Image forming system, post-processing device, processing condition setting method, and program

Abstract

The present invention provides an image forming system, a post-processing device, a processing condition setting method, and a program that can easily identify a recording medium with a quality defect from among multiple loaded recording media while suppressing cost increases. [Solution] The image forming system comprises an image forming apparatus that forms an image on a recording medium, a post-processing apparatus that performs post-processing on the recording medium on which the image has been formed based on post-processing conditions, and a control device that controls the image forming apparatus and the post-processing apparatus. The control device sets post-processing conditions for the abnormal recording medium so that, when a quality abnormality occurs in the recording medium, the size of the abnormal recording medium in which the quality abnormality has occurred is different from the size of a normal recording medium in which the quality abnormality has not occurred.

Description

Technical Field

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[0001] The present disclosure relates to an image forming system, a post-processing device, a processing condition setting method, and a program.

Background Art

[0002] An image forming apparatus that forms an image on a recording medium such as paper can form and discharge the same image on each of a plurality of recording media. In such an image forming apparatus, when the same image is formed on a plurality of recording media, quality abnormalities such as image formation defects called "yare" may occur in some of the recording media.

[0003] On the other hand, a plurality of recording media on which images are formed are usually discharged so as to be stacked at the same discharge destination. That is, both the recording medium on which the image is appropriately formed and the recording medium in which a quality abnormality has occurred are discharged to the same tray.

[0004] When both the recording medium on which the image is appropriately formed and the recording medium in which a quality abnormality has occurred are discharged and stacked in the same tray as they are, it is difficult for an operator to visually discriminate the recording medium in which a quality abnormality has occurred from the stacked recording media.

[0005] Therefore, in recent years, various methods have been proposed for easily finding yare paper from such a plurality of stacked recording media. For example, Patent Document 1 discloses an image forming system that discriminates yare paper by forming a crease in a planned cutting area of a recording medium with a concavo-convex roller when a recording medium determined to be defective by an inspection machine is determined to be defective.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] However, in the image forming system described in Patent Document 1, if the number of recording media stacked to be discharged increases, there is a risk that the creases formed on recording media with quality defects may be crushed by the weight of the stacked recording media. Therefore, there was a problem in that it may become difficult to identify recording media with quality defects.

[0008] Furthermore, the image forming system described in Patent Document 1 requires a textured roller for identifying recording media in which quality defects have occurred, and a control mechanism for controlling the driving of the textured roller, which increases product costs.

[0009] The purpose of this disclosure is to provide an image forming system, a post-processing device, a processing condition setting method, and a program that can easily identify a recording medium with a quality defect from among multiple loaded recording media while suppressing cost increases. [Means for solving the problem]

[0010] The image forming system relating to this disclosure is An image forming apparatus that forms an image on a recording medium, A post-processing apparatus that performs post-processing on the recording medium on which the image is formed based on post-processing conditions, A control device for controlling the image forming apparatus and the post-processing apparatus, Equipped with, The control device is When a quality defect occurs in the recording medium, the post-processing conditions for the defective recording medium are set such that the size of the defective recording medium differs from the size of a normal recording medium that does not have a quality defect.

[0011] The post-processing device relating to this disclosure is A post-processing apparatus that performs post-processing on a recording medium on which an image has been formed, based on post-processing conditions, The post-processing is performed so that the size of the defective recording medium in which a quality defect has occurred is different from the size of the normal recording medium in which no quality defect has occurred.

[0012] The method for setting processing conditions related to this disclosure is: Form an image on the recording medium, Based on the post-processing conditions, post-processing is performed on the recording medium on which the image has been formed. When a quality defect occurs in the recording medium, the post-processing conditions for the defective recording medium are set such that the size of the defective recording medium differs from the size of a normal recording medium that does not have a quality defect.

[0013] The program related to this disclosure is The computer is instructed to execute the above processing condition setting method. [Effects of the Invention]

[0014] According to this disclosure, it is possible to easily identify a recording medium with a quality defect from among multiple stacked recording media while suppressing cost increases. [Brief explanation of the drawing]

[0015] [Figure 1] Figure 1 is a schematic diagram showing an example of the configuration of the image forming system according to this first embodiment. [Figure 2] Figure 2 is a block diagram showing the main part of the control system of the image forming system according to this embodiment 1. [Figure 3] Figure 3 is a functional block diagram showing an example of the configuration of the control unit shown in Figure 2. [Figure 4] Figure 4 is a schematic diagram illustrating a first example of post-processing according to this embodiment 1. [Figure 5] Figure 5 is a schematic diagram illustrating a second example of post-processing according to this embodiment 1. [Figure 6] Figure 6 is a schematic diagram illustrating a third example of post-processing according to this embodiment 1. [Figure 7] FIG. 7 is a schematic diagram for explaining a fourth example of post-processing according to the first embodiment. [Figure 8] FIG. 8 is a schematic diagram for explaining a fifth example of post-processing according to the first embodiment. [Figure 9] FIG. 9 is a flowchart showing an example of the flow of processing condition setting processing according to the first embodiment. [Figure 10] FIG. 10 is a flowchart showing another example of the flow of processing condition setting processing according to the first embodiment. [Figure 11] FIG. 11 is a schematic diagram for explaining post-processing for abnormal paper when the paper discharge destination is set to the paper discharge tray of the paper discharge unit.

MODE FOR CARRYING OUT THE INVENTION

[0016] <First Embodiment> Hereinafter, the first embodiment of the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the following embodiments, and various modifications can be made without departing from the gist of the present disclosure. In each figure, those denoted by the same reference numerals are the same or corresponding ones, which is common throughout the specification. The image forming system according to the first embodiment can form an image on a sheet of paper (recording medium) such as a single sheet of paper.

