Image formation system, post-processing control method and program

Abstract

To perform post-processing such as cutting processing and so on at a proper position even if there are variations in paper size.SOLUTION: An image formation system 100 comprises: a paper feeding part 12 which loads papers, and sequentially feeds the papers onto a conveyance path one by one; an image formation part 38 which performs image formation on the paper fed from the paper feeding part 12; a size detection part 221 which is located between the paper feeding part 12 and the image formation part 38, and detects a size of the paper; a post-processing part which performs post-processing of the paper on which image formation has been performed by the image formation part 38; and an operation control part 51 which is so configured as to be capable of determining a post-processing position of the paper by the post-processing part on the basis of a size detection result by the size detection part 221.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an image forming system, a post-processing control method, and a program. [Background technology]

[0002] 2. Description of the Related Art Image forming systems are known in which an image forming apparatus and a post-processing apparatus that performs various post-processing operations on paper after image formation work in cooperation with each other. Among post-processing, examples of processing that is performed in a specific direction of the paper include cutting (cutting in the FD direction, which is the paper transport direction, such as slitting, gutter slitting, and cutting in the CD direction, which is perpendicular to the paper transport direction), crease processing, perforation processing, etc., and are performed according to user requests, etc. Among post-processing, cutting in particular requires high precision in the cutting position.

[0003] Many printing companies use paper that they cut themselves as printing paper, and the paper sizes can vary. Even when standard paper is used, there is a dimensional tolerance stipulated by the JIS (ISO) standard, so some variation can occur.

[0004] In this regard, for example, Patent Document 1 describes the following regarding an apparatus capable of cutting paper as post-processing after an image is formed on the paper. In the device described in Patent Document 1, a paper discharge sensor detects the length of the paper in the transport direction on the path after image formation, and cuts the paper according to the detection result. This makes it possible for the device to cut the paper to fit the size of the paper after image formation. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2021-14034 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, for example, when an image is heated and fixed on paper by a fixing device, the paper usually shrinks due to heating and then returns to its original size, resulting in an unstable paper size after image formation. In the device described in Patent Document 1, the length of the paper at the time of reduction can be temporarily detected in the paper discharge path after the fixing process. However, when the paper size is restored after that, the paper may be cut at an incorrect size for the product (such as a publication).

[0007] The present invention has been made in consideration of the above points, and aims to provide an image forming system, a post-processing control method, and a program that can perform post-processing such as cutting at an appropriate position even if there is variation in paper size. [Means for solving the problem]

[0008] In order to solve the above problems, the image forming system of the present invention comprises: a paper feed section that stacks the paper sheets and sequentially feeds the paper sheets one by one onto a conveyance path; an image forming unit that forms an image on the paper fed from the paper feeding unit; a size detection unit disposed between the paper feed unit and the image forming unit, the size detection unit detecting a size of the paper; a post-processing section for performing post-processing on the paper on which the image is formed in the image forming section; a control unit configured to determine a post-processing position of the sheet by the post-processing unit based on a size detection result by the size detection unit; The present invention is characterized in that it is provided with:

[0009] Further, the post-processing control method of the present invention includes the steps of: a size detection step of detecting a size of the paper between a paper feed unit that feeds the paper one by one onto a transport path and an image forming unit that forms an image on the paper fed from the paper feed unit; a post-processing position determination step of determining a post-processing position of the sheet by a post-processing unit that performs post-processing on the sheet on which the image has been formed in the image forming unit based on a result of the size detection step; The present invention is characterized in that it includes:

[0010] In addition, the program of the present invention is A computer controls a post-processing unit that performs post-processing on paper on which an image is formed in the image forming unit. The present invention is characterized by realizing a post-processing position determination function that determines a post-processing position where the post-processing is performed on the paper by the post-processing unit based on the detection result of the paper size detected between a paper feeding unit that feeds paper one sheet at a time onto a transport path and the image forming unit that forms an image on the fed paper. Effect of the Invention

[0011] According to the present invention, post-processing such as cutting can be performed at an appropriate position even when there is variation in paper size. [Brief description of the drawings]

[0012] [Figure 1] 1 is a diagram illustrating a schematic configuration of an image forming system according to an embodiment of the present invention. [Diagram 2] 2 is a block diagram showing a main part of a schematic control configuration of the image forming system according to the present embodiment. FIG. [Diagram 3] 4 is a flowchart showing the overall process of the image forming system according to the present embodiment. [Figure 4] 4 is a flowchart showing a cutting position determination process among the processes performed in the image forming system shown in FIG. [Diagram 5] 11 is an explanatory diagram of a case where the leading edge side of the paper is cut when the paper is fed. FIG. [Figure 6] 13 is an explanatory diagram of a case where the trailing edge side of the paper is cut when the paper is fed. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an image forming system, a post-processing control method, and a program according to the present invention will be described below with reference to the accompanying drawings. However, although the embodiments described below are subject to various limitations that are technically preferable for implementing the present invention, the technical scope of the present invention is not limited to the following embodiments and illustrated examples.

[0014] [Image formation system configuration] Fig. 1 shows the overall configuration of an image forming system according to the present embodiment, while Fig. 2 is a block diagram showing the main parts of the image forming system, illustrating the schematic control configuration of each unit of the image forming system. As shown in FIG. 1, an image forming system 100 of this embodiment includes a paper feeder 10, a paper characteristic detector 20, an image forming device 30, a paper reversing device 40, a post-processing device 50, a finisher 60, and the like.

[0015] These devices are arranged in the following order from the upstream side along the paper transport direction: paper feeder 10, paper characteristic detector 20, image forming device 30, paper inverting device 40, post-processing device 50, and finisher 60. A paper transport path 101 is provided continuously from the paper feed device 10 to the finisher 60. A plurality of rollers 102 including a drive roller are provided on the transport path, and each device includes a transport unit 13, 23, 39, 42, 53 (see FIG. 2) having a drive motor that rotates and drives the drive roller.

