JP2020045179A - Image formation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To speed up a sheet without crotching an image-formed sheet between devices, and to quickly convey even a long sheet to improve productivity. When the sheet received from the image forming apparatus 100 is a short sheet, the puncher control unit 971 of the puncher 400 in the image forming system 1000 conveys the short sheet to a short path 419 and is in the short path. In the first mode in which the transport speed of the short sheet is increased from low speed to high speed and the short sheet is delivered to the finisher 500, the sheet received from the image forming apparatus has a longer sheet length in the transport direction than the short sheet. In the case of a long sheet, the long sheet is transported to the punch pass 416, and the transport speed of the long sheet is increased from low speed to high speed in the punch pass, and the long sheet is delivered to the finisher. One of the modes is selected according to the length of the sheet, and the selected mode is executed. [Selection diagram] Fig. 1

Description

  The present invention relates to an image forming system that forms an image on a sheet and processes the sheet.

  Conventionally, in this type of image forming system, the image forming speed of the image forming apparatus does not match the sheet processing speed of the sheet processing apparatus, and it has been difficult to improve the productivity.

  Therefore, as an image forming system that addresses this problem, there is an image forming system described in Patent Document 1. The image forming system stores (stacks) sheets between the image forming apparatus and the sheet processing apparatus, and adjusts a speed difference between an image forming speed of the image forming apparatus and a sheet processing speed of the sheet processing apparatus. It has become.

JP 2006-56712 A

  However, in the conventional image forming system, since the sheets are stored, it is difficult to quickly convey a particularly long sheet, and it is difficult to improve the productivity.

  In view of the above, the present invention provides an image forming apparatus capable of increasing the speed without crotting an image-formed sheet between apparatuses and quickly conveying even a long sheet to improve productivity. It is to provide a forming system.

  An object of the present invention is to provide an image forming apparatus that forms an image on a sheet, and a sheet capable of receiving and conveying a sheet on which an image is formed by the image forming apparatus and performing a first process on the sheet. An image forming system comprising: a sheet processing apparatus; and a second sheet processing apparatus configured to receive a sheet conveyed through the first sheet processing apparatus and perform a second process on the sheet. A sheet is transferred to the first sheet processing apparatus at a first speed, and the first sheet processing apparatus transports the sheet received from the image forming apparatus to the second sheet processing apparatus and a second transport path. A switching means for switching the path of the sheet received from the image forming apparatus to one of the first and second transport paths; and a switching means for switching the first and second transport paths. And a control unit that controls the switching unit and the transport unit. The second transport path is longer than the first transport path, and the transport unit is configured to transport the sheet. 1, the sheet can be conveyed at a second speed higher than the first speed, and when the sheet received from the image forming apparatus is the first sheet, Conveying the first sheet to the first conveyance path, and increasing the conveyance speed of the first sheet from the first speed to the second speed in the first conveyance path, In the first mode for transferring a sheet to the second sheet processing apparatus, and when the sheet received from the image forming apparatus is a second sheet having a longer sheet length in the conveyance direction than the first sheet, Convey the second sheet to the second conveyance path And increasing the transport speed of the second sheet in the second transport path from the first speed to the second speed, and transferring the second sheet to the second sheet processing apparatus. The two modes can be executed.

  Further, according to the present invention, it is possible to provide an image forming apparatus for forming an image on a sheet, and a sheet on which an image is formed by the image forming apparatus, receiving and conveying the sheet, and performing a first process on the sheet. An image forming system comprising: a first sheet processing apparatus; and a second sheet processing apparatus that receives a sheet conveyed through the first sheet processing apparatus and performs a second process on the sheet. Transfers the sheet to the first sheet processing apparatus at a first speed, and the first sheet processing apparatus transfers a sheet received from the image forming apparatus to the second sheet processing apparatus. A second conveyance path, a switching unit for switching a conveyance path of the sheet received from the image forming apparatus to one of the first conveyance path and the second conveyance path, and a first conveyance path and a second conveyance path. And a control unit for controlling the switching unit and the conveying unit, wherein the second conveying path is longer than the first conveying path. 1 and the sheet can be conveyed at a second speed higher than the first speed, and the control unit controls the image forming apparatus to control the sheet conveyance speed in the first conveyance path. An image is formed on a sheet longer than a sheet capable of increasing the speed from the first speed to the second speed, and the sheet is sent to the second sheet processing device via the first sheet processing device. When the sheet is conveyed through the first conveyance path at the first speed in the image forming job that conveys the sheet, the first time required until the image forming job is completed, and the sheet is conveyed in the second conveyance path At the first speed And a second time required until the end of the image forming job in a case where the speed is increased at the second speed and conveyed along the second conveyance path, and the first time is calculated based on the second time. If the time is shorter than the first time, the sheet is transported to the first transport path at the first speed. If the second time is shorter than the first time, the sheet is transported to the second transport path. The problem is solved by the image forming system, wherein the speed is increased from the first speed to the second speed in the transport path and the transport is performed on the second transport path.

  The image forming system of the present invention selects a conveyance path having a length corresponding to the length of the sheet and increases the speed of the sheet in the path. Since the sheet can be transferred from the forming apparatus to the second sheet processing apparatus at an increased speed, the sheet can be processed quickly, and the productivity can be improved.

  Further, the image forming system according to the present invention has a time for conveying a sheet without increasing the speed of the first transport path having a short length, and a time for transporting the same sheet by increasing the speed of the second transport path having a long length. And selects a short conveyance path, and transfers the sheet from the image forming apparatus to the second sheet processing apparatus. Therefore, even a long sheet can be processed quickly to improve productivity. Can be improved.

FIG. 1 is a diagram illustrating a schematic configuration of an image forming system according to an embodiment. FIG. 2 is a schematic cross-sectional view of the puncher of FIG. 1 along a sheet conveyance direction. FIG. 2 is a schematic cross-sectional view of the finisher of FIG. 1 along a sheet conveying direction. FIG. 2 is a control block diagram of the image forming system of FIG. 1. FIG. 5 is a block diagram illustrating a configuration of a puncher control unit in FIG. 4. FIG. 5 is a block diagram illustrating a configuration of a finisher control unit in FIG. 4. 3 is a flowchart showing control of the puncher shown in FIGS. 1 and 2. 3 is a flowchart illustrating control of the first and second embodiments in the puncher of FIG. 2. It is a flowchart which shows the control of 2nd Embodiment in the puncher of FIG. 3 is a flowchart illustrating control of the first and second embodiments in the puncher of FIG. 2. 4 is a table based on experimental results showing a relationship between a length of a sheet and a processing time required for rear end alignment of the sheet in the finisher of FIG. 3. 2 is a table showing a sheet discharge speed and a sheet interval of the image forming apparatus in FIG. 1. 3 is a table showing sheet information received by the puncher in FIG. 2. (A) is a table of sheet information when there are three sheets. (B) is a table of sheet information for one sheet.

  Hereinafter, an image forming system according to an embodiment of the present invention will be described with reference to the drawings. The numerical values described in the embodiments are reference numerical values, and the present invention is not limited to these numerical values.