[0017] [Configuration of Image Forming System 1] FIG. 1 is a schematic diagram showing an example of the configuration of the image forming system 1 according to the first embodiment. Further, FIG. 2 is a block diagram showing the main part of the control system of the image forming system 1 according to the first embodiment. As shown in FIG. 1, the image forming system 1 includes an image forming apparatus 100, a paper feeding unit 200, an inspection unit 300, a post-processing unit 500, a paper discharge unit 400, and the like.

[0018] The image forming apparatus 100 is a color image forming apparatus that uses an intermediate transfer method utilizing electrophotographic process technology. Specifically, the image forming apparatus 100 first transfers the toner images of each CMYK color formed on the photoreceptor to an intermediate transfer surface, superimposes the four toner images on the intermediate transfer surface, and then secondarily transfers them to paper to form an image. CMYK refers to C (cyan), M (magenta), Y (yellow), and K (black). Furthermore, in the following description, the process of image formation by the image forming apparatus 100 may be referred to as "printing."

[0019] The image forming apparatus 100 employs a tandem system in which photoreceptors corresponding to the four CMYK colors are arranged in series in the direction of travel of the intermediate transfer body, and the toner images of each color are sequentially transferred to the intermediate transfer body in a single procedure.

[0020] As shown in Figure 2, the image forming system 1 includes an image processing unit 10, an image forming unit 20, a fixing unit 30, a paper transport unit 40, an operation display unit 50, a communication unit 71, a storage unit 72, a control unit 600, a paper feeding unit 200, an inspection unit 300, a post-processing unit 500, and a paper discharge unit 400, etc.

[0021] The image processing unit 10 includes circuits and other components that perform image processing on the input image data according to initial settings or user settings. The image forming unit 20 is controlled based on the image data that has undergone image processing.

[0022] The image forming unit 20 includes an image forming unit 21, an intermediate transfer unit 22, and a secondary transfer unit 23, etc. The image forming unit 21 forms an image using colored toners of each color component based on image data from the image processing unit 10. For example, it forms an image using colored toners of each color component: Y (yellow), M (magenta), C (cyan), and K (black).

[0023] The image forming unit 21 includes, for each color, an exposure device, a developing device, a photoreceptor drum, a charging device, and a drum cleaning device. Since known technologies can be used for the exposure device, developing device, photoreceptor drum, charging device, and drum cleaning device, a detailed explanation is omitted here.

[0024] The intermediate transfer unit 22 includes an intermediate transfer belt, etc. The intermediate transfer belt is stretched in a loop shape across multiple support rollers and travels in the direction of arrow A. The support rollers include backup rollers, primary transfer rollers, and drive rollers, but these are not shown in the illustration here. The intermediate transfer belt is pressed against the photoreceptor drum, thereby transferring the toner image from the photoreceptor drum to the intermediate transfer belt.

[0025] The intermediate transfer unit 22 may also be configured to include a belt cleaning device having a plate-shaped belt cleaning blade or the like that slides against the surface of the intermediate transfer belt. The belt cleaning device removes any remaining transfer toner or the like that from the surface of the intermediate transfer belt after secondary transfer.

[0026] The secondary transfer unit 23 includes a secondary transfer roller and the like. The secondary transfer roller is pressed against the intermediate transfer belt. This creates a secondary transfer nip between the intermediate transfer belt and the secondary transfer roller.

[0027] In the secondary transfer unit 23, when paper is transported to the secondary transfer nip, the toner images of each color carried on the intermediate transfer belt are transferred onto the paper all at once. The paper on which the toner images have been transferred is then transported toward the fixing unit 30 by the secondary transfer roller.

[0028] Furthermore, the secondary transfer unit 23 may be a belt-type secondary transfer unit having a secondary transfer belt stretched across multiple support rollers, instead of a roller-type secondary transfer unit having a secondary transfer roller or the like.

[0029] The fixing unit 30 includes a fixing roller and a pressure roller. The fixing roller is heated to a predetermined fixing temperature, and the pressure roller forms a fixing nip that grips and transports the paper between itself and the fixing roller. In this fixing unit 30, the toner image is fixed to the paper by heating and pressurizing the paper that has been transported after secondary transfer of the toner image using the fixing nip.

[0030] The paper transport unit 40 includes a transport path unit 41, etc. The transport path unit 41 consists of, for example, a path for transporting paper, a plurality of transport rollers, and a drive motor that rotates these transport rollers. The transport path unit 41 transports the paper supplied from the paper feeding unit 200 to the secondary transfer unit 23 and the fixing unit 30, and then transports it to the paper discharge unit 400.

[0031] In the transport path section 41, a pair of registration rollers 41a is provided upstream of the secondary transfer unit 23 in the paper transport direction D. The pair of registration rollers 41a adjusts the transport timing and orientation (angle) of the paper transported to the secondary transfer unit 23.

[0032] The operation display unit 50 is composed of, for example, a liquid crystal display (LCD) with a touch panel, and functions as both a display unit and an operation unit. The display unit displays various operation screens, image status displays, and the operating status of each function in accordance with display control signals input from the control unit 600. The operation unit is equipped with various operation keys such as a numeric keypad and a start key, accepts various input operations from the user, and outputs operation signals to the control unit 600.

[0033] The paper feeding unit 200 is located upstream of the image forming apparatus 100 in the paper transport direction D and is connected to the image forming apparatus 100. The paper feeding unit 200 has a plurality of paper trays 201, 202, and 203, and each paper tray 201, 202, and 203 contains sheets of paper (standard paper or special paper) identified based on basis weight or size, etc., according to a preset type. Based on instructions from the image forming apparatus 100, the paper feeding unit 200 supplies the instructed paper to the image forming apparatus 100.

[0034] The inspection unit 300 is positioned between the image forming apparatus 100 and the post-processing unit 500 in the paper transport direction D. The inspection unit 300 is connected to the image forming apparatus 100 on the upstream side and to the post-processing unit 500 on the downstream side.

[0035] The inspection unit 300 inspects the condition of the paper on which an image has been formed by the image forming apparatus 100. The inspection unit 300 has sensors 301 and 302 that read the paper transported from the image forming apparatus 100.

