JP6571834B2 - Sheet processing apparatus, image forming system, and sheet processing method - Google Patents

Description

  The present invention relates to a sheet processing apparatus, an image forming system, and a sheet processing method capable of performing a creasing process on a sheet.

  Patent Document 1 discloses a sheet processing apparatus that detects the leading edge of a conveyed sheet with a skew detection sensor, corrects skew with an active roller, stops the sheet at a predetermined position, and makes a streak by a creasing mechanism. Have been described. Streaking the sheet is useful to prevent cracking of the fold when folding thick sheets. In such a product, in order to improve the appearance after being folded, high folding position accuracy (crease accuracy) has been demanded. In some cases, a long sheet such as long paper is creasing.

Japanese Patent Laid-Open No. 2015-1224013

  Since the sheet is conveyed in a bent state on the conveying path with R, the sheet may be skewed. Even in such a case, it is possible to prevent the creasing process from being deteriorated by performing the creasing process after correcting the skew by the configuration for correcting the skew of the sheet. However, when scoring is performed at a plurality of locations on a sheet, even if the skew processing in the scoring process for the top portion can be avoided, the skew of the sheet may occur in the subsequent scoring processing. As a result, the plurality of streaks are not parallel to each other, and the accuracy of the scoring process is reduced.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet processing apparatus, an image forming system, and a sheet processing method that prevent a decrease in creasing accuracy due to sheet skew.

  In order to solve the above-described problem, a sheet processing apparatus according to the present invention performs creasing of a conveying unit that conveys a sheet, a first line on the sheet, and a second line different from the first line. When performing creasing of the second muscle after creasing the first muscle by the creasing means, detecting means for detecting the direction of the first muscle, and the creasing means, Control means for controlling the direction of the second stripe with respect to the width direction of the sheet based on the detection result of the detection means.

  According to the present invention, it is possible to prevent a decrease in creasing accuracy due to sheet skew.

1 is a diagram illustrating a configuration of an image forming system. FIG. 3 is a diagram illustrating a block configuration of a control unit of the image forming apparatus. It is sectional drawing of a creasing apparatus. It is a figure which shows the structure of a creasing apparatus control part. FIG. 5 is a diagram of a skew feeding correction unit including a creasing portion as viewed from the downstream side in the sheet conveyance direction. It is a figure which shows the cross section of the crooked sheet | seat. It is sectional drawing which looked at the creasing part from the sheet conveyance direction downstream. It is the figure which looked at the creasing part from the device front side. It is sectional drawing which looked at the creasing part from the sheet conveyance direction downstream. It is a figure which shows the sheet | seat in which the creasing process was performed. It is a flowchart which shows the creasing process of a sheet | seat. It is a flowchart which shows the creasing process of a sheet | seat.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments do not limit the present invention according to the claims, and all combinations of features described in the embodiments are not necessarily essential to the solution means of the present invention. . The same constituent elements are denoted by the same reference numerals, and the description thereof is omitted.

  FIG. 1 is a diagram illustrating a configuration of the image forming system 10. As shown in FIG. 1, the image forming system 10 includes an image forming apparatus 100, a sheet creasing apparatus 170, and a finisher 180. The image forming apparatus 100 forms a monochrome / color image on a recording medium such as a sheet. In this embodiment, the image forming apparatus 100 is described as a configuration that performs image formation by an electrophotographic method, but may be configured to perform image formation by another recording method such as an inkjet recording method. The sheet creasing apparatus 170 is connected to the image forming apparatus 100 and performs a creasing process on the sheet discharged from the image forming apparatus 100. The finisher 180 is a sheet processing apparatus that performs a finishing process other than the creasing process on the sheet discharged from the sheet creasing apparatus 170. For example, the finisher 180 is a device that performs a stapling process on the sheet. The image forming apparatus 100 can be used alone without connecting the finisher 180 and the creasing apparatus 170. Further, the image forming apparatus 100 may be configured by integrating the creasing device 170 and the finisher 180 as a sheet discharge device. Here, the position where the user faces the operation unit 101 for performing various inputs / settings on the image forming apparatus 100 is referred to as the front front side (hereinafter referred to as the front side) of the image forming apparatus 100, and the rear side of the apparatus is the back side. That's it. FIG. 1 shows an image forming system 10 viewed from the front side of the apparatus. The scoring device 170 and the finisher 180 are sequentially connected to the side portion (the post-processing stage side) of the image forming apparatus 100.