  An image forming system according to an embodiment of the present invention includes a first embodiment and a second embodiment, and a common part between the first embodiment and the second embodiment will be described.

  FIG. 1 is a diagram illustrating a schematic configuration of an image forming system according to an embodiment of the present invention. The image forming system 1000 mainly includes an image forming apparatus 100 that forms an image on a sheet, an image reading apparatus 200 that reads a document image, an operation display apparatus 600 that displays an operation screen, and a sheet on which an image is formed by the image forming apparatus 100. And a puncher 400 (first sheet processing apparatus) capable of perforating a sheet (performing first processing) and receiving a sheet conveyed by the puncher 400 and placing the sheet on a tray 507. And a finisher (second sheet processing apparatus) 500 that performs a rear end alignment process (performs a second process).

(Image reading device 200)
In FIG. 1, the image reading apparatus 200 mainly includes a document feeding unit 200A and a document reading unit 200B. The document feeding unit 200A conveys the documents D set on the document tray 201 one by one in the left direction in FIG. 1, and conveys the documents D to the right via a reading position on the platen glass 202 via a curved path. The sheet is discharged to a discharge tray 203. The document reading unit 200B includes a scanner unit 204 that stops at a position corresponding to a reading position that is a predetermined position below the platen glass 202, and an image sensor 205. When the document passes a reading position on the platen glass 202, the reading surface of the document is irradiated by the light source of the scanner unit 204. The reflected light of the document reaches, for example, the image sensor 205 via the mirror and the lens 206 and forms an image on the imaging surface of the image sensor 205. The optically read image is converted into image data by the image sensor 205 and sent to the exposure device 103 of the image forming apparatus 100 as an image signal.

(Image forming apparatus 100)
1, the image forming apparatus 100 mainly includes a sheet supply unit 100A, an image forming unit 100B, and a fixing unit 106. The image forming unit 100B is mainly formed by the photosensitive drum 101, the charger 102, the exposing unit 103, the developing unit 104, and the transfer unit 105. The sheet supply unit 100A includes sheet cassettes 111 and 112, and a conveyance path 110 from the sheet cassette to a discharge roller 116 via a transfer unit 105 and a fixing unit 106 near the photosensitive drum 101. The sheet supply unit 100 </ b> A is connected to a reversing path 119, which branches the conveyance path 110 on the downstream side of the photosensitive drum 101, and a reversing path 119, and has one end connected to the conveyance path 110 on the upstream side of the transfer unit 105. A path 120 is also provided. The transport path 110 includes pickup rollers 127 and 128 disposed at exits of the sheet cassettes 111 and 112, transport rollers 129 and 130 that transport the picked-up sheet to the transfer unit 105, and an upstream side of the transfer unit 105. Registration roller pair 114 and the like. In the transport path 110 on the downstream side of the fixing device 106, a transport roller 115, a path switching member 118, and a discharge roller 116 are provided. The path switching member 118 switches the transport direction of the sheet transported on the transport path 110 to the reverse path 119.

  In the image forming apparatus 100 having such a configuration, the exposing unit 103 modulates and outputs a laser beam based on an image signal input from the image reading apparatus 200. The output laser beam is irradiated on the photosensitive drum 101 while being scanned by the polygon mirror 107. An electrostatic latent image corresponding to the scanned laser light is formed on the surface of the photosensitive drum 101 irradiated with the laser light. The electrostatic latent image on the photosensitive drum 101 is visualized by a developer supplied from the developing device 104 to become a toner image.

  On the other hand, the sheet P sent from the upper sheet cassette 111 or the lower cassette 112 by the pickup roller 127 or 128 is conveyed by the conveying rollers 129 and 130, and the leading end of the sheet P is stopped by the registration roller pair 114. It is accepted. For this reason, the sheet is bent and straightened when skewed. Next, the sheet P is conveyed between the photosensitive drum 101 and the transfer unit 105 by the registration roller pair 114 which restarts rotation at a timing synchronized with the start of laser beam irradiation. Then, the transfer unit 105 transfers the toner image formed on the photosensitive drum 101 to the sheet P. The sheet P to which the toner image has been transferred is conveyed to the downstream fixing device 106, where the sheet P is heated and pressed by the fixing device 106 to fix the toner image. The sheet P on which the toner image has been fixed is discharged from the image forming apparatus 100 to the puncher 400 described below via the path switching member 118 and the discharge roller 116 with the toner image (image forming surface) facing upward (face up). .

  When the sheet is discharged with the toner image facing down (face down), the sheet P that has passed through the fixing device 106 is once guided to the reversing path 119 by the switching operation of the path switching member 118, and the rear end is moved to the path switching member. After passing through 118, the sheet is conveyed by switchback and discharged from the image forming apparatus 100 to the puncher 400 by the discharge roller 116. The operation of reversing the toner image from the upper side to the lower side is called a sheet reversing operation. This sheet reversing operation is performed when image data read by the image reading device 200 or image data transmitted from an external computer is formed on a sheet in page order.

  When an image is formed on both sides of the sheet P, the sheet is guided to the reversing path 119 by the switching operation of the path switching member 118, and then is conveyed through the two-sided conveying path 120. At this timing, the toner image is transferred to the other surface between the photosensitive drum 101 and the transfer unit 105, and finally discharged to the puncher 400 as a double-sided image sheet. On the other hand, a hard sheet such as an OHP sheet is manually fed from the manual feed sheet unit 113. In this case, the sheet is discharged to the puncher 400 by the discharge roller 116 with the image forming surface facing upward (face-up) without being guided to the reverse path 119.

(Puncher 400)
FIG. 2 is a schematic cross-sectional view of the puncher 400 in FIG. 1 along the sheet conveyance direction.
1 and 2, the puncher 400 has a punch unit 415 in which one or many holes are formed in a sheet. The puncher 400 includes a substantially straight short path (first transport path) 419 and a U-shaped punch path (second transport path) 416 as paths. The short path 419 is provided with conveying rollers 421, 410, and 409. The punch path 416 branches off from the short path 419 on the downstream side of the transport roller 421. A path switching member 420 is disposed in the branching part 431. The path switching member (switching means) 420 is rotated to a position indicated by a solid line and a broken line by a solenoid (switching means) SL3, and switches between the short path 419 and the punch path 416.

  A transport sensor S1 is provided upstream of the transport roller 421 of the short path 419. In the punch path 416, transport rollers 401 to 408 are provided. A transport sensor S2 is disposed between the transport rollers 403 and 404. A transport sensor S3 is arranged between the transport rollers 405 and 406. Further, a replaceable punch unit (first processing unit) 415 is provided between the transport roller 404 and the transport roller 405. That is, the punch unit 415 is provided exchangeably with respect to the puncher 400. The punch path 416 joins the short path 419 on the downstream side of the transport roller 408. A transport roller 409 and a transport sensor S4 are sequentially arranged downstream of the junction 432 toward the downstream.

