JP7354527B2 - Sheet processing equipment and image forming system - Google Patents

Description

The present invention relates to a sheet processing apparatus and an image forming system.

Conventionally, a stacking processing means has a skew correction means and a retraction section from which sheets are evacuated, and performs skew correction on the sheet evacuated to the retraction section and a sheet brought in by the skew correction means, and also superposes the sheet. 2. Description of the Related Art A sheet processing apparatus is known which includes a sheet processing means that performs a predetermined process on a set number of sheets stacked together by a stacking processing means.

Patent Document 1 discloses a sheet processing device that, after retracting the first sheet to a circulation conveyance path serving as a retraction section, performs the following conveyance control to form a set number of sheet bundles. Are listed. That is, it is determined whether or not the sheet newly brought into the sheet processing apparatus is the last sheet of the set number of sheets. If this sheet is not the last sheet of the set number of sheets, the sheet or sheet bundle that has been evacuated to the circulation conveyance path and the sheet that has been brought in are brought into contact with a pair of conveyance rollers serving as skew correction means to perform skew correction and overlapping. After performing this, it is evacuated to the circulation conveyance path. On the other hand, in the case of the last sheet, after similar skew correction and accurate overlapping are performed, the set number of overlapping sheet bundles are conveyed to a folding processing section serving as sheet processing means.

However, in the sheet processing apparatus described in Patent Document 1, it is necessary to determine the set number of sheets in advance before starting conveyance of sheets to the sheet processing apparatus, which may reduce productivity.

In order to solve the above-mentioned problems, the present invention has a retraction section into which a sheet skew-corrected by a skew correction means is retracted, and the sheet retracted into the retraction section and the sheet carried in are subjected to the skew correction. In the sheet processing apparatus, the sheet processing device includes a stacking unit that performs stacking by means of a stacking unit, and a sheet processing unit that performs a predetermined process on a set number of sheets stacked by the stacking unit, the stacking unit comprising: A first mode in which the stacked sheet stack is evacuated to the evacuation section regardless of whether the number of sheets stacked by the skew correction means is the set number or not; It is determined whether or not the number of sheets in the sheet bundle is the set number, and if the set number has not been reached , the sheet bundle is evacuated to the evacuation section, and if the set number has been reached , the sheet processing means a second mode in which the sheet bundle is conveyed to a second mode, and when the set number of sheets is determined at the time when the sheets are superimposed by the skew correction means, the second mode is executed;
When the set number of sheets is not determined, the first mode is executed.

According to the present invention, the productivity of sheet processing can be improved.

FIG. 1 is a diagram showing a system configuration of an image forming system including an image forming apparatus and a plurality of sheet processing apparatuses according to the present embodiment. 1 is a schematic configuration diagram of an image forming apparatus included in an image forming system according to an embodiment. FIG. 1 is a schematic configuration diagram of a post-processing device included in an image forming system according to an embodiment. 1 is a schematic configuration diagram of a folding processing device included in an image forming system according to an embodiment. FIG. 2 is a block diagram showing an example of a control circuit for controlling the folding device of the present image forming system. (a) to (f) are diagrams illustrating the sheet overlapping operation by the overlapping section of the book folding processing device. (a) to (d) are explanatory diagrams for explaining general operations when performing Z-folding processing by a folding processing section. FIG. 3 is a diagram showing an example of a setting screen displayed on the operation unit of the image forming apparatus. An example of the control flow of the folding process according to the present embodiment. An example of the control flow of the overlapping folding process of Modification 1. An example of the control flow of the second transport mode. An example of the control flow of the overlapping folding process of Modification 2. FIG. 7 is a schematic configuration diagram showing a modified folding processing device. FIG. 7 is a diagram illustrating the operation of the folding apparatus according to the modified example until the preceding sheet is skew-corrected by a pair of registration rollers. FIG. 7 is a diagram illustrating the operation of the folding apparatus of the modified example from when the preceding sheet is skew-corrected until the preceding sheet is conveyed to the switchback conveyance path. FIG. 7 is a diagram illustrating the operation of the folding apparatus of the modified example from when the preceding sheet is conveyed to the switchback conveyance path until the subsequent sheet is superimposed on the preceding sheet. (a) to (h) are diagrams illustrating general operations when Z-folding is performed by the folding device of the modified example. FIG. 7 is a schematic configuration diagram showing another example of a modified folding processing device. FIG. 19 is a diagram illustrating a problem that occurs when stacking is performed in the second conveyance mode in the folding apparatus shown in FIG. 18; FIG. 7 is a control flow diagram for determining the conveyance mode of a sheet bundle for stacking processing based on the length of the sheet in the conveyance direction.

FIG. 1 is a diagram showing the system configuration of an image forming system 4 including an image forming apparatus and a plurality of sheet processing apparatuses in this embodiment. In this embodiment, a folding device 1, which is a sheet processing device, and a post-processing device 2 are provided in this order after the image forming device 3.

The image forming apparatus 3 forms an image on a sheet based on input image data or image data of a read image. For example, this includes a copying machine, a printer, a facsimile machine, or a digital multifunction peripheral having at least two of these functions. The image forming apparatus 3 is of a known type such as an electrophotographic type or a droplet ejection type, and any image forming type may be used. Note that in this embodiment, an electrophotographic copying machine is used.

Examples of the post-processing device 2 include a punching device that punches holes in sheets, a sheet binding device that binds a bundle of sheets using a stapler, etc., and a sorting and discharging device that sorts and discharges sheets on which images have been formed to a plurality of discharge trays. Can be mentioned.

FIG. 2 is a schematic configuration diagram of the image forming apparatus 3 included in the image forming system according to the embodiment.
In the image forming apparatus main body 400, a feeding cassette that stores sheets, which are recording media, is arranged below the image forming section. The sheets stored in the feeding cassettes are fed by feeding rollers 414a and 414b, respectively, and then conveyed upward along a predetermined conveying path to reach a pair of registration rollers 413.

The image forming section includes a photosensitive drum 401 as an image carrier, a charging device 402, an exposure device 410, a developing device 404, a transfer device 405, and a cleaning device 406.

The charging device 402 is a charging unit that uniformly charges the surface of the photoreceptor drum 401. The exposure device 410 is a latent image forming unit that forms an electrostatic latent image on the photoreceptor drum 401 based on image information read by the image reading device 100. The developing device 404 is a developing unit that attaches toner to the electrostatic latent image on the photoreceptor drum 401 to make it visible. The transfer device 405 is a transfer unit that transfers the toner image on the photoreceptor drum 401 onto a sheet. The cleaning device 406 is a cleaning unit that removes toner remaining on the photosensitive drum 401 after transfer.

Further, a fixing device 407 serving as a fixing means for fixing the toner image onto the sheet is arranged downstream of the image forming section in the sheet conveyance direction.

The exposure device 410 includes a laser unit 411 that emits laser light based on image information under the control of a control unit, and scans the laser light from the laser unit 411 in the direction of the rotation axis (main scanning direction) of the photoreceptor drum 401. A polygon mirror 412 is provided.

Furthermore, an automatic document feeder (ADF) 500 is connected to the top of the image reading device 100. The automatic document feeder 500 includes a document table 501, a document separation and feeding roller 502, a conveyor belt 503, and a document discharge tray 504.

When a document is set on the document table 501 and an instruction to start reading is received, the automatic document feeder 500 feeds out the documents on the document table 501 one by one by the document separation and feeding roller 502 . Then, the document is guided onto the platen glass 309 by the conveyor belt 503 and is temporarily stopped.

The image information of the document temporarily stopped on the platen glass 309 is read by the image reading device 100. Thereafter, the conveyance belt 503 resumes conveying the document, and the document is discharged onto the document discharge tray 504.

Next, an image reading operation and an image forming operation will be explained.
When a document is conveyed onto the platen glass 309 by the automatic document feeder 500 or when the user places the document on the platen glass 309 and performs a copy start operation on the operation panel, the document on the first traveling body 303 is Light source 301 lights up. At the same time, the first traveling body 303 and the second traveling body 306 are moved along the guide rail.

The original on the platen glass 309 is irradiated with light from the light source 301, and the reflected light is guided to the mirror 302 on the first traveling body 303, the mirrors 304 and 305 on the second traveling body 306, and the lens 307. The light is then received by the CCD 308. Thereby, the CCD 308 reads the image information of the document, and the image information is converted from analog data to digital data by the A/D conversion circuit. This image information is sent from the information output section to the control section of the image forming apparatus main body 400.

