JP2017105641A - Sheet processing device and image formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet processing device which can perform punching and space-saving at the correction position.SOLUTION: A sheet processing device includes: a punching part 41 which performs punching processing on a sheet by lifting a plurality of punching blades 45F, 45R arranged in the width direction up and down; detection parts 42F, 42R which detect both edges of the sheet; and a movement device which moves the punching part 41 and detection parts 42F, 42R in the width direction. The punching part 41 is moved in the width direction by the movement device to the first punching position where one side edge of the sheet is detected by the detection part 42R and punching processing is performed by the punching blade 45R arranged on one side and the second punching position where the other side edge of the sheet is detected by the detection part 42F and the punching processing is performed by the punching blade 45F arranged on the other side. The movement device does not move the punching part 41 when the punching part 41 forms the second and subsequent holes after forming the first hole on the side edge of the sheet.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a sheet processing apparatus that performs punching processing on a sheet, and an image forming apparatus including the sheet processing apparatus.

  2. Description of the Related Art Conventionally, a sheet processing apparatus that performs punching processing (punch processing) on a sheet conveyed from an image forming apparatus such as a copier or a multifunction peripheral is known. Such a sheet processing apparatus generally performs a perforating process using a plurality of perforating blades arranged in a direction crossing the sheet conveyance direction. One reason for this is that if a plurality of perforating blades are arranged in a direction intersecting the sheet conveying direction, the number of times perforating processing is performed once on a single sheet, and productivity is not greatly reduced. Another reason is that a sheet processing apparatus capable of processing an A3 size sheet can perform punching processing on the short side of the A3 size sheet by conveying the A3 size sheet in the vertical direction.

  However, in recent years when space-saving of image forming apparatuses and sheet processing apparatuses is progressing, a method of conveying A4 size sheets in the vertical direction has become widespread, and A4 size conveyed in the vertical direction corresponding to this method. It has become necessary to perforate the edge of the sheet in the width direction. On the other hand, a perforation unit in which a plurality of perforation blades are arranged in a direction intersecting the sheet conveyance direction is configured to move between a perforation position and a standby position in a direction intersecting the sheet conveyance direction, There is also disclosed a sheet processing apparatus that performs perforation along an end in the width direction of a sheet while moving the perforation unit between a perforation position and a standby position while conveying the sheet.

  As a sheet processing apparatus configured to move the perforation unit in a direction intersecting the sheet conveyance direction, Patent Document 1 discloses a configuration in which perforation holes are overlapped when the sheet is folded in two. Has been. Further, Patent Document 2 includes a detection unit that detects an end of the sheet in the width direction, and is configured to move the detection unit in a direction that intersects the conveyance direction of the sheet to prevent perforation position deviation. A sheet processing apparatus is disclosed.

JP 2002-68777 A JP 2000-21802 A

  However, since the sheet processing apparatus described in Patent Document 1 does not include a detection unit that detects the end of the sheet in the width direction, there is a possibility that the position of the perforated hole may be displaced. Moreover, in the sheet processing apparatus described in Patent Document 2, since the punching unit and the detection unit are configured separately, there is a problem that the apparatus becomes large and the control becomes complicated.

  SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a sheet processing apparatus capable of perforating at an accurate position and saving space, and an image forming apparatus including the sheet processing apparatus.

  In order to achieve the above object, a sheet processing apparatus of the present invention is a sheet processing apparatus that processes a conveyed sheet, and moves up and down a plurality of perforating blades arranged in a width direction intersecting the sheet conveyance direction. A punching unit that punches the sheet, a detection unit that detects both side edges of the sheet in the width direction, and a moving device that moves the punching unit and the detection unit in the width direction. The perforating part is configured so that the perforating blades arranged on both sides in the width direction move up and down at the same time, perform perforation processing on one side edge side of the sheet by the perforating blade arranged on one side, and on the other side The perforating blade is provided so as to perform perforation treatment on the other side edge side of the sheet, and one side edge of the sheet is detected by the detection unit and disposed on the one side. While the punching process is performed by the punching blade, the punching blade arranged on the other side detects the first punching position separated from the sheet in the width direction and the other side edge of the sheet by the detection unit. The punching blade disposed on the other side is subjected to the punching process, while the punching blade disposed on the one side is moved to the second punching position spaced apart from the sheet in the width direction by the moving device. The moving device is provided so as to move in the width direction, and when the punching unit forms the second and subsequent holes after forming the first hole on the side edge side of the sheet, the moving device moves the punching unit. It is not moved.