  Four-color toner images are formed on the sheets supplied from the cassettes 110 and 111 in the image forming apparatus 100 by yellow, magenta, cyan, and black photosensitive drums 120, 121, 122, and 123, respectively. Is transcribed. Then, the toner image is transported to the fixing device 130 to be fixed, and in the single-sided image forming mode, the toner image is directly discharged from the discharge roller pair 140 to the outside of the apparatus. In the double-sided image forming mode, the sheet is transferred from the fixing device 130 to the reversing roller 150. Then, when the trailing edge of the sheet in the sheet conveyance direction exceeds the reverse flapper P, the reverse roller 150 is rotated in the reverse direction, and the reverse direction of the double-sided conveyance rollers 160, 161, 162, 163, 164, 165 is reversed. Be transported. Then, again, the four color toner images are transferred to the back surface by the photosensitive drums 120, 121, 122, and 123. The sheet transferred on both sides is conveyed again to the fixing device 130 to fix the toner image, and is discharged from the pair of discharge rollers 140 to the outside of the image forming apparatus 100.

  FIG. 2 is a diagram illustrating a block configuration of the control unit of the image forming apparatus 100. The controller 200 includes a CPU 201, a ROM 202, and a RAM 203. The controller 200 controls the document feeder control unit 212, the image reader control unit 213, the image signal control unit 214, the printer control unit 215, the finisher control unit 216, the scoring device control unit 217, and the external interface 211. The controller 200 reads out and executes a program stored in the ROM 202 or controls the above-described units connected to the controller 200 based on the setting of the operation unit 101. The document feeder control unit 212 controls the document feeder 102 that feeds documents one by one to the reading position of the image reader. The image reader control unit 213 controls an image reader that optically reads a document image. The image reader includes a light source that irradiates light on a document and an image sensor that detects reflected light from the document. The printer control unit 215 controls an image forming unit that forms an image on a sheet. The creasing device control unit 217 controls the creasing device 170. The finisher control unit 216 controls the finisher 180.

  In the present embodiment, the scoring device control unit 217 is described as being mounted on the scoring device 170 and the finisher control unit 216 is described as being mounted on the finisher 180. However, it is not limited to such a configuration. For example, the creasing device control unit 217 and the finisher control unit 216 are provided in the image forming apparatus 100 integrally with the controller 200 so that the creasing device 170 and the finisher 180 can be controlled from the image forming apparatus 100 side. Also good.

  The RAM 203 is used as an area for temporarily storing control data and a work area for operations associated with control. The external interface 211 is an interface from an external PC 210, for example, develops print data received from the PC 210 into an image and outputs the image to the image signal control unit 214. Image data read by the image sensor of the image reader is output from the image reader control unit 213 to the image signal control unit 214, and image data output from the image signal control unit 214 to the printer control unit 215 is not illustrated. Input to the exposure controller. The exposure control unit controls exposure by a laser applied to the photosensitive drum.

  The scoring device control unit 217 is mounted on the scoring device 170 and performs drive control of the entire scoring device 170 by communicating with the controller 200 of the image forming apparatus 100. A finisher control unit 216 is mounted on the finisher 180 and performs drive control of the entire finisher 180 by communicating with the controller 200 of the image forming apparatus 100. The scoring device control unit 217 and the finisher control unit 216 control driving of the motors and sensors in the scoring device 170 and the finisher 180, respectively.

  FIG. 3 is a cross-sectional view of the scoring device 170. The scoring device 170 sequentially takes in the sheets discharged from the image forming apparatus 100, performs a scoring process on the fetched sheets, and delivers them to the downstream finisher 180. The sheet processing in the scoring device 170 operates based on user settings in the operation unit 101 provided in the image forming apparatus 100. The user settings are, for example, a creasing position and the number of creasing.