On the other hand, the image forming apparatus main body 400 starts driving the photoreceptor drum 401, and when the photoreceptor drum 401 rotates at a predetermined speed, the charging device 402 uniformly charges the surface of the photoreceptor drum 401. Then, an electrostatic latent image is formed on the surface of the charged photoreceptor drum 401 by an exposure device 410 based on image information read by an image reading device.

Thereafter, the electrostatic latent image on the surface of the photoreceptor drum 401 is developed by a developing device 404 to become a toner image. Further, the sheets stored in the feeding cassette are fed by feeding rollers 414a and 414b, and are temporarily stopped by a pair of registration rollers 413.

Then, at the timing when the leading edge of the toner image formed on the surface of the photosensitive drum 401 reaches the transfer section facing the transfer device 405, it is sent to the transfer section by a pair of registration rollers 413. When the sheet passes through the transfer section, the toner image formed on the surface of the photoreceptor drum 401 is transferred onto the sheet by the action of the transfer electric field.

Thereafter, the sheet carrying the toner image is conveyed to the fixing device 407, undergoes a fixing process by the fixing device 407, and is then discharged to the subsequent folding device 1. Note that transfer residual toner remaining on the surface of the photoreceptor drum 401 without being transferred onto the sheet in the transfer section is removed by a cleaning device 406.

FIG. 3 is a schematic configuration diagram of the post-processing device 2 included in the image forming system according to the embodiment.
The post-processing device 2 has an introduction path 201 through which sheets are introduced from the folding device 1 . From the introduction path 201, a first ejection path 202 for ejecting the sheet to the upper tray 205, a second ejection path 203 for ejecting the sheet to the shift tray 206, and a conveyance path 204 for conveying the sheet to the binding processing section 230. It is branched into. A perforation section 210 for punching holes in the sheet is arranged in the introduction path 201. The punching unit 210 punches holes at predetermined positions in folded sheets, folded sheet bundles, and single sheets conveyed without being folded, which are discharged from the folding device 1. .

An overlapping section 220 is arranged on the conveyance path 204 . The stacking section 220 has three conveyance paths 220a, 220b, and 220c, and by sorting the conveyed sheets to each conveyance path and temporarily waiting in each conveyance path, up to three sheets can be stacked. It is now possible to transport the two on top of each other.

The binding processing unit 230 includes a processing tray 233, a jogger fence 234 that performs alignment processing on a plurality of sheets (sheet bundles) on the processing tray 233, a stapler unit 231 that performs binding processing on the sheet bundles on the processing tray 233, and It mainly includes a conveyor belt 232 that conveys the bound sheet bundle toward the shift tray 206.

When a predetermined number of folded sheets and unfolded sheets are conveyed to the processing tray 233, alignment processing is performed on the sheet bundle on the processing tray 233. After the stapler unit 231 performs a binding process on the sheet bundle on the processing tray 233 , the stapled sheet bundle is conveyed by the conveyor belt 332 and discharged onto the shift tray 206 .

FIG. 4 is a schematic configuration diagram of the folding processing device 1 provided in the image forming system according to the embodiment.
As shown in FIG. 4, the folding apparatus 1 is provided with a pair of entrance rollers 10 that convey sheets received from the image forming apparatus 3. Downstream of this pair of entrance rollers 10, the sheet conveyance path branches into a folding conveyance path W2 that conveys the sheet when performing folding processing, and a through conveyance path W1 that conveys the sheet when not performing folding processing. are doing. A first branch claw 11 that guides the sheet to the through conveyance path W1 or the folding conveyance path W2 is provided at a branching portion between the folding conveyance path W2 and the through conveyance path W1.

The folding conveyance path W2 includes a stacking unit A which is a stacking unit that stacks a plurality of sheets, and a sheet processing unit which folds one sheet or a bundle of sheets stacked in the stacking unit A. It mainly includes a folding processing section B, which is a processing means, and an additional folding section C, which additionally folds the folded portion of a folded sheet.

The overlapping processing unit A registers the sheets using a first conveying roller pair 117a, which is composed of a registration roller pair 15 serving as a skew correction means, a first pressing roller 17a of a folding mechanism 17, and a first folding roller 17b, which will be described later. A pair of conveying rollers 12 that convey the image toward a pair of rollers 15 are provided. In addition, the sheet is branched from the folding conveyance path W2 between the conveyance roller pair 12 and the registration roller pair 15, and the sheet that has been reversely conveyed (conveyed in the opposite direction to the predetermined direction) by the registration roller pair 15 is conveyed. A switchback conveyance path W3 as a section and a switchback conveyance roller pair 13 disposed on the switchback conveyance path W3 are provided. In addition, a sheet is provided at a branching point between the folding conveyance path W2 and the switchback conveyance path W3 between the conveyance roller pair 12 and the registration roller pair 15, and is used for sheets that have been reverse conveyed (conveyed in the opposite direction to the predetermined direction). It also has a second branch claw 14 for guiding the material to the switchback conveyance path W3.

A folding section B is arranged downstream of the overlapping section A. The folding processing section B includes the registration roller pair 15, a folding mechanism 17, and a second conveyance roller pair 18. The folding mechanism 17 includes a first folding roller 17b, a first pressing roller 17a that contacts the first folding roller 17b and transports the sheet switchback, and a first folding roller 17a that contacts the first folding roller 17b and forms a first folding nip B1. The second folding roller 17c forms a second folding nip B2, and the second pressing roller 17d contacts the second folding roller 17c to form a second folding nip B2. A driving force is transmitted to one of the plurality of rollers constituting the folding mechanism 17, and the other rollers are driven to rotate.

In this manner, in this embodiment, the pair of registration rollers 15 and the pair of first conveyance rollers 117a serve as the overlapping processing section A and the folding processing section B. Thereby, the number of parts can be reduced, and the cost of the device can be reduced.

Further, downstream of the pair of registration rollers 15, a third branch claw 16 is provided that guides the sheet to the nip between the first folding roller 17b and the first pressing roller 17a or the first folding nip B1.

An additional folding section C is arranged downstream of the folding section B. The additional folding section C includes an additional folding roller 20. The additional folding roller 20 has a pressing convex portion, and this pressing convex portion presses the folded portion of the sheet, so that the folded portion of the sheet is additionally folded.

FIG. 5 is a block diagram showing an example of a control circuit for controlling the folding processing device of the present image forming system.
A control unit 40 that controls the folding device 1 includes a CPU (Central Processing Unit) 41, a ROM (Read Only Memory) 42, a RAM (Random Access Memory) 43, a sheet detection sensor disposed within the folding device 1, and the like. A sensor controller 44 that controls various sensors, a first motor controller 45 that controls a plurality of transport motors that transport sheets of the folding device 1, and a second motor controller 46 that controls the additional folding motor 49 that drives the additional folding roller 20. , a communication interface 48, and the like.

These components are electrically connected to each other via bus lines 47 such as an address bus and a data bus. The communication interface 48 communicates with the image forming apparatus 3 and the post-processing apparatus 2 shown in FIG. 1, and exchanges data necessary for control. The ROM 42 stores data, programs, etc. executed by the CPU 41. The CPU 41 controls the folding device 1 by executing a computer-readable program stored in the ROM 42. The RAM 43 temporarily stores data and the like when the CPU 41 executes a program.

FIGS. 6(a) to 6(f) are diagrams illustrating an example of the sheet stacking operation by the stacking unit A of the book folding device 1.
As shown in FIG. 6(a), the first sheet P1 is conveyed to the folding conveyance path W2. The leading edge of the first sheet P1 conveyed to the folding conveyance path W2 hits the pair of registration rollers 15, and the skew is corrected. Note that this skew correction may not be performed.

Next, the first sheet P1 is transported normally (in a predetermined direction) by the registration roller pair 15 and the first transport roller pair 117a, which is a first transport member and includes a first pressing roller 17a and a first folding roller 17b. transportation). Next, when the rear end of the first sheet P1 passes through the branch between the folding conveyance path W2 and the switchback conveyance path W3, conveyance of the sheet is stopped. Next, the second branching pawl 14 is rotated clockwise in the figure to switch the posture to guide the sheet to the switchback conveyance path W3. Next, as shown in FIG. 6(b), the pair of registration rollers 15, the pair of first conveying rollers 117a, and the pair of switchback conveying rollers 13 are rotated in the opposite direction. As a result, the first sheet P1 is conveyed in a reverse direction (conveyed in a direction opposite to the predetermined direction), and the first sheet P1 is conveyed to the switchback conveyance path W3. When the leading edge of the first sheet P1 during normal conveyance (conveyance in a predetermined direction) is conveyed to the switchback conveyance path W3, sheet conveyance by the switchback conveyance roller pair 13 is stopped. After stopping, as shown in FIG. 6(c), the first sheet P1 is forwardly conveyed (conveyed in a predetermined direction) by the pair of switchback conveyance rollers 13, and the leading edge of the first sheet is transferred to the pair of registration rollers 15. It is placed on standby with the skew corrected.