  The length of the path from the branch 431 of the short path 419 and the punch path 416 to the junction 432 is longer in the punch path 416. The transport rollers 421, 410, and 409 are driven by a short-path transport motor M20, and the transport rollers 401 to 408 are driven by a bypass transport motor M21 at a first speed (e.g., 500 mm / sec). The sheet can be conveyed (can be conveyed) at a high second speed (for example, 1000 mm / sec). The transport rollers 421, 410, and 409 and the short path transport motor M20 constitute a transport unit. The transport rollers 401 to 408 and the bypass transport motor M21 also constitute a transport unit.

  The puncher 400 sequentially takes in the sheets P discharged from the image forming apparatus 100 and performs a punching process on the taken-in sheets P. The puncher 400 determines based on the sheet information indicating whether or not to perform the punching process, which is notified from the image forming apparatus 100. The sheet information will be described later.

  When a punching process is performed on the sheet P discharged from the image forming apparatus 100, a puncher control unit 971 (FIG. 5) described later activates the solenoid SL3 based on the sheet detection information of the conveyance sensor S1 to pass the sheet. The switching member 420 is switched from the position indicated by the solid line to the position indicated by the broken line. Then, the puncher 400 takes in the sheet into the punch path 416 by the conveyance of the conveyance roller 421 and the guide of the path switching member 420. The sheet P taken in the punch path 416 is conveyed by the conveyance rollers 401, 402, and 403, and is detected by the conveyance sensor S2. Further, the sheet is sent to the punch unit 415 by the transport roller 404. The punch unit 415 punches a sheet (performs a punching process).

  The sheet P after the punch processing is carried out to the downstream finisher 500 by the conveying rollers 405 to 408 and 409. At this time, the transport sensor S3 and the transport sensor S4 each detect that the sheet P has passed.

  On the other hand, when the sheet P discharged from the image forming apparatus 100 is not subjected to the punching process, the sheet P is divided into two patterns: a case where the sheet P is taken into the punch path 416 and a case where the sheet P is taken into the short path 419. The determination of the selection of these two patterns will be described later. The sheet that has not been subjected to the punch processing but has been taken into the punch path 416 is carried out to the downstream finisher 500 without being subjected to the punching (punching) processing.

(Finisher 500)
FIG. 3 is a schematic cross-sectional view of the finisher 500 of FIG. 1 along the sheet conveyance direction. The sheet discharged from the puncher 400 reaches the transport roller 503. The sheet is detected by the entrance sensor S5, and is discharged onto the tray 507 by the start rotation of the transport roller 503. When the sheet is discharged to the tray 507, the sheet upper surface detection sensor S6 detects the sheet and turns off. Thereafter, the tray 507 descends and stops for a certain distance, and receives the sheet that has passed the transport roller 503 at that position. Then, the tray 507 rises to a position where the discharged sheet is detected by the sheet upper surface detection sensor S6, and stops at that position.

  When the tray 507 rises, the arm 505 rotates from the position indicated by the solid line to the position indicated by the dotted line in FIG. 3, and the alignment roller (second processing unit) 504 attached to the tip of the arm 505 is discharged to the tray 507. Touches the top surface of the sheet. Finally, the aligning roller 504 rotates counterclockwise in FIG. 3 to bring the sheet into contact with the outer wall of the main body 500A of the finisher 500, thereby performing the trailing edge alignment of the sheet. Thus, the sheets are stacked on the tray 507 with their rear ends aligned.

  If the length of the sheet in the sheet discharge direction is longer than the length of the tray 507, the finisher 500 may cause the leading edge of the sheet to hang down from the tray 507, and may not be able to align the sheet by a single alignment (pulling-back) operation. In such a case, the matching is performed a plurality of times. Therefore, the time required for the trailing edge alignment of the sheet differs depending on the length of the sheet.

  FIG. 11 is a table based on experimental results showing the relationship between the length of the sheet and the processing time required for the trailing edge alignment of the sheet in the finisher 500 of FIG. According to the table of FIG. 11, in each case where the sheet length is less than 500 mm, 500 mm or more and less than 60 mm, or 600 mm or more, the rear end alignment processing time of the sheet (hereinafter sometimes simply referred to as “finisher processing time”). ) Are about 300 msec, about 600 msec, and about 900 msec, respectively. That is, according to the table of FIG. 11, the finisher (second processing unit) 500 has a longer sheet (second sheet described later) than a short sheet (first sheet described later). The sheet (sheet) has a longer trailing edge alignment processing time.

(Control block diagram of image forming system 1000)
FIG. 4 is a control block diagram of the image forming system 1000 of FIG. See FIG. 1 and FIG. The image forming system 1000 includes a controller CPU circuit unit 900. The controller CPU circuit unit 900 includes a CPU 901, a ROM 902, and a RAM 903. The CPU 901 performs basic control of the entire image forming system 1000.

  The CPU 901 is connected by a data bus (not shown) to a ROM 902 in which a control program is written, and to a RAM 903 which temporarily holds control data and is used as a work area for arithmetic processing accompanying control. The CPU 901 includes a document feeding unit control unit 911, a document reading unit control unit 921, an image signal control unit 922, an external I / F 904, a printer control unit 931, an operation display device control unit 941, a finisher control unit 951, and a puncher control unit. 971 so as to be able to communicate with each other, and these are generally controlled based on a control program stored in a ROM 902.

  The document feeding section control section 911 controls the driving of the document feeding section 200A of the image reading apparatus 200 based on an instruction from the controller CPU circuit section 900. The document reading unit control unit 921 performs drive control of the scanner unit 204, the image sensor 205, and the like, and transfers an image signal output from the image sensor 205 to the image signal control unit 922.

  The image signal control unit 922 converts the analog image signal from the image sensor 205 into a digital signal, performs each process, converts the digital signal into an image signal, and outputs the image signal to the printer control unit 931. Further, the image signal control unit 922 performs various processes on the digital image signal input from the computer 905 via the external I / F 904, converts the digital image signal into an image (video) signal, and sends it to the printer control unit 931. Output. The processing operation of the image signal control unit 922 is controlled by the controller CPU circuit unit 900. The printer control unit 931 controls the image forming apparatus 100 based on the input image signal, and performs image formation and sheet conveyance.

  The puncher control unit 971 is mounted on the puncher 400 and exchanges information with the controller CPU circuit unit 900 to control the driving of the entire puncher 400. The details of this control will be described later. The finisher control section 951 is mounted on the finisher 500, and exchanges information with the controller CPU circuit section 900 to control the drive of the entire finisher 500. The details of this control will also be described later.

  The operation display device control unit 941 exchanges information between the operation display device 600 and the controller CPU circuit unit 900. The operation display device 600 includes a plurality of keys for setting various functions related to image formation, a display unit for displaying information indicating a setting state, and the like. The operation display device 600 outputs a key signal corresponding to an operation of each key to the controller CPU circuit unit 900, and displays corresponding information on the display unit based on a signal from the controller CPU circuit unit 900. .