[0036] The sensor 301 is positioned above the path through which the paper is transported and facing the paper being transported. This configuration ensures that the sensor 301 reads the surface (top) of the paper being transported.

[0037] The sensor 302 is positioned below the paper transport path and facing the paper being transported. This configuration allows the sensor 302 to read the back (bottom) side of the transported paper.

[0038] Sensors 301 and 302 may include, for example, CCDs (Charge Coupled Devices) or CIS (Contact Image Sensors). Alternatively, line sensors extending over a width greater than or equal to the width of the paper (the width in the direction perpendicular to the paper transport direction D), such as a line scanner or a line sensor camera, may be used as sensors 301 and 302.

[0039] Sensors 301 and 302 read the image formed on the paper. Here, the inspection unit 300 is configured to have sensors 301 and 302 that read both sides (front and back) of the paper, as an example, but it is not limited to this configuration, and for example, it may have a configuration that has only sensor 301 that reads one side (front) of the paper.

[0040] The inspection unit 300 reads the image formed on the paper using sensors 301 and 302 and acquires information about the paper, such as the paper and the formed image, as inspection information. Once the inspection unit 300 has acquired the inspection information, it transmits the acquired inspection information to the control unit 600, which will be described later. The control unit 600 then determines whether or not there is a quality defect in the paper.

[0041] Quality defects are what are commonly referred to as "defective" paper, and include, for example, poor image formation on the paper and unsuitable paper conditions such as paper size. In the following explanation, quality defects or paper that has developed quality defects may be referred to as "defective" paper.

[0042] The paper discharge unit 400 is located downstream of the post-processing unit 500 in the paper transport direction D and is connected to the image forming apparatus 100 via the inspection unit 300 and the post-processing unit 500. The paper discharge unit 400 has a paper discharge tray 401 and a purge tray 402, and discharges the transported paper into the paper discharge tray 401 or the purge tray 402. The paper discharge unit 400 corresponds to the "discharge device" in this disclosure. The paper discharge tray 401 also corresponds to the "first discharge tray" in this disclosure.

[0043] The output tray 401 outputs paper on which an image has been formed by the image forming apparatus 100. The purge tray 402 outputs paper on which, for example, an abnormality in quality has been detected as a result of inspection by the inspection unit 300. Output to the output tray 401 and the purge tray 402 is controlled by the control unit 600.

[0044] If the size of the paper read by the inspection unit 300 does not meet the predetermined conditions, the paper output unit 400 may output the paper that does not meet the predetermined conditions from the purge tray 402, as indicated by the dashed arrow in Figure 1.

[0045] The post-processing unit 500 is positioned between the inspection unit 300 and the paper discharge unit 400 in the paper transport direction D. The post-processing unit 500 is connected to the inspection unit 300 on the upstream side and to the paper discharge unit 400 on the downstream side. The post-processing unit 500 performs predetermined post-processing on the paper on which the image has been properly formed, as needed. For example, the post-processing unit 500 performs various post-processing operations such as folding the paper, perforating the paper, gluing the paper, and cutting the paper.

[0046] In this first embodiment, the post-processing unit 500 includes a cutting unit 501, a folding unit 502, and a paper output tray 503. The post-processing unit 500 corresponds to the "post-processing device" in this disclosure. The paper output tray 503 also corresponds to the "second output tray" in this disclosure.

[0047] The cutting unit 501 performs the process of cutting paper that has been inspected by the inspection unit 300 for any quality defects. The cutting unit 501 has a cutter 511, a slitter 512, and a trimmer unit 513 on the transport path.

[0048] The cutter 511 is positioned to the side of the paper transport path and cuts the paper in a direction perpendicular to the paper transport direction. The slitter 512 is positioned on the paper transport path and cuts the paper in the direction of paper transport. The trimmer unit 513 is positioned on the paper transport path and cuts the paper into sheets so as to trim along the direction of paper transport. The operation of the cutter 511, slitter 512, and trimmer unit 513 is controlled by the control unit 600.

[0049] Furthermore, the configuration of the cutting unit 501 described above is merely an example and is not limited to this example. The cutting unit 501 may, for example, be provided with some of the cutter 511, slitter 512, and trimmer unit 513 described above, or it may be provided with other components.

[0050] The output tray 503 ejects the paper that has undergone post-processing. At this time, the paper that has undergone post-processing is ejected to the output tray 503 regardless of whether it is paper that is free from quality defects or paper that has quality defects.

[0051] The control unit 600 is connected to the image processing unit 10, image forming unit 20, fixing unit 30, paper transport unit 40, operation display unit 50, communication unit 71, storage unit 72, paper feeding unit 200, inspection unit 300, post-processing unit 500, and paper discharge unit 400 described above. The control unit 600 issues various instructions to each of these units and executes predetermined processes. In this embodiment 1, the control unit 600 performs processing condition setting processing. Details of the processing condition setting processing will be described later. The control unit 600 also corresponds to the "control device" in this disclosure.

[0052] The control unit 600 includes a CPU (Central Processing Unit) 601, a ROM (Read Only Memory) 602, and a RAM (Random Access Memory) 603, among others. The CPU 601 reads a program corresponding to the processing content from the ROM 602, loads it into the RAM 603, and works in cooperation with the loaded program to centrally control the operation of each block of the image forming system 1. At this time, various data such as LUTs (Look Up Tables) stored in the storage unit 72 are referenced. The storage unit 72 is composed of, for example, a non-volatile semiconductor memory (so-called flash memory) or a hard disk drive.

[0053] The control unit 600 transmits and receives various data to and from external devices (e.g., personal computers) connected to a communication network such as a LAN (Local Area Network) or WAN (Wide Area Network) via the communication unit 71. For example, the control unit 600 receives image data transmitted from an external device and forms an image on paper based on this image data (input image data). The communication unit 71 is composed of, for example, a communication control card such as a LAN card.