[0016] Operation control units 11, 21, 41, and 51 (see FIG. 2) of the paper feeder 10, paper characteristic detector 20, paper reversing device 40, and post-processing device 50 are connected to the main body control unit 31 of the image forming apparatus 30 so as to be able to transmit and receive control signals and various information. This allows the devices constituting the image forming system 100 to operate in cooperation with each other. Each device will be described below with reference to FIGS.

[0017] (1. Configuration of the Paper Feeder) As shown in FIG. 2, the sheet feeding device 10 includes an operation control unit 11, a sheet feeding unit 12, a transport unit 13, and the like.

[0018] The operation control unit 11 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The CPU of the operation control unit 11 reads out a program stored in the ROM, loads it into the RAM, and controls each part of the sheet feeding device 10 in accordance with the loaded program.

[0019] The paper feed unit 12 stacks paper sheets and sequentially feeds the paper sheets one by one onto the transport path 101. The paper feed unit 12 includes a plurality of paper feed trays that store different types of paper sheets according to the paper type. 1 has three paper feed trays 121 to 123 that store paper of predetermined sizes. For example, in the illustrated example, paper feed tray 121 stores paper of the smallest size. Also, paper feed tray 123 stores paper of the largest size among the three paper feed trays.

[0020] 1, the size of the paper stored in paper feed tray 123 in the transport direction is designated as "Lm." The transport direction of the paper is also referred to as the "FD direction" below. It should be noted that the paper feed trays 121 to 123 are not limited to those storing paper of different sizes. For example, the paper feed trays 121 to 123 may store paper of different thicknesses or different paper qualities.

[0021] The transport unit 13 includes a plurality of rollers 102 arranged in pairs, and a drive motor that rotates a drive roller among the rollers 102. The operation of the transport unit 13 is controlled by the operation control unit 11.

[0022] The operation control unit 11 of the paper feeding device 10 controls the transport unit 13 to take out paper one by one from any one of the paper feed trays 121-123 of the paper feeding unit 12 according to the job, and send it onto the transport path 101. Then, the operation control unit 11 operates a drive motor (not shown) of the transport unit 13 to transport the sent-out paper to the paper characteristic detection device 20.

[0023] (2. Configuration of the Paper Characteristics Detection Device) The paper characteristic detection device 20 is disposed between the paper feeder 10 and the image forming device 30. Specifically, the paper characteristic detection device 20 is located downstream of the paper feed section 12 of the paper feeder 10 in the paper transport direction and upstream of the image forming section 38 of the image forming device 30 in the transport direction. As shown in FIG. 2, the paper characteristic detection device 20 includes an operation control unit 21, a detection unit 22, a transport unit 23, and the like.

[0024] The operation control unit 21 includes a CPU, a ROM, and a RAM. The CPU of the operation control unit 21 reads out a program stored in the ROM, loads it into the RAM, and generally controls each part of the paper characteristic detection device 20 according to the loaded program.

[0025] The detection unit 22 detects the physical properties of the paper conveyed from the paper feeder 10 and obtains values ​​related to the physical properties of the paper (physical property values). The physical properties of the paper detected by the detection unit 22 include, for example, the basis weight, stiffness, moisture content, and surface properties (smoothness, smoothness) of the paper. Note that the physical properties detected by the detection unit 22 are not limited to those exemplified here. The detection unit 22 of this embodiment includes a size detection unit 221 that detects the paper size in the paper transport direction (FD direction).

[0026] The size detection unit 221 is, for example, a photosensor capable of detecting the passage of an end in the transport direction of a sheet of paper transported one by one on the transport path 101. In the embodiment, the size detection unit 221 detects the length of the sheet in the transport direction (sheet size) by measuring the time from when the leading edge of the sheet of paper passes until when the trailing edge passes. If the paper stops midway through its transport, the size detection unit 221 cannot correctly detect the time the paper passed, and therefore cannot detect the paper size.

[0027] As will be described later, in the image forming device 30, a temporary abutment unit 386 is provided in the image forming unit 38, which is located before the position where a transfer unit, which will be described later, is provided in the paper transport direction. The temporary abutment unit 386 abuts and temporarily stops the paper that is transported along the transport path 101 and enters the image forming unit 38 (the transfer unit of the image forming unit 38). As will be described later, the position where the transfer unit is provided is referred to as the "image forming operation position." After the leading end of the paper passes through the size detection unit 221, if the leading end of the paper reaches the temporary abutment unit 386 before the trailing end of the paper passes through the size detection unit 221, the transport of the paper will stop.

[0028] Therefore, the size detection unit 221 is disposed at a position at least a predetermined distance upstream in the transport direction from the temporary abutment unit 386. Here, "at least a predetermined distance" means at least the length in the transport direction (FD direction) of the paper that has the longest length in the transport direction among the papers loaded in the paper feeder 10. In the example shown in FIG. 1, the distance from the size detection unit 221 to the temporary abutment unit 386 is required to be longer than the length Lm in the transport direction of the paper stored in the paper feed tray 123. This allows the size detection unit 221 to correctly detect the paper size when paper is fed from any of the paper feed trays 121 to 123.

[0029] As described above, each of the paper feed trays 121 to 123 stores paper according to size, etc. Therefore, the approximate paper size can be detected by the paper feed device 10. However, the size detection unit 221 of the paper characteristic detection device 20 detects the size of each paper as it is transported. Therefore, it is possible to reliably detect the more detailed paper size of each paper, rather than the size of a paper stack. Although the size detection unit 221 detects the paper size in the paper transport direction, if it is configured with a line sensor (not shown) extending in the paper width direction, it is also possible to detect the paper size in a direction perpendicular to the paper transport direction (CD direction).

[0030] The transport unit 23 includes a plurality of rollers 102 arranged in pairs, and a drive motor that rotates a drive roller among the rollers 102. The operation of the transport unit 23 is controlled by the operation control unit 21.