(Block diagram of puncher control unit 971)
FIG. 5 is a block diagram showing a configuration of the puncher control unit 971 in FIG. See FIG. 1, FIG. 2, FIG. 4, and FIG. The puncher control section 971 drives and controls the puncher 400. The puncher control unit 971 includes a CPU 972, a ROM 973, a RAM 974, and the like. The puncher control unit 971 communicates with the controller CPU circuit unit 900 of the image forming apparatus 100 via a communication IC (not shown) to exchange data such as job information and sheet transfer notification. Further, the puncher control section 971 is communicably connected to a finisher control section 951 via a communication IC.

  The puncher control unit 971 also includes a short path conveyance motor M20, a bypass conveyance motor M21, a pull-in motor M22, a punch conveyance motor M23, a sheet ejection motor M24, and conveyance sensors S1 to S4 for driving conveyance rollers for conveying a sheet. It is connected. The puncher controller 971 is also connected to a punch motor M25 and a solenoid SL3 for punching (performing punching) the conveyed sheet with the punch unit 415. Then, the puncher control unit 971 executes various programs stored in the ROM 973 based on an instruction from the controller CPU circuit unit 900 to control driving of the puncher 400 by various motors and sensors provided in the puncher 400. Has become. At this time, the puncher control unit 971 outputs, for example, a drive signal to various motors and receives a detection signal from each sensor.

(Block diagram of finisher control unit 951)
FIG. 6 is a block diagram showing a configuration of the finisher control unit 951 in FIG. See FIG. 1, FIG. 3, FIG. 4, and FIG. The finisher control unit 951 includes a CPU 952, a ROM 953, a RAM 954, and the like. The finisher control unit 951 communicates with a controller CPU circuit unit 900 provided in the image forming apparatus 100 via a communication IC (not shown) to exchange data such as job information and sheet transfer notification. I have. The finisher control section 951 is also communicably connected to a puncher control section 971 via a communication IC (not shown).

  The finisher controller 951 includes an entrance sensor S5 for detecting that a sheet has been carried into the apparatus, a sheet discharge motor M3 for driving a conveying roller 503 for conveying the sheet, a tray elevating motor M15 for elevating and lowering the tray 507, and A sheet upper surface detection sensor S6 for detecting the upper surface of the sheets stacked on the tray 507, a solenoid SL1 for lowering the arm 505 when the sheets are stacked, and an alignment motor M6 for rotating an alignment roller 504 attached to the tip of the arm 505. It is connected to the.

(Image Forming System of First Embodiment)
FIGS. 7, 8, 9, and 10 are flowcharts illustrating the control of the puncher 400 of FIGS.

  When the sheet received from the image forming apparatus 100 is a short sheet (less than 390 mm, the first sheet), the puncher control unit (control unit) 971 of the puncher 400 in the image forming system according to the first embodiment sets the short sheet. The sheet is conveyed to the short path 419, and the conveying speed of the short sheet is increased from a low speed (500 mm / sec, first speed) to a high speed (1000 mm / sec, second speed) within the short path 419. In the first mode in which the sheet is transferred to the finisher 500, and when the sheet received from the image forming apparatus 100 is a long sheet (390 mm or more, a second sheet) in which the length of the sheet in the transport direction is longer than the short sheet. The long sheet is conveyed to the punch path 416, and the conveying speed of the long sheet is reduced (500 mm) in the punch path 416. sec, the first speed) to a high speed (1000 mm / sec, the second speed) to transfer the long sheet to the finisher 500. Select and execute.

  In the image forming apparatus 100 (FIG. 1), when an image starts to be formed on a sheet, the puncher control unit of the puncher 400 is transmitted from the CPU 901 of the controller CPU circuit unit 900 (FIG. 4) of the image forming apparatus 100 via a communication IC (not shown). The job information of the print job is notified to the CPU 972 of the CPU 971 (FIG. 5) (FIG. 7, S101). The job information includes the presence / absence of designation of a punch for punching a hole in the sheet, the length of the sheet in the sheet conveyance direction, the carrying speed of the sheet carried into the puncher 400 from the image forming apparatus 100 (sheet carrying speed), and the like. Thereafter, the controller CPU circuit unit 900 notifies the puncher control unit 971 of the sheet information for each sheet via the communication IC (S102). The sheet information includes information such as a sheet ID, a first sheet, an intermediate sheet, and a last sheet shown in FIG.

  The CPU 972 of the puncher control section 971 checks whether or not punching has been specified in the job information received in step S101 (S110). When the punch is designated (YES in S110), the CPU 972 stores the time 400 msec required for the punching process in the RAM 974 as the value of the sheet delay request time (S112). Further, the puncher control unit 971 adds the value of the processing time required by the finisher 500 shown in FIG. 11 according to the sheet length of the job information to the value of the sheet delay request time. The puncher controller 971 stores a value obtained by subtracting the time between sheets corresponding to the sheet discharge speed of the image forming apparatus 100 shown in FIG. 12 from the added value in the RAM 974 as the sheet delay request time (S113).

  Further, the puncher control unit 971 sets the image forming speed as the discharge speed (sheet discharge speed) of the sheet discharged from the puncher 400 to the finisher 500 included in the sheet discharge information transmitted from the puncher control unit 971 to the finisher control unit 951. The value of the sheet carrying speed (sheet carrying speed) of the sheet carried into the puncher 400 from the apparatus 100 is stored in the RAM 974 (S115).

  Thereafter, the puncher controller 971 determines whether the received sheet information is the sheet information of the first sheet (S153). If it is the sheet information of the first sheet (YES in S153), the puncher control unit 971 changes the sheet delay request time stored in the RAM 974 to 0 because the image forming apparatus 100 does not need an image forming waiting time. (S154). If the sheet information is not the sheet information of the first sheet (NO in S153), the puncher control unit 971 does not change the sheet delay request time because an image forming waiting time is required.

  Thereafter, the puncher controller 971 transmits the sheet delay request time of the RAM 974 to the CPU 901 of the image forming apparatus 100 (S162), and transmits the sheet discharge speed of the RAM 974 to the CPU 952 of the finisher controller 951 (S163).

  Subsequently, the puncher controller 971 checks whether or not there is a last sheet signal included in the sheet information in step S102 (S164). If the last sheet signal is not the sheet information (NO in S164), the process returns to step S102. Then, the processing of the next sheet information in step S102 is performed.

  If punching is not specified in step S110 (NO in S110), the puncher controller 971 checks whether there is no sheet delay due to the puncher 400 but there is a sheet delay in the finisher 500 (S120). Specifically, the puncher control unit 971 refers to the rear end alignment processing time of the sheet by the finisher 500 from the sheet length in FIG. 11 and compares the time with the time between sheets of the image forming apparatus 100 shown in FIG. If the time between the sheets of the image forming apparatus is longer than the processing time of the finisher 500 (NO in S120), the puncher control unit 971 stores the sheet delay request time 0 in the RAM 974 (S121), and performs the processing from step S115. I do.

  In step S120, if the processing time of the finisher 500 is longer than the time between sheets of the image forming apparatus, the puncher control unit 971 determines that the sheet ejection speed of the image forming apparatus 100 (the puncher 400) included in the job information in step S101. The speed of receiving the sheet from the image forming apparatus 100) is checked, and it is determined whether the speed is the same as the optimum speed of receiving the finisher 500 (S130).

