JP2015199594A - Sheet processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide simple and inexpensive re-folding means which can pressurize and reinforce a crease of a sheet without elongating, enlarging, and complicating a conveyance path, and pressurize and reinforce creases formed by a plurality of different mechanisms.SOLUTION: As a re-folding device, a re-folding roller pair comprising re-folding rollers 320, 321 is disposed. A rotary shaft of the re-folding roller pair (320, 321) is disposed in a direction intersecting with a crease of a sheet on which the crease is formed. A first roller pair (324, 325) for conveying a sheet so that the crease of the sheet intersects with the re-folding roller pair (320, 321) and a second roller pair (313, 314) for conveying the sheet from a direction facing the first roller pair are disposed in order to carry the sheet into a conveyance area of the re-folding roller pair (320, 321) from two different directions.

Description

  The present invention relates to a sheet processing apparatus, and more particularly to a sheet processing apparatus including an additional folding apparatus that pressurizes and strengthens a fold of a sheet on which a fold is formed.

  2. Description of the Related Art Conventionally, a sheet processing apparatus that performs additional sheet processing on a sheet on which an image is recorded by an image forming apparatus such as a copying machine is known. As these sheet processing apparatuses, a sheet folding apparatus that performs sheet folding processing, a binding process that binds with staples, a post-processing apparatus that performs punching processing for filing, and the like are known. Among the sheet processing apparatuses, for example, the sheet folding apparatus and the post-processing apparatus have a relationship in which, for example, the sheet folding apparatus is a front stage (image forming apparatus side), and a post-processing apparatus that performs a binding process, a punching process, and the like is a rear stage May be placed.

  In this type of sheet processing apparatus, a configuration is known in which the fold portion is secondarily pressure-enhanced (increase folding) after the middle fold (two fold: one fold) process to suppress the bulge of the sheet bundle. (For example, Patent Document 1 below). In Patent Document 1 described below, a sheet output from an image forming apparatus is subjected to a saddle stitching process, and then a first folding roller for the middle folding process, and a second folding roller disposed orthogonal to the first folding roller. A configuration in which the sheet is folded halfway and pressed is disclosed.

JP 2005-239420 A

  The pressure strengthening (additional folding) means described in Patent Document 1 is an additional folding apparatus specialized for a sheet bundle that has undergone a middle folding (two folding) process. However, the configuration described in Patent Document 1 is not necessarily suitable for pressurizing and strengthening a sheet bundle that has been subjected to a three-fold process in which two creases are applied by a sheet folding device, for example. For example, a sheet processing apparatus that performs tri-fold processing is more complicated than an apparatus that supports only middle folding. In order to incorporate an additional folding apparatus, it is necessary to add a large number of conveying rollers, and there is a problem that cost increases cannot be avoided. It was. In addition, the sheet processing apparatus that performs the three-fold process has a long sheet conveyance path due to its mechanism and is relatively complicated, and it may be difficult to arrange the additional folding apparatus on the conveyance path.

  Further, when the sheet processing apparatus is disposed at the subsequent stage of the image forming apparatus, various post-processing mechanisms may be provided. For example, in addition to a sheet folding apparatus that performs only simple folding processing, a mechanism that performs so-called saddle stitching may be provided. The saddle stitching is a post-processing in which a sheet is folded in half (two folds) and the fold portion is bound by a stapler. In the sheet processing apparatus, when an additional folding device that pressurizes and strengthens a fold is disposed, not only a fold formed by the sheet folding device but also a sheet that is saddle-stitched by the above-described mechanism by the same additional folding device. It is desirable that the crease can also be pressure strengthened.

  Accordingly, an object of the present invention is to provide a sheet processing apparatus that can pressurize and strengthen a sheet fold without lengthening or complicating the conveyance path, and can easily pressurize and strengthen a fold formed by a plurality of different mechanisms. It is to provide an additional folding means.

  In order to solve the above-described problems, in the present invention, an additional folding apparatus having a pair of additional folding rollers, each of which has a rotation shaft arranged in a direction intersecting with the fold of the sheet formed with the fold, and pressurizes and strengthens the fold of the sheet. A first roller pair for carrying the sheet into a conveyance region of the additional folding roller pair so that the fold line intersects with the additional folding roller pair, and the additional roller roller from the direction facing the first roller pair. A configuration provided with a second roller pair for carrying the sheet into the conveyance region of the folding roller pair was adopted.

  According to the above configuration, in the sheet processing apparatus, a sheet to be pressure-enhanced can be carried into the additional folding apparatus from the different opposing directions by the first roller pair or the second roller pair. For this reason, for example, a mechanism for performing a plurality of different sheet folding processes can be arranged on both sides of the additional folding apparatus without lengthening and complicating the conveyance path, and a fold formed by a plurality of different mechanisms can be easily pressed and strengthened. An inexpensive additional folding means can be provided.

1 is a cross-sectional view illustrating a structure of an image forming apparatus including a sheet folding device and a post-processing device in an embodiment of the present invention. FIGS. 2A and 2B show different modes of sheet folding performed by the sheet folding apparatus of FIG. 1, and FIG. 3A is an explanatory diagram showing three inner folds, FIG. 1B is three outer folds, and FIG. It is. FIG. 2 is a cross-sectional view along the sheet conveying direction showing the structure of the sheet folding apparatus of FIG. 1. It is sectional drawing which showed the principal part of the sheet folding apparatus of FIG. 1 in detail. FIG. 2 is a block diagram showing a control system of the sheet folding apparatus of FIG. 1. (A)-(D) is explanatory drawing which showed sequentially the operation | movement which folds a sheet | seat inside three by the sheet folding apparatus of FIG. (A) And (B) is explanatory drawing which showed sequentially the operation | movement which folds a sheet | seat inside three by the sheet folding apparatus of FIG. 1 following FIG. (A)-(D) is explanatory drawing which showed the operation | movement which folds a sheet | seat outside three by the sheet folding apparatus of FIG. FIGS. 8A and 8B are explanatory views sequentially showing the operation of folding the outer three sheets by the sheet folding apparatus of FIG. 1 following FIG. 8. (A)-(D) is explanatory drawing which showed in order the operation | movement which folds a sheet | seat one sleeve by the sheet folding apparatus of FIG. (A)-(D) is explanatory drawing which showed sequentially the operation | movement which folds a sheet | seat by the sheet folding apparatus of FIG. 1 following FIG. (A) And (B) is explanatory drawing which showed sequentially the operation | movement which folds a sheet | seat one sleeve by the sheet folding apparatus of FIG. 1 following FIG. It is sectional drawing which shows the structure of the post-processing apparatus of FIG. FIG. 2 is a cross-sectional view showing a state in which a plurality of sheets that are saddle-stitched are put on standby in the post-processing apparatus of FIG. 1. It is explanatory drawing which showed a mode that the several sheet | seat which is saddle-stitched in the post-processing apparatus of FIG. 1 was made to wait. It is explanatory drawing which showed the saddle stitching process performed with the post-processing apparatus of FIG. FIG. 8 is an explanatory diagram illustrating an operation of folding a sheet bundle that is saddle-stitched in the post-processing apparatus of FIG. 1. FIG. 18 is an explanatory diagram illustrating an operation of folding the sheet bundle that is saddle-stitched in the post-processing apparatus of FIG. 1 following FIG. 17. In embodiment of this invention, it is explanatory drawing which showed the structure and operation | movement of the additional folding mechanism.

  FIG. 1 shows an example of the configuration of an image forming apparatus employing the present invention, in particular, an image forming apparatus including a sheet folding apparatus 200 and a post-processing apparatus 300. 3 to 12 show the configuration and operation of the sheet folding apparatus 200, and FIGS. 13 to 19 show the configuration and operation of the post-processing apparatus 300.