In this way, by conveying the preceding sheet P1 to the switchback conveyance path W3 and retracting it from the folding conveyance path W2, the preceding sheet P1 does not interfere with the conveyance of the succeeding sheet, and the succeeding sheet P2 can be smoothly transported. can be transported.

Next, the sheets are stacked by abutting the leading edge of the second sheet P2 against the pair of registration rollers 15 and aligning the leading edges of the first sheet P1 and the second sheet P2. As shown in FIG. 6(d), even after the leading edge of the succeeding sheet P2 hits the registration roller pair 15, the conveying roller pair 12 continues to convey the succeeding sheet P2, bending the succeeding sheet, and correcting the skew. conduct. After a predetermined amount of time has elapsed for the subsequent sheet to bend to a predetermined amount, as shown in FIG. The first sheet P1 and the second sheet P2 are overlapped and conveyed by the pair 15 (FIG. 6(f)).

The operations shown in FIGS. 6(b) to 6(f) are repeated until the set number of folded sheets set by the user is reached. Then, when the set number of folded sheets is reached, the folding processing section B executes the folding process.

FIGS. 7A to 7D are explanatory diagrams for explaining general operations when Z-folding is performed by folding processing section B.
The leading end of the overlapping sheet bundle Pt conveyed by the registration roller pair 15 enters a first conveying roller pair 117a consisting of a first folding roller 17b and a first pressing roller 17a. Next, after the sheet bundle Pt has been transported by a predetermined transport amount Δ1, the drive motor that drives the folding mechanism 17 is temporarily stopped. Then, the drive motor that drives the folding mechanism 17 is rotated in the reverse direction. The amount of protrusion at this time is determined as appropriate depending on the length of the sheet bundle Pt in the sheet conveyance direction and the details of the folding process (folding method, etc.). Note that the drive motor that drives the registration roller pair 15 is temporarily stopped at the same time as the drive motor that drives the folding mechanism 17 is stopped, and the forward rotation drive is resumed simultaneously with the reverse rotation drive of the drive motor that drives the folding mechanism 17. Alternatively, the pair of registration rollers 15 may continue to rotate in the normal direction without stopping the drive. Further, when the sheet bundle Pt is conveyed by a predetermined conveyance amount Δ1, the trailing end side of the sheet bundle has not passed through the pair of registration rollers 15, and the leading end side of the sheet bundle pt is conveyed by the first conveyance roller pair 117a. It is in a state where the rear end side is held between the pair of registration rollers 15.

By rotating the drive motor that drives the folding mechanism 17 in the reverse direction, the part of the sheet bundle Pt sandwiched between the first pair of conveyance rollers 117a is conveyed in the reverse direction (conveyed in the opposite direction to the predetermined direction), and the part of the sheet bundle Pt sandwiched between the pair of first conveyance rollers 117a is conveyed in the opposite direction to the registration roller pair 15. The sandwiched portion of the sheet bundle Pt is transported forward. As a result, a bend is formed in the sheet bundle portion between the registration roller pair 15 and the first conveyance roller pair 117a (FIG. 7(a)). Then, this bent portion (folded portion) enters the nip of the first folding roller pair 117b consisting of the first folding roller 17b and the second folding roller 17c, so that a first folded portion is formed at the folded portion. . The first folded portion that has passed through the nip of the first folding roller 17b is conveyed toward a second conveying roller pair 18 as a second conveying member.

Then, the first folding portion of the sheet bundle Pt enters the nip of the second transport roller pair 18, and when the sheet bundle Pt is transported by a predetermined transport distance Δ2, the drive motor that drives the second transport roller pair 18 temporarily stop. Then, the drive motor that drives the second conveyance roller pair 18 is reversely rotated, and the second conveyance roller pair 18 is reversely rotated, so that the portion of the sheet bundle sandwiched between the second conveyance roller pair 18 is reversely conveyed (the predetermined direction is different from the predetermined direction). transport in the opposite direction). When the drive motor that drives the second transport roller pair 18 is temporarily stopped, the drive motor that drives the folding mechanism 17 may also be stopped to temporarily stop transporting the sheet bundle, or the drive motor that drives the folding mechanism 17 may be stopped. The motor may continue to convey the sheet bundle without stopping. The conveyance amount Δ2 at this time is also appropriately determined depending on the length of the sheet bundle Pt in the sheet conveyance direction and the details of the folding process (folding method, etc.). Further, when the sheet bundle Pt is transported by a predetermined transport amount Δ2, the rear end side of the sheet bundle is held between the first folding roller pair 117b.

The part of the sheet bundle Pt that is sandwiched between the second pair of transport rollers 18 is reversely transported (conveyed in the opposite direction to the predetermined direction), and the part of the sheet bundle Pt that is sandwiched between the first pair of folding rollers 117b is transported normally. As a result, a bend is formed in the sheet portion between the first pair of folding rollers 117b and the second pair of conveying rollers 18. Then, as shown in FIG. 7(b), this bent portion (folded portion) enters the nip of a second folding roller pair 117c, which is a second folding member consisting of a second folding roller 17c and a second pressing roller 17d. As a result, a second folded portion is formed at the folded portion.

The sheet bundle Pt on which two folded portions have been formed after passing through the nip of the second folding roller pair 117c is conveyed toward the additional folding roller 20 by the intermediate conveyance roller pair 19, as shown in FIG. 7(c). . As shown in FIG. 7(d), when the second folding portion reaches the position facing the additional folding roller 20, the conveyance of the sheet bundle Pt is stopped. Next, the additional folding roller 20 is rotated to strengthen the fold of the second folding portion, and then the conveyance of the sheet bundle Pt is resumed. When the first folding portion faces the additional folding roller 20, the conveyance of the sheet bundle Pt is resumed. Stop. After the fold of the first fold portion is strengthened by the additional folding roller 20, conveyance of the sheet bundle Pt is resumed, and the sheet bundle Pt is conveyed by the pair of conveying rollers 21 and 22, and is discharged to the post-processing device.

Note that although the above description has been made regarding the case of folding the sheet bundle Pt that has been subjected to the overlapping process, the folding process operation when folding a single sheet is also the same. Furthermore, although Z-folding has been described above, by appropriately changing the conveyance amount Δ1 and the conveyance amount Δ2, the sheet can be folded into three inner parts and three folded outward by the same operation as the Z-folding process. I can do it. For the double-folding process, the third branch claw 16 is rotated clockwise in the figure to guide the sheet to the first pair of folding rollers 117b, and the sheet conveyed from the pair of registration rollers 15 is guided to the pair of first folding rollers 117b. 117b. Then, the sheet can be folded in half by forming a folding section at the center of the sheet in the conveying direction using an operation similar to the operation of forming the second folding section.

FIG. 8 is a diagram showing an example of a setting screen displayed on the operation unit 190 of the image forming apparatus 3. As shown in FIG.
The setting screen shown in FIG. 8 is an example of a setting screen displayed on the operation unit 190 when copying image information of a document read by the image reading device 100.
The operation unit 190 includes a display operation unit such as a liquid crystal display (LCD), and a button operation unit including a numeric keypad and a start button. The display operation section has a touch panel function, and can detect various types of displays and the position touched by the user.

The setting screen shown in FIG. 8 includes a fold setting section 191 for setting folding processing for a single copied sheet, and two fold setting sections 191 for setting folding processing for multiple copied sheets. It has setting sections 192 and 193. Of the two double fold setting sections, the first double fold setting section 192 labeled "Multi fold (auto)" is set when a document is set on the document table 501 of the automatic document feeder (ADF) 500. This is what is displayed. The second multiple fold setting section 193 labeled "Multiple Fold (Manual)" is displayed when a document is placed on the platen glass 309 by the user.

Each overlap fold setting section 192, 193 displays four GUI components corresponding to the fold type (Z-fold, outer tri-fold, double-fold, inner tri-fold). When performing multiple folding, the user presses any one of these four GUI components to set the fold type and to perform multiple folding.

