JP4498226B2 - Sheet processing apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a sheet processing apparatus and an image forming apparatus, and more particularly to a sheet punching apparatus in which punch holes are formed in a sheet discharged from an image forming apparatus such as a copying machine or a printer, and a punch and a die are provided in a sheet conveyance path. It is suitable for application to.

  Conventionally, as a sheet punching device that is mounted on an image forming apparatus such as a copying machine or a laser beam printer and punches holes in a sheet, the sheet transport path has a punch and a die, and the sheet passing through the transport path is stopped once. Some punch holes are formed to form punch holes.

In such a configuration in which the punch and die are provided in the sheet conveyance path, the hole of the die and the hole of the punch guide exist in the conveyance path. For this reason, the end of the sheet may be caught in the hole and the sheet end may be bent. Therefore, conventionally, the sheet edge and the hole of the die guide or the hole of the punch guide do not coincide with each other by moving the sheet or moving the punching device before the sheet enters the punching device. It was.
Japanese Patent Laid-Open No. 10-194557

  However, when there are a large number of punch holes of the punching device or when an irregular sheet is conveyed, punching member guide means such as punching guides and holes of elements constituting punching members such as the end of the sheet and the die May coincide with the holes of the elements constituting the sheet, and the sheet may be bent.

  Accordingly, an object of the present invention is to provide a sheet processing apparatus capable of avoiding the sheet from being bent even when the end of the sheet overlaps or coincides with the hole of the punching member or the hole of the punching member guide means, and An object of the present invention is to provide an image forming apparatus having this sheet processing apparatus.

In order to achieve the above object, the present invention provides:
A punch that reciprocates and punches the sheet;
In a sheet processing apparatus comprising a die having a die hole into which the punch enters,
A sheet conveyance guide that has a long hole into which the punch can enter the conveyance guide surface that guides the sheet, and forms a sheet conveyance path facing the die ;
A biasing member that biases the sheet passing through the sheet transport path to the transport guide surface ,
The long hole is formed obliquely in a direction away from the center of the sheet width toward the outside as it becomes downstream in the sheet conveying direction ,
At the position retracted from the conveyance guide surface in the long hole,
A guide member is provided that guides the end of the sheet that has entered the elongated hole so as to approach the conveyance guide surface as it becomes downstream in the sheet conveyance direction .

  According to the present invention, even if the edge of the sheet overlaps or coincides with the hole of the punching member or the hole of the punching member guide means, it is possible to prevent the sheet from being bent.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In all the drawings of the following embodiment, the same or corresponding parts are denoted by the same reference numerals. FIG. 1 shows an example of a sheet processing apparatus provided with a sheet punching apparatus according to an embodiment of the present invention, and an image forming apparatus main body (copier main body) connected upstream. It should be noted that the illustrated apparatus is merely illustrated for explaining a series of operations performed in carrying out the embodiment of the present invention, and the present invention is not limited to this.

(Image forming device)
In the image forming apparatus main body 1 (copier main body), a document placing table 21 made of platen glass, a light source, a lens system 22, a paper feeding unit 11, an image forming unit 12, and a document feeding unit for feeding a document to the document placing table 21 are provided. A sheet processing apparatus 2 that performs post-processing and stacking on the image-formed sheets discharged from the feeding apparatus 23 and the copying machine main body is provided.

  The paper feeding unit 11 can store a sheet as a recording material, and has a cassette that is detachable from the image forming apparatus main body 1. The image forming unit 12 includes a cylindrical photosensitive drum 24, a developing device 25 around the cylindrical photosensitive drum 24, and the like. A fixing device 13 and a discharge roller pair 14 are disposed on the downstream side of the image forming unit 12.

(Operation of image forming apparatus)
Next, the operation of the image forming apparatus main body 1 according to this embodiment will be described. That is, when a paper feed signal is output from the image forming apparatus main body 1, the sheet is fed from the cassette of the paper feed unit 11. On the other hand, light reflected from the light source on the document placed on the document placing table 21 is irradiated onto the photosensitive drum 24 through the lens system 22. The photosensitive drum 24 is charged in advance by a primary charger, and an electrostatic latent image is formed by irradiation with light. Next, the electrostatic latent image is developed by the developing device 25 to form a toner image.

