JP2006069785A - Paper punching device, paper carrying device, paper processing device, and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve paper handling performance and reliability by processing paper while simultaneously achieving high productivity and high precision. <P>SOLUTION: A plurality of rear end pressing pawls 200 provided in parallel to the paper carrying direction are rotatably installed on a housing 201, and resiliently energized by a tension spring 202 around a support point 200e in such a way that they are retractable when paper passes. The housing 201 is slidably installed on a slide shaft 204 installed in parallel to the paper carrying direction through a bearing 204, and fixed to a timing belt 206 stretched between timing pulleys 207 and 208, so that driving force is transmitted by a stepping motor 211 through gear trains 209 and 210 to move the rear end pressing pawls 200 along the slide shaft 204. As a rear end of paper overpasses the rear end pressing pawls 200, the rear end pressing pawls 200 push the rear end of the paper to position the rear end of the paper. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention provides a paper punching device that punches a sheet-like recording medium (paper) that has been carried in, a paper transport device including the paper punching device, a paper processing device including the paper punching device, and the The present invention relates to an image forming apparatus provided with a sheet punching device.

  2. Description of the Related Art There is known a sheet (paper) processing apparatus that conveys sheets on which images are formed from an image forming apparatus main body one by one and performs perforation processing on the sheets by a perforating unit. In recent years, this type of sheet processing apparatus has been demanded to increase the speed, increase the accuracy, and improve the paper handling capability. However, generally speaking, the increase in the speed (high productivity) and the increase in accuracy are contradictory to each other. Therefore, at present, it is very difficult to satisfy all the above conditions.

  Therefore, for example, in Patent Document 1, a skew correction roller is provided in the upstream portion of the punch (punching) means, skew correction is performed on the front end of the sheet, and the sheet end surface is detected by the sheet conveyance direction end surface detection sensor while being conveyed to the punch position. An invention has been proposed in which punching is performed in a predetermined position by moving the punch in a direction perpendicular to the conveying direction.

  Further, in Patent Document 2, a conveying roller is disposed upstream and downstream of the punching means, a linear velocity difference is provided between both the conveying rollers, the sheet is curved between both rollers, and the trailing edge of the sheet is disposed on the upstream side. An invention has been proposed in which the punch position is determined by contacting the roller.

Further, Patent Document 3 proposes a method in which a stopper unit is provided on the downstream side of the punching unit and punching is performed on the leading end of the sheet.
Japanese Patent No. 2894269 Japanese Patent No. 3301195 Japanese Patent Laid-Open No. 2003-300666

  However, in the invention described in Patent Document 1, after skew correction, the paper is conveyed for a predetermined distance to perform the punching process. However, the paper is conveyed to the punching position due to an error in the diameter of the conveyance roller related to the conveyance, eccentricity, or the like. There is a possibility that the drilling position may vary due to the occurrence of skew or the like. In particular, it can be said that a large-size paper having a large transport amount is easily affected. Further, since skew correction is performed with respect to the leading edge of the sheet, correction may not be possible when the abutting side of the tab sheet or the like is a sheet having a non-uniform shape.

  In the invention described in Patent Document 2, the trailing edge of the sheet is brought into contact with the roller. However, the contact force depends on the strength of the waist of the sheet, and correction is insufficient for thin paper with weak waist. It is easy to cause variations in punch positions. On the other hand, in the case of thick paper or the like having a strong waist, it is pressed against the roller nip portion with a strong waist, and there is a tendency that the edge surface is easily soiled and scratched. In addition, it is necessary to provide an abutting conveying roller that determines the punching position in the conveying direction adjacent to the punch punching mechanism, which complicates the punch unit and adjusts the punching position in the conveying direction. It must be moved and the mechanical construction must be complicated.

  Further, in the invention described in Patent Document 3, a stopper means is provided on the downstream side of the punching means and punching is performed on the leading edge of the paper. However, in recent post-processing devices, face down is a common sense, and punching processing is performed on the leading edge of the paper. To do it, you need to receive it face up. Among the various combinations in recent years, face-up only when punching not only complicates the control between the image forming apparatus main body and peripheral devices, but also performs reversal operations, so that the transport reliability is improved. May lead to decline.

  The present invention has been made in view of such a background, and an object of the present invention is to provide a highly reliable paper punching apparatus that can perform processing while achieving both high productivity and high accuracy, and has excellent paper compatibility. Another object of the present invention is to provide a paper transport device, a paper processing device, and an image forming apparatus.