  By adopting such a configuration, the interval between the punching blades arranged on both sides of the punching portion can be narrowed, so that the length in the width direction of the sheet processing apparatus can be shortened.

  In the sheet processing apparatus according to the aspect of the invention, the moving device may be configured such that the perforating unit is moved from the reference position where the perforating blades disposed on both sides overlap with both side edges of the sheet in a plan view. It is good also as moving to the said width direction to a drilling position and a said 2nd drilling position.

  In the sheet processing apparatus of the present invention, the perforating part is provided so that a center of the perforating blades disposed on both sides and both side edges of the sheet overlap in a plan view at the reference position. Also good.

  By adopting such a configuration, in the punching apparatus that punches the side edge (long side) of the sheet conveyed in the vertical direction, the amount of movement of the punching unit can be reduced. Can be downsized.

  In the sheet processing apparatus of the present invention, the detection unit is disposed on the outer side in the width direction from the punching blades disposed on both sides, and an interval between the detection unit and the center of the punching blade in the width direction is It may be characterized by being within 15 mm.

  By adopting such a configuration, if the punching process is performed at a position where the detection unit detects the side edge, it is possible to punch at a position away from the side edge of the sheet by an appropriate distance.

  In the sheet processing apparatus according to the aspect of the invention, the perforating unit may include a plurality of perforating blades between the perforating blades arranged on both sides.

  By adopting such a configuration, it is possible to perform the punching process on the edge (short side) of the sheet conveyed in the vertical direction by the punching blade disposed in the middle.

  An image forming apparatus according to the present invention includes any one of the sheet processing apparatuses described above.

  According to the present invention, it is possible to provide a sheet processing apparatus capable of drilling at a precise position and saving space, and an image forming apparatus including the sheet processing apparatus.

1 is a front view schematically showing a configuration of a sheet processing apparatus and an image forming apparatus according to an embodiment of the present invention. 1 is a perspective view showing a sheet processing apparatus according to an embodiment of the present invention. 1 is a side view showing a sheet processing apparatus according to an embodiment of the present invention. It is a top view which shows a part of sheet processing apparatus concerning one Embodiment of this invention. FIG. 5A is a front view illustrating a punching unit of a sheet processing apparatus according to an embodiment of the present invention. FIG. 5A illustrates a drilling blade ascending state, and FIG. FIG. 6A is a plan view for explaining the positions of a punching unit and a detection unit in the sheet processing apparatus according to the embodiment of the present invention, FIG. 6A is a reference position, FIG. 6B is a front position, and FIG. ) Indicates the rear position. It is a top view explaining the punching operation | work in the sheet processing apparatus which concerns on one Embodiment of this invention. It is a top view explaining the punching operation | work in the sheet processing apparatus which concerns on one Embodiment of this invention. FIG. 9A is a plan view illustrating another example of the reference position in the sheet processing apparatus according to the embodiment of the present invention, FIG. 9A illustrates the front position, and FIG. 9B illustrates the rear position. FIG.

  Hereinafter, an image forming apparatus and a sheet processing apparatus according to an embodiment of the present disclosure will be described with reference to the drawings.

  First, with reference to FIG. 1, the overall configuration of an image forming apparatus 1 and a sheet processing apparatus 3 according to an embodiment of the present invention will be described. FIG. 1 is a front view schematically showing the configuration of the image forming apparatus 1 and the sheet processing apparatus 3. In the following description, the front side in FIG. 1 is the front side (front side) of the image forming apparatus 1 and the sheet processing apparatus 3, and the left and right directions are directions when the image forming apparatus 1 and the sheet processing apparatus 3 are viewed from the front. Based on

  The image forming apparatus 1 includes a substantially box-shaped housing 4. The housing 4 accommodates an image forming device 5, an image reading device 6 that reads an image on a document, and the like. Further, an automatic document feeder 7 (ADF) that automatically feeds documents one by one to the image reading device 6 is provided on the upper surface of the housing 4.