[0031] The operation control unit 21 of the paper characteristic detection device 20 causes the detection units 22, such as the size detection unit 221, to detect the physical properties such as the paper size of each sheet of paper sent from the paper feed unit 12 onto the transport path 101. The operation control unit 21 also causes the transport unit 23 to transport the paper to the image forming device 30. Furthermore, in the embodiment, the operation control unit 21 acquires physical property values ​​such as paper size (actual measurement value) that are the detection results by the detection unit 22. Then, the operation control unit 21 also outputs the detection results to the main body control unit 31 of the image forming apparatus 30, and the detection results by the detection unit 22 are shared within the image forming system 100.

[0032] (3. Configuration of Image Forming Apparatus) The image forming device 30 is located downstream of the paper characteristic detection device 20 in the paper transport direction and upstream of the post-processing device 50 and the like in the paper transport direction. As shown in FIG. 2, the image forming apparatus 30 includes a main body control unit 31, a memory unit 32, a communication unit 33, an operation unit 34, a display unit 35, a document reading unit 36, an image processing unit 37, an image forming unit 38, a conveying unit 39, etc. The image forming apparatus 30 forms a color image by electrophotography based on image data obtained by reading an image from an original or job image data of a print job received from an external device (not shown). Next, the image forming apparatus 30 conveys the paper on which the image has been formed to the post-processing apparatus 50 side.

[0033] The main body control unit 31 includes a CPU, a RAM, a ROM, and the like. The CPU of the main body control unit 31 reads out various processing programs stored in the ROM or the like and loads them in the RAM. The main body control unit 31 comprehensively controls the operation of the image forming apparatus 30 in cooperation with the various programs loaded in the RAM.

[0034] In this embodiment, the main body control unit 31 of the image forming apparatus 30 also controls the overall operation of the image forming system 100 . For example, the main body control unit 31 instructs the operation control unit 11 of the sheet feeding device 10 as to which of the sheet feeding trays 121 to 123 to feed sheets from. The main body control unit 31 also receives outputs of various detection results detected by the detection unit 22 from the operation control unit 21 of the paper characteristic detection device 20 . Further, for example, when post-processing is to be performed on paper after image formation, the main body control unit 31 instructs the post-processing device 50 to execute a predetermined post-processing.

[0035] The storage unit 32 is a non-volatile storage device such as a hard disk drive (HDD) or a semiconductor memory that stores various data such as programs and image data. The storage unit 32 stores data such as program data and various setting data in a manner that allows the main body control unit 31 to read and write the data. The storage unit 32 stores therein the paper feed trays 121 to 123 in association with information on the characteristics of the paper sheets stored therein (for example, paper size, paper type, basis weight, etc.).

[0036] The communication unit 33 includes a communication control card such as a LAN (Local Area Network) card. The communication unit 33 transmits and receives various data to and from an external device (for example, a personal computer) connected to a communication network such as a LAN or a WAN (Wide Area Network).

[0037] The operation unit 34 includes a touch panel formed to cover the display screen of the display unit 35, as well as various operation buttons such as numeric buttons and a start button. The operation unit 34 outputs an operation signal to the main body control unit 31 based on a user's operation. In the operation unit 34, for example, the type of paper used for image formation (characteristics such as paper size and paper type) can be set. In addition, the image formation position, the processing contents and post-processing position of the post-processing device 50 described later, for example, the cutting position when cutting in the CD direction, can be set. These items set by the user's operation are stored in the storage unit 32 etc. as preset setting information (this is referred to as "profile setting information").

[0038] The display unit 35 includes an LCD (Liquid Crystal Display) or the like. The display unit 35 displays various screens according to the instructions of a display signal input from the main body control unit 31.

[0039] The document reading unit 36 ​​includes an automatic document feeder (ADF), a scanner, and the like. The document reading unit 36 ​​reads the image of the document and outputs the image data obtained to the main body control unit 31.

[0040] The image processing unit 37 performs necessary image processing on the image data stored in the storage unit 32, the image data obtained by reading an image from a document using the document reading unit 36, and the image data input from an external device. Next, the image processing unit 37 transmits the image data after the image processing to the image forming unit 38. The image processing includes gradation processing, halftone processing, color conversion processing, etc. Gradation processing is a process of converting the gradation value of each pixel of image data into a corrected gradation value so that the density characteristics of the image formed on the paper match the target density characteristics. Halftone processing is an error diffusion process, a screen process using an ordered dither method, etc. Color conversion processing is a process of converting each RGB gradation value into each CMYK gradation value.

[0041] Image forming unit 38 forms an image on paper fed from paper feed unit 12 of paper feed device 10. Specifically, image forming unit 38 forms an image on paper conveyed from paper characteristic detection device 20 by an intermediate transfer method based on image data that has been image-processed by image processing unit 37. In this embodiment, the paper is a sheet of paper. The image forming unit 38 includes photoconductor drums 381Y, 381M, 381C, 381K, and 381S corresponding to each of the colors yellow (Y), magenta (M), cyan (C), black (K), and spot colors, an intermediate transfer belt 382, ​​a secondary transfer roller 383, a fixing unit 384, a reversing path 385, and a temporary abutment unit 386.

[0042] For example, the image forming unit 38 uniformly charges the photoconductor drum 381Y, and then scans and exposes the photoconductor drum 381Y with a laser beam based on image data of yellow color to form an electrostatic latent image. Next, the image forming unit 38 causes yellow toner to adhere to the electrostatic latent image on the photoconductor drum 381Y, thereby developing the electrostatic latent image. The photoconductor drums 381M, 381C, 381K, and 381S are similar to the photoconductor drum 381Y except for the colors they handle, and therefore descriptions thereof will be omitted.

[0043] The image forming unit 38 sequentially transfers (primary transfer) the toner images of each color formed on the photoconductor drums 381Y, 381M, 381C, 381K, and 381S onto the rotating intermediate transfer belt 382. That is, the image forming unit 38 forms a color toner image on the intermediate transfer belt 382 by superimposing the toner images of five colors. The image forming unit 38 transfers the color toner images on the intermediate transfer belt 382 all at once (secondary transfer) onto a sheet of paper by the secondary transfer roller 383. A nip portion formed by the intermediate transfer belt 382 and the secondary transfer roller 383 is the transfer portion. As described above, in this embodiment, the position where the transfer unit is provided is referred to as the "image forming operation position."