  In order to achieve the object, the first means is a paper punching device comprising a paper transporting means for transporting a paper and a punching means for punching the paper transported by the transporting means. A rear end pushing means is provided that abuts the rear end of the sheet that has been pressed and pushed downstream in the sheet transport direction to position the rear end of the sheet at a predetermined position.

  The second means is characterized in that in the first means, means for moving the punching means and the trailing edge pushing means integrally in a direction perpendicular to the sheet conveying direction is provided.

  The third means is characterized in that, in the first or second means, means for moving the trailing edge pushing means to the predetermined position along the sheet conveying direction is provided.

  The fourth means is characterized in that, in the third means, positioning of the punching position in the paper transport direction with respect to the paper is performed based on the position of the trailing edge pushing means moved by the first moving mechanism.

  The fifth means is characterized in that in the first or third means, there is provided a deflection amount setting means for setting the deflection amount of the sheet based on the size in the width direction of the sheet and / or the thickness of the sheet. And

  The sixth means is characterized in that, in the fifth means, the amount of bending is set by changing the position of the trailing edge of the trailing edge pushing means.

  The seventh means is characterized in that, in the fifth or sixth means, the amount of bending is set by a nearest carrying roller located downstream of the trailing edge pushing means in the paper carrying direction.

  The eighth means is characterized in that in the first or third means, skew correction means for correcting the skew of the paper is provided in two stages.

  The ninth means is characterized in that, in the eighth means, the skew correction means in the first stage is composed of a transport roller on the upstream side in the paper transport direction of the trailing edge pushing means.

  A tenth means is the eighth means, characterized in that the skew correction means in the next stage comprises the rear end pushing means.

  The eleventh means is characterized in that in any one of the first to tenth means, a plurality of the rear end pushing means are provided.

  The twelfth means is characterized in that in the eleventh means, the trailing edge pushing means pushes the trailing edge of the sheet by combining at least two trailing edge pushing means.

  A thirteenth means is the twelfth means, wherein the trailing edge pushing means is at least two pairs of two trailing edges that come into contact with the trailing edge of the sheet at both ends of the sheet in a direction perpendicular to the sheet conveying direction. It is composed of pushing means, one of which is arranged on the outside so as to push in a large size paper in the direction orthogonal to the paper transport direction, and the other set is a small size paper in the direction orthogonal to the paper transport direction. It is arrange | positioned inside so that it may push in, It is characterized by the above-mentioned.

  In a thirteenth means according to the thirteenth means, the abutting portion of the other set of rear end pushing means arranged on the inner side with respect to the sheet is the rear end of the one set arranged on the outer side. It is characterized in that it is provided at a position retracted with respect to the paper transport direction from the abutting portion of the pushing means to the paper.

  The fifteenth means is characterized in that, in the fourteenth means, the contact portion is pushed by the leading edge of the entering paper and retracts from the paper conveyance path.

  In a sixteenth means, in the third to fifteenth means, after stopping the paper so that the rear end of the paper is located within a movement range of the rear edge pushing means in the paper conveyance direction, the rear edge Control means for moving the pushing member in the paper transport direction is provided.

  The seventeenth means includes control means in the third to sixteenth means, wherein the punching means starts drilling and starts moving the rear end pushing means toward the home position before completing the drilling operation. It is characterized by.

  According to an eighteenth means, in the third to seventeenth means, after the paper passes through the contact portion of the trailing edge pushing means, the trailing edge pushing means starts to move before the paper stops. Control means is provided.

  The nineteenth means is characterized in that in the third to eighteenth means, there is provided control means for starting reception of the next sheet before the movement of the home position of the trailing edge pushing means is completed. .

  The twentieth means is characterized in that the paper conveying apparatus includes the paper punching apparatus according to any one of the first to nineteenth means.

  The twenty-first means is characterized in that the paper processing apparatus includes the paper punching apparatus according to any one of the first to nineteenth means.

  The twenty-second means is characterized in that the image forming apparatus includes a paper punching device according to any one of the first to nineteenth means.

  In the following embodiments, the sheet conveying means is pushed into the conveying rollers 102.103, 104, 105, 106, 107, 108, 109, 112, 114, 115, 118, and the punching means is pushed into the punch unit 111 at the rear end. The rear end pressing claw 200, the housings 201 and 216, the tension spring 202, the bearing 203, the slide shafts 204 and 215, and the shafts 211 and 200e are integrally formed with the punching means and the rear end pushing means perpendicular to the sheet conveying direction. The lower guide plate 213a, the shaft 27, the holder 28, and the stepping motor 30a are moved to the predetermined position along the sheet conveying direction. The timing pulleys 207 and 208, and the gears 209 and 220 are moved to the predetermined position. , Stepping motors 211, 218, rack 214, pinion 21 The contact portion at a rear end pressing pawl 200 and 200 a, 200b, 200c, in 200d, the paper transport path in drilling path 100B, the control means corresponds respectively to the CPU 51.