  The image forming device 5 performs image forming processing based on image data transmitted from, for example, a personal computer or the image reading device 6. The image forming device 5 includes a sheet storage unit 8 that stores an A4 size sheet S, four image forming units 10 that transfer toner images to the sheet S supplied from the sheet storage unit 8, and the transferred toner image. A fixing device 11 that fixes the sheet S and a sheet discharge unit 12 that is a discharge destination of the sheet S after fixing are provided. Note that the sheet S includes not only a paper recording material but also a sheet-like recording material such as a resin film or an OHP sheet.

  An exposure unit 13 composed of a laser scanning unit is disposed above the sheet storage unit 8. Above the exposure unit 13, an intermediate transfer belt 14 as an image carrier is installed between a plurality of rollers, and above the intermediate transfer belt 14, four toner containers 15 are provided for each toner color. Yes. Further, four image forming units 10 are provided for each toner color along the lower side of the intermediate transfer belt 14.

  Each image forming unit 10 includes a charger 17, a developing unit 18, a primary transfer unit 19, a cleaning device 20, a removal unit disposed around the photosensitive drum 16 rotatably provided in the order of the primary transfer process. And the electric appliance 21.

  Inside the housing 4, a conveyance path 9 that conveys the sheet in a vertical orientation from the sheet storage unit 8 toward the sheet discharge unit 12 is provided along the left side surface. In the upstream portion of the conveyance path 9, a paper feed unit 22 that takes out the sheet S from the sheet storage unit 8 or the like in a vertical orientation is provided. A secondary transfer portion 23 is provided between the end portion of the intermediate transfer belt 14 in the middle portion of the conveyance path 9. A fixing device 11 including a heating roller and a pressure roller is provided in the transport path 9 on the downstream side of the secondary transfer unit 23.

  At the downstream end of the transport path 9, a switching unit 26 that switches the transport direction of the sheet S to the first sheet discharge unit 24 or the second sheet discharge unit 25 is provided. The sheet S discharged from the first sheet discharge unit 24 to the outside of the housing 4 is stacked on the sheet discharge unit 12. On the other hand, the sheet S discharged from the second sheet discharge unit 25 to the outside of the housing 4 is carried into the sheet processing apparatus 3.

  Note that the image reading device 6 and the automatic document feeder 7 have the same configuration as a general device having these functions, and thus description thereof is omitted.

  Next, an image forming operation of the image forming apparatus 1 will be described. When image data is input (print start instruction) from a computer or image reading device 6 connected to the image forming apparatus 1, first, the exposure device 13 is applied to the surface of the photosensitive drum 16 charged by the charger 17. Thus, exposure according to the image data is performed. The electrostatic latent image formed on the photosensitive drum 16 by exposure is developed into a toner image of each color by the developing unit 18. This toner image is primarily transferred onto the intermediate transfer belt 14 in the primary transfer portion 19. Each image forming unit 10 sequentially repeats the above operation, whereby a full-color toner image is formed on the intermediate transfer belt 14. The residual toner and electric charge on each photoconductor drum 16 are removed by the cleaning device 20 and the static eliminator 21.

  On the other hand, the sheet S taken out from the sheet storage unit 8 or the like by the sheet feeding unit 22 is conveyed to the secondary transfer unit 23 in synchronization with the above-described image forming operation. The full-color toner image on the intermediate transfer belt 14 is secondarily transferred to the sheet S, and the sheet S is conveyed to the fixing device 11 through the conveyance path 9. The sheet S on which the toner image has been fixed by the fixing device 11 enters the first sheet discharge portion 24 or the second sheet discharge portion 25 and is discharged into the sheet discharge portion 12 or the sheet processing apparatus 3.

  Next, the sheet processing apparatus 3 will be described. The sheet processing apparatus 3 performs a punching process on the sheet S discharged from the second sheet discharge unit 25 of the image forming apparatus 1.