<Overall structure>
The image forming apparatus 100 in FIG. 1 includes an apparatus main body 100A, a sheet folding apparatus 200, and a post-processing apparatus 300. Among these, for example, the sheet folding apparatus 200 or the post-processing apparatus 300 at the subsequent stage can be configured to be housed in independent housings.

  In that case, the sheet folding apparatus 200 and the post-processing apparatus 300 are supplied as optional apparatuses and can be connected to the apparatus main body 100A as necessary. However, the sheet folding apparatus 200 and the post-processing apparatus 300 are not necessarily configured separately. For example, the configuration described later can be implemented even when the sheet folding apparatus 200 and the post-processing apparatus 300 are housed in a common housing.

  In FIG. 1, an apparatus main body 100A is a part for forming an image on a sheet (PA), and a sheet folding apparatus 200 is an apparatus for applying a folding process to an ejected sheet formed with an image by the apparatus main body 100A. The sheet folding apparatus 200 according to the present embodiment is configured to be able to fold the sheet into two parts by being folded twice, in addition to being folded twice at the center of the sheet. Further, the sheet folding apparatus 200 can pass through the sheet carried in from the apparatus main body 100 </ b> A without applying a folding process and deliver it to the post-processing apparatus 300.

  The post-processing device 300 can be configured to execute at least one post-processing from the following post-processing. For example, in this post-processing, a sheet passing through the sheet folding apparatus 200 or a sheet folded by the sheet folding apparatus 200 is discharged as it is, a process of making a hole in the sheet, a process of marking, and a bundle The binding process is included. In particular, the post-processing apparatus 300 according to the present embodiment can perform an additional folding process that pressurizes and strengthens a sheet that has been folded by the sheet folding apparatus 200 as described later. Further, the post-processing apparatus 300 according to the present embodiment can add a center (two) folding process or a further saddle stitching process to the sheet as will be described later. The additional folding process can be performed on the processed sheet.

  The post-processing device 300 according to the present embodiment is provided with an additional folding device that includes a pair of additional folding rollers (FIGS. 1, 13, and 19) including a later-described additional folding roller 320 and an additional folding roller 321 as main functional parts. There is a feature. As shown in FIG. 19, this additional folding apparatus is provided with a pair of additional folding rollers (320, 321) having a rotation axis arranged in a direction intersecting with the fold of the sheet on which the fold is formed, and pressurizing and strengthening the fold of the sheet. Have. Then, a first roller pair (324, 325) for carrying the sheet into the conveyance region of the additional folding roller pair (320, 321) is provided so that the fold line intersects with the additional folding roller pair. Further, a second roller pair (313, 314) for carrying the sheet into the conveyance region of the additional folding roller pair (320, 321) from the direction facing the first roller pair is provided.

  The additional folding roller pair (320, 321) can be switched between a separated state and a pressure contact state by a solenoid or the like. Further, an additional folding positioning roller 322 and a pinch roller 323 that can be separated and pressed by a solenoid or the like are arranged at the center of the conveyance area of the additional folding roller pair (320, 321).

  In the present embodiment, the additional folding device having the roller arrangement as shown in FIG. 19 is provided on the side of the post-processing device 300. The sheet folding apparatus 200 has a sheet carry-out path (increase folding path 259) that conveys a sheet in which a crease is formed toward the first roller pair (324, 325) of the additional folding apparatus in the middle of the sheet conveyance path. Provide.

  Further, the post-processing apparatus 300 is provided with a mechanism for performing a predetermined post-processing, for example, a so-called saddle stitching process in which a sheet bundle is bound by a stapler (370) at the center and then folded (folded in two) at that position. The second roller pair (313, 314) constitutes a carry-in roller into the conveyance region of the additional folding roller pair (320, 321), and performs the middle folding process on the sheet bundle in the saddle stitching process. Also serves as a folding roller.

  As described above, the sheet processing apparatus (the sheet folding apparatus 200 and the post-processing apparatus 300) of the present embodiment folds not only from one direction but also from two opposite directions to the conveyance region of the additional folding roller pair (320, 321). It is characterized in that a sheet to be pressure-enhanced can be carried in. For this reason, on both sides of the additional folding roller pair (320, 321), a mechanism for performing a plurality of different folding processes and post-processes for generating a sheet to be pressure-enhanced can be disposed. Further, the sheet folding apparatus 200 can convey the sheet in which the crease is formed toward the first roller pair (324, 325) of the additional folding apparatus from the middle of the sheet conveying path. For this reason, it is possible to pressurize and strengthen the sheet fold without increasing the length and complexity of the conveyance path.

  In FIG. 1, an image reading device 120 and a document feeding device (ADF) 110 that feeds a document to a reading position of the image reading device 120 are provided on the upper portion of the apparatus main body 100 </ b> A of the image forming apparatus. . The document feeder 110 feeds the documents D placed on the stacker 111 by the user one by one to the platen glass 121 of the image reading device 120. The document feeder 110 is provided on the image reading device 120 so as to be freely opened and closed via a swing mechanism. By opening the document feeder 110, the platen glass 121 can be exposed, and a document to be read can be placed thereon.

  The image reading device 120 reads a document fed onto the platen glass 121 by the document feeding device 110 or a document placed on the platen glass 121, processes the read image information, and sends the processed image information to the laser scanner unit 130. .

  The laser scanner unit 130 irradiates a charged photosensitive drum 140 with a laser to form an electrostatic latent image on, for example, the photosensitive drum 140 that is an image forming unit. The electrostatic latent image is developed by the developing device 141 to become a toner image. The toner image formed on the photosensitive drum 140 is transferred by the transfer charger 142 to the sheet PA fed from the supply cassettes 150a and 150b. The sheet PA to which the toner image is transferred is heated and pressed by the fixing device 143 to fix the toner image. The sheet PA on which the toner image is fixed is discharged to the sheet folding apparatus 200 by the main body discharge roller pair 160. Further, when forming a toner image on both sides of the sheet PA, the sheet PA can be fed to the photosensitive drum 140 after being reversed in the reverse path 144.

  When the sheet PA is discharged through the main body discharge roller pair 160, the main body discharge port sensor 161 detects the sheet PA. When the main body discharge port sensor 161 detects the discharge of the sheet PA, a main body discharge signal ES (FIG. 5) is transmitted from the CPU 289 (FIG. 5) of the apparatus main body to the CPU 290 of the sheet folding apparatus 200. The CPU 290 (FIG. 5) of the sheet folding apparatus 200 determines the operation timing based on the main body discharge signal ES from the CPU 289 of the apparatus main body. Further, the CPU 290 determines processing to be performed on the sheet PA sent to the sheet carry-in entrance 210 (FIG. 1) based on the size signal DS, the folding mode signal FS, and the like.

  A sheet carry-in roller 211A is provided at the carry-in entrance of the sheet folding apparatus 200, and the sheet PA taken in from the sheet carry-in roller 211A is conveyed by a switching member 240 (FIG. 3) provided immediately after the sheet carry-in roller 211A. Routes are sorted.

  When the folding process is not designated, the sheet PA passes through the passing conveyance path 253 (FIG. 3) of the sheet folding apparatus 200 and is sent to the post-processing apparatus 300. The passing conveyance path 253 includes a carry-in unit 253a including a pinch roller 231 and a sheet carry-in roller 211A, and a carry-out unit 253b including a pinch roller 232 and a sheet carry-in roller 211B.

  Further, when the folding process is designated in the sheet folding apparatus 200, the sheet PA is conveyed to the receiving conveyance path 250 (FIG. 3), and based on the size signal DS and the folding mode signal FS (FIG. 5), FIG. A folding process as shown is applied. 2A, 2 </ b> B, and 2 </ b> C respectively show the sheet PA that has been subjected to each folding process (described later) of the inner folding process, the outer folding process, and the one-sleeve folding process by the sheet folding apparatus 200. Yes.