  According to the present invention, punching can be performed with reference to the trailing edge of the paper without switching back the paper, so that high productivity and high accuracy can be processed at the same time. In addition, since the rear end of the paper is positioned at the two outer positions in accordance with the paper size in the direction orthogonal to the transport direction, the highly reliable paper punching device and paper transport device with excellent response to the difference in paper size A sheet processing apparatus and an image forming apparatus can be provided.

  Embodiments of the present invention will be described below with reference to the drawings. Note that, in the following embodiments, equivalent parts are denoted by the same reference numerals, and overlapping descriptions are omitted as appropriate.

<First Embodiment>
FIG. 1 is a diagram showing a schematic configuration of a paper punching device according to a first embodiment of the present invention. The paper punching device 100 has a function of receiving a paper on which an image has been formed from the image forming device PR and passing it to a post-processing device FR such as an alignment device or a folding device without punching or punching. And optionally attached to the image forming apparatus as required by the user.

  The paper punching apparatus 100 includes a punching path 100B and a non-perforating path 100C, and one of the paths is selected by the branching claw 102. In the perforation path 100 </ b> B, pairs of conveyance rollers 105, 106, 107, 108, 109, a skew correction roller 110, and conveyance rollers 112, 114, 115, 118 are arranged. Further, an entrance roller 101 is disposed in the carry-in path from the image forming apparatus PR, and a discharge roller 104 is disposed in the carry-out path to the post-processing apparatus FR. A transport roller is provided in the non-perforated path 100C between the rollers 101 and 104. 103 is arranged.

  The punch unit 111 is provided between the skew correction roller 110 and the conveyance roller 112, and a lateral registration detection sensor SN3 and a registration sensor SN2 are arranged upstream of the punch unit 111 in the conveyance direction. An entrance sensor 101 is provided on the upstream side of the entrance roller 101 in the carry-in path, and a paper discharge sensor SN4 is provided on the upstream path of the discharge roller 104. Reference numeral 119 denotes a punch scrap hopper that collects punch scraps punched by the punch unit 111.

  In the paper punching device 100 configured as described above, the paper is carried in from A of the image forming apparatus PR main body, and the paper is received by the entrance roller 101. A branching claw 102 is disposed downstream of the entrance roller 101, and a switching operation is performed in two directions of a solid line or a two-dot chain line by a driving unit (not shown). In the case of punching, the position is indicated by a solid line, and the sheet is guided downward (B direction). When punching processing is not required, the sheet is conveyed in the C direction at the position indicated by a two-dot chain line and guided to the sheet discharge roller 104.

  At the time of punching processing, the sheet conveyed in the B direction, that is, in the punching path 100B, when a predetermined time elapses after the trailing end of the sheet passes through the sensor SN1, the entrance approach linear velocity V0 is obtained in order to earn the punching processing time. Is further accelerated to V1 at a higher speed and conveyed by the conveying rollers 105 to 109, and the leading edge of the sheet is abutted against the nip of the skew correction roller 110. After the paper abutted for a certain period of time is bent by an appropriate amount, the skew correction roller 110 is rotated to resume the conveyance of the paper. The stop time and rotation start timing of the skew correction roller 110 are performed by the registration sensor SN2 as triggered by the detection of the leading edge of the sheet. The paper whose skew has been corrected by the skew correction roller 110 is re-accelerated to V1, passes through the lateral registration detection sensor SN3, detects the end face of the paper, and is then guided to the punch unit 111.

  FIG. 2 is a front view showing details of the lateral registration detection unit 3 and the punching unit 4. The punch unit 111 includes a lateral registration detection unit 3 and a punching unit 4. The lateral registration detection unit 3 is provided on the upstream side of the punching unit 4 in the sheet conveyance direction, and the punch lower guide 20 and the punch upper guide 21 are provided further on the upstream side of the lateral registration detection unit 3 in the sheet conveyance direction. The detection unit 3 is provided with a sheet edge detection sensor group 14 that detects an edge position parallel to the sheet conveyance direction.