When the user places the originals on the platen glass 309 and reads the image information of multiple sheets of originals (hereinafter also referred to as manual reading), after placing the originals on the platen glass 309, Press the start button to start the loading operation. When the reading operation is completed, the next document is placed on the platen glass 309 and the start button on the operation unit 190 is pressed. By repeating such operations multiple times, image information of the set number of sheets of documents to be folded is read. Therefore, in the apparatus, it is not possible to determine at what stage the document reading operation has been completed and the set number of folded sheets has been determined. Therefore, the second multiple fold setting section 193 is provided with an "execute" button as a confirmation button for determining the set number of multiple folds. As a result, when the user presses the "execute" button after the document reading operation is completed, the apparatus can recognize that the set number of folded sheets has been determined.

Further, by providing the "execute" button in the second fold setting section 193, the following advantages are provided. That is, for example, in the case where the set number of sheets to be folded is entered and the set number of sheets is determined, the user has to count and input the number of sheets of the document. In contrast, in this embodiment, the set number of sheets is determined by simply pressing the "Execute" button after completing the document reading process, which has the advantage of reducing the burden on the user.

On the other hand, the first multiple fold setting section 192 does not have an "execute" button for determining the set number of multiple folds. This is because when the automatic document feeder (ADF) 500 reads the image information of the document (hereinafter also referred to as automatic reading), the number of sheets of the document set on the document table 501 is the set number of sheets for folding and folding. This is because at the end of reading, the set number of sheets to be folded is automatically determined, and the apparatus can grasp the set number of sheets to be folded.

As in the invention described in Patent Document 1, it is determined whether or not the sheet conveyed to the folding process conveyance path W2 is the last sheet of the set number of folded sheets, and the sheet bundle is overlaid by the pair of registration rollers 15. When deciding whether to transport the sheet to the switchback transport path W3 or to the folding processing section B, it is necessary to transport the sheet to the folding device after the set number of sheets to be folded is determined. This is because, if the set number of sheets to be folded is not determined, it cannot be determined whether the sheet conveyed to the folding process transport path W2 is the last sheet of the set number of sheets to be folded, and the sheet remains there. As a result, the leading edge of the next sheet collides with the trailing edge of the previous sheet that remains in place, resulting in a jam.

Automatic reading of a plurality of original documents by the automatic document feeder (ADF) 500 does not take much time. Therefore, if the user specifies multiple folding for automatically scanned copies, the productivity will not be much higher even if the image information of all documents is read and the set number of multiple folds is determined before starting the image forming operation. Does not decrease.

Also, when printing multiple image data sent from a PC (personal computer), etc., the number of sheets to be printed is determined in advance, and when folding multiple printed sheets, it is possible to Even if the image forming operation is started after the set number of sheets to be folded is determined, productivity does not decrease much.

On the other hand, manual reading in which the user sets the original on the platen glass 309 and reads it takes a long time because the user replaces the original one by one and reads the image information. Therefore, when the user specifies multiple folding for manually scanned copies, the user scans the last document for the set number of multiple folds, presses the "Execute" button on the operation unit 190, and confirms the set number of multiple folds before the image is displayed. If the forming operation is started, productivity will drop significantly.

Furthermore, even automatic reading takes a certain amount of time when reading a large number of documents. Therefore, if the image forming operation is started after the image information of all documents is read and the set number of folded sheets is determined, productivity will decrease.

Therefore, in the present embodiment, the stacked sheet stack is transported to the switchback conveyance path W3 regardless of whether the number of sheets stacked by the pair of registration rollers 15 is the set number of folded sheets. I did it like that. As a result, the leading edge of the next sheet carried into the sheet processing apparatus will not collide with the trailing edge of the previous sheet, and jams will not occur. Therefore, the image forming operation can be started without waiting for the set number of folded sheets to be determined, and the sheets can be sequentially conveyed to the folding device 1, thereby suppressing a decrease in productivity. A detailed explanation will be given below using FIG. 9.

FIG. 9 is an example of the control flow of the overlap folding process of this embodiment.
As shown in FIG. 9, in this embodiment, as described above, the sheet or sheet bundle that has been evacuated to the switchback conveyance path W3 and the sheet that has been conveyed to the folding conveyance path W2 are moved between the registration rollers. The skew correction and superimposition are performed by abutting against the surface (S1). Next, the control unit 40 transports the stacked sheet bundle to the switchback transport path W3 by switchback transport, regardless of whether the number of sheets in the stacked sheet bundle is the set number of folded sheets. (S2).

After conveying the stacked sheet bundle to the switchback conveyance path W3, the control unit 40 confirms whether the set number of folded sheets has been determined (S3). If the set number of folded sheets has not been determined (S3 No), the next sheet is carried into the folding device 1 (S4). When the next sheet is carried into the folding processing device 1 (S4 Yes), the flow from S1 onwards is repeated, and the next sheet carried in is superimposed on the sheet bundle evacuated to the switchback conveyance path W3. After performing this, the stacked sheet bundle is switchback transported to the switchback transport path W3.

On the other hand, if the set number of folded sheets has already been determined, or if the user presses the "execute" button in the second folded fold setting section 193 of the operation section 190 while waiting on the switchback conveyance path W3, the set number of folded sheets is determined. If this is the case (Yes in S3), it is checked whether the number of sheets in the stack of sheets waiting in the switchback conveyance path W3 is the set number of folded sheets (S5). If the number of sheets in the waiting sheet bundle has not reached the preset number of folded sheets, the flow from S1 onwards is repeated, and the next sheet brought in is combined with the sheet bundle evacuated to the switchback conveyance path W3. After the stacking is performed, the stacked sheet bundle is switchback transported to the switchback transport path W3.

On the other hand, when the number of sheets in the waiting sheet bundle has reached the preset number of folded sheets (Yes in S5), the sheet bundle waiting in the switchback conveyance path W3 is conveyed to the folding processing section B (S6).

In this manner, in this embodiment, the sheet bundle that has been superimposed by the pair of registration rollers 15 is once transported to the switchback transport path W3, regardless of whether the set number of overlapping sheets has been reached or not. As a result, the leading edge of the next sheet carried into the sheet processing apparatus will not collide with the trailing edge of the previous sheet, and jams will not occur. Therefore, it is possible to start the image forming operation without waiting for the set number of folded sheets to be determined and to sequentially transport the sheets to the folding processing apparatus 1, thereby suppressing a decrease in productivity. In particular, it is possible to effectively suppress a decrease in productivity when it comes to over-folding manually read copies, which require time to determine the set number of sheets to be folded, or when automatically reading copies of large volumes of originals.

Next, a modification of the overlapping process in this embodiment will be described.

[Modification 1]
FIG. 10 is an example of the control flow of the overlapping folding process of Modification 1, and FIG. 11 is an example of the control flow of the second conveyance mode.
This modification 1 includes two transport modes for the stacked sheet bundle. As shown in FIG. 9, the first conveyance mode is a conveyance mode in which the stacked sheet bundle is conveyed to the switchback conveyance path W3 regardless of whether the number of overlapping sheets is equal to the set number of overlapping sheets or not.

On the other hand, in the second conveyance mode, as shown in FIG. After superimposing the stacked sheet bundle (S21: Yes), it is checked whether the stacked sheet bundle has reached the set number of sheets to be folded or not (S22). Then, when the sheet bundle has not reached the set number of overlapping sheets (No in S22), the overlapping sheet bundle is conveyed to the switchback conveyance path W3. On the other hand, when the sheet bundle has reached the set number of folded sheets (Yes in S22), the conveyance mode is in which the sheet bundle is conveyed to the folding processing section B (S24).

In this second conveyance mode, unlike the first conveyance mode, when the stack of sheets overlapped by the pair of registration rollers 15 reaches the preset number of folded sheets, the sheet bundle is not conveyed to the switchback conveyance path W3 and is folded as is. Transport to section B. Therefore, regardless of whether the number of sheet bundles overlaid by the pair of registration rollers 15 is the set number of overlapping sheets or not, the first conveyance mode is set in which the overlapping sheet bundle is conveyed to the switchback conveyance path W3. In comparison, productivity can be increased. However, in the second transport mode, the set number of sheets to be folded must be determined at the time when the pair of registration rollers 15 performs the overlapping.

