Image formation system and method

Abstract

To provide an image formation system and a method which can appropriately keep sizes of paper to be output.SOLUTION: An image formation system includes: a paper feeding part which stores a recording medium, and sets a storage size of the recording medium to be stored; a reading part for reading the recording medium; an acquisition part for acquiring information on the size of the recording medium on the basis of the reading result of the reading part; and a control part for performing control so that as for a recording medium stored in the paper feeding part whose predetermined storage size is set, a recording medium in which a difference between the information on the size acquired by the acquisition part and information on a reference size preset corresponding to the storage size is within the range of a preset allowable value, and a recording medium in which the difference is out of the range of the allowable range are discharged in a discriminative manner.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to imaging systems and methods. [Background technology]

[0002] Conventionally, image forming apparatuses that form and output images on paper, which is a recording medium, are known. In such image forming apparatuses, when the same image is to be formed on multiple sheets of paper, a stack of multiple sheets of paper is set in a paper feed unit, and the sheets are fed one by one in sequence to form the same image on the sheets (see, for example, Patent Document 1). In such image forming apparatuses, packaged stacks of paper are often used. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-189419 Summary of the Invention [Problem to be solved by the invention]

[0004] However, although the paper in the package is manufactured to be the same size according to a common standard, the size of each sheet varies slightly, and for example, the size of the top sheet and the bottom sheet may differ significantly. This is because the sheets that make up the paper stack are cut from a single large sheet, and errors that occur when cutting them are the cause.

[0005] Therefore, if the same image is formed on each sheet of paper using such a paper stack, the image formation quality desired by the user cannot be achieved. Also, if a large amount of paper is output using sheets from multiple paper stacks, there is a possibility that the ejected sheets will be significantly misaligned, and the sheets will not be properly aligned.

[0006] The present disclosure has been made in consideration of the problems in the conventional technology described above, and aims to provide an image forming system and method that can properly align the size of output paper. [Means for solving the problem]

[0007] The paper discharge device according to the present disclosure includes: a paper feed unit in which recording media are accommodated and in which a storage size relating to the size of the accommodated recording media is set; a reading unit that reads the recording medium; an acquisition unit that acquires information about the size of the recording medium based on the reading result of the reading unit; a control unit that controls the recording media stored in the paper feed unit, which has a predetermined storage size set, so that recording media whose difference between the information about the size acquired by the acquisition unit and information about a reference size that is preset corresponding to the storage size is within a predetermined tolerance range and recording media whose difference is not within the tolerance range are separately discharged; Equipped with.

[0008] The method according to the present disclosure comprises: A method executed in an image forming system including a paper feed unit in which recording media are accommodated and in which a storage size relating to the size of the accommodated recording media is set, reading the recording medium by a reading unit; acquiring information about the size of the recording medium based on the reading result of the reading unit; a step of controlling the ejection of recording media stored in the paper feed unit, which has a predetermined storage size set, so that recording media whose difference between the acquired information about the size and information about a reference size preset corresponding to the storage size is within a predetermined tolerance range and recording media whose difference is not within the tolerance range; Equipped with. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to properly align the size of output paper. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram showing an example of the configuration of an image forming system according to the present embodiment. [Figure 2] FIG. 2 is a block diagram showing the main parts of a control system of the image forming system according to this embodiment. [Figure 3] FIG. 3 is a schematic diagram for explaining the paper size of a paper stack. [Figure 4] FIG. 4 is a flowchart showing an example of the flow of the correction coefficient calculation process performed by the image forming system according to the present embodiment. [Figure 5] FIG. 5 is a schematic diagram showing an example of an actual size setting screen displayed on the operation display unit. [Figure 6] FIG. 6 is a flowchart showing an example of the flow of the purge process by the image forming system according to the present embodiment. [Figure 7] FIG. 7 is a schematic diagram showing an example of a purge setting screen displayed on the operation display unit for setting the difference deviation amount and the number of consecutive NG sheets. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments 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 are possible without departing from the spirit of the present disclosure. In addition, in each drawing, the same reference numerals are used to denote the same or equivalent parts, and this is common throughout the entire specification.

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An image forming system according to an embodiment of the present disclosure is capable of forming an image on a sheet of paper (recording medium), such as a paper sheet.

[0013] [Configuration of image forming system 1] Fig. 1 is a schematic diagram showing an example of the configuration of an image forming system 1 according to the present embodiment. Fig. 2 is a block diagram showing the main parts of a control system of the image forming system 1 according to the present embodiment. As shown in Fig. 1, the image forming system 1 is configured to include an image forming device 100, a paper feed unit 200, a reading unit 300, an upstream paper discharge unit 600, and a downstream paper discharge unit 400. The configuration including the reading unit 300 and the upstream paper discharge unit 600 or the downstream paper discharge unit 400 constitutes a paper discharge device according to the present embodiment.