  The punching unit 4 includes the punch blade 15, a holder 37 provided integrally with the upper end of the punch blade 15, a cam 38 inserted into the holder 37 and eccentrically engaged with the shaft 16, and the clutch 17. A motor 18 that drives the punch blade 15, a second stepping motor 23 that moves the punch blade 15 in a direction perpendicular to the sheet conveying direction, a timing belt 24, a gear / pulley 36, a rack 19, a lower guide 21, and the lower guide The home position sensor 29a for detecting the home position position.

  FIG. 3 is a side view of the lateral registration detection unit 3, and FIG. 4 is a side view of the punching unit 4. In these drawings, sensors 14a, 14b, 14c, and 14d that detect end positions parallel to the conveyance direction of the sheet conveyed to the lateral registration detection unit 3 (hereinafter, collectively represented by reference numeral 14). 1 (corresponding to SN3) is configured to be movable in a direction (arrow direction in FIG. 3) orthogonal to the transport direction. As can be seen from FIG. 3, the sheet end position detection sensor group 14 is attached to the upper guide 26, and the upper guide 26 is attached to the holder 28. The holder 28 moves in a direction perpendicular to the conveying direction while sliding on the shaft 27. A timing belt 32 is engaged with the holder 28. The timing belt 32 is stretched between the driving pulley 30a and the driven pulley 34 of the first stepping motor 30, and the timing belt 32 rotates and moves between the pulleys 30a and 34 by the rotation of the first stepping motor 30. Thus, the holder 28, the upper guide 26, and the sheet edge detection sensor group 14 can be reciprocated in a direction orthogonal to the sheet conveyance direction. The home position (standby position) HP of the sheet end detection sensor group 14 is determined by detecting a part of the shape of the holder 28 by the home position sensor 29. The sheet end detection sensor group 14 stands by at this waiting position, slides along the shaft 27 according to the rotation of the timing belt 32 using the first stepping motor 30 as a driving source, and is parallel to the sheet conveying direction. In order to detect the end S1, it moves in the left direction in the figure. Reference numerals 33 and 35 are guide plates, and reference numeral 31 is a base for supporting the guide plates 35.

  A plurality of the sheet end detection sensor groups 14 (four in this embodiment, 14a, 14b, 14c, and 14d) for detecting the end parallel to the sheet conveyance direction are arranged, and FIG. And the sensor to be used is changed according to the paper width size as shown in FIG.

  As shown in FIG. 6, the control device 50 is composed of a microcomputer having a CPU 51, an I / O interface 52, and the like. Each switch of the control panel of the image forming apparatus PR main body, the entrance sensor SN1, the registration sensor SN2, the horizontal Signals from sensors such as the registration sensor SN3 (14a to 14d), the paper discharge sensor SN4, and the home position sensor 29 are input to the CPU 51 via the I / O interface 52.

  The CPU 51 performs drilling by controlling the first and second stepping motors 30 and 23 and the motor 18 that drive the drilling unit 4 based on the input signal. A transport motor that drives each transport roller and a paper discharge motor that drives each paper discharge roller are controlled. The paper punching device 100 is controlled by the CPU 51 executing a program written in a ROM (not shown) while using a RAM (not shown) as a work area. The program data is downloaded from a server via a network or from a recording medium such as a CD-ROM or SD card to a storage medium such as a hard disk device (not shown) via a recording medium driving device instead of or in addition to the ROM. It can also be used after being upgraded.

  There are various variations in the mechanism for adjusting the lateral registration depending on the installation position and installation method of the lateral registration detection sensor, and the example shown here is an example.

FIG. 7 is a front view showing details of the trailing edge pressing mechanism for positioning the paper in the sub-scanning direction (conveyance direction) during punching.
In the drawing, a rear end holding claw 200 is rotatably attached to a housing 201 provided on the opposite side of the punch unit 111 with respect to the paper conveyance path 100B, and is shown clockwise around the fulcrum 200e by a tension spring 202. It is elastically biased so that it can be retracted when passing through the paper. A plurality of the rear end holding claws 200 are arranged in parallel with respect to the transport direction as shown in the view perpendicular to the sheet transport path 100B in FIG. 8 (four in the figure, 200a, 200b, 200c, 200d). The case is shown). The position of the rear end pressing claw 200 is set to a position corresponding to the paper size, and an optimum abutting position can be secured for each size. Further, in this embodiment, the rear end pressing claw 200 is formed in a right triangle as viewed from the front as shown in FIG. 7, and the surface abutting on the rear end of the sheet is perpendicular to the sheet conveyance direction when pressing the sheet. Has been placed.