[0044] The fixing unit 384 includes a heating roller that heats the paper onto which the color toner image has been transferred, and a pressure roller that pressurizes the paper. The fixing unit 384 fixes the color toner image onto the paper by applying heat and pressure.

[0045] In this embodiment, the image forming unit 38 is configured to be capable of both single-sided printing and double-sided printing. The type of printing to be performed is set by the user, for example, through the operation unit 34. Image formation in the image forming unit 38 is basically set based on the position of the leading edge of the paper when it is fed. Therefore, the image formation position in the transport direction when an image is formed on the surface of the paper is a predetermined position from the leading edge of the paper when it is fed. The specific image formation position is specified based on paper transport information that is understood from the number of rotations of the drive motor of the transport unit 39 that transports the paper. The paper transport information is transport length information (transport distance, feed amount information) of the paper transported in the transport direction (FD direction).

[0046] In contrast, when image formation is performed from the rear end of the paper when it is fed, such as when printing on the back side, the main body control unit 31 determines how far from the rear end of the paper when it is fed, the image formation position, based on the paper size (actual measurement value) information, which is the detection result of the detection unit 22 output from the operation control unit 21 of the paper characteristic detection device 20.

[0047] In the case of single-sided printing in which an image is formed on one side of a sheet in the image forming apparatus 30, the main body control unit 31 conveys the sheet from the fixing unit 384 toward the post-processing device 50. On the other hand, in the case of double-sided printing in which images are formed on both sides of the paper, the main body control unit 31 transports the paper from the fixing unit 384 to a reversing path 385 and reverses the paper surface. In this case, the main body control unit 31 feeds the reversed paper again upstream of the temporary abutment unit 386 in the paper transport direction.

[0048] The temporary abutment unit 386 is a registration unit that includes a registration roller and transports the paper to the transfer unit. The temporary abutment unit 386 is disposed in front of the position where the transfer unit is provided, which is the "image forming operation position" in the image forming unit 38, in the paper transport direction. The temporary abutment section 386 abuts the paper conveyed from the paper characteristic detection device 20 etc. and entering the "image forming operation position" temporarily to correct the paper skew and adjust the paper conveyance timing.

[0049] (4. Configuration of the Paper Reversing Device) The paper reversing device 40 is located downstream of the image forming device 30 in the paper transport direction, and reverses the paper on which an image has been formed by the image forming device 30 as necessary. As shown in FIG. 2, the sheet reversing device 40 includes an operation control unit 41 and a transport unit . For example, the orientation in which a sheet of paper is discharged from the apparatus after post-processing in the post-processing device 50 described below is set on the operation unit 34 of the image forming apparatus 30. The discharge orientation refers to the orientation of the sheet of paper when discharged, such as whether the sheet is discharged with its front side facing up or its back side facing up.

[0050] Information such as the discharge orientation set in the image forming device 30 is output from the main body control unit 31 to the operation control unit 41 of the paper reversing device 40. When it is determined that the paper needs to be reversed based on the information output from the main body control unit 31, the operation control unit 41 controls the operation of the transport unit 42 to appropriately pull the paper into a reversing path 43 and reverse the paper. Then, the transport unit 42 transports the reversed paper to the post-processing device 50.

[0051] (5. Configuration of post-processing device) The post-processing device 50 is located downstream of the paper inverting device 40 in the paper transport direction, and performs various post-processing operations on the paper transported from the paper inverting device 40 . As shown in FIG. 2, the post-processing device 50 includes an operation control section 51, a post-processing unit 52, a conveying section 53, and the like.

[0052] The operation control unit 51 includes a CPU, a RAM, a ROM, and the like. The CPU of the operation control unit 51 reads out various processing programs stored in the ROM and loads them in the RAM. The operation control unit 51 comprehensively controls the operation of the post-processing device 50 in cooperation with the various programs loaded in the RAM.

[0053] In particular, the operation control unit 51 of this embodiment determines a post-processing position for performing processing in a predetermined direction of the paper. For example, it determines a cutting position when cutting the paper in the CD direction perpendicular to the FD direction, which is the paper transport direction. The operation control unit 51 determines the cutting position based on, for example, setting information for the paper that is set in advance in the operation unit 34 of the image forming device 30, and the paper size detected by the detection unit 22 of the paper characteristic detection device 20. The operation control unit 51 may also determine the cutting position taking into consideration the image forming position where the image is formed by the image forming unit 38 of the image forming device 30, settings related to the paper discharge direction, and the like. The determination of the paper cutting position by the operation control unit 51 will be described in detail later.

[0054] The post-processing unit 52 performs post-processing on the paper on which an image has been formed by the image forming device 30. Examples of the post-processing include cutting, folding, perforation, crease (crease-making), foil stamping, varnishing, various bookbinding processes, etc. Among these post-processing, cutting, perforation, and crease processes are particularly examples of processes that are performed in a predetermined direction on the paper. Among these, cutting in the CD direction (eg, cutting the leading and trailing ends of the paper), perforation in the CD direction, and crease processing are post-processing in the CD direction perpendicular to the FD direction, which is the paper transport direction. In post-processing in the CD direction, the post-processing position can be determined by determining the paper transport length (paper transport distance, feed amount) from the leading edge of the paper, using the leading edge of the paper as a reference. Examples of post-processing in the FD direction, which is the paper transport direction, include cutting in the FD direction (such as slitting using a rotary blade rotating in the FD direction or gutter slitting), perforation processing in the FD direction, and crease processing.

[0055] 1 and 2 show an example in which four post-processing units 52 are provided: a first unit M1, a second unit M2, a third unit M3, and a fourth unit M4. The specific contents of the first unit M1 to the third unit M3 can be arbitrarily combined by the user who installs the post-processing device 50 by selecting necessary functional units. The fourth unit M4 is a paper cutting section that includes a CD cutting blade 521 that cuts the paper in the CD direction perpendicular to the FD direction, which is the paper transport direction.