  The sheet processing apparatus 3 includes a substantially box-shaped casing 31 and leg portions 32 that support the casing 31. The housing 31 is formed with a carry-in portion 33 into which the sheet S discharged from the second sheet discharge portion 25 of the image forming apparatus 1 is loaded on the side surface on the image forming apparatus 1 side, and on the opposite side surface. The discharge tray 34 is arranged. A sheet conveyance path 35 for conveying the sheet S from the carry-in unit 33 toward the discharge tray 34 is provided inside the housing 31. In the sheet conveyance path 35, a sensor 37 that detects the leading edge position of the sheet S is disposed downstream of the carry-in unit 33. A rail portion 44 extending in the front-rear direction is formed downstream of the sensor 37, and a punching device 40 that performs a predetermined punching process on the sheet S is provided on the rail portion 44. Further, a registration roller 38 is disposed downstream of the rail portion 44. Note that a stapling device 70 that stacks a plurality of sheets S and staples them may be provided on the downstream side of the registration roller 38.

  Next, the perforation apparatus 40 will be described with reference to FIGS. 2 is a perspective view of the punching device, FIG. 3 is a side view of the punching device, FIG. 4 is a plan view showing a part of the punching device, and FIG. 5A shows a state in which the punching blade is retracted in the punching device. FIG. 5B is a front view showing a state in which the drilling blade is lowered in the drilling device.

  As shown in FIGS. 2 to 4, the punching device 40 detects the positions of the punching unit 41 that performs the punching process and the side edges of the sheet S in the front-rear direction (width direction) orthogonal to the conveyance direction of the sheet S. It has the detection part 42 (refer FIG. 4), and the moving apparatus 43 which moves the perforation part 41 and the detection part 42 in the front-back direction. The perforation part 41 and the detection part 42 can be moved in the front-rear direction by a moving device 43 on a rail part 44 (see FIG. 1) provided in the housing 31.

  As shown in FIGS. 2 and 3, the perforating unit 41 includes four perforating blades 45 arranged at a predetermined interval in the front-rear direction, a fixed blade 46 that perforates the sheet S together with the perforating blades 45, and And an elevating mechanism 47 that elevates and lowers each of the perforating blades 45. The punching blade 45 and the lifting mechanism 47 are supported by an upper guide plate 48, and the fixed blade 46 is supported by a lower guide plate 49 that faces the upper guide plate 48 across the sheet conveyance path 35.

  The upper guide plate 48 is a frame-like member that extends in the front-rear direction and has a substantially U-shaped cross-section with an open top surface, and the lower guide plate 49 has a substantially U-shaped cross-section with an open bottom surface. A frame-like member extending in the front-rear direction. At the lower end portion of the lower guide plate 49, a roller 49a capable of traveling the rail portion 44 in the front-rear direction is provided near both ends in the front-rear direction.

  The piercing blade 45 includes a piercing blade 45F arranged on the front side, a piercing blade 45R arranged on the rear side, and two piercing blades 45M arranged in the middle. As shown in FIG. 5, each of the perforating blades 45 has a cylindrical shape, and a lower end is divided into two forks to form a pair of semicircular blade portions. The punching blade 45 is provided so as to move up and down along the guide tube 50. The guide cylinder 50 has a through-hole through which the drilling blade 45 can be inserted, and is supported by the upper guide plate 48 so that the through-hole extends upward at a right angle. Here, the guide cylinders 50 corresponding to the front and rear perforating blades 45F and 45R so that the distance between the perforation centers of the front and rear perforating blades 45F and 45R is equal to the distance between both side edges of the sheet S (sheet width). Is positioned on the upper guide plate 48.

  As shown in FIG. 2 and the like, the fixed blade 46 is formed of a rectangular parallelepiped box-shaped member extending in the front-rear direction of the sheet processing apparatus 3. The fixed blade 46 is used in common for all the drilling blades 45. As shown in FIG. 4, on the upper surface of the fixed blade 46, holes 51 through which the perforating blades 45 pass are formed at positions corresponding to the perforating blades 45. The fixed blade 46 is fixed to the lower guide plate 49 so that the holes 51 are aligned with the drill blade 45 in a straight line. When the punching blade 45 is inserted into the hole 51, the sheet S is punched by the punching blade 45 and the periphery of the hole 51.

  As shown in FIG. 5, the elevating mechanism 47 includes a support member 53 that supports each drilling blade 45 and a cam 54 that engages with each support member 53. The support member 53 is formed of a flat plate portion 53a that is long in the transport direction and a curved portion 53b that is formed by bending a plate-like piece into a substantially semicircular shape. In the vicinity of the center of the lower surface of the flat plate portion 53a in the conveying direction, the punching blade 45 is fixed so as to be substantially vertical. Both ends of the bending portion 53b are supported by both ends in the left-right direction on the upper surface of the flat plate portion 53a, and a substantially semicircular hollow portion 53c between the flat plate portion 53a and the bending portion 53b when viewed from the front. Is formed.