[0054] Figure 3 is a functional block diagram showing an example of the configuration of the control unit 600 in Figure 2. As shown in Figure 3, the control unit 600 includes an information acquisition unit 611, a processing condition setting unit 612, an abnormality determination unit 613, a printing control unit 614, a post-processing control unit 615, a paper discharge control unit 616, and a storage unit 617.

[0055] The information acquisition unit 611 acquires various types of information. For example, when printing on paper, the information acquisition unit 611 acquires a print job. A print job is data that includes information related to printing, such as the image formed during printing, the type of paper, and the details of post-processing such as the type of cutting. The information acquisition unit 611 also acquires inspection information obtained when the inspection of the paper is performed by the inspection unit 300.

[0056] The processing condition setting unit 612 sets post-processing conditions based on the print job. Furthermore, if a paper quality defect occurs, the processing condition setting unit 612 sets the post-processing conditions to change the post-processing applied to the affected paper. The post-processing conditions are information indicating the conditions for post-processing performed by the post-processing unit 500 on the paper on which the image has been formed. These post-processing conditions include, for example, the configurations used for post-processing, such as the cutter 511 and slitter 512, and their usage conditions.

[0057] The abnormality detection unit 613 determines whether or not there are any quality abnormalities in the paper printed by the image forming apparatus 100, based on the inspection information obtained from the inspection unit 300.

[0058] The print control unit 614 controls printing on paper by the image forming apparatus 100. For example, the print control unit 614 controls the image forming apparatus 100 to perform printing according to a print job.

[0059] The post-processing control unit 615 controls the post-processing by the post-processing unit 500 based on the set post-processing conditions. In this embodiment 1, the post-processing control unit 615 controls the post-processing unit 500 so that post-processing is performed to make the size of the paper with quality defects different from the size of normal paper.

[0060] The paper output control unit 616 controls the paper output unit 400 so that printed paper is ejected from a designated tray.

[0061] The memory unit 617 stores various data used by each part of the control unit 600. For example, the storage unit 617 stores print jobs and post-processing conditions set based on those print jobs. The storage unit 617 also stores inspection information obtained from the inspection unit 300.

[0062] The control unit 600 may be located in any of the devices, or it may be configured separately from each device. Furthermore, the control unit 600 may be divided and located in each device according to its specific function.

[0063] [Operation of Image Forming System 1] The operation of the image forming system 1 according to this embodiment 1, which has the above configuration, will now be described. In the image forming system 1, when an image is to be formed on paper, which is the recording medium, the paper is placed in the paper trays 201, 202, and 203 of the paper feeding unit 200. The paper supplied from the paper feeding unit 200 is then transported to the image forming apparatus 100. The paper transported to the image forming apparatus 100 is printed in the image forming apparatus 100 according to the contents of the print job, and then transported to the inspection unit 300.

[0064] The paper transported to the inspection unit 300 has images formed on it read by sensors 301 and 302, and is inspected for any quality abnormalities. After the inspection is complete, the paper is transported to the post-processing unit 500. The paper transported to the post-processing unit 500 undergoes predetermined post-processing according to the post-processing conditions set based on the print job, and is discharged into the output tray 503 of the post-processing unit 500.

[0065] Note that depending on the print job, post-processing may not be performed on the printed paper. In such cases, the paper is usually transported to the paper output unit 400.

[0066] The paper transported to the paper output unit 400 is discharged into either the paper output tray 401 or the purge tray 402, depending on the inspection results in the inspection unit 300. For example, if there are no quality defects in the paper on which the image has been formed, the paper without quality defects (hereinafter referred to as "normal paper") is discharged into the paper output tray 401. Also, for example, if a quality defect occurs in the paper on which the image has been formed, the paper with the quality defect (hereinafter referred to as "abnormal paper") is discharged into the purge tray 402. Normal paper and abnormal paper correspond to the "normal recording medium" and "abnormal recording medium" in this disclosure, respectively.

[0067] (Identifying abnormal paper) As mentioned above, when post-processing is performed on printed paper, the processed paper is usually discharged into the same tray, i.e., the output tray 503 of the post-processing unit 500, regardless of whether it is normal or abnormal paper. However, in this case, both normal and abnormal paper are loaded, so abnormal paper can get mixed in with the normal paper. Therefore, it becomes difficult for the operator to identify abnormal paper.

[0068] Therefore, in this embodiment 1, abnormal paper is subjected to different post-processing than normal paper so that the size of the abnormal paper after post-processing is different from that of normal paper, making it easy to identify abnormal paper from among the stacked papers. At this time, the control unit 600 performs processing condition setting processing to change the post-processing conditions from those for normal paper based on the content of the post-processing applied to normal paper.

[0069] The following section will explain, using specific examples, how to set post-processing conditions for defective paper, depending on the post-processing applied to normal paper.

[0070] (Example 1) The first example is a case where four-sided trimming is performed as a post-processing step for normal paper. Four-sided trimming involves trimming both ends in the direction of paper transport and in a direction perpendicular to the transport direction to produce a single sheet of paper that has undergone post-processing (hereinafter referred to as "processed paper" as appropriate). In the following explanation, the "direction of paper transport" may be referred to as the "FD (Feed Direction) direction," and the "direction perpendicular to the paper transport direction" may be referred to as the "CD (Cross Direction) direction."

[0071] Figure 4 is a schematic diagram illustrating a first example of post-processing according to this embodiment 1. Figure 4 shows how four-sided trimming is performed as a post-processing step on normal paper, and how a different post-processing step is performed on abnormal paper compared to normal paper.

[0072] In the first example, when performing four-sided trimming as a post-processing step on normal paper, the post-processing conditions are set such that the slitter 512 is used when trimming the paper in the FD direction and the cutter 511 is used when trimming the paper in the CD direction.