  The sheet fed from the sheet feeding unit 11 is corrected for skew by the registration roller 26 and further conveyed to the image forming unit 12 at the same timing to form an image. Then, the image-formed sheet is conveyed to the fixing device 13 and the transferred image is permanently fixed. The sheet on which the image is fixed is discharged from the image forming apparatus main body 1 by the discharge roller pair 14. In this way, an image is formed on the sheet fed from the sheet feeding unit 11 and conveyed to the sheet processing apparatus 2.

(Sheet processing equipment)
Next, the sheet processing apparatus 2 according to this embodiment will be described. That is, the sheet processing apparatus 2 mainly includes an inlet conveyance roller pair 102, a sheet punching device 201 as a sheet punching unit, a sheet end detection device 301, and a sheet moving device 401. The inlet conveyance roller pair 102 is a roller pair for receiving a sheet discharged from the image forming apparatus main body 1. Details of the sheet punching device 201, the sheet end detection device 301, and the sheet moving device 401 will be described later.

  Further, in the sheet processing apparatus 2, the pair of intermediate rollers 104, 106, 111, 113 for conveying the sheet, the sensors 101, 103, 107, 109, 112, 114 for detecting the presence or absence of the sheet on the conveyance path, Flappers 105 and 108 for changing the conveyance path are provided.

  When the flapper 108 is switched to the stacking tray 121 side, the sheet is discharged onto the stacking tray 121 by the discharge roller pair 110. On the other hand, when the flapper 108 is switched to the stacking tray 122 side, the sheets are sequentially conveyed by the pair of intermediate rollers 111 and 113 and discharged onto the processing tray 117 by the pair of discharge rollers 115.

  The sheet discharged onto the processing tray 117 is abutted against the sheet rear end alignment wall 123 installed on the processing tray 117 by the rotation of the return belt 116 and the return paddle 118. The sheet trailing edge alignment wall 123 performs alignment in the conveyance direction of the abutted sheet, and alignment in the conveyance thrust direction is performed by an alignment plate (not shown). In this way, after a predetermined number of sheets are aligned, sheet bundle processing such as binding processing by the stapler 120 is performed. After the sheet bundle processing is performed, the sheet is discharged onto the stacking tray 122 by the bundle discharge roller pair 119.

(Sheet edge detection device)
Next, the sheet edge detection device 301 according to this embodiment will be described. FIG. 2 shows the sheet end detection device 301 as viewed from the downstream side in the sheet conveyance direction.

  As shown in FIG. 2, when a sheet passes through a conveyance path 309 constituted by conveyance guides 307 and 308, the sensor 302 detects the thrust end of the sheet, and the position of the sheet in the conveyance thrust direction can be specified. It is configured. The sensor 302 is provided with bearings 303 and 304. These bearings 303 and 304 are configured to be movable along guides 305 and 306 fixed to the sheet processing apparatus 2, respectively. The sensor 302 has been moved to a position corresponding to the sheet size in advance based on sheet size information input from an operation unit (not shown) of the image forming apparatus main body 1. The sensor 302 has a recess, and detects the thrust end of the sheet that has entered the recess.

  A driving source for moving the sensor 302 is a motor 314 fixed to the sheet processing apparatus 2. The timing belt 311 is operated by a pulley 313 provided in the motor 314 and a pulley 312 fixed to the sheet processing apparatus 2. The sensor 302 and the timing belt 311 are connected by a fixed plate 310 so that the sensor 302 can be moved in accordance with the operation of the timing belt 311.

(Sheet moving device)
Next, the sheet moving apparatus 401 according to this embodiment will be described. FIG. 3 is a view of the sheet moving device 401 according to this embodiment as viewed from the downstream side in the sheet conveyance direction.

  That is, in the sheet moving device 401, a conveyance path 423 is configured by the conveyance guides 403a and 403b. Further, the sheet is sandwiched and conveyed by the conveyance roller pairs 402 and 404 (conveyance roller pairs 402a, 402b, 404a, and 404b). The pair of conveyance rollers 402 and 404 are connected to a motor 417 via gears 415 and 416 and configured to be able to rotate forward and backward according to the rotation of the motor 417.

  The conveyance roller pairs 402 and 404 and the conveyance guides 403a and 403b are supported by frames 405, 406, 407, and 408. The bearings 409, 410, 411, and 412 fixed to the frames 405, 406, 407, and 408 are configured to be movable along the guides 413 and 414. The frames 405, 406, 407, and 408 are connected to the timing belt 418 by a fixing plate 419. The fixed plate 419 is configured to be movable via a timing belt 418 by a motor 422 and pulleys 420 and 421.