  The sheet discharged from the image forming apparatus 100 is transferred to the entrance roller pair 301 of the creasing apparatus 170. The sheet is conveyed to the creasing unit 305 by a pair of conveying rollers 302, 303, and 304, passes through the conveyance path of the creasing unit 305, and is detected by the sheet leading edge skew detection sensor 306 placed on the front back side of the apparatus. The amount of skew is detected. Then, according to the skew amount as the detection result, the skew amount of the sheet is corrected by changing the conveyance amount by the skew correction roller pair 307 placed on the front and back side of the apparatus. Then, after the sheet stops at a predetermined position in the conveyance direction, the creasing drive unit 308 operates the creasing unit 305 to perform creasing on the sheet. When performing the second creasing, the sheet is conveyed again by the skew correction roller pair 307. By detecting the valley portion of the line of the sheet by the line skew detection sensor 309 placed on the front back side of the apparatus, the amount of skew of the line is detected. Then, by changing the conveyance amount of the skew correction roller pair 307 based on the detection result, the skew amount of the sheet is corrected again. The third and subsequent creasing is performed in the same manner as the second creasing.

  The sheet on which the creasing has been performed is conveyed by the conveyance roller pairs 310 and 311 and the discharge roller pair 312 and is delivered to the downstream finisher 180. Details of the configuration of each unit will be described later. A conveyance roller drive motor (M6) 313 controls driving of the inlet roller pair 301 and conveyance roller pairs 302, 303, and 304, and a conveyance roller drive motor (M7) 314 includes conveyance roller pairs 310 and 311 and discharge roller pair 312. Control the drive. The driven rollers 322, 323, 324, 325, 326, and 327 are driven rollers of each roller pair.

  FIG. 4 is a diagram illustrating a configuration of the scoring device control unit 217. As illustrated in FIG. 4, the scoring device control unit 217 includes a CPU 401, a RAM 402, a ROM 403, input / output units (I / O) 406, 407, 408, a communication interface 404, and a network interface 405. The I / O 406 performs input / output control with the transport control unit 409. A conveyance control unit 409 controls sheet conveyance processing. The conveyance control unit 409 controls the conveyance roller drive motors 313 and 314 and transmits detection signals from the inlet sensor 315 and the outlet sensor 316 to the I / O 406.

  The I / O 407 performs input / output control with the creasing drive control unit 410. The creasing drive control unit 410 controls the drive of the cam 317 via the cam shaft 319 by the cam drive motor 318. The I / O 408 performs input / output control with the skew correction control unit 411. The skew correction control unit 411 includes a skew correction roller driving motor (M2) 501, a skew correction roller driving motor (M3) 502, a sheet leading edge detection sensor 320, a sheet leading skew detection sensor 306, and a skew feeding. A detection signal from the detection sensor 309 is transmitted to the I / O 408. The skew correction controller 411 controls the skew correction roller 321 by the skew correction roller drive motors 501 and 502. Various sensor signals are input to the input ports of the I / O 406, 407, and 408. The output ports of the I / Os 406, 407, and 408 are connected to each drive system connected via a control block (not shown) and various drivers (not shown).

  7 is a cross-sectional view of the creasing portion 305 as viewed from the downstream side in the sheet conveying direction, and FIG. 8 is a view of the creasing portion 305 as viewed from the front side of the apparatus. The die plate 701 has a creasing groove 702. Shaft guides 703a and 703b are erected on the die plate 701, and support the movable plate 704 and the blade plate 705 in a slidable manner. The scoring blade 706 is installed on the blade plate 705, and is configured to engage with the scoring groove 702 so that the sheet can be scored. As shown in FIG. 6, the cross section of the lined sheet has a valley 601.

  The pressing springs 707a, 707b, and 707c are installed between the movable plate 704 and the blade plate 705, and the pressing springs 707a, 707b, and 707c are pressed by pushing down the movable plate 704 as shown in FIG. 9 with the cam 317 in FIG. The blade plate 705 is pushed down, and the creasing blade 706 is configured to engage the creasing groove 702. The release springs 708a and 708b are springs that push up the pressed blade plate 705, and the top dead center of the blade plate 705 is a position in contact with the stoppers 709a and 709b. Further, the top dead center of the movable plate 704 is a position in contact with the stoppers 710a and 710b. The scoring blade 706 is configured to apply a force evenly to the entire region in the sheet width direction when engaged with the scoring groove 702.