  On the other hand, the housing 201 is slidably attached to a slide shaft 204 installed in parallel with the paper conveyance direction via a bearing 203, and is further fixed to a timing belt 206 stretched between timing pulleys 207 and 208. A driving force is transmitted by the stepping motor 211 via the gear trains 209 and 210. Thereby, the rear end pressing claw 200 can be moved along the slide shaft 204. The housing 201 is provided with a filler 205. The filler 205 is detected by the HP sensor SN10, and the stepping motor 211 is driven by an instruction from the CPU 51 based on the position detected by the HP sensor SN10. The movement of the end pressing claw 200 and the stop position control are performed.

  FIG. 9 is an operation explanatory view showing the operation of the trailing edge pressing mechanism when the sheet passes through the punch unit 111.

 As shown in FIG. 9, first, the paper corrected by the skew correction roller 110 enters the punch unit 111 (operation [I]). In the drawing, a state in which the leading end of the sheet is in contact with the inclined surface of the trailing edge pressing claw 200 is shown.

 As the paper enters from the state of the operation [I], the trailing edge pressing claw 200 is pushed, rotates counterclockwise, retreats from the paper conveyance path 100B, and the paper is further conveyed ((operation [I At this time, the trailing edge pressing claw 200 is slidably in contact with the back surface of the sheet to maintain the retracted state, and when the trailing edge of the sheet passes the trailing edge pressing claw 200, the trailing edge pressing claw 200 Then, the trailing edge pressing claw 200 moves in a direction to advance with respect to the sheet conveying direction, and the trailing edge of the sheet is a predetermined distance from the punching position (after the sheet). Stop at the position where the distance from the edge to the punching position (d) and the specified deflection amount α are added (operation [III]). At this time, the positional information on the sheet end surface position of the lateral registration sensor SN3 (14a to 14d) is used. Based on how the punch unit 111 transports paper Moves in a direction perpendicular to, to position the direction perpendicular to the sheet conveying direction.

 Then, with the paper stopped, the trailing edge pressing claw 200 moves in the direction of the arrow until the distance d is reached, and a punching operation is performed immediately after the bending is formed (operation [IV]). After that, while the perforated paper is being conveyed again, the trailing edge pressing claw 200 is returned to HP to prepare for the next paper intrusion (operation [V]).

The control procedure of this operation is shown in the flowchart of FIG.
In this control procedure, first, an initial operation is executed (step S1), and the start of a job is waited (step S2). When the job is started, the entrance roller 101 is driven (step S3), and then the transport rollers 105, 106, 107, 108, 109 are driven (step S4). At that time, the branching claw 102 is switched in advance so as to guide the sheet to the punching path 100B side.

  When the sheet is conveyed by the conveying rollers 105, 106, 107, 108, 109 and the leading edge of the sheet cuts the registration sensor SN2 (step S5) and a predetermined abutting time has elapsed (step S6), it is considered that the skew has been corrected. The skew correction roller 110 is driven (step S7). In response to this, the transport rollers 112, 114, 115, 118 are driven (step S8—operation [I, II]), and the paper discharge roller 104 is further driven (step S9). When the trailing edge of the sheet passes through the registration sensor SN2 (step S10) and the trailing edge of the sheet passes the trailing edge aligning claw 200 (step S11), the CPU 51 first sets the first movement position P1 to (punching position -d). Setting is made (step S12), and based on this, the movement of the rear end aligning claw 200 to the position P1 is started (step S13). Next, the next movement position P2 is set to (perforation position-d-α) (step S14). When the rear end of the sheet reaches the position P2 (step S15-operation [III]), the skew correction roller 110 is driven. Stop (step S116). Further, the transport rollers 112 and 114 are stopped to hold the sheet (step S17), and when the movement of the trailing edge aligning claw 200 is stopped (step S18-operation [IV]), the punching operation by the punch unit 111 is started. (Step S19).

 When the punch blade reaches the punching position, that is, when the punch blade punches the paper (step S20), the trailing edge aligning claw 200 starts moving to the home position side (step S21), and punch punching operation is performed. Is completed, that is, when the punch blade completes punching and returns to the initial position (step S22), the transport rollers 112 and 114 are driven to transport the paper in the paper discharge direction (step S23—operation [V]). Next, when the rear end holding claw 200 reaches the home position (step S24), the movement of the rear end alignment claw 200 is stopped (step S25), and it is checked whether or not the job is finished (step S26). If the job is completed, the process returns to step S1 to wait for the start of the next job, and if the job is not completed, the process returns to step S3 to wait for the next sheet to be carried. At this time, if the entrance roller 101 is driven and the next sheet is received in step S3 before the movement of the trailing edge pressing claw 200 to the home position is completed, the dead time between step S26 and step S3 is minimized. Become.