  In the present embodiment, the sheet carrying speed from the image forming apparatus 100 to the puncher 400 and the sheet discharging speed from the puncher 400 to the finisher 500 are 1000 mm / sec (high speed, first speed) and 500 mm / sec (low speed, second speed). Speed) (FIG. 12). The finisher 500 can receive a sheet at any of two speeds, high speed and low speed, and the consistency is the same regardless of the receiving speed. When the finisher 500 receives a sheet at a high speed (1000 mm / sec), the time from the start to the completion of the transfer of the sheet from the puncher 400 is shortened, and the productivity is improved. For this reason, the high speed is set as the optimum sheet receiving speed of the finisher 500.

  In step S130, when the sheet carrying speed from the image forming apparatus to the puncher 400 (the sheet discharging speed of the image forming apparatus) is high (1000 mm / sec) (YES in S130), the optimal sheet receiving speed of the finisher 500 (1000 mm / sec). sec), there is no need to change (increase) the sheet conveying speed in the puncher. Therefore, the puncher control section 971 selects the short path 419 (FIG. 1) with a short sheet passage time and stores this in the RAM 974 (S131). The puncher control unit 971 does not need the punching time in the puncher 400, and thus compares the sheet processing time of the finisher 500 with the time between sheets of the image forming apparatus 100 shown in FIG. 12 with reference to FIG. If the time between sheets of the image forming apparatus is longer than the processing time of the finisher 500, the puncher control unit 971 sets 0 to the sheet delay request time. In other cases, the puncher control unit 971 sets a value obtained by subtracting the time between sheets of the image forming apparatus from the processing time of the finisher 500 as the sheet delay request time, stores the value in the RAM 974 (S132), and further discharges the sheet. The high speed (1000 mm / sec) is set as the speed setting value and stored in the RAM 974 (S135).

  Next, in step S130, the puncher control unit 971 determines that the sheet discharge speed of the image forming apparatus 100 is a low speed of 500 mm / sec different from the optimal receiving speed of the finisher 500 (high speed of 1000 mm / sec) (NO in S130). ), It is determined whether the sheet length is a short path speed increase possible length (S140). The “length that can be increased by a short path” refers to a path that allows the puncher 400 to change a sheet conveyed from the image forming apparatus 100 at a low speed (500 mm / sec) to a high speed (1000 mm / sec) before starting to convey the sheet to the finisher 500. It is the head. That is, the puncher control unit 971 determines whether the sheet length is long enough to increase the sheet conveying speed from a low speed to a high speed in a short path.

  Specifically, assuming that the length of the short path 419 is 420 mm and the distance that the sheet travels through the short path 419 during acceleration from a low speed (500 mm / sec) to a high speed (1000 mm / sec) is 30 mm, The short path speed increase possible length is 420 mm−30 mm = 390 mm. That is, in the case of a short sheet (first sheet) having a length of less than 390 mm, the sheet conveyance speed in the short path (first conveyance path) 419 is changed from a low speed (500 mm / sec, the first speed) to a high speed (1000 mm / sec). sec, the second speed). If the sheet length is less than 390 mm, which is shorter than the short path speed increase possible length in step S140 (YES in S140), the puncher control unit 971 stores in the RAM 974 the selection of the short path 419 (FIG. 1) as the use path. (S141).

  Next, the puncher control unit 971 calculates a required sheet delay time. At the time of step S140, the sheet length is less than 390 mm (YES in S140). For this reason, the processing time of the finisher 500 shown in FIG. 11 is 300 msec as shown in FIG. 11 (without considering the reduction of the processing time caused by the speed increase in the puncher), and the processing time of the image forming apparatus 100 shown in FIG. The time between sheets will not be exceeded. Therefore, the puncher control unit 971 stores the sheet delay request time 0 in the RAM 974 (S142). Further, the puncher control section 971 stores a high-speed value (1000 mm / sec) as the sheet discharge speed of the puncher 400 in the RAM 974 (S149), and proceeds to step S153.

  In step S140, if the sheet length is a long sheet (second sheet) equal to or longer than the short path speed increaseable length (390 mm or longer) (NO in S140), the puncher control unit 971 determines that the punch path 416 ( The selection of FIG. 1) is stored in the RAM 974 (FIG. 8, S145).

  Next, the puncher control unit 971 calculates a required sheet delay time. At the time of step S145, since the sheet length is 390 mm or more, the processing time of the finisher 500 shown in FIG. 11 is 600 msec or 900 mmsec from FIG. Here, due to the speed increase from the low speed (500 mm / sec) in the puncher to the high speed (1000 mm / sec), in the finisher 500, the time from the start of loading of the leading edge of the sheet to the end of loading of the trailing edge of the sheet is shortened.

The finisher carry-in time is obtained as follows depending on the sheet length.
In the case of a sheet length of 390 mm and a low speed of 500 mm / sec,
Finisher loading time = 390mm / 500mm / sec
= 780 msec,
When the sheet length is 390mm and the high speed is 1000mm / sec,
Finisher loading time = 390mm / 1000mm / s
= 390 msec,
Difference in finisher loading time between low speed and high speed
= 780 msec-390 msec
= 390 msec,
Therefore, the difference 390 msec can be added to the time 300 msec between sheets in the image forming apparatus 100 to be used as the processing time of the finisher 500,
(300 msec + 390 msec)> 600 msec (processing time of finisher 500),
Therefore, the image forming apparatus 100 does not delay the image formation, and the sheet delay request time becomes 0 (S146).

In FIG. 11, the processing time of the finisher 500 is the same 600 msec when the sheet length is from 390 mm to less than 600 mm, and the difference between the finisher carry-in time at the low speed and the high speed at the high speed is calculated by the same calculation as described above. Only) it will be longer,
(300 msec + 390 msec + αmsec)> 600 msec (processing time of finisher 500)
, And the sheet delay request time becomes 0 (S146).

  In FIG. 11, when the sheet length is 600 mm or more, the processing time of the finisher 500 is 900 msec. However, from the same calculation as above, the sheet delay request time becomes 0 (S146), and the process continues to step S149 in FIG. . If the sheet information of the last sheet is received in step S164 of FIG. 7 (YES in S164), the process waits for reception of a sheet carry-in notice corresponding to the ID included in the sheet information (FIG. 10, S302).

  Upon receiving the first sheet advance notice after the start of image formation (YES in S302 in FIG. 10), the puncher control unit 971 of the puncher 400 rotates the transport roller 410 (FIG. 2) for transporting the sheet. The path transport motor M20, the bypass transport motor M21 for rotating the transport rollers 401 to 408, the pull-in motor M22 for rotating the transport roller 421, the punch transport motor M23, and the sheet discharge motor M24 for rotating the transport roller 409 are started (S303). After the start of image formation, the conveyance system motor has already been driven for the second and subsequent sheets.