  A coil spring 55 is interposed on the outer periphery of the guide tube 50 between the support member 53 and the upper guide plate 48. The coil spring 55 urges the support member 53 upward.

  The cam 54 has a flat cylindrical shape, and is supported by the rotating shaft 56 at a position eccentric from the axis. The rotary shaft 56 passes through the hollow portion 53c of the support member 53, and the front and rear ends thereof are erected from the front and rear ends of the upper surface of the upper guide plate 48, as shown in FIGS. The front plate 48a and the rear plate 48b are pivotally supported.

  A coil spring 57 is interposed between the front end of the rotating shaft 56 and the front side plate portion 48a. The coil spring 57 urges the rotating shaft 56 forward. The rotary shaft 56 is movable in the axial direction by a solenoid (not shown), and the cam 54 and the support member are selectively used in the two lift mechanisms 47 at the center and the two lift mechanisms 47 at both ends. 53 is engaged. That is, when the cam 54 is engaged with the support member 53 in the two lift mechanisms 47 at both ends, the cam 54 is detached from the support member 53 in the two lift mechanisms 47 at the center, and the two front and rear perforating blades 45F. 45R only moves up and down. On the other hand, when the cam 54 is engaged with the support member 53 in the two lift mechanisms 47 at the center, the cam 54 is detached from the support member 53 in the two lift mechanisms 47 at both ends, and the two drilling blades 45M at the center. Only go up and down. In the normal state, the rotating shaft 56 is biased forward by the coil spring 57 as described above, and the cam 54 is engaged with the support member 53 in the two lifting mechanisms 47 at both ends, so that the two front and rear perforations are provided. Only the blades 45F and 45R are moved up and down. When the solenoid is switched, the rotating shaft 56 moves rearward against the urging force of the coil spring 57, and the cam 54 is engaged with the support member 53 in the two central lifting mechanisms 47, so that Only the perforating blade 45M moves up and down.

  As shown in FIG. 2 and the like, the rotating shaft of the motor 58 is connected to the rear end of the rotating shaft 56 through a gear train. When the motor 58 is driven and the rotating shaft 56 is driven, the cam 54 rotates in the hollow portion 53 c of the support member 53. At this time, as shown in FIG. 5A, when the cam surface 54a of the cam 54 is engaged with the inner surface of the curved portion 53b of the support member 53, the drilling blade 45 is maintained in the raised state. 5B, when the cam surface 54a of the cam 54 is engaged with the upper surface of the flat plate portion 53a of the support member 53, the support member 53 is pushed down against the biasing force of the coil spring 55. As shown in FIG. . As a result, the punching blade 45 is guided by the guide tube 50 and descends substantially vertically, protrudes into the sheet conveyance path 35, and punches the sheet S between the tip of the punching blade 45 and the hole 51 of the fixed blade 46.

  As shown in FIG. 2 and the like, a sensor 61 for detecting the home position, a rotary encoder 62 for controlling the rotational speed of the rotary shaft 56, and the like are provided at the rear end of the rotary shaft 56.

  As shown in FIG. 4, the detection unit 42 includes a front detection unit 42F disposed on the upstream side in the transport direction on the front side of the front perforation blade 45F, and an upstream in the transport direction on the rear side of the rear perforation blade 45R. And a rear detection unit 42R disposed on the side. The distance L between the centers of the front and rear perforating blades 45F and 45R and the front and rear detectors 42F and 42R is within 15 mm. That is, when the position of the front and rear side edges of the sheet S is detected by the detection unit 42, the front and rear perforating blades 45F and 45R are located at a distance L from the front and rear side edges of the sheet S, and the perforation is performed at this position. Will do.