[0056] The transport section 53 includes a plurality of roller pairs, and transports the paper transported from the image forming device 30 via the paper reversing device 40 to the post-processing unit 52. In addition, within the post-processing device 50, a reversing path 55 is provided downstream of the post-processing unit 52 in the transport direction. When it is necessary to turn the paper over, the paper is turned over in the inversion path 55. For example, in the finisher 60 described below, when the paper discharge direction is set to discharge the paper with the front side facing up, the paper may be processed with the back side facing up. In this case, the paper is turned over in the inversion path 55 and then conveyed to the finisher 60.

[0057] Specifically, when reversing the paper, the transport unit 53 appropriately draws the paper into the reversing path 55 and switches it back according to the control of the operation control unit 51. Then, after performing the necessary processing, the operation control unit 51 controls the operation of the transport unit 53 to transport the paper after post-processing such as cutting to the finisher 60.

[0058] Furthermore, when cutting the paper, it is necessary to stop the paper temporarily. However, for example, when cutting the rear end of the paper, if the leading edge of the paper advances to the finisher 60 side, it becomes necessary to synchronize the cutting process on the post-processing device 50 side with the transport and stopping on the finisher 60 side. In this regard, if the transport of the paper is temporarily stopped while the paper is pulled into the reversing path 55, and the rear end of the paper is cut, the process can be completed within the post-processing device 50, and synchronization with the finisher 60 side is not required.

[0059] (6. Finisher Configuration) The finisher 60 is located downstream of the post-processing device 50 in the paper transport direction, and includes, for example, a paper output tray T1. Paper that has undergone various post-processing processes by the post-processing device 50 is output to the paper output tray T1 of the finisher 60 in a paper output direction specified by the main body control unit 31 or the like. The finisher 60 may have multiple paper discharge trays. In this case, the paper discharge trays may include one to which paper is discharged one by one, and another to which a resultant product such as a booklet obtained by performing various bookbinding processes on a stack of paper is discharged. When there are multiple paper discharge trays, the transport path 101 branches inside the finisher 60, and the paper (or the resultant product) is discharged (discharged) to a paper discharge tray designated by the main body control unit 31 or the like.

[0060] [Operation of image forming system, post-processing control method] Next, the operation of the image forming system 100 will be described, particularly with respect to a method for controlling the paper cutting process in the post-processing unit 52 (fourth unit M4 which is a paper cutting section) of the post-processing device 50. In this case, as the paper cutting process, a CD cutting process will be described in which the paper is cut in the CD direction perpendicular to the FD direction, which is the paper transport direction.

[0061] FIG. 3 is a flowchart illustrating the overall flow of the operation of the image forming system 100. As shown in FIG. As shown in FIG. 3, when processing a sheet in the image forming system 100, first, the main body control unit 31 of the image forming apparatus 30 acquires profile setting information (step S1). As described above, the "profile setting information" is information that is set in advance by the user operating the operation unit 34, etc. The profile setting information includes setting information related to paper, such as paper size information on what size of paper to form an image on among the papers stored in the paper feeder 10. The paper size information included in the profile setting information is the "set paper size (setting value) La" shown in FIG. 5, etc. The profile setting information also includes information related to image formation, such as whether to perform single-sided printing on only the front side of the paper or double-sided printing on both sides of the paper, and the image formation position, such as how much margin to leave from the leading edge of the image.

[0062] The profile setting information also includes information on what type of post-processing is to be performed in the post-processing device 50. The details of the post-processing include information on the cutting position, such as whether to cut only the leading edge of the paper or both the leading and trailing edges. The profile setting information also includes cutting position setting information L1, which indicates the position from the leading edge of the paper to be cut. Furthermore, the profile setting information includes information on the orientation in which the paper is to be discharged onto the paper discharge tray T1 of the finisher 60.

[0063] Next, the main body control unit 31 instructs the operation control unit 11 of the sheet feeding device 10 to start feeding sheets one by one from any one of the sheet feeding trays 121-123 of the sheet feeding unit 12 of the sheet feeding device 10 (step S2). The type of sheets (sheet size, etc.) to be fed from the sheet feeding unit 12 is based on the profile setting information acquired in step S1. In the paper characteristic detection device 20, the detection unit 22 detects various physical properties of the paper fed one by one. In this embodiment, the size detection unit 221, which is a size detection unit, detects the paper size (actual measurement value Lb, see FIG. 5, etc.) of the fed paper (step S3). The detection result detected by the paper characteristic detection device 20 is output to the image forming device 30 and acquired by the main body control unit 31.

[0064] The main body control unit 31 determines the image forming position by the image forming unit 38 based on the profile setting information and the paper size of the paper detected by the size detection unit 221 (step S4). Specifically, when performing single-sided printing only on the front side of the paper, the main body control unit 31 determines the image formation position so that an image is formed at a predetermined position based on the leading edge of the paper when it is fed from the paper feeder 10. For example, if an image is to be formed 1 cm from the edge, the main body control unit 31 causes the image forming unit 38 to form the image from a position where the paper has been transported 1 cm from the leading edge. The distance from the leading edge can be ascertained by looking at the transport distance (transport length) of the paper by the transport unit 39.

[0065] On the other hand, when performing double-sided printing on both sides of the paper, when forming an image on the back side of the paper, the paper enters the image forming unit 38 from the rear end side when fed. Therefore, if there is variation in the paper size in the paper transport direction, the image cannot be formed in the correct position. Therefore, when forming an image on the back side of the paper, the main body control unit 31 determines the image formation position based on the paper size (actual measurement value Lb) of the paper detected by the size detection unit 221. As a result, even if there is variation in the paper size in the transport direction, it is possible to form an image at a position on the back side that is not misaligned with the image formed on the front side of the paper.