[0073] In contrast, when post-processing is performed on abnormal paper, the post-processing conditions are changed so that the length of the processed paper in the FD direction becomes longer than the length of normal paper. Specifically, the post-processing conditions are changed so that cutting by the cutter 511 is changed from "yes" to "no". Cutting by the slitter 512 is not changed.

[0074] As a result, the defective paper is not trimmed in the CD direction, and its length in the FD direction is longer than that of normal paper in the FD direction. Therefore, even when processed paper is discharged and normal and defective paper are stacked in the same tray, the defective paper will protrude in the FD direction from among the stacked normal paper. Consequently, defective paper can be easily identified by visual inspection by an operator.

[0075] (Second example) The second example is a case where a normal sheet of paper is split into two sheets as a post-processing step. Splitting into two sheets involves cutting both ends of the paper in the FD direction and CD direction, and then cutting near the center in the FD direction along the CD direction to produce two processed sheets.

[0076] Figure 5 is a schematic diagram illustrating a second example of post-processing according to Embodiment 1. Figure 5 shows how normal paper is cut into two sheets as a post-processing step, and how abnormal paper is subjected to a different post-processing step than that performed on normal paper.

[0077] In the second example, when a normal sheet of paper is cut into two sheets as a post-processing step, the post-processing conditions are set such that the slitter 512 is used when cutting the paper in the FD direction and the cutter 511 is used when cutting the paper in the CD direction.

[0078] In contrast, when post-processing is performed on abnormal paper, the post-processing conditions are changed so that the length of the processed paper in the FD direction becomes longer than the length of normal paper. Specifically, the post-processing conditions are changed so that cutting by the cutter 511 is changed from "yes" to "no". Cutting by the slitter 512 is not changed.

[0079] As a result, the defective paper is not cut in the CD direction, and becomes a single processed sheet whose length in the FD direction is longer than that of the normal paper in the FD direction. Therefore, even if the processed paper is discharged and normal and defective paper are stacked in the same tray, the defective paper will protrude in the FD direction from among the stacked normal paper. Consequently, defective paper can be easily identified by visual inspection by an operator.

[0080] (Third example) The third example is a case where multiple sheets are cut as a post-processing step for normal paper. Multiple sheet cutting involves cutting both ends and near the center of the paper in the FD direction and CD direction to produce three or more processed sheets.

[0081] Figure 6 is a schematic diagram illustrating a third example of post-processing according to this embodiment 1. Figure 6 shows how multiple sheets are cut as a post-processing step on normal paper, and how different post-processing steps are performed on abnormal paper compared to normal paper.

[0082] In the third example, when performing multiple sheet cutting as a post-processing step on normal paper, the post-processing conditions are set such that the slitter 512 and trimmer unit 513 are used when cutting the paper in the FD direction, and the cutter 511 is used when cutting the paper in the CD direction.

[0083] In contrast, when post-processing is performed on abnormal paper, the post-processing conditions are changed so that the length of the processed paper in the FD direction is longer than the length of normal paper. Specifically, the post-processing conditions are changed so that cutting by the cutter 511 is changed from "yes" to "no". Cutting by the slitter 512 and trimmer unit 513 remains unchanged.

[0084] As a result, the defective paper is not cut in the CD direction, and becomes two processed sheets whose length in the FD direction is longer than that of the normal paper in the FD direction. Therefore, even when the processed paper is discharged and normal and defective paper are loaded into the same tray, the defective paper will protrude in the FD direction from among the loaded normal paper. Consequently, defective paper can be easily identified by visual inspection by an operator.

[0085] (Fourth example) The fourth example is a case where top and bottom trimming is performed as a post-processing step on normal paper. Top and bottom trimming is a process that produces processed paper by cutting off both ends of the paper in the CD direction.

[0086] Figure 7 is a schematic diagram illustrating a fourth example of post-processing according to this embodiment 1. Figure 7 shows how top and bottom trimming is performed as a post-processing step on normal paper, and how different post-processing is performed on abnormal paper compared to normal paper.

[0087] In the fourth example, when performing top and bottom trimming as a post-processing step on normal paper, the post-processing conditions are set so that the slitter 512 is used when trimming the paper in the FD direction. In this post-processing condition, trimming by the cutter 511 and trimmer unit 513 in the CD direction is not used.

[0088] In contrast, when post-processing is performed on abnormal paper, the post-processing conditions are changed so that the length of the processed paper in the CD direction is longer than the length of normal paper. Specifically, the post-processing conditions are changed so that cutting by the slitter 512 is changed from "yes" to "no". Cutting by the cutter 511 and trimmer unit 513 remains unchanged. In other words, in this example, no post-processing is performed on the abnormal paper.

[0089] As a result, the defective paper is not cut in the FD direction or CD direction, and the processed paper becomes longer in the CD direction than the normal paper in the CD direction. Therefore, even when the processed paper is discharged and normal and defective paper are stacked in the same tray, the defective paper will protrude in the CD direction from among the stacked normal paper. Thus, defective paper can be easily identified by visual inspection by an operator.

[0090] (Example 5) The fifth example is a case where tri-folding is performed as a post-processing step for normal paper. Tri-folding is a process that creates processed paper by folding the paper into three sections.

[0091] Figure 8 is a schematic diagram illustrating a fifth example of post-processing according to this embodiment 1. Figure 8 shows how a normal sheet of paper is subjected to tri-folding as a post-processing step, and how a different post-processing step is performed on an abnormal sheet of paper compared to a normal sheet.

[0092] In the fifth example, when tri-folding is performed as a post-processing step on normal paper, the post-processing conditions are set so that the folding section 502 is used when folding the paper in the FD direction or CD direction. At this time, the folding section 502 folds the paper twice so that the processed paper becomes tri-folded.

[0093] In contrast, when post-processing is performed on abnormal paper, the post-processing conditions are changed so that the length of the processed paper in the FD direction or CD direction becomes longer than the length of normal paper. Specifically, for example, the post-processing conditions are changed so that the folding by the folding section 502 is reduced from "twice" to "once".