  As the detection unit 42, for example, an optical sensor can be used. The optical sensor has a light emitting portion and a light receiving portion arranged to face each other, one of which is fixed to the upper guide plate 48 and the other is fixed to the lower guide plate 49. That is, the detection unit 42 is provided integrally with the perforation unit 41. When the sheet S exists between the light emitting unit and the light receiving unit, the optical path of the light emitted from the light emitting unit is blocked, and the amount of light received by the light receiving unit changes. Based on the change in the amount of light, the front and rear edges of the sheet S are detected.

  As shown in FIG. 2 and the like, the moving device 43 is disposed below the rear end portion of the perforated part 41, and includes a drive mechanism 66 composed of a rack and a pinion gear, and a motor 67 that rotates the pinion gear. Have. The rack is disposed on the lower surface of the lower guide plate 49 so as to extend in the front-rear direction, and the pinion gear is connected to the rotating shaft of the motor 67 and attached to the support plate 68 together with the motor 67. The support plate 68 is fixed to the side plate of the sheet processing apparatus 3. When the pinion gear is rotated by the motor 67, the perforation unit 41 and the detection unit 42 together with the rack meshing with the pinion gear are moved forward and backward (first perforation position) and rear position (second perforation position) around the reference position. It is designed to reciprocate back and forth between the two.

  With reference to FIG. 6, a reference position, a front position, and a rear position where the punching unit 41 and the detection unit 42 are positioned in the punching device 40 will be described. 6 is a plan view of the punching device 40, FIG. 6 (A) shows a reference position, FIG. 6 (B) shows a front position, and FIG. 6 (C) shows a rear position.

  At the reference position shown in FIG. 6A, the punching portion 41 is positioned so that the punching centers of the front and rear punching blades 45F and 45R overlap the front and rear side edges S1 and S2 of the conveyed sheet S in plan view. The

  In the front position shown in FIG. 6B, the position of the rear edge S2 of the sheet S is detected by the rear detector 42R, and the rear perforation blade 45R is a distance L from the rear edge S2 of the sheet S. Located in the front drilling position. On the other hand, the front punching blade 45F is separated forward from the front edge S1 of the sheet S.

  In the rear position shown in FIG. 6C, the position of the front edge S1 of the sheet S is detected by the front detector 42F, and the front punching blade 45F is punched rearward from the front edge S1 of the sheet S by a distance L. Located in position. On the other hand, the rear perforating blade 45R is separated rearward from the rear edge S2 of the sheet S.

  In the punching apparatus 40 having the above-described configuration, the operation of punching along the conveying direction of the sheet S will be described with reference to FIGS. 7 to 9 are plan views of the punching device 40 and the sheet S. FIG. In this example, an operation for perforating along the front long side of the sheet S will be described.

  When the sheet S is carried into the punching device 40 from the carry-in portion 33 (see FIG. 1), as shown in FIG. 7A, in the punching device 40, the punching portion 41 and the detection unit 42 are at the reference positions. (See FIG. 6A). Further, the registration roller 38 is stopped.

  The sheet S carried in from the carry-in unit 33 (see FIG. 1) is a predetermined time after the leading edge in the transport direction of the sheet S is detected by the sensor 37 (after the leading edge in the transport direction of the sheet S reaches the registration roller 38). The time until the deflection for correcting the skew of the sheet is formed).

  After a predetermined time elapses, the registration roller 38 is rotated, and the sheet S is conveyed to the punching position of the first hole as shown in FIG. 7B. When the sheet S is conveyed to the first hole punching position, the registration roller 38 is stopped and the punching device 40 is moved backward by the moving device 43. When the punching device 40 moves backward to the position where the front detection unit 42F detects the front side edge S1 of the sheet S, the movement of the punching device 40 is stopped (for example, the stop time is 100 msec to 200 msec). Depending on the specifications in which the distance from the side edge of the sheet S to the punching position is different, the sheet S may be moved further by a predetermined distance after the front side edge S1 is detected. Then, the sheet S is punched with the front punching blade 45F to form the first hole P1. Since the rear perforating blade 45R is separated rearward from the rear edge S2 of the sheet S, it is idled.

  Thereafter, the punching device 40 is moved forward. At this time, the punching device 40 is not returned to the reference position, and is moved to a position where the front detection unit 42F does not detect the front edge of the sheet S as shown in FIG. Let By not returning the punching device 40 to the reference position, the movement time of the punching device 40 can be shortened.