  When the inner or outer tri-fold process (FIG. 2 (A) or (B)) is selected and the additional folding process is not selected (FIGS. 6, 7, 8, and 9 described later), the sheet After the folding process, the PA is discharged into the folded sheet storage box 280 and stored. The folded sheet storage box 280 functions as a sheet storage unit that stores folded sheets. When the one-sleeve folding process (FIG. 2C) is selected (FIGS. 10 to 12), the sheet PA is subjected to the one-sleeve folding process and then passed through the discharge transport path 252. (253b: FIG. 3) is merged and sent to the post-processing apparatus 300. The post-processing device 300 performs a binding process or a punching process on the conveyed sheet PA.

  On the other hand, when the inner folding process or the outer folding process is designated for the sheet folding apparatus 200 and the additional folding process is selected, the sheet PA is conveyed to the receiving conveyance path 250, and the size signal DS and the folding signal are fed. The folding process is performed based on the mode signal FS. Thereafter, the sheet PA is sent to the post-processing apparatus 300 via a conveyance path dedicated to additional folding (configuration around the additional folding path 259 described below), unlike the case of the above folding process. Then, after receiving the crease strengthening process in the post-processing apparatus 300, it is stored in the storage box 390 of the post-processing apparatus 300.

  As shown in FIGS. 3 and 4, the above-described trifold sheet additional folding exclusive path includes an additional folding path 259, a conveyance roller 229, and a conveyance pinch roller 239 provided in the middle of the discharge conveyance path 252.

  The conveyance path switching in the direction of the additional folding path 259 or the discharge conveyance path 252 is performed by the additional folding path switching member 249. When the conveyance path is switched in the direction of the discharge conveyance path 252, the additional folding path switching member 249 is swing-switched from the position of the broken line in FIG. 4 to the position of the solid line. Further, when the conveyance path is switched in the direction of the additional folding path 259, the additional folding path switching member 249 is swing-switched from the solid line position in FIG. 4 to the broken line position. The swing control of the additional folding path switching member 249 is performed by the additional folding path solenoid SL9.

  The post-processing device 300 (FIGS. 1, 13 to 19) includes a stapler 304 that binds the sheet PA on a passing conveyance path 302 that connects the upper sheet carry-in port 307 and the staple tray 303. The sheet bundle bound by the stapler 304 is discharged to the stacking tray 301. Instead of the stapler 304, a gluing device for gluing one side edge of the sheet, a punching device for making a hole in the sheet PA, or a stamp device for marking the sheet PA can be provided as necessary.

  When the half-folding (two-folding) process is designated, the sheet PA passes through the middle folding path 306 from the sheet carry-in entrance 307 facing the passing conveyance path 253 (the carry-out unit 253b) of the sheet folding apparatus 200. Then, the sheet PA is subjected to the middle folding process based on the size signal DS and the folding mode signal FS. After the middle folding process is performed, the crease is strengthened and stored in the storage box 390.

  Further, the sheet folding apparatus 200 can perform a three-fold process for folding the sheet PA twice. 2A to 2C illustrate an example of a tri-fold process. The three-folding process that can be performed by the sheet folding apparatus 200 is, for example, the three-folding process in FIG. 2 (FIG. 2A), the outer three-folding process (FIG. 2A), and the one-sleeve folding process (FIG. 2A). One of them.

  As shown in FIG. 2A, the inner three-fold process is performed by folding the (1/3) position on the leading end side in the sheet conveying direction, and (1/3) on the trailing end side of the sheet on the folded piece. These positions are overlapped to form. For example, there is a letter in the sheet PA that is folded in three, and this three-fold is used for the purpose of sealing in an envelope.

  The outer tri-folding process is formed by folding the (1/3) position on the front end side and the (1/3) position on the rear end side to the opposite side as shown in FIG. To do. For example, the sheet PA that is folded into three outer folds includes direct mail. The outer three folds are used for applications such as sealing in an envelope.

  In the one-sleeve folding process, as shown in FIG. 2 (C), the sheet is folded in half at the position (1/2) in the center of the sheet conveyance direction, and then the piece folded in two is further (1/2). It is formed by folding in two on the opposite side in position. However, in the present embodiment, as will be described later, first, the sheet is folded in half at the (1/4) position on the leading side in the sheet conveying direction, and then the position of the folded leading end of the folded sheet (the conveying direction of the sheet before being folded) It is formed by folding in two on the opposite side at the center position). The sheet PA folded in this way is bound as a series of sequentially stacked documents, or is punched and filed. The single-sleeve folding process is suitable for applications such as filing large and small documents, for example, A3 size documents aligned with A4 size documents.

  Hereinafter, the structures and operations of the sheet folding apparatus 200 and the post-processing apparatus 300 will be described in more detail.

<Sheet folding device>
As shown in FIGS. 1, 3, and 4, the sheet folding apparatus 200 includes a sheet carry-in port 210 that takes in the sheet PA discharged from the main body 100 </ b> A of the image forming apparatus. In addition, the sheet folding apparatus 200 includes two roller pairs, a sheet carry-in roller 211A and a pinch roller 231 that convey the sheet PA sent to the sheet carry-in port 210, and a sheet carry-in roller 211B and a pinch roller 232. . The two pinch rollers 231 and 232 constitute a pinch roller unit 230. The switching member 240 disposed immediately after the pinch roller 231 on the sheet carry-in side selectively selects the receiving conveyance path 250 and the passing conveyance path 253 depending on whether or not the sheet folding apparatus 200 performs the sheet folding process. It is supposed to switch.

  When the sheet folding apparatus 200 does not perform the sheet folding process, the switching member 240 is controlled to a solid line position without switching, and selects the passing conveyance path 253 as the conveyance path. At this time, the sheet PA is guided to a horizontal passing conveyance path 253 formed by the pinch roller unit 230 and the two sheet carry-in rollers 211A and 211B, and is sent to the post-processing apparatus 300. Further, when the sheet PA is jammed in the passing conveyance path 253, the pinch roller unit 230 opens upward with the sheet pin 237 as a center so that the jammed sheet (jam sheet) can be removed.

  On the other hand, when the sheet folding apparatus 200 folds the sheet PA, the CPU 290 (FIG. 5) of the sheet folding apparatus 200 turns on the switching member solenoid SL1 to switch the switching member 240 from the solid line position to the broken line position. . Accordingly, the receiving conveyance path 250 is selected by the switching member 240 as the conveyance path of the sheet PA.

  In the receiving conveyance path 250, there are an inlet sensor S1 that detects the sheet PA that has been carried in, a path sensor S2 that detects sheet detection and sheet jamming, a roller pair of the carry-in roller 212 and the pinch roller 233, and a sheet trailing edge stopper 242. They are arranged in order. When the entrance sensor S1 detects the sheet PA, the folding drive motor M2 for performing the folding process starts driving. The folding drive motor M2 rotationally drives the first roller 214, the second roller 215, and the third roller 216.

  Further, a first roller 214, a second roller 215, and a third roller 216 are disposed downstream of the receiving conveyance path 250. The first roller 214 and the second roller 215 are in pressure contact with each other, and the second roller 215 and the third roller 216 are in pressure contact with each other. A folded one loop forming portion 255 is formed between the receiving conveyance path 250 and the pressure contact roller between the first roller 214 and the second roller 215. A switching member 260 is installed in the fold 1 loop forming portion 255. The switching member 260 also serves as a static elimination brush, and removes static electricity from the sheet PA charged on the apparatus main body 100A side of the image forming apparatus.