(Sheet punching device)
Next, the sheet punching device 201 according to this embodiment will be described. FIG. 4 shows a view of the sheet punching device 201 as viewed from the upstream side in the sheet conveying direction. 5 is a sectional view taken along the line CC in FIG. 4, FIG. 6 is a sectional view taken along the arrow B in FIG. 4, FIG. 7 is a sectional view taken along the line HH in FIG. FIG. 8 shows a view in the direction of arrow A in FIG.

  As shown in FIG. 4, in the sheet punching device 201, a punch guide 204 serving as a punching member guide and a transport guide 205 serving as a sheet transport guide are fixed by caulking, and the transport guide 205 and the second perforation are fixed. A die 206 as a member is fixed by caulking. A conveyance path 207 as a sheet conveyance path is formed between the conveyance guide 205 and the die 206.

  As shown in FIG. 5, the punch blade 209 as the first perforating member is supported by the sliding support portions 204 a and 204 b of the punch guide 204 and is configured to be slidable up and down. Parallel pins 223 (parallel pins 223a, 223b, 223c, 223d in FIG. 4) are driven into the punch blades 209 (in FIG. 4, punch blades 209a, 209b, 209c, 209d), respectively.

  As shown in FIG. 4, one end of each of parallel pins 223a, 223b, 223c, and 223d enters the cam grooves 208a, 208b, 208c, and 208d formed in the slide rack 208, respectively. The slide rack 208 is operated by the motor 212 through the gears 213, 214, and 215 and the rack portion 208f of the slide rack 208 in the direction of arrow D in FIG. At this time, the parallel pins 223a to 223d and the punch blades 209a to 209d operate in the E direction in accordance with the shapes of the cam grooves 208a to 208d.

  Punch blades 209 (punch blades 209a to 209d in FIG. 4) enter the die holes 218 of the die 206 (die holes 218a, 218b, 218c, and 218d in FIG. 6), respectively, and holes are formed in the sheet P. Can be opened. Note that punch scrap generated by the perforation falls from the die hole 218 and is stored in the punch scrap box 203 (see FIG. 1).

  Further, the rear end of the sheet P is abutted against the rear end stopper 221 shown in FIGS. 5 and 6 (rear end stoppers 221a and 221b in FIG. 6). The rear end stopper 221 is for making the distance from the rear end of the sheet P to the punch punching portion constant. And the sheet | seat P which approached from the arrow F direction shown in FIG. 5 pushes the rear-end stopper 221 in the arrow G direction at the front-end | tip. At this time, the rotation fulcrum 224 (224a and 224b in FIG. 6) becomes the rotation center of the rear end stopper 221.

  When the rear end of the sheet P passes through the rear end stopper 221, the sheet P returns to the original position by a spring (not shown) connected to the rear end stopper 221. Thereafter, the sheet P is switched back by the pair of conveying rollers 402 and 404 shown in FIG. Then, it is abutted against the abutting portion 225 of the rear end stopper 221 so that the punching position of the sheet P from the rear end of the sheet P is determined.

  The urging members 220a, 220b, and 220c shown in FIG. 6 are provided at positions that avoid the die holes 218a, 218b, 218c, and 218d and the rear end stoppers 221a and 221b. Further, as shown in FIG. 7, the urging member 220 (the urging members 220 a to 220 c in FIG. 6) is provided so as to urge the sheet P from the die 206 toward the conveyance guide 205. In this way, the sheet P is urged from the die 206 toward the conveyance guide 205, so that the sheet P is not caught in the die hole 218 of the die 206. Further, as shown in FIG. 7, the urging member 220 bends when the sheet P comes into contact with it, and has an appropriate elasticity that can press the sheet P toward the conveyance guide 205.

Further, as shown in FIG. 7, the sheet end pressing member 222 is a guide member that guides the end portion of the sheet P that has entered the punch blade entry hole 216. That is, the sheet end pressing member 222
When the end portion of the sheet P urged by the urging member 220 enters the punch blade entry hole 216, the end portion of the sheet P is received and the jumping of the end portion is suppressed, and the conveyance guide 205 further It is a guide member which guides to the downstream conveyance guide. Therefore, the sheet end pressing member 222 is inclined so that the end of the sheet P is guided to the guide surface of the conveyance guide 205 as it becomes downstream in the sheet conveyance direction. Further, as shown in FIG. 8, the sheet end pressing member 222 is received by the end portion of the sheet P when the end portion of the sheet P and the punch blade entry hole 216 as a hole coincide (overlap). (Sheet end pressing members 222a to 222d in FIG. 8).