  Next, as shown in FIG. 8B, the registration roller 38 is rotated to convey the sheet S to a position where the second hole is punched. When the sheet S is conveyed to the punching position of the second hole, the registration roller 38 is stopped and the punching device 40 is moved backward. When the punching device 40 moves rearward until the front detection unit 42F detects the front edge S1 of the sheet S, the movement of the punching device is stopped, and the sheet S is punched by the front punching blade 45F. Hole P2 is formed.

  As described above, the perforation unit 41 is reciprocated between the position where the front detection unit 42F does not detect the front edge of the sheet S (see FIG. 8A) and the rear position. A predetermined number of holes can be drilled along the front edge. When the punching process is performed along the rear edge S2 of the sheet S, the punching unit 41 is reciprocated between a position where the rear detection unit 42R does not detect the rear edge S2 of the sheet S and the front position. Move.

  In addition, after the front detection unit 42F has punched at the position where the front side edge S1 of the sheet S is detected to form the first hole, the second and subsequent holes are not moved without moving the punching device 40 in the front-rear direction. Can also be perforated. In this case, since the skew of the sheet S is already corrected by the registration roller 38, it is not necessary to detect the position of the front side edge for each hole, and the movement time of the punching device 40 can be shortened.

  As described above, in the sheet processing apparatus 3 according to the embodiment of the present invention, the front and rear perforation blades 45F and 45R of the perforation unit 41 are viewed in plan view from the front and rear side edges S1 and S2 of the sheet S. The distance between the front and rear drilling blades 45F and 45R can be shortened, and the length of the drilling device 40 in the front-rear direction can be shortened.

  Furthermore, the punching process can be performed along the front side edge of the sheet S by moving the punching part 41 backward from the reference position by the distance L. Also, when the punching process is performed along the rear side edge of the sheet S, the punching portion 41 is moved forward by a distance L from the reference position. That is, the moving distance of the punching portion 41 for punching the front edge and the rear edge of the sheet S is twice the distance L. By setting the distance L to 15 mm or less, the moving distance of the punching portion 41 can be shortened, and the punching device 40 can be saved in space.

  When the front and rear perforating blades 45F and 45R are arranged outside the front and rear side edges S1 and S2 of the sheet S, the distance between the front and rear perforating blades 45F and 45R becomes longer and the length of the perforating apparatus 40 becomes longer. Also, the moving distance to the front position and the rear position becomes longer. On the other hand, when the front and rear perforation blades 45F and 45R are arranged on the inner side of the front and rear side edges S1 and S2 of the sheet S, when the perforation blade 45 arranged on one side is moved to the front position or the rear position, The arranged perforation blade 45 may not be sufficiently separated from the side edge of the sheet S in the width direction, and the other side may be perforated. Therefore, it is preferable to arrange the front and rear perforating blades 45F and 45R so as to overlap with the front and rear side edges S1 and S2 of the sheet S in plan view in consideration of the size and moving distance of the perforating device 40. It is particularly preferable to arrange the front and rear perforating blades 45F and 45R so that the perforation center of each blade overlaps with the front and rear side edges S1 and S2 of the sheet S in plan view. However, it is not necessary that the perforation center of the perforation blade 45 exactly overlaps the front and rear side edges S1 and S2 of the sheet S, and a case where a certain amount of deviation is included is also included in this embodiment.

  With reference to FIG. 9, another example in which the front and rear perforating blades 45F and 45R are arranged so as to overlap the front and rear side edges S1 and S2 of the sheet S will be described. FIG. 9 is a plan view of the punching device, FIG. 9A is a plan view for explaining the front position, and FIG. 9B is a plan view for explaining the rear position.

  At the reference position, the inner edge of the front punching blade 45F overlaps the front edge S1 of the sheet S in a plan view, and the inner edge of the rear punching blade 45R overlaps the rear edge S2 of the sheet S in a plan view. .

  9A, the position of the rear side edge S2 of the sheet S is detected by the rear detection unit 42R, and the rear perforation blade 45R is moved from the rear side edge S2 of the sheet S. It is located at the front drilling position by a distance L. On the other hand, the perforation blade 45F at the front end is separated forward from the front edge S1 of the sheet S. The amount of movement from the reference position to the previous position (see arrow B1 in FIG. 9A) is a distance L + r obtained by adding the radius r of the drilling blade 45R to the distance L.