  Further, a folding conveyance path 251 is formed on the downstream side of the nip between the first roller 214 and the second roller 215. Further, a folded two-loop forming portion 256 is formed between the folding conveyance path 251 and the pressure contact roller between the second roller 215 and the third roller 216.

  Further, a pre-registration sensor S3, a registration SB roller 213 and a pinch roller 234, a post-registration sensor S4, and a folding 1 sheet rear path 254 are arranged in this order on the downstream side of the folding 1 loop forming portion 255 of the receiving conveyance path 250. Yes. Here, “SB” means “switchback”, and the sheet PA is normally switched back (reversely fed) from the position of these “SB” rollers during registration. The registration SB roller 213 and the pinch roller 234 perform registration (registration) and skew correction of the sheet PA. The folded one-sheet rear path 254 is a portion that stores a leading portion of a long sheet when processing a long sheet in the sheet conveyance direction.

  The folding conveyance path 251 is formed of a pair of plate-like members that are curved in the direction in which the folded sheets PA are overlapped. The first roller 214 and the second roller 215 as folding means for folding the sheet PA are conveyed by sandwiching the sheet PA at the nip, and the sheet is folded for the first time. A folding reference stopper 243 made up of a position-variable lever member is disposed in the vicinity of the most downstream portion of the folding conveyance path 251. The folding reference stopper 243 has a rotation fulcrum on the curvature center side of the folding conveyance path 251 and is rotated by a predetermined angle by a stopper moving motor M4. Therefore, the position of the folding reference stopper 243 in the folding conveyance path 251 can be adjusted by the stopper moving motor M4.

  Further, the folding conveyance path 251 is provided with a sheet pressing guide 244 that swings when the sheet is folded and prevents the ear folding due to floating of the sheet end. Further, a folded sheet detection sensor S5 that detects sheet jamming during sheet folding is provided in the vicinity of the downstream side of the sheet pressing guide 244.

  The second roller 215 and the third roller 216 constitute a folding unit that folds another sheet PA, conveys the sheet PA at the nip, and performs the second sheet folding. The first roller 214, the second roller 215, and the third roller 216 are a pair of rotating bodies that are pressed against each other in this arrangement, and are an example of the configuration of a plurality of folding means.

  The conveyance roller 217 and the discharge pinch roller 235 are configured to crease the sheet PA with the sheet PA sandwiched between the nips. On the discharge conveyance path 252, a plurality of roller pairs including conveyance rollers 218, 219, 220, 221, 222, and 223 and conveyance pinch rollers 236, 236,. With these roller pairs, the sheet PA that has been subjected to the folding process can be conveyed to the post-processing apparatus 300 via the discharge conveyance path 252. .

  A storage gate 241 is provided on the downstream side of the transport roller 218. The storage gate 241 is configured to selectively guide the sheet PA that has been subjected to the inner three-fold process and the outer three-fold process to a folded sheet storage box 280 that is installed below the sheet PA. In addition, the storage gate 241 includes a folded portion discharge sensor S6 (FIG. 3) that detects the sheet PA passing through the storage gate 241. At the upper part of the folded sheet storage box 280, a full detection sensor S7 (FIG. 3) for detecting the fullness of the sheet is provided via a folded sheet press rotating piece 282 that rotates about a shaft 283. Further, the folded sheet storage box 280 can be attached to and detached from the sheet folding apparatus by a guide rail 284 provided on the sheet folding apparatus side. In addition, a trapezoidal protrusion 287 is provided at one end of the rack 286 that rotates the pinion 285 integrated with the folded sheet pressing rotation piece 282. The trapezoidal protrusion 287 is configured to abut the fold sheet storage box 280 of the sheet folding device against the end of the detachable opening when the fold sheet storage box 280 is detached. Thereby, the folded sheet pressing rotation piece 282 can be rotated and retracted in the folded sheet storage box 280. The rack 286 is always urged in the direction of the arrow by a spring 288.

  The sheet PA that has undergone the one-sleeve folding process passes through the storage gate 241 and is conveyed by a plurality of roller pairs including conveyance rollers 219, 220, 221, 222, and 223 and conveyance pinch rollers 236. Further, the sheet PA is conveyed to the post-processing apparatus 300 through a horizontal passing conveyance path 253 (unloading unit 253b).

  Immediately after the merging point toward the passing conveyance path 253, a sheet discharge sensor S8 is provided. This sheet discharge sensor S8 monitors the conveyance of the folded sheet on the carry-out side of the passing conveyance path 253. The CPU 290 of the sheet folding apparatus transmits a sheet detection signal to the post-processing apparatus 300 according to the output state of the sheet discharge sensor S8.

  When the inner three-fold process and the outer three-fold process are performed and the additional folding process is selected, the switching member 249 is moved to the position of the broken line in FIG. 4 by the additional folding path solenoid SL9. As a result, the sheet PA that has been folded in three passes through the storage gate 241 and is conveyed to the additional folding path 259 by the conveying roller 219 and the conveying pinch roller 236. The additional folding path 259 is provided with a conveying roller 229 and a conveying pinch roller 239, and the sheet PA that has been folded in three is conveyed to the post-processing apparatus 300 by these roller pairs.

  FIG. 5 shows the configuration of the control system of the sheet folding apparatus 200. Hereinafter, the control system of the sheet folding apparatus 200 in FIG. 5 will be described with reference to the members in FIGS. 3 and 4. The CPU 290 of the sheet folding apparatus 200 is connected to the CPU 289 of the apparatus main body 100A via a predetermined interface or communication means. Then, the CPU 290 of the sheet folding apparatus 200 controls the sheet folding apparatus 200 based on information signals such as a main body discharge signal ES, a size signal DS, and a folding mode signal FS sent from the CPU 289 of the image forming apparatus 100. . The CPU 290 is connected to a ROM 204 that stores a sequence of each unit, that is, a control procedure, and a RAM 203 that temporarily stores various information as necessary.

  The CPU 290 serving as a control unit that controls the entire sheet folding apparatus 200 is connected with the following sensors in order to control sheet conveyance and folding processing. These sensors are composed of mechanical / electrical sensors combining limit switches and levers, or optical sensors.

  The folding reference home detection sensor HS1 detects the home position of the folding reference stopper 243 by detecting the rotation of the mask plate coaxially fixed to the drive shaft of the stopper moving motor M4 that drives the folding reference stopper 243.

  The entrance sensor S1 detects the sheet PA near the entrance of the receiving conveyance path 250. Further, the path sensor S2 detects the sheet PA passing through the receiving conveyance path 250, and is also used for detecting a jam (jam) of the sheet PA.

  The pre-registration sensor S3 detects the leading edge of the sheet immediately before reaching the registration SB roller 213 and the pinch roller 234. The post-registration sensor S4 detects the leading edge of the sheet that has passed through the registration SB roller 213 and the pinch roller 234.

  The folded sheet detection sensor S5 is disposed in the vicinity of the downstream side of the sheet pressing guide 244, and detects sheet jamming (jam) during sheet folding. The folded portion discharge sensor S6 detects the sheet PA passing through the storage gate 241.

  The full detection sensor S7 detects that the sheet PA in the folded sheet storage box 280 is full via the folded sheet press rotating piece 282.

  The sheet discharge sensor S8 detects that the folded sheet PA is conveyed to the post-processing device 300. The connection detection sensor S295 detects whether or not the apparatus main body 100A of the image forming apparatus is connected to the upstream side of the sheet folding apparatus.

  The CPU 290 is connected to the following motors. The transport motor M1 rotationally drives the rollers 211A, 212, 217 to 223, 211B, etc. of each transport system via a timing belt. The folding drive motor M2 is a motor that rotationally drives the first roller 214, the second roller 215, and the third roller 216, and includes, for example, a brushless motor. The registration motor M3 is a motor that rotationally drives the registration SB roller 213 separately from other rollers for sheet skew correction and folding processing, and is constituted by, for example, a pulse motor. The stopper moving motor M4 is a motor that rotationally drives the folding reference stopper 243, and is constituted by, for example, a pulse motor.