  Next, based on the job information received from the image forming apparatus 100 and stored in the RAM 974, it is determined whether or not the conveyed sheet is designated for punching (S304). If punching is specified (YES in S304), the puncher control section 971 sets the path switching member 420 to the punch path 416 side (S305). As a result, the sheet is taken into the punch path 416. The sheet taken into the punch path 416 is conveyed to the punch unit 415 (S306), and is subjected to a punching process by the punch unit 415 (S307).

  The sheet after the punch processing is transported to the finisher 500 by the transport rollers 405 to 408 and 409 (S308). Next, the process is divided depending on whether or not the processed sheet is the last sheet (S330). If it is not the last sheet (NO in S330), the process returns to step S302.

  On the other hand, if there is no punch designation in step S304 (NO in S304), the puncher control unit 971 determines whether the transport path stored in the RAM 974 is a short path or not (S310).

  When the punch path 416 is used without using the short path 419 (FIG. 1) (NO in S310), the puncher controller 971 switches the path switching member 420 to the punch path 416 side (S311), and transfers the sheet to the punch path 416 (FIG. 1). 1), and waits for the trailing edge of the sheet to pass through the conveyance sensor S1 (S312). When the trailing edge of the sheet has passed the conveyance sensor S1, the puncher control unit 971 increases the sheet conveyance speed from a low speed (500 mm / sec) as the loading speed to a high speed (1000 mm / sec) as the discharging speed (S313). Then, the sheet is conveyed to the finisher 500 (S314).

  That is, if the sheet received from the image forming apparatus 100 is a long sheet (second sheet) having a length of 390 mm or more, and the punch processing is not performed on the long sheet, the puncher control unit 971 Is transported to the punch path 416, and the transport speed of the long sheet is increased from a low speed (500 mm / sec, first speed) to a high speed (1000 mm / sec, second speed) within the punch path 416, and This means that the second mode of transferring the length sheet to the finisher 500 has been executed.

  On the other hand, when the short path 419 (FIG. 1) is used in step S310 (YES in S310), the puncher control unit 971 switches the path switching member 420 to the short path side (S321), and switches the sheet to the short path 419. Lead to.

  Next, the puncher controller 971 compares the sheet carry-in speed with the sheet discharge speed stored in the RAM 974 (S324). If the sheet carry-in speed is different from the sheet discharge speed (NO in S324), the punching control unit 971 compares the sheet discharge speed with the sheet discharge speed. It waits for the rear end to pass through the transport sensor S1 (S326). When the trailing edge of the sheet has passed the conveyance sensor S1, the puncher control unit 971 increases the sheet conveyance speed from a low speed (500 mm / sec) as the loading speed to a high speed (1000 mm / sec) as the discharging speed (S327). Then, the sheet is conveyed to the finisher 500 (S328).

  That is, when the sheet received from the image forming apparatus 100 is a short sheet (first sheet) having a length of less than 390 mm, the puncher control unit 971 conveys the sheet to the short path 419 and In a first mode 419, the sheet conveying speed is increased from a low speed (500 mm / sec, first speed) to a high speed (1000 mm / sec, second speed) in 419, and the sheet is transferred to the finisher 500. You have done it.

  If the sheet carry-in speed and the sheet discharge speed are the same in step S324 (YES in S324), the puncher controller 971 conveys the sheet to the finisher 500 without increasing the speed in the middle (S328), and proceeds to step S330 described above. Continue.

  If the sheet is the last sheet in step S330 (YES in S330), the trailer end of the sheet passes through the conveyance sensor S4, and waits for the completion of the sheet conveyance to the finisher 500 (S331), and step S331. When the sheet is completely loaded, the entire driving of the puncher 400 is stopped (S332). Thus, the control flow of the puncher 400 ends.

  The image forming system according to the first embodiment described above increases the short path 419 for a sheet having a length that can be conveyed at an increased speed in the short path 419 without straddling the image forming apparatus 100 and the puncher 400. In the case of a sheet having a length that cannot be speeded up and conveyed in the short path 419 in the short path 419, the sheet is passed through the punch path 416 at an increased speed. Productivity can be increased.

  Further, the image forming system according to the first embodiment can increase the speed in the puncher 400 and convey the sheet to the finisher 500 without straddling the sheet between the image forming apparatus 100 and the puncher 400. The sheet discharge interval can be shortened to increase the sheet supply productivity of the entire system.

(Image Forming System of Second Embodiment)
The image forming system according to the second embodiment differs from the image forming system according to the first embodiment only in the control content of a puncher control unit (control unit) 971 of the puncher 400.

  The puncher control unit (control unit) 971 of the puncher 400 in the image forming system according to the second embodiment controls the sheet conveying speed in the short path (first conveying path) 419 to be low (500 mm / sec. A long sheet (length of 390 mm or more, 500 mm) longer than a length of a short sheet (length less than 390 mm) capable of increasing speed from the first speed) to a high speed (1000 mm / sec, the second speed). In an image forming job in which an image is formed and the sheet is conveyed to a finisher (second sheet processing apparatus) 500 via a puncher (first sheet processing apparatus) 400, a long sheet (length 500 mm) is short-circuited at a low speed. The first time required until the image forming job is completed when the path 419 is conveyed, and the long sheet is fed from the low speed in the punch path 416. And the second time required to finish the image forming job when the punch path 416 is conveyed at an increased speed, and if the first time is shorter than the second time, the long sheet is used. Is conveyed to the short path 419 at a low speed, and if the second time is shorter than the first time, control can be performed to increase the speed of the long sheet from a low speed to a high speed in the punch path 416 and convey the punch sheet 416. It has become.

  Since the control flow is the same up to step S140 (FIG. 7), description will be made from step S140. Step S140 in FIG. 9 is the same as step S140 in FIG. In step S140 of FIG. 9, when the sheet length is a short sheet (less than 390mm, YES in S140) that is shorter than the short path speed increase possible length (390mm), the description after step S141 is the same as the description after step S141. Therefore, description of this part is omitted.

  If the sheet length is a long sheet that is equal to or greater than the short path accelerating length (390 mm or more) in step S140 in FIGS. 7 and 9 (NO in S140), the sheet information in step S120 in FIG. It is checked from the information included in the first sheet whether the sheet is the first sheet and the last sheet (that is, whether it is a single sheet job) (FIG. 9, S201). If the job is a one-sheet job (YES in S201), the puncher control unit 971 performs sheet processing in the finisher 500 by passing one sheet at an increased speed (1000 mm / sec) through the punch path 416 (FIG. 1). (Tp, second time) until the calculation is completed (S202).

  The calculation in step S202 is as follows. The length of the punch path 416 (FIG. 1) is 1100 mm, the conveyance distance required for accelerating the sheet during acceleration is 30 mm, the length of the sheet is 500 mm shorter than the length 1100 mm of the punch path 416, and the finisher path 501 ( The length of FIG. 1) is 150 mm.

  The sheet has a length of 500 mm and is a long sheet. However, in the following description, the sheet is simply referred to as the sheet. The “puncher sheet” refers to a sheet entering the puncher 400 or a sheet in the puncher 400. Further, the finisher sheet refers to a sheet entering the finisher 500 or a sheet in the finisher 500.