The punch blade entry holes 216a, 216b, 216c, and 216d of the conveyance guide 205 are long holes that are inclined at an angle along the sheet conveyance direction. These punch blade entry holes 216a to 216d are formed at positions corresponding to the die holes 218a to 218d, respectively. The punch blade entry holes 216a to 216d are formed at the sheet end portion P when the sheet P is shifted in the conveyance thrust direction (arrows I and J in FIG. 8) during conveyance or skewed in order to adjust the punching position. since _{the I} or P _J is prevented from being damaged in contact with the punch blade entrance hole 216, with increasing downstream of the sheet conveying direction, has a structure that is formed obliquely in a direction away from the sheet width center to the outside.

  In the die 206, a long hole for attaching the rear end stopper 221 is formed, and is similarly formed obliquely. A biasing member 220 is attached to the die 206. Therefore, although there is little possibility that the edge part of the sheet | seat P will approach into the long hole by the side of the die | dye 206, even if it approachs, the same effect is acquired. Similarly to the conveyance guide 205, a sheet end pressing member 222 may be provided in the long hole on the die 206 side.

  Further, as shown in FIG. 7, the conveyance downstream end of the long hole of the punch hole entry hole 216 is retracted from the conveyance guide surface. As a result, the sheet P can be pressed by the sheet end pressing member 222 without the sheet P being caught by the downstream end of the punch hole entering hole 216 in the conveying direction.

  FIG. 10 is a block diagram of a sheet punching device according to this embodiment. As shown in FIG. 10, the control unit of the sheet punching device includes a CPU 501 that executes information processing, a motor driver 502, a motor 503, a first sensor 504, and a second sensor 505. The home position is detected by the first sensor 504. Further, the second sensor 505 detects a perforation operation. Further, various motors 503 are driven and controlled via the motor driver 502.

(Punching operation)
Next, a series of punching operations in the sheet punching device 201 will be described.

  That is, first, as shown in FIG. 9A, the sheet P discharged from the image forming apparatus main body 1 is detected by the sensor 101 to enter the sheet processing apparatus 2. Thereafter, the sheet P is nipped and conveyed by the inlet conveyance roller pair 102 and reaches the sheet punching device 201.

  Subsequently, the sheet P sequentially reaches the sheet end detection device 301 and the sheet moving device 401 by pushing the trailing end stopper 221. At this time, the sheet end detection device 301 scans in the thrust direction, and the thrust position of the sheet P is confirmed. When the thrust position of the sheet P is confirmed, it is moved to a predetermined thrust position by the sheet moving device 401 so as to match the punching position of the sheet punching device 201. These operations are performed while the sheet P is being conveyed.

  Next, as shown in FIG. 9B, when the trailing end of the sheet P is removed from the trailing end stopper 221, the trailing end stopper 221 is returned to its original position by a spring (not shown). Thereafter, the reverse rotation is started after the conveying roller pairs 402 and 404 of the sheet moving device 401 are once stopped. The stop and reverse timings of the conveyance roller pairs 402 and 404 vary depending on the conveyance length of the sheet, and are counted by the sheet detection signal of the sensor 101. The stop and reverse timings of the conveyance roller pairs 402 and 404 are before the conveyance rear end of the sheet P exits the urging member 220.

  Next, as illustrated in FIG. 9C, the pair of conveying rollers 402 and 404 that have started to rotate reversely are skewed while forming a predetermined loop with the trailing edge of the sheet P abutting against the trailing edge stopper 221. Thereafter, the punch blade 209 is driven to form a hole in the sheet P. Thereafter, as shown in FIG. 9D, the conveyance roller pair 402, 404 is rotated forward to convey the sheet P.

  As described above, according to one embodiment of the present invention, the punch blade entry hole 216 of the conveyance guide 205 is formed as an oblique long hole in a direction away from the center of the sheet width toward the outside as it becomes downstream in the sheet conveyance direction. It has become. Thus, even when the end portion of the sheet P passing between the punch blade 209 and the die 206 coincides with or overlaps with the position of the punch blade entry hole 216 in the die hole 218 or the punch guide 204, the sheet P It is possible to prevent the corner breakage that has conventionally occurred due to the end of this being caught in the hole.