  The CPU 290 is connected to the next solenoid. The switching member solenoid SL1 switches the switching member 240 between a solid line position and a broken line position in FIG. The separation solenoid SL2 is in an ON state, and operates to separate the pinch roller 233 from the carry-in roller 212. The pressure solenoid SL3 operates to press the pinch roller 233 against the carry-in roller 212 in the ON state. The presser solenoid SL4 operates to press the sheet PA via the sheet presser guide 244 in the ON state.

  The ratchet solenoid SL5 is controlled to be ON when the registration motor M3 is stationary in an excited state, thereby operating the clutch portion of the registration motor M3 and connecting the registration SB roller 213 to the registration motor M3. The storage gate solenoid SL6 operates to switch the storage gate 241 to the folded sheet storage box side in the ON state. The first folding flapper solenoid SL8 operates the switching member 260, and the additional folding path solenoid SL9 operates to operate the additional folding path switching member 249 to switch to the additional folding path 259 side.

  Hereinafter, basic operations of the sheet folding apparatus will be described in more detail with reference to FIGS. 1 and 3 to 12.

  The sheet PA discharged from the apparatus main body 100A and designated for the folding process is subjected to any of the above-described folding process of inner three-fold, outer three-fold, or one-sleeve folding according to the folding mode.

  In this embodiment, it is assumed that the power supply is wired so that when the power of the apparatus main body 100A of the image forming apparatus is turned on, the power of the sheet folding apparatus 200 is also turned on. When the power of the sheet folding apparatus 200 is turned on, the CPU 290 compares the state of actuators such as sensors and solenoids with preset initial values and communicates with the CPU 289 side of the apparatus body, and if necessary, the sheet folding apparatus 200 The initial operation of the apparatus 200 is performed. Simultaneously with the initial confirmation, the CPU 290 starts the transport motor M1 and the folding drive motor M2.

  When the sheet PA is conveyed from the apparatus main body 100A to the sheet carry-in entrance 210 of the sheet folding apparatus 200, information of the main body discharge signal ES, the size signal DS, and the folding mode signal FS is transmitted from the CPU 289 of the apparatus main body 100A to the CPU 290 of the sheet folding apparatus. Entered. Based on the input information, the sheet PA is guided to the receiving and conveying path 250 into the sheet folding apparatus by the switching member 240 immediately after the sheet carry-in port 210 of the sheet folding apparatus (FIG. 6A).

  The sheet PA conveyed to the receiving conveyance path 250 is detected by the entrance sensor S1 and the path sensor S2, and further conveyed by the carry-in roller 212 and the pinch roller 233, and the leading end thereof is detected by the pre-registration sensor S3. Thereafter, the sheet PA is abutted against the nip between the pinch roller 234 and the resist SB roller 213 whose rotation is stopped after the pre-registration sensor S3 is turned ON. Further, the sheet PA is conveyed by the carry-in roller 212 and the pinch roller 233 for a predetermined time, and a loop (deflection) is formed in the folding 1 loop forming unit 255 (FIG. 6B). At this time, the rotation of the registration motor M3 is stopped in an excited state, the ratchet solenoid SL5 of the clutch portion is turned on, and the registration SB roller 213 is connected to the registration motor M3.

  After the loop is formed in the sheet PA, when the pressure solenoid SL3 of the pinch roller 233 is turned off and the separation solenoid SL2 of the pinch roller 233 is turned on, the pressure contact of the pinch roller 233 facing the carry-in roller 212 is released. This gives a degree of freedom to the sheet PA. Thus, the sheet PA is skew-corrected with reference to the nip between the registration SB roller 213 and the pinch roller 234, and the registration process is completed. In this way, when the sheet PA is slanted, it is corrected straight (registration process).

  After the registration (registration) process, the sheet PA is subjected to any one of the inner three-fold, outer three-fold, and one-sleeve folding processes described with reference to FIG. 2 based on the folding mode signal FS. Hereinafter, an operation when the sheet folding apparatus 200 performs these folding processes will be described.

<Trifold processing>
With reference to FIGS. 6 and 7, the three-fold process will be described. 6 (A) to 6 (D), 7 (A), and 7 (B) sequentially show the movement of the main part of the sheet PA and the sheet folding apparatus 200 during the folding process in a simplified form of FIG. is there.

  After the above skew correction, the separation solenoid SL2 is turned OFF, the pinch roller 233 is pressed against the carry-in roller 212 again, the registration motor M3 is driven to rotate forward, and the registration SB roller 213 folds the sheet PA to the one-sheet rear path 254. (FIGS. 6A to 6D). The rotation of the registration motor M3 is reliably transmitted to the registration SB roller 213 by turning on the ratchet solenoid SL5 of the clutch portion.

  The registration motor M3 is a pulse motor, and the conveyance amount of the sheet is pulse-count controlled by the CPU 290. The registration motor M3 rotates and stops until the trailing edge of the sheet passes through the trailing edge stopper 242 in the downstream conveyance path of the carry-in roller 212. To do. The pulse amount corresponding to the trailing edge of the sheet passing through the sheet trailing edge stopper 242 is set according to the sheet size and folding mode, and is pulse-counted with the post-registration sensor S4 detecting the leading edge of the sheet. .

  When the trailing edge of the sheet passes the sheet trailing edge stopper 242, the registration motor M3 of the registration SB roller 213 is reversely rotated with the ratchet solenoid SL5 of the registration SB roller 213 kept ON (FIG. 6C). ). As a result, the sheet PA is reversely fed by the reverse rotation of the registration SB roller 213, the rear end (upper end) is received by the sheet rear end stopper 242, and a loop (deflection) is formed in the space of the folding 1 loop forming portion 255. Is done. Then, the sheet PA is nipped between the two folding rollers so as to follow the roller surfaces of the first roller 214 and the second roller 215 (FIG. 6D).

  Subsequently, the sheet PA is nipped and conveyed by the two folding rollers 214 and 215, but the ratchet solenoid SL5 and the registration motor M3 are controlled to be OFF after a predetermined time after the post-registration sensor S4 detects the sheet end again. The As a result, the registration SB roller 213 is rotatable, and is rotated by the movement of the sheet, so that an unnecessary stress (tensile force) is not applied to the sheet PA. For the same purpose, control for separating the pinch roller 234 from the registration SB roller 213 may be performed instead of turning off the drive transmission of the registration SB roller 213.

  As described above, the sheet PA is transferred to the first roller 214 and the second roller 215, is nip-conveyed by these two roller pairs, and is subjected to the first folding process. The sheet PA is fed with the folded portion at the head, detected by the folded sheet detection sensor S5, and received by the folding reference stopper 243 provided on the downstream folding conveyance path 251 and moved to a predetermined position. As a result, a loop (deflection) is formed on the sheet PA by the folded two-loop forming part 256 (FIG. 7A).

  In particular, in the inner three-folding process, when the loop is formed on the sheet PA by the folding two-loop forming unit 256, the sheet end surface subjected to the first folding process comes to the loop side. Is likely to cause an ear fold or the like on the end face of the sheet. For this reason, in the three-fold process, the folded sheet detection sensor S5 detects and after a predetermined time has elapsed, the presser solenoid SL4 is turned on to operate the sheet presser guide 244 to press the sheet end surface subjected to the first folding process. Prevents entrainment due to floating of the end face. After the first folding process, the sheet PA is conveyed while being sandwiched between the folding rollers 215 and 216 so as to follow the roller surfaces of the second roller 215 and the third roller 216. As a result of the folding process, three of the foldings are completed (FIG. 7B).