 The punched paper is transported to the discharge roller 104 by transport rollers 112, 114, 115, and 118 and transported to the next unit. Punch scraps generated during punching are accommodated in the hopper 119. This hopper is detachable from the apparatus body when it is full, as in the conventional machine.

 When configured and processed in this way, the deflection amount α can be set to an arbitrary deflection amount by changing the stop position of the sheet (FIG. 9 [III]). As a result, it is possible to set an arbitrary amount of paper deflection according to the paper state (stretch strength, size, direction), and it is possible to perform highly accurate punching processing for various types of paper.

 Also, with respect to the predetermined distance d, which is the punch position in the transport direction, by setting (or adjusting) the stop position of the rear end pressing claw 200 arbitrarily, it is possible to punch at an arbitrary position with high accuracy. . In particular, the latter is not a fixed value determined by a mechanical configuration as in the prior art, but can be arbitrarily set by control, so that it is a user-friendly function.

 Further, in this embodiment, the pushing operation of the trailing edge of the sheet by the trailing edge pressing claw 200 is performed in two stages of steps S12 and S14. As a result, the amount of pushing the trailing edge of the sheet by the trailing edge pressing claw 200 can be reduced, and the bending is gradually formed, so that the punching position can be set with high accuracy.

 In addition, the skew correction roller 110 first performs skew correction at the front end of the sheet, and then performs skew correction at the rear end of the sheet. Therefore, the amount of movement of the rear end pressing claw 200 can be reduced, which is also the perforation position. Contributes to improved position accuracy.

 Furthermore, in this embodiment, the paper is abutted against the rear edge aligning claw 200 to perform alignment and perforation. However, at the time of abutting, the paper is not moved but the rear edge aligning claw 200 side is operated. Therefore, when punching to the rear end side as in this embodiment, it is not necessary to switch back the paper, and the influence of the transport roller on the paper (mainly roller marks) when switching back is minimized. can do.

 In addition, since the time required for punching is basically only to stop the paper and not to switch back, it is easy to cope with a high-speed machine.

  In this embodiment, the rear end pressing mechanism is provided in each of the rear end pressing claws 200 and can press the rear end of the paper independently. In this embodiment, the sheet punching device 100 is configured as a single unit and is provided between the image forming apparatus PR and the post-processing apparatus FR. However, the sheet punching apparatus 100 is provided on the image forming apparatus PR side or the post-processing apparatus PR side. Needless to say, the image forming apparatus PR and the sheet post-processing apparatus FR may be integrated with each other.

<Second Embodiment>
This embodiment is a modification of the rear end pressing mechanism in the first embodiment. Since the configuration other than the rear end pressing mechanism is the same as that of the first embodiment, a duplicate description is omitted.

  FIG. 11 is a plan view of a rear end pressing mechanism according to the second embodiment. In FIG. 12, four rear end holding claws 400a to 400d are independently attached to a shaft 211 fixed to the housing 206 so as to be freely rotatable, and the timepiece shown in FIG. It is elastically biased in the direction so that it can be retracted from the paper transport path when the paper passes. Further, as shown in FIG. 11, a plurality of rear end pressing claws 200a, 200b, 200c, and 200d are attached in parallel in the transport direction according to the sheet size. Thereby, the optimal abutting position for each size can be ensured. However, an offset of x is provided in the sheet conveyance direction between the abutting position of the rear end pressing claws 200b and 200c on the center side and the abutting position of the rear end pressing claws 200a and 200d on the sheet end side. Narrow size and wide size paper, or the positions of the rear end pressing claws 200a to 200d that abut against each other in the paper direction, in other words, the combination of the rear end pressing claws 200b and 200c and the combination of 200a and 200b are set differently. Has been.

 This is specifically shown in FIG. 13, FIG. 14 and FIG. FIG. 13 is a view of FIG. 12 as viewed from the direction of arrow A, and FIG. It shows the state that has been. At this time, since the rear end of the sheet is supported at two points and abuts the rear end of the sheet with a width (wide span) close to the width of the sheet, stable skew correction can be performed. Even if the four rear end pressing claws 200a to 200d are designed to be on the same plane in the layout, the positions of the rear end pressing claws 200b may be slightly shifted due to the effects of component variations and assembly errors. , 200c, when the rear end of the sheet is abutted, the width for supporting two points is narrowed. If the width is narrowed, the paper may be inclined and stable skew correction cannot be performed.