[0094] As a result, defective paper is folded in half, and the length in the FD direction or CD direction becomes longer than that of normal paper in the FD direction or CD direction. Therefore, even when paper is discharged and normal and defective paper are stacked, the defective paper will protrude from the stacked normal paper in the FD direction or CD direction. Consequently, defective paper can be easily identified by visual inspection by an operator.

[0095] In the second example, the post-processing conditions were described as being changed so that the number of folds by the folding section 502 is 1, but this is not limited to this example. For example, the post-processing conditions may be changed so that the number of folds is "0," that is, no folding occurs.

[0096] As explained in the first to fifth examples, the processing condition setting process sets the post-processing conditions so that if a quality defect occurs in the paper, the size of the defective paper after post-processing will differ from the size of the normal paper. When processed paper is produced by this process, the defective paper will stand out from among the stacked processed paper. Therefore, even if normal and defective paper are stacked when the processed paper is discharged, the defective paper can be easily identified from among the stacked normal paper.

[0097] Furthermore, as in the fourth example, it is possible to make the size of abnormal paper different from that of normal paper by not performing any post-processing on the abnormal paper.

[0098] Here, for example, when performing post-processing on normal paper using a processing unit such as a slitter 512 located on the paper transport path of the cutting unit 501, when performing post-processing on abnormal paper without using the slitter 512, the processing unit is moved out of the way so as not to be used.

[0099] However, in this case, time is required to move the processing unit, which may significantly reduce paper productivity. Therefore, when changing post-processing conditions for defective paper, it is preferable not to significantly change the position of processing units such as slitters that are located on the paper transport path.

[0100] [Processing condition setting process] Figure 9 is a flowchart showing an example of the processing condition setting process according to this embodiment 1. Each process shown in this flowchart is executed by the respective parts of the control unit 600 (see Figure 3).

[0101] In step S1, the information acquisition unit 611 of the control unit 600 acquires a print job. The information acquisition unit 611 stores the acquired print job in the storage unit 617.

[0102] In step S2, the processing condition setting unit 612 sets the post-processing conditions for the post-processing to be performed by the post-processing unit 500 based on the acquired print job. The processing condition setting unit 612 stores the set post-processing conditions in the storage unit 617.

[0103] When paper is transported from the paper feed unit 200 to the image forming apparatus 100, the print control unit 614 controls the image forming apparatus 100 in step S3 to perform printing based on the print job.

[0104] When the paper printed by the image forming apparatus 100 is transported to the inspection unit 300, the information acquisition unit 611 acquires inspection information obtained during the inspection of the paper performed by the inspection unit 300 in step S4. The information acquisition unit 611 stores the acquired inspection information in the storage unit 617.

[0105] In step S5, the abnormality determination unit 613 reads inspection information from the storage unit 617 and determines whether or not there is a quality abnormality in the paper based on the read inspection information. If it is determined that a quality abnormality has occurred (step S5: Yes), the process proceeds to step S6. If it is determined that no quality abnormality has occurred (step S5: No), the process proceeds to step S7.

[0106] In step S6, the processing condition setting unit 612 changes the set post-processing conditions based on the judgment result in step S5. Specifically, if the inspection results indicate that a quality abnormality has occurred, the processing condition setting unit 612 changes the post-processing conditions so that the size of the abnormal paper differs from the size of the normal paper. The processing condition setting unit 612 then stores the changed post-processing conditions in the storage unit 617.

[0107] In step S7, the post-processing control unit 615 controls the post-processing unit 500 so that post-processing is performed so that the size of the abnormal paper differs from the size of the normal paper, according to the changed post-processing conditions. Then, in step S8, the paper discharge control unit 616 controls the paper discharge unit 400 so that the processed paper is discharged from a predetermined tray (for example, the paper discharge tray 401).

[0108] If any abnormal paper is found among the paper discharged and stacked in a designated tray such as the output tray 401, the abnormal paper is removed by the operator. At this time, since the abnormal paper is a different size from the normal paper due to post-processing, the operator can identify and remove the abnormal paper from the stacked paper.

[0109] (Processing condition setting that takes recovery printing into consideration) If the inspection unit 300 detects a paper quality abnormality, the image forming system 1 according to this embodiment 1 can perform recovery printing on the abnormal paper automatically or manually. If the recovery of the abnormal paper is performed automatically, the operation of the image forming system 1 is continued. On the other hand, if it is performed manually, the operation of the image forming system 1 is temporarily stopped.

[0110] Figure 10 is a flowchart showing another example of the processing condition setting process according to Embodiment 1. This example shows the processing condition setting process corresponding to recovery printing, which is performed automatically or manually. Each process shown in this flowchart is executed by the respective parts of the control unit 600 (see Figure 3). Note that the post-processing process in the event of a paper quality abnormality is the same as the process shown in Figure 9, so the explanation is omitted. Here, we will explain the process when a quality abnormality occurs.

[0111] In step S11, the information acquisition unit 611 of the control unit 600 acquires a print job. The information acquisition unit 611 stores the acquired print job in the storage unit 617.

[0112] In step S12, the processing condition setting unit 612 sets the post-processing conditions for the post-processing to be performed by the post-processing unit 500 based on the acquired print job. The processing condition setting unit 612 stores the set post-processing conditions in the storage unit 617.

[0113] In step S13, the control unit 600 sets a continuation condition for whether to continue or stop the operation of the device if a quality abnormality occurs with respect to the paper.

[0114] When paper is transported from the paper feed unit 200 to the image forming apparatus 100, the print control unit 614 controls the image forming apparatus 100 in step S14 to perform printing based on the print job.

[0115] When the paper printed by the image forming apparatus 100 is transported to the inspection unit 300, the information acquisition unit 611 acquires inspection information obtained during the inspection of the paper performed by the inspection unit 300 in step S15. The information acquisition unit 611 stores the acquired inspection information in the storage unit 617.