  3 has a cam 317, a camshaft 319, and a cam drive motor for rotating the camshaft 319 that push down the upper surface of the movable plate 704 of the creasing portion 305 or the upper surface of the movable plate 704 of the creasing portion 305. M1) 318 is included. The cam 317 is eccentric with respect to the axial center of the camshaft 319, and is configured to be able to rotate between a position where the upper surface of the movable plate 704 is pressed down and a position where it is not pressed down.

  In the present embodiment, the skew correction of the sheet is performed by a skew correction unit including the sheet leading edge detection sensor 320, the sheet leading edge skew detection sensor 306, the stripe skew detection sensor 309, and the skew correction roller pair 307 in FIG. . The sheet leading edge detection sensor 320 detects the leading edge position in the sheet conveyance direction, and after detecting the leading edge of the sheet, the sheet is conveyed by a predetermined amount by the skew feeding correction roller pair 307 so that the sheet is positioned at the creasing position from the sheet leading edge. Used to position The sheet leading edge skew detection sensor 306 is configured as the sheet skew detecting sensors 306a and 306b as shown in FIG. 5, detects the leading edge of the conveyed sheet (sheet detection), and detects the streak from the detection time difference between the two sensors. This is used to measure the skew amount of the leading edge of the sheet with respect to the attaching unit 305. The creasing portion 305 and the sheet leading edge skew detection sensors 306a and 306b are placed so as to be parallel to each other. The sheet leading edge skew detection sensors 306a and 306b are sensors that project light onto paper and detect the sheet leading edge based on a voltage output value of reflected light.

  The muscle skew detection sensor 309 is configured as the muscle skew detection sensors 309a and 309b as shown in FIG. 5, and detects the groove of the muscle attached to the conveyed sheet (muscle detection). This is used to measure the amount of skew of the muscle relative to the scoring unit 305 from the detection time difference. The creasing portion 305 and the skew feeding detection sensors 309a and 309b are placed so as to be parallel to each other. As shown in FIG. 6, the streak detection sensors 309a and 309b are length measurement sensors that measure a distance D (depth of a streak groove) from the paper surface to the bottom of a trough of the streak. Based on the time difference when the distance D is the maximum for each sensor placed on the front-rear side, with the position where the measured distance D is the largest as the center in the direction of muscle conveyance, the amount of skew of the muscle is measured Is done.

  FIG. 5 is a diagram of the skew feeding correction unit viewed from the downstream side in the sheet conveyance direction. A sheet passing path 505 is formed by the upper guide 503 and the lower guide 504, and skew correction driving rollers 321a and 321b and driven rollers 322a and 322b for conveying the sheet are provided. The skew correction drive roller 321a is driven from the drive motor 501 via gears 506a and 507a and a roller shaft 508a. Further, the skew correction driving roller 321b is driven from the driving motor 502 via gears 506b and 507b and a roller shaft 508b. The skew feeding is performed by making a difference in rotational speed between the skew correction driving rollers 321a and 321b so as to cancel the skew feeding amounts detected by the sheet leading edge skew detection sensors 306a and 306b and the muscle skew detection sensors 309a and 309b. Correction is performed.

[Explanation of creasing mode operation]
The operation of the sheet creasing mode in this embodiment will be described below. 11 and 12 are flowcharts showing the sheet creasing process in the creasing mode. The processing shown in FIGS. 11 and 12 is realized, for example, when the CPU 401 reads out the program stored in the ROM 403 to the RAM 402 and executes it. However, the processing of S101 to S105 is realized by the CPU 201 of the image forming apparatus 100 reading out the program stored in the ROM 202 to the RAM 203 and executing it. 11 and 12 may be realized by the CPU 201 of the image forming apparatus 100 reading out the program stored in the ROM 202 to the RAM 203 and executing it.

  In step S <b> 101, the operation unit 101 of the image forming apparatus 100 receives a selection of the scoring mode on the main screen from the user. When receiving the selection of the creasing mode, the operation unit 101 displays a setting screen for the creasing mode. In step S102, the operation unit 101 accepts selection of the sheet size and the number of sheets. In step S103, the operation unit 101 receives an input of the number of lines, and in step S104, receives an input of a line position. In step S105, the operation unit 101 receives a copy start instruction. When an instruction to start copying is received, the image forming apparatus 100 starts printing.