  9B, the position of the front edge S1 of the sheet S is detected by the front detector 42F, and the front perforation blade 45F is a distance L from the front edge S1 of the sheet S. In the rear position indicated by the two-dot chain line in FIG. Located in the rear drilling position. On the other hand, the rear perforating blade 45R is separated rearward from the rear edge S2 of the sheet S. At this time, the amount of movement from the reference position to the rear position (see arrow B2 in FIG. 9B) is a distance L + r obtained by adding the radius r of the punching blade 45R to the distance L.

  In this way, the moving distance is the length of the diameter (2 × r) of the punching blade 45 as compared to the case where the punching centers of the front and rear punching blades 45F and 45R overlap with the front and rear side edges S1 and S2 of the sheet S. Becomes longer. Therefore, it is particularly preferable to arrange the front and rear perforating blades 45F and 45R so as to overlap the front and rear side edges S1 and S2 of the sheet S in plan view.

  In the present embodiment, the upper guide plate 48 and the lower guide plate 49, which are part of the perforation unit 41, are provided with the detection unit 42 so that the perforation unit 41 and the detection unit 42 are moved together. Therefore, the relative position between the perforated part 41 and the detecting part 42 does not change, and the positional deviation of the perforated hole is unlikely to occur. Moreover, the position control of the punching part 41 and the detection part 42 becomes easy.

  Further, in the present embodiment, a punching treatment is performed along the left and right edges (short sides) of the sheet S by moving the rotary shaft 56 in the punching portion 41 so that the central punching blade 45M can be moved up and down. You can also

  Furthermore, since the above description of the embodiments of the present invention describes preferred embodiments of the sheet processing apparatus and the image forming apparatus according to the present invention, various technically preferable limitations are attached. However, the technical scope of the present invention is not limited to these embodiments unless specifically described to limit the present invention. That is, the above-described components in the embodiment of the present invention can be appropriately replaced with existing components and the like, and various variations including combinations with other existing components are possible. The description of the embodiment of the present invention described above does not limit the contents of the invention described in the claims.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 3 Sheet processing apparatus 40 Punching apparatus 41 Punching part 42 Detection part 43 Moving apparatus 45 Punching blade

Claims (6)

A sheet processing apparatus that performs processing on a conveyed sheet,
A perforation unit that perforates the sheet by moving up and down a plurality of perforation blades arranged in the width direction intersecting the sheet conveyance direction; and a detection unit that detects both side edges of the sheet in the width direction. A moving device for moving the perforation part and the detection part in the width direction,
The perforating part is disposed on the other side while performing perforation processing on one side edge side of the sheet by the perforating blades disposed on one side and the perforating blades disposed on both sides in the width direction at the same time. The punching blade is provided so as to perform punching treatment on the other side edge side of the sheet,
One side edge of the sheet is detected by the detection unit, and punching processing is performed by the punching blade disposed on the one side, while the punching blade disposed on the other side is separated from the sheet in the width direction. The first drilling position
The other side edge of the sheet is detected by the detection unit, and the punching process is performed by the punching blade disposed on the other side, while the punching blade disposed on the one side is separated from the sheet in the width direction. The second drilling position is provided to move in the width direction by the moving device,
The sheet processing apparatus according to claim 1, wherein when the punching unit forms the second and subsequent holes after forming the first hole on the side edge side of the sheet, the moving device does not move the punching unit.   In the moving device, the first perforation position and the second perforation are moved from a reference position where the perforation part is disposed so that perforation blades disposed on both sides overlap with both side edges of the sheet in plan view. The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is moved to the position in the width direction.   3. The sheet according to claim 2, wherein the punching portion is provided so that a center of the punching blades disposed on both sides and both side edges of the sheet overlap in a plan view at the reference position. Processing equipment.   The detection part is arranged outside in the width direction from the perforation blades arranged on both sides, and the distance between the detection part and the center of the perforation blade in the width direction is within 15 mm. The sheet processing apparatus according to any one of claims 1 to 3.   The sheet processing apparatus according to any one of claims 1 to 4, wherein the perforating unit includes a plurality of perforating blades between the perforating blades disposed on both sides. An image forming apparatus comprising the sheet processing apparatus according to claim 1.

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