Therefore, in this modification example 1, as shown in FIG. 10, when the set number of folded sheets is determined at the time of superposition processing such as automatic reading copying (Yes in S12), the second transport mode is set (S14). ). On the other hand, if the set number of sheets to be folded is not determined at the time of superimposition processing such as manual scanning copying (No in S12), the first transport mode is set (S13). As a result, stacking can be performed even when the set number of folded sheets is not determined, and when the set number of folded sheets is determined at the time of stacking processing, folding can be performed with high productivity. .
Note that the point in time when the registration roller pair 15 performs overlapping is the point in time when the leading edge of the second sheet abuts against the registration roller pair 15.

Furthermore, in this embodiment, the timing for determining the conveyance mode is the time when the registration roller pair 15 superposes the sheet (the time when the leading edge of the second sheet hits the registration roller pair 15). It may be any timing before the superposition is performed. For example, the transport mode may be determined at the time when the image forming mode (print mode, automatic reading copy mode, manual reading copy mode, etc.) is determined. In this case, if the image forming mode is a print mode that quickly determines the number of folded sheets or a copy mode that uses automatic reading, set the second transport mode, and set the image forming mode that takes time to determine the number of folded sheets. When in copy mode using manual reading, set to first transport mode.

[Modification 2]
FIG. 12 is an example of a control flow of the overlapping folding process according to the second modification.
As shown in FIG. 12, in this modification example 2, the leading edge of the sheet conveyed to the folding conveyance path W2 is brought into contact with the pair of registration rollers 15 to perform skew correction, and the sheet (sheet bundle) in the switchback conveyance path W3 is ) (Yes in S31), it is checked whether the set number of sheets to be folded has been determined (S32). When the set number of folded sheets is determined (Yes in S32), the conveyance control is performed based on the set number of folded sheets. That is, when the number of stacked sheet bundles has not reached the set number of stacked and folded sheets, the stacked sheet stack is conveyed to the switchback conveyance path W3 (S38), and when the set number of stacked and folded sheets has been reached. If there is, the control is to transport the paper to the folding processing section B (S39).

On the other hand, when the set number of overlapping sheets has not been determined (No in S32), the overlapping sheet bundle is conveyed to the switchback conveyance path W3 (S33). Similarly to the control flow shown in FIG. 9, if the next sheet is conveyed without the set number of folded sheets being determined (S34 No, S36 Yes), the flow from S31 onward is repeated.

On the other hand, if the user presses the "execute" button of the second fold setting section 193 of the operation unit 190 while waiting on the switchback conveyance path W3 and the set number of folds is confirmed (Yes in S34), the switchback conveyance It is checked whether the number of sheets in the stack of sheets waiting in path W3 is the set number of folded sheets (S35). If the number of sheets in the waiting sheet bundle has not reached the preset number of folded sheets, the flow from S31 onward is repeated. From now on, since the set number of folded sheets has been determined, the conveyance control is performed based on the set number of folded sheets in S37 to S39. This allows the user to press the "Execute" button on the operation display section to set up multiple folding when manually scanning copy sheets. Once the number of sheets is determined, multiple folding can be performed without reducing productivity.

In this way, in the second modification, each time the registration roller pair 15 performs overlapping, it is checked whether the set number of folded sheets is determined, and the conveyance control is performed depending on whether the set number of folded sheets is determined. We are making a switch. As a result, even if the set number of sheets to be folded is determined during the stacking process, if it is before the last sheet is stacked, the set number of sheets will be determined immediately after the set number of sheets are stacked (without being conveyed to the switchback conveyance path W3). The stacked sheet bundle can be conveyed to the folding processing section B. Therefore, compared to Modification 1, it is possible to suppress a decrease in productivity during manual reading and folding.

It should be noted that checking whether the set number of folded sheets has been determined is done by checking the timing at which the transported sheet joins the sheet (sheet bundle) waiting in the switchback transport path W3, and the timing at which the transported sheet joins the sheets (sheet bundle) waiting in the switchback transport path W3. The timing may be just before the tip hits the pair of registration rollers 15. However, it is preferable to check whether the set number of folded sheets has been determined after the sheets have been stacked as described above. This is because, in order to increase productivity as much as possible, it is desirable to wait until the very last moment before the start of transport control to determine the set number of folded sheets.

FIG. 13 is a schematic configuration diagram showing a modified folding processing device.
The folding device of this modification is configured to be able to be placed inside the barrel of an image forming apparatus.
The folding device of this modification includes a through conveyance path W1 for conveying the sheet P discharged from the image forming apparatus 3 to the subsequent post-processing device 2 without folding the sheet P. It also includes a folding conveyance path W2 that branches from the through conveyance path W1 and that folds the sheet P discharged from the image forming apparatus 3 and conveys the sheet P to the subsequent post-processing device 2. . In addition, the switchback conveyance unit serves as a receiving section for temporarily holding a sheet that has branched from the through conveyance path W1 and conveyed in a switchback manner, and conveying the sheet while overlapping it with a subsequent sheet discharged from the image forming apparatus 3. It is equipped with a road W3.

A pair of carry-in rollers 610 is disposed on the entrance side (on the right side in the figure) of the through conveyance path W1 that receives the sheet P discharged from the image forming apparatus 3. The carry-in roller pair 610 is composed of a pressing roller 610a, which is a rotating member, and a drive roller 610b, which is an opposing member.The drive roller 610b is rotationally driven by the driving force of a carry-in motor, which is a drive source.

Furthermore, a pair of registration rollers 611 serving as skew correction means is arranged downstream of the pair of carry-in rollers 610 in the through conveyance path W1. The registration roller pair 611 is composed of a pressing roller 611a that is a rotating member and a driving roller 611b that is an opposing member. Drive rotation.

Further, on the exit side (left side in the figure) of the through conveyance path W1, a first folding roller 612, a first forward/reverse roller 613 disposed in contact with the first folding roller 612, and a stopper member 628 are provided. ing. By passing through the nip between the first folding roller 612 and the first forward/reverse rotation roller 613, the sheet P can move from the through conveyance path W1 to the folding conveyance path W2. Further, the stopper member 628 is configured to be retractable from the through conveyance path W1 and movable in the sheet conveyance direction as shown by arrow D in the figure. By retracting the stopper member 628 from the through conveyance path W1, the sheet P can be conveyed to the subsequent post-processing device 2 via the through conveyance path W1.

Furthermore, a second folding roller 615 is provided on the exit side of the folding conveyance path W2, and is disposed in contact with the first forward/reverse rotation roller 613. In addition, the sheet P from the through conveyance path W1 enters the folding conveyance path W2 on the opposite side of the second folding roller 615 across the nip between the first folding roller 612 and the first forward/reverse roller 613. , a second pair of forward and reverse rotation rollers 616 are provided. The second forward/reverse roller pair 616 is composed of a pressing roller 616a, which is a rotating member, and a drive roller 616b, which is an opposing member. Drive rotation.

The first forward/reverse roller 613 can be rotationally driven in a forward/reverse manner by the driving force of a first forward/reverse motor 613m capable of forward/reverse rotation. The first folding roller 612 and the second folding roller 615, which are disposed in contact with the first forward/reverse rotation roller 613, are both driven rollers that rotate in accordance with the rotation of the first forward/reverse rotation roller 613.

Further, the drive roller 616b constituting the second forward/reverse rotation roller pair 616 can be rotationally driven in the forward and reverse directions by the driving force of the second forward and reverse rotation motor 616m that is capable of forward and reverse rotation. The pressure roller 616a constituting the second forward/reverse roller pair 616 is a driven roller that rotates as the drive roller 616b rotates.

Further, a switchback conveyance roller pair 617 is arranged on the switchback conveyance path W3. The switchback transport roller pair 617 is composed of a pressing roller 617a, which is a rotating member, and a driving roller 617b, which is an opposing member. Rotationally driven by force.

Furthermore, a film member 618 is provided at the branching portion of the switchback conveyance path W3 and the through conveyance path W1. This film member 618 has a leading end located on the side of the through conveyance path W1, and guides the sheet that has been switchback conveyed to the switchback conveyance path W3.

The roller shafts of all the driven rollers are biased by pressure springs 610s, 611s, 612s, 614s, 615s, 616s, and 617s as biasing means, which creates a nip between the opposing rollers. It is beginning to form.

Further, an entrance sensor 624 as a sheet end detection means for detecting the end of the sheet P is provided on the upstream side in the sheet transport direction of the pair of carry-in rollers 610 (on the entrance side of the through transport path W1). When the leading edge or trailing edge of the sheet P conveyed from the image forming apparatus 3 reaches its detection area, the entrance sensor 624 outputs a detection signal indicating this to the control unit. As such a sensor, a wide variety of known sensors can be used.