  In step S <b> 106, the CPU 401 drives the conveyance roller drive motors 313 and 314 of the scoring device 170 to rotate the inlet roller pair 301, the conveyance roller pairs 302, 303, 304, 310, 311, and the outlet roller pair 312.

  In S107, when the sheet is transferred from the image forming apparatus 100 to the scoring apparatus 170 and the entrance sensor 315 is turned on, in S108, the CPU 401 drives the skew feeding correction roller driving motors 501 and 502, and the skew feeding correction roller 321a. 321b and driven rollers 322a and 322b are rotated.

  In S109, when the sheet leading edge skew detection sensors 306a and 306b detect the leading edge of the conveyed sheet, in S110, the CPU 401 cancels the nip of the driven rollers 323, 324, 325, 326, and 327 by a solenoid (not shown). State. In step S <b> 111, the CPU 401 measures the skew amount of the sheet from the detection time difference between the sheet leading edge skew detection sensors 306 a and 306 b and acquires the skew amount to be corrected by the skew correction roller 321.

  The sheet easily passes through the conveyance in the image forming apparatus 100 and the conveyance path R <b> 1 with an R in the scoring apparatus 170 to receive resistance of a conveyance guide constituting the conveyance path. In particular, the cardboard has high rigidity, and is thus easily subjected to the resistance of the conveyance guide. In this embodiment, when such a skew has occurred, correction is performed before the scoring process.

  In S112, the CPU 401 corrects the skew by individually changing the conveying speed of the skew correction rollers 321a and 321b for a predetermined time by the skew correction roller drive motors 501 and 502 so as to cancel the skew. In S113, when correcting the skew, the CPU 401 changes both the skew correction rollers 321a and 321b to the same transport speed. In S114, when the sheet leading edge detection sensor 320 detects the leading edge of the sheet, in S115, the CPU 401 rotates the skew correction rollers 321a and 321b by a predetermined amount based on the distance of the leading edge of the sheet from the creasing portion 305, and the sheet. It is determined whether or not it has been transported to the creasing position. The process of S115 is repeated until it is determined that the sheet has been conveyed to the creasing position. If it is determined that the sheet has been conveyed to the scoring position, the CPU 401 stops the skew correction rollers 321a and 321b by the skew correction roller drive motors 501 and 502 in S116.

  In S117 and S118, the CPU 401 performs the creasing process by driving the cam drive motor 318 once. That is, in S117, the CPU 401 turns on the cam drive motor 318, and in S118, the CPU 401 turns off the cam drive motor 318. In step S119, the CPU 401 drives the skew correction roller driving motors 501 and 502 to convey the sheet. At that time, the streak 1001 in FIGS. 10A and 10B is attached to the sheet S. As described above, in the present embodiment, before the creasing process, the amount of skew of the sheet is detected and the skew is corrected, and then the creasing process is performed. As shown in FIG. 10B, the length 1011 = the length 1021.

  In S <b> 120, the CPU 401 determines whether or not to perform the second location. This determination is performed based on, for example, the setting content on the setting screen of the creasing mode. If it is determined that the second location is to be performed, the process proceeds to S121. If it is determined not to perform the second location, the process proceeds to S131.

  When it is determined that the second creasing is to be performed, in S121, the skew feeding detection sensors 309a and 309b detect the streaks previously attached on the sheet in S117 and 118 for the conveyed sheet. In S122, the CPU 401 detects the amount of skew of the muscle based on the detection time difference between the muscle skew detection sensors 309a and 309b, and based on the detection result, the amount of skew to be corrected by the skew correction rollers 321a and 321b. To get. If the skew amount detected in S122 is within a predetermined range, the skew correction rollers 321a and 321b may not be corrected.

  Even if the sheet has been skew-corrected once, it is conveyed in a state where the rear end side of the sheet is applied to the conveying path R1 with R in the scoring device 170 and the leading end side is applied to the conveying path R2. Suppose that In this case, the skew is caused by the resistance of the conveyance guide constituting the conveyance path, and the sheet is conveyed obliquely as shown in FIG. 10C, and the relative position of the first line 1001 and the second line 1002 to be applied second time. As a relationship, there is a high possibility of becoming diagonal. Therefore, in this embodiment, the skew correction of the sheet is performed again according to the skew state before the subsequent creasing process so that the subsequent creasing process is not performed while the sheet is inclined.