[0116] In step S16, the abnormality determination unit 613 determines whether or not there is a quality abnormality in the paper based on the inspection information read from the storage unit 617. If it is determined that a quality abnormality has occurred, the processing condition setting unit 612 changes the set post-processing conditions in step S17. Specifically, if the inspection results indicate that a quality abnormality has occurred, the processing condition setting unit 612 changes the post-processing conditions so that the size of the abnormal paper differs from the size of the normal paper. The processing condition setting unit 612 then stores the changed post-processing conditions in the storage unit 617.

[0117] In step S18, the paper output control unit 616 controls the paper output unit 400 so that the processed paper is discharged from a predetermined tray.

[0118] Next, in step S19, the control unit 600 determines whether the device is "automatically continuing" or "stopped" based on the continuation condition set in step S13. If the determination shows that "automatically continuing" is set as the continuation condition (step S19: Yes), the process proceeds to step S20.

[0119] In step S20, the print control unit 614 performs automatic recovery printing to automatically print recovery copies of defective paper.

[0120] When the paper printed by automatic recovery printing is transported to the inspection unit 300, the information acquisition unit 611 acquires inspection information for the transported paper from the inspection unit 300 in step S21. The information acquisition unit 611 stores the acquired inspection information in the storage unit 617.

[0121] In step S22, the abnormality determination unit 613 reads the inspection information stored in the storage unit 617 in step S21, and determines whether or not there is a quality abnormality in the paper based on the read inspection information. If it is determined that a quality abnormality has occurred (step S22: Yes), the process proceeds to step S23. Furthermore, if it is determined that no quality abnormalities have occurred (step S22: No), the process proceeds to step S40.

[0122] In step S23, the paper output control unit 616 controls the paper output unit 400 so that any paper with quality defects is ejected from a designated tray. Then, the process returns to step S20, and steps S20 to S23 are repeated until the paper printed by automatic recovery printing is determined to be normal paper.

[0123] On the other hand, if "Stop" is set as the continuation condition in step S19 (step S19: No), the process proceeds to step S30. In step S30, the control unit 600 stops the operation of the image forming system 1.

[0124] At this time, any abnormal paper included in the paper that has been discharged and stacked in the designated tray is removed by the operator. Since the abnormal paper is a different size from the normal paper due to post-processing, the operator can identify and remove the abnormal paper from the stacked paper.

[0125] Next, in step S31, the print control unit 614 performs manual recovery printing to manually print recovery copies of defective paper.

[0126] When the paper printed by manual recovery printing is transported to the inspection unit 300, the information acquisition unit 611 acquires inspection information for the transported paper from the inspection unit 300 in step S32. The information acquisition unit 611 stores the acquired inspection information in the storage unit 617.

[0127] In step S33, the abnormality determination unit 613 reads the inspection information stored in the storage unit 617 in step S32, and determines whether or not there is a quality abnormality in the paper based on the read inspection information. If it is determined that a quality abnormality has occurred (step S33: Yes), the process proceeds to step S34. If it is determined that no quality abnormality has occurred (step S33: No), the process proceeds to step S40.

[0128] In step S34, the paper output control unit 616 controls the paper output unit 400 so that any paper with a quality defect is ejected from a designated tray. Then, the process returns to step S31, and steps S31 to S34 are repeated until the paper printed by manual recovery printing is determined to be normal paper.

[0129] In step S40, the processing condition setting unit 612 changes the set post-processing conditions. That is, the processing condition setting unit 612 changes the post-processing conditions currently set for abnormal paper to the conditions for normal paper. Then, the processing condition setting unit 612 stores the changed post-processing conditions in the storage unit 617.

[0130] As described above, in the image forming system 1 according to this embodiment 1, the processing condition setting unit 612 of the control unit 600 sets post-processing conditions for abnormal paper so that the size of the abnormal paper differs from the size of the normal paper when an abnormality in paper quality occurs. As a result, even when normal and abnormal paper are loaded, the size of the abnormal paper differs from the size of the normal paper, so the operator can distinguish the abnormal paper from the loaded paper.

[0131] Furthermore, since there is no need to use a dedicated processing unit or the like when distinguishing between normal and abnormal paper, the cost increase of the image forming system 1 can be suppressed.

[0132] <Embodiment 2> Next, Embodiment 2 will be described. Embodiment 2 differs from Embodiment 1 described above in that it changes the post-processing conditions for abnormal paper depending on the destination of the paper output. In Embodiment 2, the same reference numerals are used for parts common to Embodiment 1, and detailed descriptions are omitted.

[0133] In the embodiment 1 described above, the paper that has undergone post-processing is discharged to the output tray 503 of the post-processing unit 500. On the other hand, in the image forming system 1, if the output unit 400 is located downstream of the post-processing unit 500 in the paper transport direction, the paper that has undergone post-processing can also be discharged to the output tray 401 of the output unit 400, etc.

[0134] Here, in the paper output tray 401 of the paper output unit 400, a roller consisting of two or more pairs of rollers arranged in parallel in the CD direction is typically used as the drive roller for transporting the paper. When processed paper with a length in the CD direction shorter than the distance between rollers is transported to such a paper output tray 401, the processed paper will be transported by only one pair of rollers. In this case, the processed paper may be bent during transport, and there is a possibility that the processed paper will not be transported properly.

[0135] Therefore, when processing paper is discharged to the paper output tray 401 of the paper output unit 400, the processing paper must have a length in the CD direction that is longer than the length between the rollers. In this embodiment 2, the post-processing conditions for abnormal paper are changed so that the processing paper is properly discharged from the tray set as the paper output destination.

[0136] For example, consider the case where multiple sheets are cut as a post-processing step for normal paper. Figure 11 is a schematic diagram illustrating the post-processing step for abnormal paper when the paper output destination is set to the output tray 401 of the output unit 400.