 On the other hand, as shown in FIG. 15, the narrow paper sheet has two paper pressing claws 200b and 200c on the center side abutting on the rear end side of the paper with two-point support. At this time, the outer two rear end pressing claws 200a and 200d do not interfere with the rear end of the sheet, and the positions are aligned at the two points.

  In this embodiment, the housing 216 is slidably attached to a slide shaft 215 fixed to the lower guide plate 211, and the upper guide plate 213 b is connected via a pinion 217 from a stepping motor 218 fixed to the housing 206. The sliding movement is performed by engaging with the rack 214 fixed to the rack. Therefore, the housing 216, the stepping motor 218, the pinion 217, the rear end pressing claws 200a to 200d, etc. are slid and moved along the paper transport direction in a state where they are integrated. In this sliding operation, the filler 219 attached to the housing 216 is detected by the HP sensor 220, and the stepping motor 218 is driven and controlled on the basis of the home position as in the first embodiment. Further, since the lower guide plate 213a is fastened to the punch unit 111, all the components attached to the lower guide plate 213a are integrated with the punch unit 111 and moved in a direction perpendicular to the paper transport direction. In the case of this embodiment as well, it goes without saying that the lateral registration position is adjusted according to the detection state of the lateral registration detection sensor SN3 (14a to 14d) as in the first embodiment.

  Further, the control of the rear end pressing mechanism is the same as in the first embodiment. Other parts that are not particularly described are configured in the same manner as the first embodiment and function in the same manner.

  As described above, according to the present exemplary embodiment, the rear end pressing claw is provided that contacts the rear end of the conveyed paper and pushes it downstream in the paper transport direction to position the rear end of the paper at a predetermined position. Therefore, there is no need to switch back the paper, the influence on the paper at the time of switch back (roller roller traces etc.) can be minimized, and the processing time can be saved by not performing the operation of switching back. It is possible to increase productivity.

  Since the plurality of paper rear edge holding claws move in a direction perpendicular to the paper conveyance direction, it is possible to always contact the paper rear edge at a symmetrical position with respect to the conveyance center and perform stable skew correction. Can do. This improves the position accuracy of the drilling position.

  Since the amount of movement of the trailing edge pressing claw can be changed and the punching position in the paper transport direction can be positioned, the punching position can be freely changed.

  The amount of flexure of the paper can be changed by the trailing edge presser claw, so the optimal amount of flexure should be set for a wide variety of paper types with different paper sizes, paper thicknesses, etc. Is possible. Thereby, it is possible to obtain a more accurate position accuracy of the drilling position.

  Since a plurality of rear end pressing claws are provided, it is possible to secure an optimum abutting position according to the size, and it is possible to provide a device with higher accuracy and reliability.

  A plurality of trailing edge holding claws are provided, and the trailing edge of the paper is pushed by a combination of at least two trailing edge pressing claws. In addition, the skew correction can be performed more stably in the city in contact with the paper. This improves the position accuracy of the drilling position.

It is a figure which shows schematic structure of the paper punching apparatus which concerns on the 1st Embodiment of this invention. It is a front view which shows the detail of the horizontal registration detection unit and perforation unit which concern on 1st Embodiment. It is a side view of the horizontal registration detection unit concerning a 1st embodiment. It is a side view of the perforation unit concerning a 1st embodiment. It is a figure which shows the selection state of the sensor in the horizontal registration detection unit which concerns on 1st Embodiment. FIG. 3 is a block diagram illustrating a control device of the paper punching device according to the first embodiment. FIG. 5 is a front view showing details of a sheet trailing edge pressing mechanism that positions the sheet in the sub-scanning direction (conveyance direction) during punching according to the first embodiment. FIG. 8 is a schematic configuration diagram of the sheet pressing mechanism of FIG. 7 as viewed from a direction orthogonal to the sheet conveyance path. FIG. 10 is an operation explanatory diagram illustrating an operation of a trailing edge pressing mechanism when a sheet passes through a punch unit. 10 is a flowchart illustrating a control procedure when performing the operation of FIG. 9. FIG. 6 is a plan view of a rear end pressing mechanism according to a second embodiment of the present invention. FIG. 12 is a front view of the rear end pressing mechanism of FIG. 11. It is A arrow view which looked at FIG. 12 from the arrow A direction. FIG. 6 is a plan view showing a state in which a rear end of a sheet having a wide size in a direction orthogonal to the sheet conveyance direction is abutted by a rear end pressing claw. FIG. 6 is a plan view illustrating a state in which a rear end of a sheet having a narrow size in a direction orthogonal to the sheet conveyance direction is abutted by a rear end pressing claw.