The finisher path 501 is a path for conveying and guiding a sheet from the puncher 400 to the tray 507. The time Tp from the loading of the leading end of the puncher sheet in step S202 to the completion of sheet processing in the finisher 500 can be obtained as follows. As a precondition, the puncher 400 increases the sheet conveyance speed from a low speed (500 mm / sec, first speed) to a high speed (1000 mm / sec, second speed).
Tp = t1 + t2 + t3 + t4,
t1: Time from the leading edge of the puncher sheet to the leading edge of the finisher sheet,
t2: Time from the leading edge of the finisher sheet to the trailing edge of the finisher sheet,
t3: Time from the rear end loading of the finisher sheet to the start of alignment (pull-back),
t4: time required for finisher alignment (pull-back),
t1 = Transport time before acceleration + Transport time during acceleration + Transport time after acceleration = 500 mm / 500 mm / sec + 40 msec + (1100 mm-500 mm-30 mm) / 1000 mm / sec = 1610 msec
t2 = 500 mm / 1000 mm / sec = 500 msec,
t3 = 150 mm / 1000 mm / sec = 150 msec,
t4 = 600 msec (see FIG. 11, values in the case of a sheet length of 500 mm),
Therefore,
Tp = 1610msec + 500msec + 150msec + 600msec
= 2860 msec.

  Subsequently, the puncher control unit 971 calculates a time (Ts, a first time) until one sheet passes through the short path 419 without increasing the speed and finishes the sheet processing in the finisher 500 (S203).

The calculation of the time (Ts) in step S203 is as follows. The job sheet to be conveyed has no punch, one sheet, and the length of the short path 419 (FIG. 1) is 420 mm. The length of the sheet (500 mm) and the length (150 mm) of the finisher path 501 (FIG. 1) are the same as in step 202. As a prerequisite, since the result of step S130 in FIG. 7 is NO, assuming that the sheet discharging speed of the image forming apparatus 100 (sheet receiving speed of the puncher 400) is a low speed of 500 mm / sec.
Ts = t11 + t12 + t13 + t14,
t11: time from the leading edge of the puncher sheet to the leading edge of the finisher sheet,
t12: Time from the leading edge of the finisher sheet to the trailing edge of the finisher sheet,
t13: Time from the rear end loading of the finisher sheet to the start of alignment (pull-back),
t14: time required for finisher alignment (pull-back),
t11 = 420 mm / 500 mm / sec = 840 msec,
t12 = 500 mm / 500 mm / sec = 1000 msec,
t13 = 150 mm / 500 mm / sec = 300 msec,
t14 = 600 msec (see FIG. 11, values in the case of a sheet length of 500 mm),
Therefore,
Ts = 840msec + 1000msec + 300msec + 600msec
= 2740 msec.

Next, the puncher controller 971 compares the calculation result (Tp) of step S202 with the calculation result (Ts) of step S203 (S209). In the calculation examples of step S202 and step S203,
Tp (2860 msec, second time)> Ts (2740 msec, first time)
And NO in step S209.

  The puncher controller 971 proceeds to step S231, selects the short path (first transport path) 419 (FIG. 1), and transports the sheet at a low speed (500 mm / sec, the first transport speed). .

  Next, in step S201, the puncher control unit 971 sets the first sheet to the punch pass 416 (FIG. 1) if it is the first sheet and not the last sheet, that is, if the job is a multiple sheet job (NO in S201). The time from when the loading is started to when the second sheet continuously passes through the punch path 416 at an increased speed and the sheet processing is completed by the finisher 500 is calculated (S205).

The time Tp2 (second time) from when the leading edge of the first puncher sheet is loaded at the time of use of the punch pass in step S205 to when the second sheet finishes the sheet processing in the finisher is calculated in steps S202 and S203 and the job. Is the same under the same conditions except that the number is two or more. The puncher 400 increases the sheet conveying speed from a low speed (500 mm / sec) to a high speed (1000 mm / sec).
Tp2 = (Ttop-end) + Tgap + Tp,
(Ttop-end): time from the start of loading of the front end of the puncher sheet to the end of loading of the rear end,
Ttop-end = 500 mm / 500 mm / sec = 1000 msec,
Tgap: the time from the end of loading of the rear end of the first sheet of the puncher to the start of loading of the second leading sheet.
Tgap = 300 msec (see FIG. 12, the value of the time between sheets corresponding to a sheet discharge speed of 500 mm / sec),
(Because it is not necessary to wait for the sheet to be discharged from the image forming apparatus during the processing time in the finisher 500 by increasing the speed in the punch path 416.)
Tp: time from one sheet of the puncher sheet being loaded to completion of sheet processing at the finisher;
Tp = 2860 msec (calculation result in step S202).
Therefore,
Tp2 = 1000msec + 300msec + 2860msec
= 4160 msec

  Next, the puncher control unit 971 determines that the second sheet has passed through the short path 419 at a low speed (500 mm / sec) without increasing the speed after the first sheet started being carried into the short path 419 (FIG. 1). Is calculated until the sheet processing is completed by the finisher 500 (S206).

The time Ts2 (first time) from when the leading edge of the first puncher sheet is loaded to when the second puncher sheet completes the sheet processing in the finisher 500 when the short path 419 is used in step S206 is calculated as follows. . As a prerequisite, since the result of step S130 in FIG. 7 is NO, assuming that the sheet discharge speed of the image forming apparatus 100 (sheet receiving speed of the puncher 400) is a low 500 mm / sec.
Ts2 = (Ttop-end) + Tgap + Ts
(Ttop-end): time from the start of loading of the front end of the puncher sheet to the end of loading of the rear end,
(Ttop-end) = 500 mm / 500 mm / sec
= 1000msec
Tgap: the time from the end of loading of the rear end of the first sheet of the puncher to the start of loading of the second leading sheet.
Tgap = 600 msec (see FIG. 11, a value corresponding to a sheet length of 500 mm);
Ts: time from one sheet of the puncher sheet being loaded to completion of sheet processing at the finisher;
Ts = 2740 msec (calculation result in S203).
Therefore,
Ts2 = 1000msec + 600msec + 2740msec
= 4340 msec

  Then, the puncher control unit 971 compares the calculation result of step S205 with the calculation result of step S206 (S209).

From the calculation examples of step S205 and step S206,
Since Ts2 (4340 msec, first speed)> Tp2 (4160 msec, second speed), the puncher control unit 971 proceeds to step S145 in FIG. The speed is increased and the punch path 416 is transported.

  If the job end is earlier when passing through the short path 419 in step S209, the puncher controller 971 stores in the RAM 974 that the path to be used is the short path (S231). Since the (punch) processing time in the puncher 400 is unnecessary, the puncher control unit 971 compares the value obtained by referring to the sheet delay time of the finisher 500 from FIG. 11 with the time between sheets of the image forming apparatus 100 shown in FIG. I do. If the time between sheets of the image forming apparatus 100 is longer than the processing time of the finisher 500, 0 is set to the sheet delay request time. In other cases, the puncher control unit 971 sets a value obtained by subtracting the time between sheets of the image forming apparatus from the processing time of the finisher 500 as the sheet delay request time and stores the value in the RAM 974 (S232).