[0137] As explained in the third example of Embodiment 1 (see Figure 6), when cutting multiple sheets, the paper is cut so that the length of the paper in the CD direction is shortened by cutting both ends and near the center in the CD direction.

[0138] In this case, if the paper is to be discharged to the output tray 503 of the post-processing unit 500, the abnormal paper should be cut so that its length in the FD direction is longer than the length of a normal sheet of paper, as explained in Figure 6.

[0139] On the other hand, if the paper is discharged to the output tray 401 of the output unit 400, as shown in Figure 6, if post-processing is performed on abnormal paper, the length of the processed paper in the CD direction may become shorter than the length between the rollers. Therefore, it may not be possible to properly transport the processed paper.

[0140] Therefore, in this case, as shown in Figure 11, the abnormal paper is cut so that the length of the abnormal paper in the CD direction is longer than the length between the rollers, and the size of the abnormal paper is different from that of the normal paper. Specifically, for example, the post-processing conditions are changed so that cutting by the slitter 512 and trimmer unit 513 is changed from "yes" to "no". Cutting by the cutter 511 is not changed.

[0141] As a result, the abnormal paper is not cut in the FD direction, and becomes two processed sheets of paper, with the length in the CD direction being longer than that of the normal paper in the CD direction. Therefore, even when the processed paper is discharged from the output tray 401 and normal and abnormal paper are stacked in the same tray, the abnormal paper will protrude in the CD direction from among the stacked normal paper. Thus, the paper is discharged appropriately, and abnormal paper can be easily identified by the operator's visual inspection.

[0142] Thus, in this second embodiment, post-processing conditions for abnormal paper are set according to the destination of the paper. This allows for the discharge of abnormal paper of a size appropriate for the destination, so that even when normal and abnormal paper are discharged into the same tray, the paper can be discharged appropriately.

[0143] While embodiments 1 and 2 have been described above, this disclosure is not limited to embodiments 1 and 2 described above, and various modifications and applications are possible without departing from the spirit of this disclosure. For example, normal paper and abnormal paper are not limited to being discharged from the same tray; each type of paper may be discharged from a different tray. [Explanation of symbols]

[0144] 1. Image forming system 10 Image Processing Unit 20 Image forming unit 21 Image forming unit 22 Intermediate Transfer Unit 23 Secondary Transfer Unit 30 Fixing section 40 Paper transport section 41 Conveyor Path Section 41a Resist Roller 50 Operation display section 71 Communications Department 72 Memory section 100 Image forming apparatus 200 Paper feed section 201 Paper feed tray 202 Paper feed tray 203 Paper feed tray 300 Inspection Department 301 Sensor 302 Sensor 400 Paper output section 401 Paper Output Tray 402 Purge Tray 500 Post-processing 501 Cutting section 511 Cutter 512 Slitter 513 Trimmer Unit 502 Folding section 503 Paper Output Tray 600 Control Unit 601 CPU 602 ROM 603 RAM 611 Information Acquisition Department 612 Processing Condition Setting Unit 613 Abnormality judgment unit 614 Printing Control Unit 615 Post-processing control unit 616 Paper output control unit 617 Storage section

Claims

1. An image forming apparatus that forms an image on a recording medium, A post-processing apparatus that performs post-processing on the recording medium on which the image is formed based on post-processing conditions, A control device for controlling the image forming apparatus and the post-processing apparatus, Equipped with, The control device is If a quality defect occurs in the recording medium, the post-processing conditions for the defective recording medium are set such that the size of the defective recording medium differs from the size of a normal recording medium that does not have a quality defect. Image forming system.

2. The control device is The post-processing conditions are set such that the size of the abnormal recording medium is larger than the size of the normal recording medium. The image forming system according to claim 1.

3. The control device is The post-processing conditions are set such that the length of the transport direction of the abnormal recording medium is longer than the length of the transport direction of the normal recording medium. The image forming system according to claim 2.

4. The control device is The post-processing conditions are set such that the length of the abnormal recording medium in the direction perpendicular to the transport direction is longer than the length of the normal recording medium in the direction perpendicular to the transport direction. The image forming system according to claim 2.

5. The control device is The post-processing conditions are set such that the number of times the abnormal recording medium is folded is less than the number of times the normal recording medium is folded. The image forming system according to claim 2.

6. The discharge device further comprises a first discharge tray for discharging the recording medium, The aforementioned post-processing device is It has a second discharge tray for discharging the recording medium after the post-processing described above, The control device is Depending on the destination of the recording medium, the post-processing conditions for the defective recording medium are set. The image forming system according to claim 1.

7. The control device is When the recording medium is discharged to the first discharge tray, the post-processing conditions are set such that the length of the abnormal recording medium in the direction perpendicular to the transport direction is longer than the length of the normal recording medium in the direction perpendicular to the transport direction. The image forming system according to claim 6.

8. The control device is If a quality abnormality occurs in the aforementioned recording medium, the system will continue operation and perform automatic recovery printing. The image forming system according to claim 1.

9. The control device is If a quality abnormality occurs in the aforementioned recording medium, the operation will be stopped. The image forming system according to claim 1.

10. The post-processing device is a cutting device that cuts the recording medium on which the image has been formed. The image forming system according to claim 1.

11. The post-processing device is a folding device that folds the recording medium on which the image has been formed. The image forming system according to claim 1.

12. A post-processing apparatus that performs post-processing on a recording medium on which an image has been formed, based on post-processing conditions, The post-processing is performed such that the size of the defective recording medium in which a quality defect has occurred is different from the size of the normal recording medium in which no quality defect has occurred. Post-processing equipment.

13. Form an image on a recording medium, Based on the post-processing conditions, post-processing is performed on the recording medium on which the image has been formed. If a quality defect occurs in the recording medium, the post-processing conditions for the defective recording medium are set such that the size of the defective recording medium differs from the size of a normal recording medium that does not have a quality defect. How to set machining conditions.

14. A program that causes a computer to execute the processing condition setting method described in claim 13.

Images