Explanation of symbols

14, SN3 lateral registration detection sensor 27 axis 28 holder 30a stepping motor 51 CPU
100 paper punching apparatus 100B punching path (paper transport path)
DESCRIPTION OF SYMBOLS 101 Entrance roller 102-109, 112-118 Conveyance roller 110 Skew correction roller 111 Punch unit 200, 200a, 200b, 200c, 200d Rear end holding claw 201, 216 Housing 202 Tension spring 203 Bearing 204, 215 Slide shaft 206 Timing belt 207 , 208 Timing pulley 209, 210 Gear 211, 218 Stepping motor 213a Lower guide plate 214 Rack 217 Pinion 220, SN10 HP sensor PR Image forming apparatus FR Paper post-processing apparatus

Claims (22)

Paper transport means for transporting paper,
Perforating means for perforating paper conveyed by the conveying means;
In the paper punching device provided with
A sheet having a trailing edge pushing means for contacting the trailing edge of the sheet conveyed by the sheet conveying means and pushing the sheet downstream in the sheet conveying direction to position the trailing edge of the sheet at a predetermined position. Drilling device.   2. The paper punching apparatus according to claim 1, further comprising means for moving the punching means and the trailing edge pushing means integrally in a direction perpendicular to the paper transport direction.   3. The paper punching device according to claim 1, further comprising means for moving the trailing edge pushing means to the predetermined position along a paper transport direction.   4. The paper punching device according to claim 3, wherein the punching position in the paper transport direction relative to the paper is determined based on the position of the trailing edge pushing means moved by the first moving mechanism.   The paper punching device according to claim 1, further comprising a deflection amount setting unit that sets a deflection amount of the paper based on a size in the width direction of the paper and / or a thickness of the paper.   6. The sheet punching device according to claim 5, wherein the amount of bending is set by changing a position of a sheet trailing edge of the trailing edge pushing means.   The paper punching device according to claim 5 or 6, wherein the amount of bending is set by a nearest transport roller located downstream of the trailing edge pushing means in the paper transport direction.   4. The paper punching device according to claim 1, wherein skew correction means for correcting the skew of the paper is provided in two stages.   9. The paper punching device according to claim 8, wherein the skew correction means at the first stage comprises a transport roller upstream of the trailing edge pushing means in the paper transport direction.   9. The paper punching device according to claim 8, wherein the skew correction means at the next stage comprises the trailing edge pushing means.   The paper punching device according to claim 1, wherein a plurality of the rear end pushing means are provided.   12. The sheet punching device according to claim 11, wherein the trailing edge pushing means pushes the trailing edge of the sheet by combining at least two trailing edge pushing means. The trailing edge pushing means includes at least two pairs of trailing edge pushing means that come into contact with the trailing edge of the paper at both ends of the paper in a direction orthogonal to the paper conveyance direction,
One of the groups is arranged on the outside so as to push in a large size sheet in the direction orthogonal to the sheet conveying direction, and the other group is arranged on the inside so as to push in a small size sheet in the direction orthogonal to the sheet conveying direction. 13. The paper punching device according to claim 12, wherein the paper punching device is arranged.   The contact portion of the other set of rear end pushing means arranged on the inner side with respect to the sheet is more than the contact portion of the one set of rear end pushing means arranged on the outer side with respect to the sheet. 14. The paper punching device according to claim 13, wherein the paper punching device is provided at a position retracted with respect to the paper transport direction.   15. The paper punching device according to claim 14, wherein the abutting portion is pushed by the leading edge of the entering paper and retracts from the paper transport path.   Control means for moving the trailing edge pushing member in the sheet conveying direction after stopping the sheet so that the trailing edge of the sheet is positioned within the movement range of the trailing edge pushing means in the sheet conveying direction. The paper punching device according to any one of claims 3 to 15, wherein the paper punching device is one.   17. The control device according to any one of claims 3 to 16, further comprising control means for starting the punching means and starting the rear end pushing means toward the home position before completing the punching operation. The paper punching device according to item 1.   4. The apparatus according to claim 3, further comprising a control unit that starts movement of the trailing edge pushing unit after the sheet has passed through the contact portion of the trailing edge pushing unit and before the sheet stops. 5. The paper punching device according to any one of 17.   The sheet punching according to any one of claims 3 to 18, further comprising control means for starting reception of the next sheet before the movement of the home position of the trailing edge pushing means is completed. apparatus.   A paper conveying device comprising the paper punching device according to any one of claims 1 to 19.   A paper processing apparatus comprising the paper punching device according to claim 1.   An image forming apparatus comprising the paper punching device according to any one of claims 1 to 19.

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