Further, a skew sensor 621 is provided on the upstream side of the pair of registration rollers 611 in the sheet conveyance direction (near the center of the through conveyance path W1) as a sheet edge detection means for detecting the edge of the sheet P. When the leading edge of the sheet P conveyed from the image forming apparatus 3 reaches its detection area, the skew sensor 621 outputs a leading edge detection signal indicating this to the control unit. As such a sensor, a wide variety of known sensors can be used.

Further, a sheet detection sensor 626 for detecting the leading edge of the sheet P is provided downstream of the second forward/reverse roller pair 616 in the sheet conveyance direction (opposite to the exit side of the folding conveyance path W2). When the leading edge of the sheet P sent from the through conveyance path W1 to the folding conveyance path W2 reaches the detection area, this sheet detection sensor 626 outputs a leading edge detection signal indicating this to the control unit. As such a sheet detection sensor 626, a wide variety of known sensors can be used, similar to the above-described entrance sensor 624 and skew sensor 621.

The folding unit, which is a sheet processing unit, includes a registration roller pair 611 as a conveying unit, a folding unit forming unit including a first folding roller 612 and a first forward/reverse roller 613, and a stopper member 628. ing. Further, the first forward/reverse roller 613 and the second folding roller 615 also constitute folding portion forming means.

Further, the switchback conveyance path W3 is connected to the folding conveyance path W2. As a result, a part of the switchback conveyance path W3 can be used as the conveyance path for the sheet that has entered the second forward/reverse roller pair 616 of the folding conveyance path W2, and the apparatus can be made more compact. .

Further, the carry-in roller pair 610 may not be necessary, and by eliminating the carry-in roller pair 610, further miniaturization can be realized.

Next, sheet stacking in a modified folding apparatus will be described.
14 to 16 are explanatory diagrams illustrating the operation of sheet stacking processing by the folding processing apparatus 1 of the modified example.
FIG. 14 is a diagram illustrating the operation until the preceding sheet P1 is skew corrected by the registration roller pair 611 in the sheet stacking process operation, and FIG. FIG. 7 is a diagram illustrating an operation from the time the preceding sheet P1 is corrected until the preceding sheet P1 is conveyed to the switchback conveyance path W3. Further, FIG. 16 is a diagram illustrating an operation in the sheet overlapping processing operation from when the preceding sheet P1 is conveyed to the switchback conveyance path W3 until the subsequent sheet P2 is overlaid on the preceding sheet P1.

As shown in FIG. 14A, the carry-in roller pair 610 receives the preceding sheet P1 from the discharge roller pair 408 of the image forming apparatus and conveys it downstream. The film member 618 is elastically deformed counterclockwise in the figure by the preceding sheet P1 that is conveyed by applying a conveying force from the pair of carry-in rollers 610, thereby parrying the conveyance of the preceding sheet P1. Then, the leading edge of the preceding sheet P1 hits the registration roller pair 611, as shown in FIG. 14(b), and the skew is corrected.

After the skew sensor 621 detects the leading edge of the sheet and the sheet is conveyed by the specified abutment amount by the pair of carry-in rollers 610, the pair of registration rollers 611 is rotated in normal rotation to start conveying the preceding sheet P1. At this time, the stopper member 628 is retracted from the through conveyance path W1.

Next, as shown in FIG. 15(a), after the sheet has been conveyed by a specified conveyance amount until the rear end of the preceding sheet P1 passes through the branch of the through conveyance path W1 and the switchback conveyance path W3, the registration roller The rotation of pair 611 is stopped. The film member 618 returns to its original shape when the trailing end of the preceding sheet P1 passes through the branch between the through conveyance path W1 and the switchback conveyance path W3. In this example, the designated conveyance amount is from the start of sheet conveyance by the pair of registration rollers 611 until the trailing edge of the sheet passes the branching portion. It may also be a designated conveyance amount until the end passes the branch.

Next, the skew forward/reverse motor 611m is driven in the reverse direction, and the preceding sheet P1 is conveyed in the reverse direction (conveyed in the opposite direction to the predetermined direction). As shown in FIG. 15(b), the trailing edge of the preceding sheet P1 that has been reversely conveyed (conveyed in the opposite direction to the predetermined direction) is guided by the film member 618 during normal conveyance (conveyed in the predetermined direction). , and transported to the switchback transport path W3. Next, after the specified amount of reverse conveyance (conveyance in the opposite direction to the predetermined direction), as shown in FIG. 15(c), the reverse rotation of the skew forward/reverse motor 611m and the switchback forward/reverse motor 617m is stopped. The specified amount of reverse conveyance (conveyance in the opposite direction to the predetermined direction) is such that after the start of reverse conveyance (conveyance in the opposite direction to the predetermined direction) of the sheet, the leading edge of the sheet when being conveyed is located at the registration roller pair 611. This is the amount of transport until it is located in front of .
Next, the switchback forward/reverse motor 617m is rotated forward by a specified abutting amount to abut the leading edge of the preceding sheet P1 against the pair of registration rollers 611 to perform skew correction.

Next, as shown in FIG. 16(a), a subsequent sheet P2 is conveyed from the image forming apparatus. At this time, the preceding sheet P1, which is waiting in front of the pair of registration rollers 611, is on the skew sensor 621, and the skew sensor 621 cannot detect the leading edge of the succeeding sheet P2. Therefore, from the second sheet onwards, the designated amount of sheets are conveyed after the entrance sensor 624 detects the leading edge of the succeeding sheet P2. As shown in FIG. 16(b), the leading edge of the subsequent sheet P2 hits the registration roller pair 611, and the skew is corrected. By correcting the skew of the succeeding sheet P2 by the pair of registration rollers 611 and aligning the leading edges of the preceding sheet P1 and the succeeding sheet P2, the preceding sheet P1 and the succeeding sheet P2 are overlapped. Then, the registration roller pair 611 transports the preceding sheet P1 and the succeeding sheet P2 in an overlapping manner. This process is repeated until the set number of sheets to be folded is reached.

Even in this modification, by performing the control according to the embodiment (the control flow shown in FIG. 9) and the overlap folding process according to modification 1 or modification 2, even if the set number of sheets to be folded is not determined, the sheet transport can be started, and a decrease in productivity can be suppressed.

Next, folding processing by the folding processing apparatus 1 of the modified example will be explained.
FIGS. 17A to 17H are explanatory diagrams illustrating general operations when Z-folding is performed by a modified folding apparatus.
When the number of sheet bundles Pt that have been overlaid by the registration roller pair 611 reaches the preset number of overfolding sheets, the stopper member 628 is moved from the retracted position to the through conveyance path W1 and to the position corresponding to the fold type. . Next, as shown in FIG. 17(b), the skew forward/reverse motor 611m is controlled to start the rotation of the registration roller pair 611, and the sheet bundle Pt is conveyed toward the exit side of the through conveyance path W1. .

As shown in FIG. 17(c), the leading end of the sheet Pt conveyed through the through conveyance path W1 hits the stopper member 628, and as shown in FIG. A deflection is formed in the sheet in between.

Thereafter, the first forward/reverse rotation motor 613m is controlled to start reverse rotation of the first forward/reverse rotation roller 613. Then, this bent portion (folded portion) enters the nip between the first folding roller 612 and the first forward/reverse rotation roller 613, thereby forming a first folded portion at the folded portion. As shown in FIG. 17(e), the first folding portion that has passed through the nip between the first folding roller 612 and the first forward/reverse roller 613 enters the folding conveyance path W2, and enters the folding conveyance path W2. is conveyed toward a second forward/reverse rotation roller pair 616.

Then, as shown in FIG. 17(f), the first folded portion of the sheet bundle Pt enters the nip of the second forward/reverse rotation roller pair 616, and is detected by the sheet detection sensor 26 after passing through this nip. The control unit that receives the leading edge detection signal from the sheet detection sensor 26 that detects this performs the following control. That is, when the first folded portion of the sheet P protrudes by a predetermined amount from the nip position of the second forward/reverse roller pair 616, the first forward/reverse motor 613m is controlled to rotate the first forward/reverse roller 613. Stop rotation. At the same time, the rotation of the second pair of forward/reverse rollers 616 and the pair of registration rollers 611 is stopped. The amount of protrusion at this time is determined as appropriate depending on the length of the sheet bundle Pt in the sheet conveyance direction and the details of the folding process (folding method, etc.). The amount of protrusion of the first folded portion of the sheet bundle Pt can be determined, for example, from the reception timing of the leading edge detection signal output from the sheet detection sensor 626 and the amount of rotation of the second forward/reverse rotation roller pair 616.