  In the case of performing additional folding on the sheet PA that has been folded in three, the sheet PA is conveyed from the position of FIG. 7B via the conveying rollers 217, 218, and 219. Then, the switching member 249 is switched to the position indicated by the broken line in FIG.

<Outside tri-fold process>
Next, the outer trifold process will be described with reference to FIGS. FIGS. 8A to 8D, 9A, and 9B sequentially show the movement of the main parts of the sheet PA and the sheet folding apparatus 200 during the folding process in a simplified form of FIG. is there.

  First, the sheet folding apparatus 200 performs skew correction of the sheet PA (FIGS. 8A and 8B) in the same manner as the inner folding process (FIGS. 6A and 6B). Thereafter, the separation solenoid SL2 is controlled to be OFF, the pinch roller 233 is again brought into pressure contact with the carry-in roller 212, and the registration motor M3 of the registration SB roller 213 is driven to rotate forward. As a result, the registration SB roller 213 and the pinch roller 234 convey the sheet PA. At this time, the CPU 290 (FIG. 1) counts the pulse of the registration motor M3 with a counter (not shown) to detect the sheet conveyance amount, and the sheet PA is ((1/3) -α of the sheet conveyance direction length L. ) When the equivalent is sent, the registration motor M3 is stopped.

  Here, the registration motor M3 of the registration SB roller 213 stops rotating while the ratchet solenoid SL5 of the registration SB roller 213 is ON. As a result, the lower end (front end) of the sheet PA remains sandwiched between the registration SB roller 213 and the pinch roller 234. When the pressure solenoid SL3 is turned on, the conveyance force of the carry-in roller 212 and the pinch roller 233 is increased, and the sheet PA is further conveyed by the carry-in roller 212 and the pinch roller 233. Then, a sheet loop (bending) occurs in the space of the folding 1 loop forming portion 255 (FIG. 8C). The conveyance of the sheet by the carry-in roller 212 and the pinch roller 233 is continued, and the loop of the sheet gradually increases, and between the two folding rollers 214 and 215 so as to follow the roller surfaces of the first roller 214 and the second roller 215. And is folded (Fig. 8 (D)). In this way, the sheet PA undergoes the first folding process. At this time, the CPU 290 performs the following control so as not to apply an excessive tensile force to the sheet PA. That is, as in the case of the inner three-fold process, the registration SB roller 213 is made rotatable and the pressure solenoid SL3 is turned OFF, and the pinch roller 233 is separated from the carry-in roller 212.

  After the first folding process, the sheet PA is conveyed to the top of the folded portion, and the top is received by the folding reference stopper 243 set to be moved to a predetermined position, as in the case of the third folding process. As a result, a loop (deflection) is generated in the space of the folded two-loop forming portion 256 in the sheet PA (FIG. 9A). At this time, the end of the sheet subjected to the first folding process is on the opposite side between the sheet loop generated in the folding 2 loop forming unit 256 and the sheet PA. The sheet edge is not caught in the sheet. For this reason, it is not necessary to press the sheet PA using the sheet pressing guide 244 as described above in the outer trifold process.

  The loop of the sheet generated in the folding 2 loop forming unit 256 is sandwiched between the two folding rollers 215 and 216 so as to follow the roller surfaces of the second roller 215 and the third roller 216 as in the first folding process. And folded (FIG. 9B). As described above, the sheet PA is subjected to the second folding process, and the outer three-fold is completed.

  When additional folding is performed on the outer three-folded sheet PA, the sheet PA is further transported from the position of FIG. 9B via transport rollers 217, 218, and 219. Then, the switching member 249 is switched to the position of the broken line in FIG. 4, the sheet PA is increased by the conveying roller 229 and the conveying pinch roller 239, and conveyed to the folding path 259 and sent to the post-processing apparatus 300.

<Single sleeve folding process>
Hereinafter, the single sleeve folding process will be described with reference to FIGS. FIGS. 10A to 10D, FIGS. 11A to 11D, FIGS. 2A and 2B are views of the sheet PA and the sheet folding apparatus 200 being folded in a simplified form of FIG. The movement of the main part is shown sequentially.

  First, the sheet folding apparatus 200 performs skew correction of the sheet PA in the same manner as the above-described inner trifold process and outer trifold process (FIGS. 10A and 10B). Thereafter, the separation solenoid SL2 of the pinch roller 233 is turned off, and the pinch roller 233 is pressed against the carry-in roller 212 again. Further, the pressure solenoid SL3 of the pinch roller 233 is turned on, whereby the pinch roller 233 and the carry-in roller 212 increase the conveying force and convey the sheet PA. After that, when the registration motor M3 stops rotating in an excited state and the ratchet solenoid SL5 is turned on, the registration SB roller 213 can be rotated by the registration motor M3. The sheet PA conveyed on the receiving conveyance path 250 by the carry-in roller 212 and the pinch roller 233 comes into contact with the resist SB roller 213 and the pinch roller 234 in a stationary state, and a loop (deflection) is formed in the folding 1 loop forming unit 255. (FIGS. 10B and 10C).

  Thereafter, the sheet PA starts to be conveyed with the loop portion being sandwiched between the first roller 214 and the second roller 215. At this time, the sheet PA is controlled so as not to be stressed more than necessary (tensile force). Therefore, when the sheet PA is delivered to the first roller 214 and the second roller 215 (when a predetermined time has elapsed after the pinch roller 233 is re-pressed against the carry-in roller 212), the ratchet solenoid SL5 and the registration motor M3 are moved. Set to OFF. As a result, the registration SB roller 213 becomes rotatable and rotates following the movement of the sheet PA, so that an unnecessary stress (tensile force) is not applied to the sheet PA. Further, since the pressure solenoid SL3 is turned off and the pressure contact between the carry-in roller 212 and the pinch roller 233 is released, no stress is applied to the sheet PA.

  When the conveyance is further continued, the sheet PA is conveyed while being sandwiched between two folding rollers so as to follow the roller surfaces of the first roller 214 and the second roller 215, and undergoes a first folding process. At this time, the conveyance path length between the nip between the registration SB roller 213 and the pinch roller 234 and the nip between the first roller 214 and the second roller 215 is substantially ¼ of the length L in the conveyance direction L of the sheet PA. It corresponds. Thus, the first folding process is performed at a portion corresponding to approximately ¼ of the conveyance direction length L of the sheet PA (FIG. 10D).

  At this time, the folding reference stopper 243 on the downstream folding conveyance path 251 has moved to a position corresponding to the one-sleeve folding process, and receives the folded portion of the conveyed sheet PA (FIG. 11A). The sheet PA is received by the folding reference stopper 243 at the first folding portion, nipped between the two folding rollers 214 and 215, and further conveyed, so that a loop is formed in the folding 2 loop forming portion 256. . Then, the sheet PA is subjected to a second folding process by the second roller 215 and the third roller 216. As described above, the single sleeve folding process is performed on the sheet PA (FIGS. 11B and 11C).

  The sheet PA for which the one-sleeve folding process has been completed is transferred from the conveyance roller 217 to the conveyance roller 218 on the discharge conveyance path 252 (FIG. 11D). As described above, the storage gate 241 is provided immediately after the conveyance roller 218, and the additional folding path switching member 249 is provided after the conveyance roller 219, so that the sheet path after the folding process can be selectively switched. .