  In S123, the CPU 401 causes the skew feeding correction roller drive motors 501 and 502 to individually change the transport speed of the skew feeding correction rollers 321a and 321b for a predetermined time so as to cancel the skew feeding. So that it is within the range. In S124, the CPU 401 changes the skew correction rollers 321a and 321b to the same conveyance speed by the skew correction roller drive motors 501 and 502. In S125 and S126, the CPU 401 rotates the skew feeding correction rollers 321a and 321b by a predetermined amount to stop the sheet at the scoring position. Then, the CPU 401 performs the creasing process by driving the cam drive motor 318 once. That is, the CPU 401 turns on the cam drive motor 318 in S127, and turns off the cam drive motor 318 in S128. Thereafter, in S129, the CPU 401 drives the skew correction roller drive motors 501 and 502 to convey the sheet. At this point, the streaks 1002 of FIGS. 10A and 10B can be attached to the sheet S.

  In the present embodiment, the positions of the creasing portion 305 and the skew feeding detection sensors 309a and 309b are arranged so as not to sandwich the portion R in the conveyance path. This is because if the skew of a line is detected at a position sandwiching R after the creasing process, the generated skew may not be detected correctly depending on the degree of bending of the sheet S at the R portion. is there. By arranging the creasing part 305 and the stray skew detection sensors 309a and 309b as in the present embodiment, it is possible to correctly detect the skew occurring in the sheet S even after the creasing process. it can.

  As described above, in this embodiment, since the skew 1002 is attached after detecting the skew amount of the muscle 1001 and correcting the skew before the creasing process, the muscle 1002 is not inclined with respect to the muscle 1001 and is long. 1012 = length 1022. That is, it is possible to improve the parallelism by setting the stripe 1001 and the stripe 1002 within a predetermined oblique range. If the creasing process is performed without performing the skew correction, the streak 1002 becomes oblique with respect to the streak 1001, as shown in FIG. 10C, and the length 1032 ≠ the length 1042. .

  In S130, the CPU 401 determines whether or not the scoring process is finished. If it is determined that the scoring process has not ended, that is, if a scoring process is to be performed on a different part of the same sheet, the processes from S121 are repeated. On the other hand, if it is determined that the scoring process has been completed, the process proceeds to S131.

  In S131, the CPU 401 brings the driven rollers 323, 324, 325, 326, and 327 into a nip state by a solenoid (not shown). Then, the CPU 401 delivers the sheet from the scoring device 170 to the finisher 180. When the exit sensor 316 detects the discharge of the scoring device 170 outside the apparatus in S132, the CPU 401 stops driving the skew correction rollers 321a and 321b by the skew correction roller drive motors 501 and 502 in S133. To do.

  In step S134, the CPU 401 determines whether or not it is the final sheet that is the target of the scoring process. If it is determined that the sheet is not the final sheet, the processing from S107 is repeated. On the other hand, if it is determined that the sheet is the final sheet, the CPU 401 stops the conveyance roller drive motors 313 and 314 to stop the conveyance roller pair and completes the job. Thereafter, the processes in FIGS. 11 and 12 are terminated.

(Other embodiments)
In the present embodiment, the tip skew detection sensor 306 and the muscle skew detection sensor 309 are configured as separate bodies, but the tip skew detection sensor 306 may be used as a distance measuring sensor and may also serve as the muscle skew detection sensor. By adopting this configuration, it is possible to shorten the sheet conveyance distance from the detection and skew correction of the first line to the second line, so that the first and second lines can be shortened. It becomes possible to further improve the parallelism of the muscles. Further, the sheet leading edge detection sensor 320 can also detect the passage of a line, and after the sheet leading edge detection sensor 320 detects the passage of the first line, the sheet is conveyed by a predetermined distance, and the second line is detected. You may attach With this configuration, it is possible to improve the accuracy of the distance from the first streak to the second streak.