Thereafter, as shown in FIG. 17(g), the second forward/reverse rotation motor 616m is controlled to reversely rotate the second forward/reverse rotation roller pair 616 in a direction to direct the sheet bundle Pt toward the exit side of the folding conveyance path W2. Start. Further, the reverse rotation of the first forward/reverse rotation roller 613 and the rotation of the registration roller pair 611 are restarted. As a result, a deflection is formed in the sheet portion between the first forward/reverse rotation roller 613 and the second forward/reverse rotation roller pair 616. Then, this bent portion (folded portion) enters the nip between the first forward/reverse roller 613 and the second folding roller 615, thereby forming a second folded portion at the folded portion.

As shown in FIG. 17(h), the second folded portion that has passed through the nip between the first forward/reverse roller 613 and the second folding roller 615 is conveyed toward the exit side of the folding conveyance path W2. . Then, the sheet bundle Pt in which the two folded portions are formed in this manner is conveyed to the subsequent post-processing device 2 by receiving the conveying force from the first forward/reverse rotation roller 613.

In addition, the folding device of this modified example is provided with a stopper member 628, and the sheet bundle is bent by abutting the leading end of the sheet bundle against the stopper member 628. A pressing roller 614 that presses against the forward/reverse roller 613 may be provided, and the sheet bundle pt may be bent by rotating it in the opposite direction at a predetermined timing based on the detection result of the leading end detection sensor 622.

In the configuration shown in FIG. 18, when the leading edge of the sheet P protrudes by a predetermined amount from the nip position between the first forward and reverse roller 613 and the pressing roller 614, the first forward and reverse roller 613 and the registration roller The rotation of pair 611 is stopped. The amount of protrusion at this time is determined as appropriate depending on the length of the sheet P in the sheet conveyance direction and the details of the folding process (folding method, etc.).

Next, by starting the reverse rotation of the first forward/reverse rotation roller 613 and restarting the rotation of the registration roller pair 611, the portion of the sheet bundle between the registration roller pair 611 and the first forward/reverse rotation roller 613 is bent. is formed. Then, this bent portion (folded portion) enters the nip between the first folding roller 612 and the first forward/reverse rotation roller 613, thereby forming a first folded portion at the folded portion. The subsequent operations are similar to those shown in FIGS. 17(e) to (h).

In the folding device of the modified example, since the folding device is arranged in a limited space inside the body of the image forming device, as shown in FIG. The conveyance path length L to the nip position may be shorter than at least the maximum size in the sheet conveyance direction that can be processed by the book-folding apparatus.

Therefore, when sheets whose length in the transport direction is longer than the transport path length L are stacked in the second transport mode shown in FIG. 11, as shown in FIG. The rear side of the sheet may remain in the image forming apparatus 3.

As described above, in order to form a deflection in the portion of the sheet bundle between the registration roller pair 611 and the first forward/reverse rotation roller 613, when switching the first forward/reverse rotation roller 613 from normal rotation to reverse rotation, The rotation of the forward/reverse roller 613 and the registration roller pair 611 is temporarily stopped. At this time, if the trailing edge of the last sheet remains in the image forming apparatus, it becomes necessary to temporarily stop the rotation of the paper ejection roller 408 and the like on the image forming apparatus as well, which complicates control.

Therefore, by making the conveyance path length L longer than the maximum size in the sheet conveyance direction that can be processed by the main folding device, even when overlapping is performed in the second conveyance mode, during the overlap folding process, The rear end side of the last sheet does not remain in the image forming apparatus 3. However, the folding device 1 becomes large in size.

Therefore, as shown in FIG. 20, when the length of the sheets to be folded in the sheet conveyance direction is equal to or greater than the threshold value, the stacking process is performed in the first conveyance mode, regardless of whether the set number of folded sheets is determined or not. You may also do this. The threshold value is, for example, the conveyance path length L from the carry-in section H to the nip position between the first forward/reverse roller 613 and the pressing roller 614. As a result, when performing stack folding on sheets whose length in the sheet conveyance direction is longer than this threshold value, when the stacked sheet bundle reaches the set number of sheets, the folding process starts after being conveyed to the switchback conveyance path W3. be done. As a result, during the folding process, the rear end side of the last sheet is in the switchback conveyance path and does not remain in the image forming apparatus. Therefore, multiple folding can be performed only by controlling each roller of the folding device 1, and complication of control can be suppressed. Further, it is preferable that the conveyance path length L is longer than the length in the conveyance direction of a sheet of commonly used A4 portrait size or the sheet conveyance direction of a letter portrait size. By making the conveyance path length L longer than the sheet conveyance direction length of commonly used sizes, it is possible to select the second conveyance mode when stacking and folding sheet bundles of these sheet sizes. Therefore, it is possible to suppress a decrease in productivity.

Further, sheets whose sheet conveyance length is equal to or greater than a threshold value may not be allowed to be folded over and over again. By doing so, it is possible to suppress the enlargement of the switchback conveyance path W3, and it is possible to reduce the size of the folding apparatus 1.

What has been described above is just an example, and each of the following aspects has its own unique effects.
(Aspect 1)
It has a retraction section such as a switchback conveyance path W3 in which a sheet whose skew has been corrected by a skew correction means such as a pair of registration rollers 15 is retracted, and the sheet that has been retracted to the retraction section and the sheet that has been carried in are separated by the skew correction means. A folding processing device comprising a stacking unit such as a stacking unit A that performs stacking, and a sheet processing unit such as a folding unit B that performs a predetermined process on a bundle of sheets overlaid by a set number of sheets by the stacking unit. In a sheet processing apparatus such as No. 1, the overlapping processing means conveys the stacked sheet bundle to the evacuation section, regardless of whether the number of sheets stacked by the skew correction means is a set number of sheets or not. .
In the sheet processing apparatus described in Patent Document 1, it is determined whether or not the second and subsequent sheets that are carried into the sheet processing apparatus are the last sheet of a set number of sheets, and the stacked sheet bundle is sent to a circulating conveyance path. I am deciding whether to evacuate it or transport it to the folding processing section. Therefore, if the set number of sheets has not been determined by the time it is decided whether to evacuate the sheet bundle consisting of at least the second sheet and the first sheet to the circulation conveyance path or to convey it to the folding processing section, The combined sheet bundle will remain in place. If the next sheet (third sheet) is carried into the sheet processing device in this state, the leading edge of the next sheet may hit the trailing edge of the second sheet that remains in place, causing a jam. There is. Therefore, in the sheet processing apparatus described in Patent Document 1, it is necessary to determine the set number of sheets in advance before starting to carry sheets into the sheet processing apparatus (before starting image formation).
To copy original images of multiple originals (for example, thick paper) that cannot be placed on the automatic document feeder (ADF), the user can replace the originals placed on the original platen one by one and copy the original images of multiple originals. Perform scans sequentially. Therefore, when performing overfolding on multiple sheets on which original images of originals that cannot be set in the ADF are copied, the user places the last original of the set number of sheets on the document table, scans the original images, and then sets the It takes time to determine the number of sheets.
Therefore, in the sheet processing apparatus described in Patent Document 1, in which it is necessary to determine the set number of sheets in advance before conveying the sheets to the sheet processing apparatus, multiple sheets on which original images of originals that cannot be set in the ADF are copied. However, when performing overlapping folding, productivity is significantly reduced.
On the other hand, in aspect 1, the stacked sheet bundle is evacuated to the retraction section regardless of whether the number of stacked sheet bundles is the set number or not. As a result, the leading edge of the next sheet carried into the sheet processing apparatus will not collide with the trailing edge of the previous sheet, and jams will not occur. Therefore, it is possible to start conveying sheets to the sheet processing apparatus before the set number of sheets has been determined, and it is described in Patent Document 1 that it is necessary to start conveying sheets to the sheet processing apparatus after the set number of sheets has been determined. Productivity can be increased compared to the previous one.