[0066] When the image forming position is determined, the main body control unit 31 operates the transport unit 39 to transport the paper to the image forming unit 38, and causes the image forming unit 38 to perform image formation processing at the determined image forming position (step S5). After the image is formed on the paper in the image forming section 38, the paper is sent to the paper inverting device 40 by the transport section 39. The paper is then transported to the post-processing device 50 via the paper inverting device 40.

[0067] In the post-processing device 50, an operation control unit 51 that cooperates with the main body control unit 31 controls the operation of a post-processing unit 52, and performs various post-processing processes on the paper in accordance with the profile setting information. The operation control unit 51 also determines the cutting position of the paper in the fourth unit M4 (step S6). Once the cutting position has been determined, the paper is cut by the CD cutting blade 521 of the fourth unit M4 at the determined cutting position (step S7). Once the paper has been cut, the operation control unit 51 operates the transport unit 53 to transport the paper to the finisher 60 and eject the paper onto the paper ejection tray in a predetermined orientation.

[0068] FIG. 4 is a flowchart showing the cutting position determination process (step S6 in FIG. 3) in this embodiment. In the following description, a case will be described in which the control unit that determines the cutting position is the operation control unit 51 of the post-processing device 50. Note that the control unit that determines the cutting position is not limited to the operation control unit 51.

[0069] First, the operation control unit 51 obtains profile setting information from the main body control unit 31 and determines whether or not to perform cutting processing on the paper from the leading edge side when the paper is fed (step S11). When cutting processing is performed from the leading edge side during paper feeding (step S11; YES), the operation control unit 51 acquires setting information for the leading edge cutting position included in the profile setting information ("cutting position setting information L1" in FIG. 5, etc.) (step S12).

[0070] Fig. 5 is an explanatory diagram for guiding the cutting position X of the paper when cutting is performed from the leading edge side during paper feeding. Note that the "face-up processing" in Fig. 5 means that various processes are performed with the paper facing up. In FIG. 5, the set paper size (set value) is La, the paper size (actual value) detected by the detection unit 22 is Lb, and the cutting position X of the paper is shown in the case of cutting position setting information L1. As mentioned above, in the CD direction, which is perpendicular to the FD direction, the paper is transported in a straight line, the edge of the leading edge of the paper is used as the reference point. Therefore, when cutting is performed from the leading edge of the paper as it is fed, the cutting can be performed at the intended position, regardless of variations in paper size.

[0071] In other words, if the "cutting position setting information L1" is set, for example, to 1 cm from the leading edge of the paper when fed, the cutting position X of the paper is L1 (1 cm in the above example) from the leading edge of the paper when fed. In this case, the operation control unit 51 determines the cutting position X of the paper to be L1 based on the "cutting position setting information L1" (step S13). That is, in the above example, the cutting position X of the paper is the position where the paper is transported 1 cm from the end of the leading edge side of the paper when it is fed.

[0072] On the other hand, when cutting processing is performed from the rear end side when the paper is fed (step S11; NO), the cutting position X of the paper is determined as follows. In other words, in this case, if there is variation in the paper size in the FD direction, which is the paper transport direction, the finished dimensions of the paper ("finished dimensions L2" in Fig. 6) will also change. For this reason, it is necessary to detect the actual accurate length (actual measurement value) in the paper transport direction, correct the paper size based on the difference with the paper size La in the profile setting information, which is a preset value, and optimize the paper cutting position.

[0073] Fig. 6 is an explanatory diagram for deriving the cutting position X of the paper when cutting processing is performed from the rear end side at the time of paper feeding. Note that "face-down processing" in Fig. 6 means performing various processes with the paper facing down with the front side (back side facing up). In Fig. 6, as in Fig. 5, the set paper size is La, the paper size (actual measurement value) detected by detection unit 22 is Lb, and the cutting position setting information is L1. Also in Fig. 6, the finished dimension of the resultant product after cutting processing is L2.

[0074] In this case, the operation control unit 51 acquires the set paper size (setting value) La included in the profile setting information (step S14). The operation control unit 51 also acquires the paper size (actual measurement value) Lb detected by the detection unit 22 (step S15). Furthermore, the operation control unit 51 acquires the "cutting position setting information L1" and the setting information (L2) of the finished size (steps S16 and S17).

[0075] Then, the operation control unit 51 determines the cutting position X of the paper based on the detection result of the paper size (Lb) and the cutting position setting information (L1) (step S18). In the example shown in Fig. 6, the cutting position X of the paper is "Lb-L1-L2". As a result, particularly when cutting from the rear end side of the paper, cutting can be performed at an appropriate cutting position even if there is variation in the length of the paper in the FD direction, which is the transport direction.

[0076] [effect] As described above, the image forming system 100 according to this embodiment includes a paper feed section 12, an image forming section 38, a size detection section 221 disposed between the paper feed section 12 and the image forming section 38 and detecting the paper size of the paper, a post-processing section (post-processing unit 52 of the post-processing device 50) that performs post-processing of the paper on which the image is formed in the image forming section 38, and an operation control section 51 configured to be able to determine the post-processing position of the paper by the post-processing section based on the size detection result by the size detection section 221. For example, even if the size of the entire stack of paper appears to be roughly uniform, when viewed individually, there may be variations in paper size. In this regard, by detecting the paper size (actual measurement value) of each sheet of paper conveyed from the paper feed unit 12 to the image forming unit 38, the paper size can be accurately determined. Then, the post-processing position is determined based on this paper size (actual measurement value), so that the final product has a uniform post-processing position.

[0077] Note that the post-processing in the embodiment is processing that is performed across a predetermined direction of the paper, and the processing includes at least one of cutting, perforation, and crease processing. Among post-processing (processing), cutting in particular has a large effect on the finished product if the processing position is shifted. In this embodiment, the operation control unit 51 is configured to be able to determine the cutting position X of the paper by the paper cutting unit (fourth unit M4 of the post-processing unit 52) ​​that performs the paper cutting process based on the size detection result by the size detection unit 221. This makes it possible to obtain a final product with aligned cutting positions.