  When the one-sleeve folding process is selected (FIG. 11D), for example, the binding process can be performed by the upper stapler 304 of the post-processing apparatus 300. For this reason, in the present embodiment, the sheet PA that has been subjected to the one-sleeve folding process is not in the direction of the additional folding path 259 in the storage gate 241 and the additional folding path switching member 249, but in the direction of the discharge conveyance path 252 (FIG. 12A). Control is performed to convey the sheet PA. That is, when the one-sleeve folding process is selected, the sheet PA is conveyed as it is from the discharge conveyance path 252 (FIG. 12A) to the passing conveyance path 253 (FIG. 12B). When the sheet discharge sensor S8 detects the sheet PA, a sheet detection signal is transmitted from the CPU 290 of the sheet folding apparatus to the post-processing apparatus 300. When the additional folding process is not performed, the folding process of the sheet folding apparatus 200 is completed as described above.

  For a sheet PA that has undergone the inner three-fold process or the outer three-fold process and the additional folding process is not selected, the storage gate solenoid SL6 is turned ON, and the storage gate 241 is moved to the folded sheet storage box 280 side. Switch. Thus, the sheet PA that has undergone the inner three-fold process or the outer three-fold process is stored in the folded sheet storage box 280, and the folding process is completed. Note that the CPU 290 can confirm sheet discharge in the direction of the folded sheet storage box 280 via the folded portion discharge sensor S6.

  On the other hand, when the inner three-fold process and the outer three-fold process are performed and the additional folding process is selected, the sheet PA is transferred from the transport roller 217 to the transport roller 218 on the discharge transport path 252. A storage gate 241 is provided immediately after the conveyance roller 218, and an additional folding path switching member 249 is provided after the conveyance roller 219. The path of the sheet PA after the folding process is selectively switched. When the additional folding process is selected, the storage gate 241 is not switched, and the additional folding path solenoid SL9 is driven and the additional folding path switching member 249 is switched to the additional folding path 259, whereby the sheet PA is further folded. It is conveyed to pass 259. Thereafter, the sheet PA is fed to the trifold sheet carry-in port 331 (FIG. 13) of the post-processing apparatus 300 by the conveyance roller 229 and the conveyance pinch roller 239. Then, the sheet PA is carried from the right side of FIG. 13 into the conveyance area of the additional folding roller 320 and the additional folding roller 321 constituting the additional folding device.

  Note that the sheet PA to be subjected to the middle (two) folding or saddle stitching process passes through the passing conveyance path 253 of the sheet folding apparatus 200 as described above, and is carried into the sheet carry-in port 307 of the post-processing apparatus 300. To do. Then, the first folding roller 313 and the second folding roller 314 at the bottom of the post-processing apparatus 300 can be subjected to center folding, or further, the stapler 370 can perform saddle stitching processing. The sheet PA that has been subjected to half-folding or further saddle-stitching can be further folded by performing pressure strengthening with the additional folding roller 320 and the additional folding roller 321 (FIG. 13) constituting the additional folding device. In that case, the sheet PA that has been folded or saddle-stitched is carried from the left side of FIG. 13 into the conveyance area of the additional folding roller 320 and the additional folding roller 321.

<Structure of post-processing device>
Hereinafter, the configuration and operation of the post-processing apparatus 300 will be described in detail with reference to FIGS. In this embodiment, the additional folding device including the additional folding roller 320 and the additional folding roller 321 is disposed on the post-processing device 300 side. A sheet PA to be pressure-enhanced can be carried in from the sheet folding apparatus 200 via the three-fold sheet carry-in port 331 (FIG. 13) to the additional folding apparatus of the present embodiment. Further, the additional folding device of the present embodiment carries in and pressurizes the sheet PA that has been post-processed (for example, half-folded or further saddle-stitched) by the post-processing device 300 from the side opposite to the three-fold sheet carrying-in port 331. be able to.

  As shown in FIG. 13 (or FIG. 1), the post-processing apparatus 300 of the present embodiment has a sheet carry-in port 307 for carrying in the sheet PA discharged from the sheet folding apparatus 200. The sheet carry-in port 307 is provided so as to face the passing conveyance path 253 of the sheet folding apparatus 200. The sheet PA sent to the post-processing apparatus 300 from the sheet carry-in port 307 is carried by the sheet carry-in roller 315 and the pinch roller 316.

  Further, the post-processing device 300 includes a three-fold sheet carry-in port 331 in addition to the sheet carry-in port 307. The three-fold sheet carry-in port 331 is provided to face the additional folding path 259 of the sheet folding apparatus 200. The sheet PA sent to the trifold sheet carry-in port 331 is conveyed by a sheet carry-in roller 324 and a pinch roller 325, and the sheet PA conveyed by this roller pair is conveyed to an additional folding path 332.

  The post-processing device 300 can also perform a folding process on the sheet PA loaded from the sheet carry-in port 307 as well as the sheet carried from the tri-fold sheet carry-in port 331 facing the additional folding path 259 of the sheet folding device 200. It is configured to be able to.

  A switching member 342 disposed immediately after the sheet carry-in roller 315 and the pinch roller 316 provided at the sheet carry-in entrance 307 switches the conveyance path depending on whether or not the post-processing device 300 performs the sheet folding process.

  When the post-processing apparatus 300 does not perform the half-folding process of the sheet PA, the switching member 342 is not driven and is controlled to select the passing conveyance path 302 as the sheet conveyance path. As a result, the sheet PA carried in from the sheet carry-in entrance 307 is conveyed to the passing conveyance paths 302 and 303, and then conveyed to the stacking tray 301 through the position of the stapler 304.

  The operation of the stapler 304 is controlled according to the setting contents, and the binding process of the stapler 304 is performed only when the binding process is designated. For example, the binding process can be performed by driving the stapler 304 by transporting it to the passing transport paths 302 and 303 with respect to the sheet PA folded in a single sleeve, which is transported from the sheet transport inlet 307 as described above. .

  On the other hand, when the post-processing device 300 performs a half-folding process on the sheet PA carried in from the sheet carry-in entrance 307, the post-processing device 300 turns on the switching member solenoid SL37 and sets the guide direction of the switching member 342 in the middle. Switch to the folding path 306 side. As a result, the sheet PA carried in from the sheet carry-in entrance 307 is guided to the middle folding path 306 side. In the middle folding path 306, a conveyance roller 317 and a pinch roller 318 for conveying the conveyed sheet PA are disposed.

  The sheet PA that has passed through the half-fold path is conveyed to a sheet size sorting path 308 by a conveyance roller 317. The sheet size sorting path 308 is provided with a carry-in roller 310 and a pinch roller 311, and a medium size switching member 340 and a small size switching member 341 for switching the path for each sheet size. The medium size switching member 340 and the small size switching member 341 are driven by switching member drive solenoids SL35 and SL36, respectively.

  The sheet PA conveyed to the sheet size sorting path 308 is conveyed by the carry-in roller 310. Here, the medium size switching member 340 or the small size switching member 341 is driven by turning on the switching member driving solenoid SL35 or the switching member driving solenoid SL36 according to the sheet size. As a result, the sheet PA can be guided to the conveyance path according to the sheet size. Thereafter, the sheet PA is conveyed to the middle folding processing path 309 below the sheet size sorting path 308.

  As shown in FIG. 14, the sheet PA conveyed to the half-folding processing path 309 is conveyed to the position of the sheet positioning plate 360 by the conveying roller 312 and temporarily stored at this position. At this time, the sheet PA stored in the sheet positioning plate 360 is aligned by the alignment plate 348 and the alignment plate 349 as shown in FIG. FIG. 15 shows the sheet PA, the alignment plate 348, and the alignment plate 349 accommodated in the sheet positioning plate 360 from the left side of FIGS. The alignment plate 348 and the alignment plate 349 operate so that the edges of the plurality of sheets PA are all aligned by, for example, movement in the direction of the arrow in FIG. For this operation, the alignment plate 348 and the alignment plate 349 are configured to be movable along the width of the sheet PA by a solenoid (not shown) or the like.