(Aspect 2)
In aspect 1, the overlapping processing means such as the overlapping processing unit A is configured to process the overlapping sheets regardless of whether or not the number of sheet bundles overlapping is the set number by the skew correction means such as the registration roller pair 15. In the first mode, such as the first transport mode, in which the bundle is transported to a retraction section such as the switchback transport path W3, it is determined whether the number of stacked sheet bundles is the set number, and if the number of sheets is less than or equal to the set number. When the set number of sheets is reached, the sheet bundle is transported to the retraction section, and when the set number of sheets is reached, the sheet bundle is transported to the sheet processing means.
According to this, as explained in Modification 1, if the set number of sheets is not determined at the time of overlapping, by executing the first mode, the set number of sheets is not determined. , the conveyance of the sheet can be started, and a decrease in productivity can be suppressed. On the other hand, if the set number of sheets is determined at the time of overlaying, executing the second mode can suppress the drop in productivity compared to executing the first mode. .

(Aspect 3)
In aspect 2, if the set number of sheets is determined at the time when the sheets are superimposed by the skew correction means such as the registration roller pair 15, a second mode such as the second transport mode is executed to adjust the set number of sheets. If this is not determined, a first mode such as the first transport mode is executed.
According to this, as explained in the first modification, it is possible to increase productivity when the set number of sheets is determined at the time when the sheets are stacked by the skew correction means such as the registration roller pair 15. can,

(Aspect 4)
In aspect 2 or 3, when the length of the sheet in the conveyance direction is equal to or greater than the threshold value, a first mode such as a first conveyance mode is executed.
According to this, as explained using FIGS. 19 and 20, during sheet bundle processing by sheet processing means such as folding processing section B, the rear side of the last sheet remains in an upstream machine such as an image forming apparatus. There is no. Thereby, during sheet bundle processing, only the sheet processing device needs to be controlled, and control can be simplified. In addition, when executing a second mode such as the second conveyance mode, in order to prevent the rear side of the last sheet from remaining in the upstream machine for all sizes, the distance from the carry-in section where sheets are carried in from the upstream machine to the sheet processing means is The size of the device can be reduced compared to a device in which a transport route is set.

(Aspect 5)
It has a retraction section such as a switchback conveyance path W3 in which a sheet whose skew has been corrected by a skew correction means such as a pair of registration rollers 15 is retracted, and the sheet that has been retracted to the retraction section and the sheet that has been carried in are separated by the skew correction means. A sheet processing device that includes a stacking unit such as a stacking unit A that performs stacking, and a sheet processing unit such as a folding unit B that performs a predetermined process on a set number of stacked sheets by the stacking unit. In the above, when the stacking of sheets is performed by the skew correction means, if the set number of sheets is not determined, or if the number of stacked sheets has not reached the set number, the stacking processing unit performs stacking. When the aligned sheet stack is conveyed to the evacuation section and the sheets are stacked using the skew correction means, if the set number of sheets has been determined and the number of stacked sheet stacks is the set number, The stacked sheet bundle is conveyed to sheet processing means.
According to this, as explained in Modification 2, if the set number of sheets is not determined when stacking is performed, the stacked sheet bundle is conveyed to the switchback conveyance path W3, and the next No jams occur when sheets are brought in. Thereby, it is possible to start carrying in sheets without determining the set number of sheets, and it is possible to suppress a decrease in productivity. In addition, if the set number of sheets is determined when stacking is performed, and the number of sheets in the stacked sheet bundle is the set number, the stacked sheet stack is conveyed to the sheet processing means. Compared to the case where the paper is always transported to the evacuation section after the processing, a decrease in productivity can be suppressed.

(Aspect 6)
In any one of aspects 1 to 5, the sheet processing means includes a conveying means such as a registration roller pair 15 that conveys the sheet bundle, and a folding part forming means (for example, forming a first folding nip B1) that forms a folded part in the sheet bundle. (a first folding roller 17b, a second folding roller 17c, etc.) which bends the sheet bundle conveyed by the conveyance means (the first folding roller 17b and the first pressing roller 17a bend the sheet bundle to the leading side of the sheet bundle). (The sheet bundle is bent by being conveyed in a direction opposite to the conveying direction of the conveying means, or the tip of the sheet bundle is bent by hitting the stopper member 238.), and the bent portion of the sheet bundle is used to form a folding part. This is a folding unit such as a folding unit B that folds a bundle of sheets by introducing the folding unit into the unit.
According to this, multiple folding can be performed as described in the embodiment.

(Aspect 7)
In an image forming system 4 comprising an image forming apparatus 3 that forms an image on a sheet and a sheet processing apparatus such as a folding apparatus 1 that performs predetermined processing on the sheet, the sheet processing apparatus may be any one of Aspects 1 to 7. A sheet processing device was used.
According to this, even if the set number of sheets to be stacked is determined at an arbitrary timing after image formation is started, such as by manual reading, the sheet stacking process can be performed.

(Aspect 8)
In aspect 7, an operation unit 190 that accepts user operations is provided, and the operation unit 190 has a confirmation button such as an “execute” button for the user to confirm the set number of sheets.
According to this, as explained in the embodiment, when superimposing multiple sheets of copies of manually scanned original images, by pressing a confirmation button such as this "Execute" button, settings can be made. The number of sheets can be determined, and even when the set number of sheets cannot be automatically determined due to manual reading or the like, overlapping processing can be performed.

1: Folding processing device 2: Post-processing device 3: Image forming device 4: Image forming system 10: Entrance roller pair 11: First branching claw 12: Conveyance roller pair 13: Switchback conveyance roller pair 14: Second branching claw 15 : Registration roller pair 16 : Third branch claw 17 : Folding mechanism 17a : First pressing roller 17b : First folding roller 17c : Second folding roller 17d : Second pressing roller 18 : Second transport roller pair 19 : Intermediate transport roller Pair 20: Additional folding roller 21: Conveyance roller pair 26: Sheet detection sensor 40: Control section 100: Image reading device 117a: First conveyance roller pair 117b: First folding roller pair 117c: Second folding roller pair 190: Operation section 191: Fold setting section 192: First fold setting section 193: Second fold setting section 309: Platen glass 500: Automatic document feeder 501: Document table 610: Pair of carry-in rollers 611: Pair of registration rollers 612: First Single folding roller 613 : First forward/reverse roller 614 : Pressing roller 615 : Second folding roller 616 : Second forward/reverse roller pair 617 : Switchback transport roller pair 618 : Film member 621 : Skew sensor 622 : Leading edge detection sensor 624 : Entrance sensor 626 : Sheet detection sensor 628 : Stopper member A : Layer processing part B : Folding part B1 : First folding nip B2 : Second folding nip C : Folding part H : Carrying in part L : Conveyance path length W1 : Through Conveyance path W2: Folding conveyance path W3: Switchback conveyance path

Japanese Patent Application Publication No. 2014-125312

Claims (5)

Overlapping processing means having a retraction section into which the sheet skew-corrected by the skew correction means is retracted, and overlapping the sheet evacuated to the retraction section and the sheet carried in by the skew correction means;
a sheet processing device that performs predetermined processing on a set number of sheets stacked by the stacking processing device;
The overlapping processing means has a first mode in which the overlapping sheet bundle is evacuated to the retraction section regardless of whether the number of overlapping sheet bundles overlapping by the skew correction means is the set number of sheets or not. ,
It is determined whether the number of stacked sheet bundles is equal to the set number, and if the set number is not reached , the sheet bundle is evacuated to the evacuation section to ensure that the set number is reached.
a second mode of conveying the sheet bundle to the sheet processing means;
If the set number of sheets is determined at the time when the sheets are stacked by the skew correction means, the second mode is executed, and if the set number of sheets is not determined, the first mode is executed. A sheet processing device characterized in that: The sheet processing apparatus according to claim 1,
The sheet processing apparatus is characterized in that the first mode is executed when the length of the sheet in the conveying direction is equal to or greater than a threshold value. The sheet processing apparatus according to claim 1 or 2,
The sheet processing means includes a conveying means for conveying the sheet bundle, and a folding part forming means for forming a folded part in the sheet bundle, and bends the sheet bundle conveyed by the conveying means, and A sheet processing apparatus characterized in that the sheet processing apparatus is a folding means for folding the sheet bundle by introducing a bent portion of the sheet bundle into the folding section forming means. an image forming device that forms an image on a sheet;
An image forming system comprising: a sheet processing device that performs predetermined processing on the sheet;
An image forming system characterized in that the sheet processing apparatus according to any one of claims 1 to 3 is used as the sheet processing apparatus. The image forming system according to claim 4,
Equipped with an operation section that accepts user operations,
The image forming system is characterized in that the operation unit includes a confirmation button for a user to confirm the set number of sheets.

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