[0078] In addition, the operation control unit 51 of the embodiment determines a post-processing position in the paper transport direction (FD direction) (for example, cutting position X in the CD direction perpendicular to the paper transport direction (FD direction)) based on the size detection result by the size detection unit 221. By accurately detecting the paper size in the paper transport direction (FD direction), post-processing can be performed at the correct position. For example, even when cutting the leading or trailing edge of the paper, cutting can be performed at the correct position.

[0079] In addition, in the embodiment, when the rear end side of the paper when fed from the paper feed unit 12 is transported to a post-processing device (e.g., a paper cutting unit, etc.) prior to the front end side of the paper when fed from the paper feed unit 12 and post-processed (e.g., processing such as cutting), the operation control unit 51 determines a post-processing position (e.g., cutting position X) based on the size detection result by the size detection unit 221. When post-processing (e.g., processing such as cutting) is performed from the front end side of the paper when the paper is fed, if the processing is not performed taking into consideration variations in paper size, the post-processing position (e.g., cutting position X, etc.) of the resultant product after post-processing (e.g., processing such as cutting) will be shifted from its intended position. In this regard, by determining the post-processing position (e.g., cutting position X, etc.) based on the actual measured value of the paper size, post-processing (e.g., cutting, etc.) can be performed at the correct position regardless of variations in paper size.

[0080] In addition, in the embodiment, when the rear end side of the paper when the paper is fed from the paper feed unit 12 is transported to the post-processing device (e.g., a paper cutting unit, etc.) before the front end side of the paper when the paper is fed, the operation control unit 51 determines the post-processing position (e.g., a cutting position, etc.) based on the size detection result by the size detection unit 221, and when the front end side of the paper when the paper is fed from the paper feed unit 12 is transported to the post-processing device (e.g., a paper cutting unit, etc.) before the rear end side of the paper when the paper is fed, the operation control unit 51 determines the post-processing position (e.g., cutting position X, etc.) based on the transport length information of the paper transported in the paper transport direction. In a situation where the variation in paper size affects the deviation of the post-processing position (e.g., cutting position X, etc.), the actual measurement value of the paper size acquired by the size detection unit 221 is used, and in a situation where the variation in paper size does not affect the deviation, the post-processing position (e.g., cutting position X, etc.) is determined based on the conveying length from the leading edge of the paper, thereby preventing the deviation of the post-processing position (e.g., cutting position X, etc.) simply and efficiently.

[0081] In addition, in the embodiment, the image forming unit 38 forms an image at a position set based on the leading end, which is the first end of the paper in the transport direction, and when the post-processing device (e.g., a paper cutting unit, etc.) first processes (processes such as cutting) the second end (the trailing end) opposite the first end of the paper in the transport direction of the paper, the operation control unit 51 determines the post-processing position (e.g., cutting position X, etc.) based on the size detection result by the size detection unit 221. In a situation where the variation in paper size affects the deviation of the post-processing position (e.g., cutting position X, etc.), the actual measurement value of the paper size acquired by the size detection unit 221 is used, and in a situation where the variation in paper size does not affect the deviation, the post-processing position (e.g., cutting position X, etc.) is determined based on the conveying length from the leading edge of the paper, thereby preventing the deviation of the post-processing position (e.g., cutting position X, etc.) simply and efficiently.

[0082] In addition, in the embodiment, a temporary abutment section 386 is provided in front of the image forming operation position of the image forming section 38 in the paper transport direction, which abuts the paper entering the image forming operation position, and the size detection section 221 is positioned at a position upstream in the transport direction, at least a predetermined distance from the temporary abutment section 386. When the leading edge of the paper reaches temporary abutment portion 386, the transport of the paper is temporarily stopped, and the size detection unit 221 is unable to detect the paper size correctly. By locating size detection unit 221 away from temporary abutment portion 386, it is possible to detect the paper size before the paper stops at temporary abutment portion 386. This makes it possible to obtain an accurate paper size (actual measurement value).

[0083] In addition, in the embodiment, a reversal path 55 is provided which is a switchback section that switches the paper back downstream in the conveying direction from the post-processing device (e.g., a paper cutting section, etc.), and the cutting process of the rear end side of the paper by the post-processing device (e.g., a paper cutting section, etc.) is performed when the paper has entered the reversal path 55. This makes it possible to prevent a situation in which, for example, when the rear end of the paper is to be processed (processed such as cutting), the leading edge of the paper has already entered the next finisher 60. Therefore, it is not necessary to synchronize the processing (cutting, etc.) by the post-processing device (for example, the paper cutting section, etc.) with the transport within the finisher 60, making the process simpler.

[0084] In addition, in the embodiment, the image forming unit 38 is capable of double-sided printing on paper, and the image formation position when printing on the back side of the paper in the image forming unit 38 is determined based on the size detection result by the size detection unit 221. The problem of misalignment caused by variations in paper size occurs during image formation as well as during post-processing (cutting and other processing). In this regard, the image formation position also uses the actual measurement value detected by the size detection unit 221. This makes it possible to form images at the correct position based on the actual measurement value even when images are formed on the front and back of a sheet of paper, and produces a high-quality result with no misalignment between the images on the front and back.

[0085] [Variations] It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0086] For example, in this embodiment, the main body control unit 31 of the image forming apparatus 30 centrally controls the entire image forming system 100, but this is not limited to the above. For example, any one of the operation control units 11, 21, 41, 51 of the paper feeder 10, the paper characteristic detector 20, the paper reversing device 40, and the post-processing device 50 may be configured to centrally control the entire image forming apparatus 1.

[0087] In addition, in this embodiment, an example is given in which the control unit that determines the post-processing position (e.g., cutting position, etc.) is the operation control unit 51 of the post-processing device 50, but the control unit that determines the post-processing position (e.g., cutting position, etc.) is not limited to the operation control unit 51. For example, the main body control unit 31 that controls the entire image forming system 100 may function as a control unit that determines the post-processing position (for example, the cutting position, etc.).