  The embodiment of the present invention has been specifically described above, but the present invention is not limited to the above-described embodiment, and various modifications based on the technical idea of the present invention are possible. For example, in the above-described embodiment, the number of perforations by punching is four, but the number of perforations is not necessarily limited to four.

1 is a cross-sectional view illustrating an image forming apparatus including a sheet punching device according to an embodiment of the present invention. 1 is a schematic view of a sheet edge detection device according to an embodiment of the present invention. It is the schematic of the sheet | seat movement apparatus by one Embodiment of this invention. 1 is a schematic view of a sheet punching device according to an embodiment of the present invention. It is sectional drawing along CC line of the sheet | seat punching apparatus shown in FIG. FIG. 5 is a B arrow view of the sheet punching device shown in FIG. 4. It is sectional drawing along the HH line of the sheet | seat punching apparatus shown in FIG. It is A arrow line view of the sheet | seat punching apparatus shown in FIG. It is a figure which shows the flow of the sheet | seat of the sheet punching apparatus by one Embodiment of this invention. It is a block diagram which shows control of the sensor of the sheet punching apparatus by one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus main body 2 Sheet processing apparatus 11 Paper feeding part 12 Image forming part 13 Fixing apparatus 14 Discharge roller pair 21 Document mounting table 22 Lens system 23 Document feeding apparatus 24 Photosensitive drum 25 Developer 26 Registration roller 101,103,107 109, 112, 114, 302 Sensor 102 Inlet transport roller pair 104, 106, 111, 113 Intermediate roller pair 105, 108 Flapper 110, 115 Paper discharge roller pair 116 Belt 117 Processing tray 118 Paddle 119 Bundle paper discharge roller pair 120 Stapler 121, 122 Stacking tray 123 Sheet rear end alignment wall 201 Sheet punching device 203 Punch waste box 204 Punch guide 204a, 204b Slide support part 205 Transport guide 206 Die 207, 309, 423 Transport path 208 Slide rack 2 08a, 208b, 208c, 208d Cam groove 208f Rack part 209, 209a, 209b, 209c, 209d Punch blade 212, 314, 417, 422 Motor 213, 214, 215, 415, 416 Gear 216, 216a, 216b, 216c, 216d Punch blade entry hole 218, 218a, 218b, 218c, 218d Die hole 220, 220a, 220b, 220c Biasing member 221, 221a, 221b Rear end stopper 222 Sheet end pressing member 223, 223a, 223b, 223c, 223d Parallel pin 224 Rotating fulcrum 225 Abutting portion 301 Sheet edge detection device 303, 304, 409, 410, 411, 412 Bearing 305, 306, 413, 414 Guide 307, 308, 403a, 403b Conveying guide 3 DESCRIPTION OF SYMBOLS 10 Fixed plate 311 Timing belt 312,313,420,421 Pulley 401 Sheet moving device 402,404 Conveying roller pair 405,406,407,408 Frame 418 Timing belt 419 Fixed plate P Sheet

Claims (3)

A punch that reciprocates and punches the sheet;
In a sheet processing apparatus comprising a die having a die hole into which the punch enters,
A sheet conveyance guide that has a long hole into which the punch can enter the conveyance guide surface that guides the sheet, and forms a sheet conveyance path facing the die ;
A biasing member that biases the sheet passing through the sheet transport path to the transport guide surface ,
The long hole is formed obliquely in a direction away from the center of the sheet width toward the outside as it becomes downstream in the sheet conveying direction ,
At the position retracted from the conveyance guide surface in the long hole,
A sheet processing apparatus , comprising: a guide member that guides an end portion of the sheet that has entered the elongated hole so as to approach the conveyance guide surface as it becomes downstream in the sheet conveyance direction . The slot of the downstream end in the sheet conveying direction, the sheet processing apparatus according to claim 1, wherein the retreated before Ki搬 feed guide surface. An image forming unit that forms an image on a sheet;
A sheet processing apparatus for processing the image-formed sheet,
Image forming apparatus, wherein the sheet processing apparatus is a sheet processing apparatus according to claim 1 or 2 wherein.

Images