  In addition, sensors at a plurality of positions in the sheet width direction (direction intersecting (orthogonal) with the conveyance direction) installed on the front back side, that is, the sheet leading edge skew detection sensors 306a and 306b and the skew skew detection sensors 309a and 309b Instead, a line sensor may be used, or skew correction may be performed by reading a sheet on which the user has performed the creasing process with a reading device.

  As described above, according to the present embodiment, the parallelism between the streaks formed on the sheet can be improved. In the present embodiment, the skew of the first line is detected, the sheet is corrected in accordance with the skew, and the second line creasing process is performed. However, the present invention is not limited to such a structure. . For example, even when the creasing process for the second location is not performed, the skew of the sheet may be corrected according to the skew of the first location. With this configuration, the sheet can be conveyed with less skew.

  In the above-described embodiment, the skew of the first streak is detected, and the position of the sheet is changed (the sheet is corrected) according to the skew. However, in order to perform the second creasing process, the configuration is not limited to the configuration in which the position of the sheet is changed, and other configurations may be used. For example, the creasing process may be performed so that the skew of the first streak is within a predetermined range by changing the direction of the scoring unit 305. In such a case, for example, a turntable configuration is provided at the bottom of the creasing portion 305 so that the creasing portion 305 can rotate with respect to the shaft. When the skew of the first line is detected, the scoring unit 305 is rotated according to the detected value (for example, an angle with respect to the conveyance direction).

  Furthermore, it is good also as a structure which combined rotation of the skew correction roller and the creasing part 305. FIG.

  DESCRIPTION OF SYMBOLS 100 Image forming apparatus: 170 creasing apparatus: 305 creasing part: 306 sheet front skew detection sensor: 309 stripe skew detection sensor: 401 CPU: 402 RAM: 403 ROM

Claims (10)

Conveying means for conveying the sheet;
Creasing means for creasing the sheet with a first muscle and a second muscle different from the first muscle;
Detecting means for detecting a direction of the first muscle;
When creasing the second muscle after creasing the first muscle by the creasing means, based on the detection result of the detecting means, the second with respect to the width direction of the sheet. Control means for controlling the direction of the muscles of
A sheet processing apparatus comprising: A leading edge detecting means for detecting an inclination of the leading edge of the sheet with respect to a conveying direction;
The sheet processing apparatus according to claim 1, wherein the control unit controls a direction of the first muscle based on a detection result of the tip detection unit.   The leading edge detecting means is composed of a plurality of sheet detecting means provided in a width direction intersecting with the conveying direction, and the inclination of the leading edge with respect to the conveying direction is determined based on a detection result by each of the plurality of sheet detecting means. The sheet processing apparatus according to claim 2, wherein the sheet processing apparatus detects the sheet processing apparatus. The conveying means has a plurality of rollers provided in a width direction orthogonal to the conveying direction of the sheet,
4. The control unit according to claim 1, wherein the control unit controls a direction of the second stripe with respect to a width direction of the sheet by controlling a conveyance speed of each of the plurality of rollers. 5. The sheet processing apparatus according to 1.   The sheet processing apparatus according to claim 1, wherein the detection unit is a line sensor.   5. The detection unit according to claim 1, wherein the detection unit includes a plurality of streak detection units provided at a plurality of positions in a width direction orthogonal to the conveyance direction of the sheet. Sheet processing equipment.   The control means controls the direction of the second stripe by the creasing means based on the detection result of the detection means in order to control the direction of the second stripe with respect to the width direction of the sheet. The sheet processing apparatus according to claim 1, wherein:   The sheet processing apparatus according to claim 1, wherein the sheet conveyed to the creasing unit is supplied from an image forming apparatus that forms an image on the sheet.   An image forming system comprising: an image forming apparatus that forms an image on a sheet; and the sheet processing apparatus according to claim 1. A sheet processing method executed in a sheet processing apparatus,
A conveying step for conveying the sheet;
A first scoring step of scoring a first streak to the sheet by a scoring means;
A detecting step of detecting a direction of the first muscle;
After the first scoring step, a second scoring direction is controlled based on the detection result in the detection step, and a second streak different from the first muscle is crooked by the scoring means. The scoring process,
A sheet processing method comprising:

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