[0088] Furthermore, when the image forming unit 38 performs double-sided printing on the paper, the operation control unit 51 of the post-processing device 50 may determine a post-processing position for processing the leading edge of the paper (e.g., a cutting position in the case of cutting) based on the position where the image forming unit 38 formed an image on the front side of the paper. Furthermore, the operation control unit 51 of the post-processing device 50 may determine a post-processing position for processing the trailing edge of the paper (e.g., a cutting position in the case of cutting) based on the position where the image forming unit 38 formed an image on the back side of the paper. In other words, when the image forming unit 38 performs double-sided printing on a sheet of paper, the image formation position when the image forming unit 38 forms an image on the back side of the sheet of paper is determined based on the size detection result by the size detection unit 221, and the operation control unit 51 may determine the post-processing position (e.g., the cutting position, etc.) based on information on the image formation position by the image forming unit 38.

[0089] By determining the post-processing position (e.g., cutting position, etc.) in accordance with the image formation position, it is possible to align the image formation position with the post-processing position in the CD direction (e.g., cutting position, etc.). In this case, by determining the image formation position based on the actual measurement value detected by the size detection unit 221, it is possible to perform image formation and post-processing (e.g., cutting process, etc.) at the correct position regardless of the variation in paper size. Therefore, it is possible to obtain a high-quality result without misalignment. In addition, by aligning the post-processing position (e.g., cutting position, etc.) with the image forming position, the processing burden on the operation control unit 51 of the post-processing device 50 can be reduced compared to determining the post-processing position (e.g., cutting position, etc.) separately from the image forming position.

[0090] Furthermore, the configuration and operation of the image forming system 100 and each device constituting the image forming system 100 may be modified as appropriate without departing from the spirit of the present invention. [Explanation of symbols]

[0091] 10 Paper feeder 12 Paper feed section 20 Paper characteristic detection device 22 Detection unit 221 Size detection unit 30 Image forming device 31 Main unit control section 38 Image forming section 40 Paper Reversing Device 50 Aftertreatment device 51 Motion control section 52 Post-processing unit (post-processing section) M1 1st Unit M2 2nd Unit M3 3rd unit M4 4th unit (paper cutting unit) 100 Image forming system

Claims

1. a paper feed section that stacks the paper sheets and sequentially feeds the paper sheets one by one onto a transport path; an image forming unit that forms an image on the paper fed from the paper feeding unit; a size detection unit disposed between the paper feed unit and the image forming unit, the size detection unit detecting a size of the paper; a post-processing section for performing post-processing on the paper on which the image is formed in the image forming section; a control unit configured to determine a post-processing position of the sheet by the post-processing unit based on a size detection result by the size detection unit; An image forming system comprising:

2. 2. The image forming system according to claim 1, wherein the post-processing is a processing process performed over the paper in a predetermined direction.

3. 3. The image forming system according to claim 2, wherein the processing includes at least one of a cutting process, a perforation process, and a creasing process.

4. 4. The image forming system according to claim 3, wherein the processing includes a cutting process.

5. The image forming system of claim 2, wherein the processing is performed in a direction perpendicular to the transport direction of the paper, and the control unit determines the post-processing position in the transport direction of the paper based on the size detection result by the size detection unit.

6. The image forming system of claim 2, characterized in that when the rear end side of the paper when fed from the paper feed unit is transported to the post-processing unit prior to the front end side of the paper when fed from the paper feed unit and the processing is performed, the control unit determines the post-processing position based on the size detection result by the size detection unit.

7. When the rear end side of the paper when the paper is fed from the paper feed unit is transported to the post-processing unit prior to the front end side of the paper when the paper is fed, the control unit determines the post-processing position based on a size detection result by the size detection unit, The image forming system of claim 2, characterized in that when the leading end side of the paper when fed from the paper feed unit is transported to the post-processing unit prior to the trailing end side of the paper when fed from the paper feed unit and the processing is performed, the control unit determines the post-processing position based on transport length information of the paper transported in the transport direction.

8. the image forming unit forms the image at a position that is set based on a first end of the paper in a transport direction; The image forming system of claim 2, characterized in that when the post-processing unit first processes a second end of the paper opposite the first end of the paper in the paper transport direction, the control unit determines the post-processing position based on a size detection result by the size detection unit.

9. a temporary abutment portion that abuts the paper entering the image forming operation position is provided before an image forming operation position in the image forming unit in a conveying direction of the paper, 2. The image forming system according to claim 1, wherein the size detection unit is disposed at a position upstream in the transport direction from the temporary abutment unit by a predetermined distance or more.

10. a switchback unit that switches back the paper on a downstream side of the post-processing unit in a paper conveying direction; 3. The image forming system according to claim 2, wherein the processing of the rear end side of the sheet by the post-processing section is performed in a state in which the sheet has entered the switchback section.

11. The image forming unit is capable of performing double-sided printing on the paper, an image forming position when forming an image on the back side of the paper in the image forming unit is determined based on a size detection result by the size detection unit; 2. The image forming system according to claim 1, wherein:

12. an image forming position when forming an image on the back side of the paper in the image forming unit is determined based on a size detection result by the size detection unit; 2. The image forming system according to claim 1, wherein the control unit determines a post-processing position based on information on an image forming position by the image forming unit.

13. a size detection step of detecting a size of the paper between a paper feed unit that feeds the paper one by one onto a transport path and an image forming unit that forms an image on the paper fed from the paper feed unit; a post-processing position determination step of determining a post-processing position of the sheet by a post-processing unit that performs post-processing on the sheet on which the image has been formed in the image forming unit based on a result of the size detection step; A post-processing control method comprising:

14. A computer controls a post-processing unit that performs post-processing on paper on which an image is formed in the image forming unit. a post-processing position determination function is realized that determines a post-processing position where the post-processing is performed on the paper by the post-processing unit based on a detection result of a paper size of the paper detected between a paper feed unit that feeds the paper one by one onto a transport path and the image forming unit that forms an image on the fed paper; A program characterized by:

Images