  The operation of stocking the sheet PA on the sheet positioning plate 360 is repeated for the number of sheets to be folded or saddle stitched. At that time, the alignment process (FIG. 15) by the alignment plate 348 and the alignment plate 349 is performed each time one sheet PA is stocked, for example.

  When the saddle stitching process is performed on the sheet PA, the sheet positioning plate 360 causes the sheet PA to stand by at a position where the center of the sheet PA is aligned with the position n where the stapler 370 strikes the needle. After the stock for the number of processed sheets PA is completed, as shown in FIG. 16, the stapler 370 performs saddle stitching on the sheet PA. The stapler 370 swings as indicated by an arrow N in FIG. 16, and strikes a needle (not shown) at a position n at the center of the sheet PA. After the saddle stitching process by the stapler 370, the sheet positioning plate 360 moves so that the center position of the sheet matches the folding position.

  When the saddle stitching process is not performed on the sheet PA, the sheet PA stands by at a place where the center position of the sheet matches the folding position, and the number of sheets to be processed is stored.

  After the saddle stitching process is completed, the center position of the sheet moves to the folding position, or after the number of sheets to be processed is stored at the center position of the sheet without performing saddle stitching, the first folding roller 313 and the second folding roller 314 are moved. The covered guide plate 362 is lowered (FIG. 17). After the guide plate 362 is lowered, the center of the sheet bundle is pushed by the sheet pushing plate 361 and the center portion of the sheet bundle is conveyed between the first folding roller 313 and the second folding roller 314. After the conveyance, the sheet bundle is sandwiched by two folding rollers 313 and 314 to be folded in half (two folds) (FIG. 18). The sheet PA that has undergone the middle folding process is conveyed to the additional folding path 332 by the first folding roller 313 and the second folding roller 314.

  In the post-processing apparatus 300 of this embodiment, the additional folding path 332 is configured to carry in the sheet folds from both the left and right directions in FIG. The sheet PA that has been folded in three by the sheet folding device 200 and then carried in from the three-fold sheet carry-in port 331 can be sent to the additional folding path 332 by the sheet carry-in roller 324 and the pinch roller 325. On the other hand, in the post-processing device 300, the folding roller 313 and 314 can apply the middle folding process to the sheet PA as described above, and the sheet PA can be further conveyed by continuing the folding with the folding rollers 313 and 314. It can be sent to the additional folding path 332.

  An additional folding roller 320 and an additional folding roller 321 are disposed in the additional folding path 332. The rotating shafts of the additional folding roller 320 and the additional folding roller 321 facing each other are arranged substantially parallel to the conveying direction of the additional folding path 332 (the left-right direction in FIG. 13). Further, whether the additional folding rollers 320 and 321 are pressed against each other or retracted upward and downward in the drawing can be controlled by the additional folding roller opening / closing solenoid SL31 and the additional folding roller opening / closing solenoid SL32.

  Further, an additional folding positioning roller 322 and a pinch roller 323 are arranged at the center of the additional folding path 332 as indicated by a broken line in FIG. The additional folding positioning roller 322 and the pinch roller 323 can be retracted upward or downward by the positioning roller opening / closing solenoid SL33 and the positioning roller opening / closing solenoid SL34, respectively.

  FIG. 19 is a perspective view showing the positional relationship between the rollers around the additional folding path 332. The folding rollers 313 and 314, the sheet carry-in roller 324, and the pinch roller 325 have substantially the same overall length as the width of the additional folding path 332, and can convey the sheet PA from the left and right in the drawing as indicated by arrows.

  In the present embodiment, the total lengths of the additional folding positioning roller 322 and the pinch roller 323 that can be retracted up and down are configured to be smaller than the width of the additional folding path 332 as illustrated. Further, the total length of the additional folding rollers 320 and 321 that can be retracted in the vertical direction is the length that extends over the entire length of the additional folding path 332 (the horizontal direction in the drawing) in this embodiment. However, the total lengths of the additional folding rollers 320 and 321 and the additional folding positioning roller 322 and the pinch roller 323 are design matters that can be arbitrarily selected depending on the control mode when performing additional folding.

  In the configuration of FIG. 19, the sheet PA that has been folded in three by the sheet folding apparatus 200 and then carried in from the three-fold sheet carry-in port 331 is conveyed to the additional folding path 332 by the sheet carry-in roller 324 and the pinch roller 325. The sheet PA that has been subjected to the middle folding process and then conveyed to the additional folding path 332 is conveyed to the additional folding position by the additional folding positioning roller 322 and the pinch roller 323 (FIG. 19). After the sheet is conveyed, the additional folding roller opening / closing solenoid SL31 and the additional folding roller opening / closing solenoid SL32 are turned ON to close the additional folding roller 320 and the additional folding roller 321 (pressure contact), and the sheet PA is nipped by closing the rollers. The After the sheet nip, the positioning roller opening / closing solenoid SL33 and the positioning roller opening / closing solenoid SL34 are turned ON, and the additional folding positioning roller 322 and the pinch roller 323 are opened to release the holding of the sheet.

  The sheet PA nipped only by the additional folding roller 320 and the additional folding roller 321 is conveyed while being sandwiched between the additional folding roller 320 and the additional folding roller 321, thereby performing an additional folding process and strengthening the fold. I can do it. After the conveyance, the sheet PA is conveyed to the storage box 390.

  As described above, according to the present embodiment, the additional folding roller pair (320, 320) of the additional folding device from the different opposing directions by the first roller pair (324, 325) or the second roller pair (313, 314). 321) can carry in the sheet PA to be reinforced. For this reason, for example, a mechanism for performing a plurality of different sheet folding processes can be arranged on both sides of the additional folding apparatus without lengthening and complicating the conveyance path, and a fold formed by a plurality of different mechanisms can be easily pressed and strengthened. An inexpensive additional folding means can be provided.

SL1 ... switching member solenoid, 100 ... image forming apparatus, 100A ... image forming apparatus body, 140 ... photosensitive drum (image forming unit), 200 ... sheet folding apparatus, 214 ... first roller, 215 ... second roller, 216 ... first 3 rollers, 240... Switching member, 250 .. acceptance conveyance path, 252... Discharge conveyance path, 253... Passing conveyance path, 289. 320, 321, ... additional folding roller, 322 ... additional folding positioning roller, 323, 325 ... pinch roller, 324 ... sheet carry-in roller

Claims (6)

An additional folding device having a pair of additional folding rollers, the rotation axis of which is arranged in a direction intersecting with the fold of the sheet on which the fold is formed, and which pressurizes and strengthens the fold of the sheet;
A first roller pair for carrying the sheet into a conveyance region of the additional folding roller pair such that the fold line intersects with the additional folding roller pair;
A second roller pair for carrying the sheet into a conveyance region of the additional folding roller pair from a direction facing the first roller pair;
A sheet processing apparatus comprising:   A sheet folding device that forms a fold that is pressure-enhanced by the additional folding device, and the sheet folding device forms a fold toward the first roller pair of the additional folding device in the middle of the sheet conveying path; The sheet processing apparatus according to claim 1, further comprising a sheet carry-out path for conveying the processed sheet.   The sheet processing apparatus according to claim 2, wherein the sheet folding apparatus forms a crease with respect to the carried-in sheet by performing an inner fold or an outer fold.   The sheet processing apparatus according to claim 2, wherein the sheet folding apparatus includes a sheet storage unit that stores a sheet on which a crease is formed without sending the sheet to the additional folding apparatus.   A post-processing device is provided for applying a predetermined post-processing to the carried-in sheet, and the post-processed sheet is carried from the post-processing device to the additional folding device by the second roller pair. The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is a sheet processing apparatus.   The sheet processing apparatus according to claim 5, wherein the post-processing applied to the loaded sheet by the post-processing apparatus is a half-folding process or a saddle stitching process.

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