unit moving from the other end side to the one end side in the width direction, the link mechanism is pushed by the second pushing portion of the positional deviation detection mechanism, and the condensation removal portion moves from the sliding position to the storage position. (Appendix 4) the amount of positional misalignment is detected by the detection sensor during the process in which the sensor unit moves from a retracted position on one end side in the width direction to a detection end position in the center, A perforation device as described in Appendix 2 or Appendix 3, characterized in that during the process of the sensor unit moving from the detection end position to the other end side in the width direction, the condensation removal section moves from the storage position to the sliding contact position. (Appendix 5) A perforation device described in any of Appendix 2 to Appendix 4, characterized in that a condensation removal mode in which the condensation removal unit is moved from the storage position to the sliding position is executed before the first perforation process is started after power is turned on. (Appendix 6) A punching device described in any one of Appendix 1 to Appendix 5, characterized in that an adjustment mode in which the moving mechanism moves the punching unit in the width direction based on the amount of positional misalignment detected by the detection sensor is executed each time the punching process is performed. (Appendix 7) 7. The punching device according to any one of claims 1 to 6, wherein the condensation removing section is an elastic member. (Appendix 8) 8. The punching device according to any one of claims 1 to 7, wherein the condensation removing section is a moisture absorbing member. (Appendix 9) The punching device according to any one of Supplementary Note 1 to Supplementary Note 8, wherein the positional deviation detection mechanism is provided with a plurality of the condensation removal units. (Appendix 10) A post-processing device that performs post-processing on a sheet on which an image has been formed by an image forming device, A post-processing device comprising the punching device according to any one of Supplementary Notes 1 to 9. (Appendix 11) An image forming system comprising: an image forming apparatus that forms an image on a sheet; and a punching device according to any one of appendices 1 to 9, or a post-processing device according to appendix 10, that performs a punching process on the sheet on which the image has been formed by the image forming apparatus. [Prior art documents] [Patent documents]

[0052] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-3045

Claims

1. a punching unit including a conveying guide member for guiding a sheet conveyed in a predetermined conveying direction, the punching unit performing a punching process on the sheet; a positional deviation detection mechanism including a detection sensor capable of detecting an edge of the sheet in a width direction perpendicular to the conveying direction, and configured to move the detection sensor in the width direction to detect a positional deviation amount of the sheet in the width direction; a movement mechanism that moves the punching unit in the width direction based on the amount of positional misalignment detected by the positional misalignment detection mechanism so as to offset the amount of positional misalignment; Equipped with The positional deviation detection mechanism is characterized in that it is equipped with a condensation removal section that returns condensed portions on the transport guide surface of the transport guide member to their pre-condensation state or a state close to it in conjunction with the movement of the detection sensor.

2. the positional deviation detection mechanism includes a sensor unit that holds the detection sensor and a link mechanism that holds the condensation removal unit and is movable in the width direction; The punching device described in claim 1, characterized in that during the process of the sensor unit moving from one end side to the other end side in the width direction, the link mechanism is pushed by the pushing portion of the positional deviation detection mechanism, and the condensation removal portion moves from a storage position that does not interfere with the transport of the sheet to a sliding contact position in which it slides against the transport guide surface.

3. The drilling device described in claim 2, characterized in that during the process of the sensor unit moving from the other end side to the one end side in the width direction, the link mechanism is pushed by the second pushing portion of the positional deviation detection mechanism, and the condensation removal portion moves from the sliding position to the storage position.

4. the amount of positional misalignment is detected by the detection sensor during the process in which the sensor unit moves from a retracted position on one end side in the width direction to a detection end position in the center, The drilling device according to claim 2, wherein the condensation removal section moves from the storage position to the sliding contact position during the process in which the sensor unit moves from the detection end position to the other end side in the width direction.

5. The punching device according to claim 4, wherein a condensation removal mode in which the condensation removal unit is moved from the storage position to the sliding position is executed before the first punching process is started after power is turned on.

6. The punching device according to claim 5, characterized in that an adjustment mode in which the moving mechanism moves the punching unit in the width direction based on the amount of positional misalignment detected by the detection sensor is executed each time the punching process is performed.

7. 3. The drilling device according to claim 1, wherein the condensation removing portion is an elastic member.

8. 3. The drilling device according to claim 1, wherein the condensation removing section is a moisture absorbing member.

9. 3. The punching device according to claim 1, wherein the misalignment detection mechanism is provided with a plurality of the condensation removal units.

10. A post-processing device that performs post-processing on a sheet on which an image has been formed by an image forming device, A post-processing device comprising the punching device according to claim 1 or 2.

11. An image forming system comprising: an image forming apparatus that forms an image on a sheet; and a punching device according to claim 1 or a post-processing device according to claim 10 that performs a punching process on the sheet on which the image has been formed by the image forming apparatus.

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