  Further, the puncher control unit 971 sets a low value as the set value of the sheet discharge speed, stores the set value in the RAM 974 (S235), proceeds to step S153 in FIG. 7, and thereafter performs the processing according to the flowchart in FIG.

  In the image forming system according to the second embodiment described above, in the case of a sheet having a length that can be conveyed at an increased speed in the short path 419, the long sheet (length 500 mm) is conveyed at a low speed in the short path 419. A first time required to complete the image forming job and a second time required to complete the image forming job when the long sheet is conveyed through the punch path 416 at a high speed from a low speed to a high speed in the punch path 416. Each calculation is performed, and if the first time is shorter than the second time, the long sheet is conveyed to the short path 419 at a low speed. If the second time is shorter than the first time, the long sheet is conveyed. Since the control of conveying the punch path 416 by increasing the speed of the long sheet in the punch path 416 from a low speed to a high speed can be performed, the sheet processing can be performed faster than before, and the productivity of the sheet processing can be improved. It is Mel possible.

  The image forming system according to the second embodiment can also convey a sheet to the finisher 500 at an increased speed in the puncher 400 without straddling the sheet between the image forming apparatus 100 and the puncher 400. The sheet discharge interval can be shortened to increase the sheet supply productivity of the entire system.

  100: image forming apparatus, 200: image reading apparatus, 400: puncher (first sheet processing apparatus), 401 to 410, 421: transport roller (transport unit), 415: punch unit (first processing unit), 416: punch pass (Second transport path), 419: short path (first transport path), 420: path switching member (switching means), 500: finisher (second sheet processing device), 504: alignment roller (second processing unit), Reference numeral 971: a puncher control unit (control means), 1000: an image forming system, SL3: solenoid (switching means), M20: short-path conveyance motor (conveyance means), M21: bypass conveyance motor (conveyance means).

Claims (8)

An image forming apparatus for forming an image on a sheet,
A first sheet processing apparatus capable of receiving and conveying a sheet on which an image is formed by the image forming apparatus and performing a first process on the sheet;
A second sheet processing apparatus that receives the sheet conveyed through the first sheet processing apparatus and performs a second process on the sheet;
The image forming apparatus transfers a sheet to the first sheet processing apparatus at a first speed,
The first sheet processing apparatus includes:
A first conveyance path and a second conveyance path for conveying the sheet received from the image forming apparatus to the second sheet processing apparatus;
Switching means for switching a transport path of a sheet received from the image forming apparatus to one of the first transport path and the second transport path;
Conveying means for conveying a sheet in the first conveying path and the second conveying path, respectively;
Control means for controlling the switching means and the transport means,
The second transport path is longer than the first transport path,
The transport means is capable of transporting the sheet at the first speed, and at a second speed higher than the first speed,
The control means includes:
When the sheet received from the image forming apparatus is the first sheet, the first sheet is transported to the first transport path, and the transport speed of the first sheet is set within the first transport path. A first mode for increasing the speed from a first speed to the second speed and transferring the first sheet to the second sheet processing apparatus;
When the sheet received from the image forming apparatus is a second sheet having a longer sheet length in the conveyance direction than the first sheet, the second sheet is conveyed to the second conveyance path, and A second mode for increasing the transport speed of the second sheet from the first speed to the second speed in the second transport path, and transferring the second sheet to the second sheet processing apparatus; Is executable,
An image forming system, characterized in that: The length of the first sheet is equal to or less than the length of a sheet capable of increasing the sheet conveyance speed in the first conveyance path from the first speed to the second speed,
The length of the second sheet is longer than the length of a sheet capable of increasing the sheet conveyance speed in the first conveyance path from the first speed to the second speed,
The image forming system according to claim 1, wherein: The first sheet processing apparatus includes a first processing unit that is provided on the second transport path and performs the first processing on a sheet transported on the second transport path.
The control unit conveys the second sheet to the second conveyance path without performing the first processing in the first processing unit when the second mode is executed,
The image forming system according to claim 1, wherein: The second sheet processing apparatus has a second processing unit that performs the second processing on a sheet,
The second processing unit has a longer time to perform the second processing on the second sheet than a time to perform the second processing on the first sheet,
The image forming system according to any one of claims 1 to 3, wherein: An image forming apparatus for forming an image on a sheet,
A first sheet processing apparatus capable of receiving and conveying a sheet on which an image is formed by the image forming apparatus and performing a first process on the sheet;
A second sheet processing apparatus that receives the sheet conveyed through the first sheet processing apparatus and performs a second process on the sheet;
The image forming apparatus transfers a sheet to the first sheet processing apparatus at a first speed,
The first sheet processing apparatus includes:
A first conveyance path and a second conveyance path for conveying the sheet received from the image forming apparatus to the second sheet processing apparatus;
Switching means for switching a transport path of a sheet received from the image forming apparatus to one of the first transport path and the second transport path;
Conveying means for conveying a sheet in the first conveying path and the second conveying path, respectively;
Control means for controlling the switching means and the transport means,
The second transport path is longer than the first transport path,
The transport means is capable of transporting the sheet at the first speed, and at a second speed higher than the first speed,
The control means includes:
The image forming apparatus forms an image on a sheet longer than a sheet capable of increasing a sheet conveying speed in the first conveying path from the first speed to the second speed, In an image forming job that conveys the sheet to the second sheet processing device via the first sheet processing device,
When the sheet is conveyed along the first conveyance path at the first speed, a first time required until the image forming job is completed, and the sheet is conveyed from the first speed within the second conveyance path from the first speed. Calculating a second time required to end the image forming job when the image forming job is conveyed along the second conveying path at a second speed,
When the first time is shorter than the second time, the sheet is conveyed to the first conveyance path at the first speed;
If the second time is shorter than the first time, the sheet is increased from the first speed to the second speed in the second conveyance path to move the sheet along the second conveyance path. Transport,
An image forming system, characterized in that: The control unit, when the image forming job is a job for forming an image continuously on a plurality of sheets,
The first time is a time required for ending the image forming job when two consecutive sheets are conveyed through the first conveyance path at the first speed,
The image forming job is performed when the continuous two sheets are transported in the second transport path by increasing the speed from the first speed to the second speed in the second transport path during the second time. The time it takes to finish,
The image forming system according to claim 5, wherein: The first sheet processing apparatus includes a first processing unit that is provided on the second transport path and performs the first processing on a sheet transported on the second transport path.
The image forming job is an image forming job in which the first processing is not performed by the first processing unit.
The image forming system according to claim 5, wherein: The second sheet processing apparatus has a second processing unit that performs the second processing on a sheet,
A sheet having a length equal to or less than a sheet capable of increasing the sheet conveying speed from the first speed to the second speed in the first conveying path is a first sheet, and a sheet longer than the length is set as a first sheet. In the case of the second sheet,
The second processing unit has a longer time to perform the second processing on the second sheet than a time to perform the second processing on the first sheet,
The image forming system according to any one of claims 5 to 7, wherein:

Images