[0014] Image forming apparatus 100 is an intermediate transfer type color image forming apparatus that utilizes electrophotographic process technology. That is, image forming apparatus 100 forms an image by primarily transferring toner images of each color (CMYK) formed on a photosensitive member to an intermediate transfer member, superimposing the four color toner images on the intermediate transfer member, and then secondary transferring the images onto paper. CMYK stands for cyan (C), magenta (M), yellow (Y), and black (K).

[0015] The image forming apparatus 100 employs a tandem system in which photosensitive elements corresponding to the four colors CMYK are arranged in series in the direction of travel of the intermediate transfer body, and toner images of each color are transferred sequentially to the intermediate transfer body in a single step.

[0016] As shown in FIG. 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 memory unit 72, a control unit 500, a paper feed unit 200, a reading unit 300, an upstream paper discharge unit 600, and a downstream paper discharge unit 400.

[0017] The image processing unit 10 includes a circuit for performing image processing on input image data according to initial settings or user settings, etc. The image forming unit 20 is controlled based on the image data that has undergone image processing.

[0018] The image forming section 20 includes an image forming unit 21, an intermediate transfer unit 22, and a secondary transfer unit 23. The image forming unit 21 forms an image using color toners of each color component based on image data from the image processing section 10. For example, the image is formed using color toners of each color component of Y (yellow), M (magenta), C (cyan), and K (black).

[0019] The image forming unit 21 has, for each color, an exposure device, a developing device, a photosensitive drum, a charging device, a drum cleaning device, etc. Known technologies can be used for the exposure device, developing device, photosensitive drum, charging device, and drum cleaning device, so detailed explanations will be omitted here.

[0020] The intermediate transfer unit 22 includes an intermediate transfer belt and other components. The intermediate transfer belt is looped and stretched around multiple support rollers, and travels in the direction of arrow A. The support rollers include a backup roller, a primary transfer roller, a drive roller, and other rollers, but these are not shown here. The intermediate transfer belt is pressed against the photosensitive drum, thereby transferring the toner image from the photosensitive drum to the intermediate transfer belt.

[0021] The intermediate transfer unit 22 may 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 residual toner and the like that remains on the surface of the intermediate transfer belt after the secondary transfer.

[0022] The secondary transfer unit 23 includes a secondary transfer roller, etc. The secondary transfer roller is pressed against the intermediate transfer belt, thereby forming a secondary transfer nip between the intermediate transfer belt and the secondary transfer roller.

[0023] In the secondary transfer unit 23, when a sheet of paper is transported to the secondary transfer nip, the toner images of each color carried on the intermediate transfer belt are transferred onto the sheet of paper at once. The sheet of paper onto which the toner images have been transferred is transported toward the fixing unit 30 by the secondary transfer roller.

[0024] The secondary transfer unit 23 may be a belt-type secondary transfer unit having a secondary transfer belt stretched over a plurality of support rollers, instead of a roller-type secondary transfer unit having a secondary transfer roller or the like.

[0025] 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 between the fixing roller and the pressure roller, which sandwiches and transports the paper. In the fixing unit 30, the toner image is fixed to the paper by applying heat and pressure to the paper, which has been secondarily transferred, in the fixing nip.

[0026] The paper transport unit 40 includes a transport path unit 41. The transport path unit 41 is configured with, for example, a path for transporting paper, multiple transport rollers, and a drive motor for driving the transport rollers to rotate. The transport path unit 41 transports paper supplied from the paper feed unit 200 to the secondary transfer unit 23 and the fixing unit 30, and then transports the paper to the downstream paper discharge unit 400.

[0027] 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 direction (angle) of the paper to be transported to the secondary transfer unit 23.

[0028] The operation display unit 50 is configured, for example, with a liquid crystal display (LCD) with a touch panel, and functions as 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 a display control signal input from the control unit 500. The operation unit has various operation keys such as a numeric keypad and a start key, accepts various input operations by the user, and outputs operation signals to the control unit 500.

[0029] Paper feed unit 200 is disposed upstream of image forming apparatus 100 in paper transport direction D, and is connected to image forming apparatus 100 via reading unit 300 and upstream paper discharge unit 600, which will be described later. Paper feed unit 200 has multiple paper feed trays 201, 202, and 203, and each of paper feed trays 201, 202, and 203 stores sheets of paper (standard paper or special paper) identified based on basis weight, size, etc., by preset type. Paper feed unit 200 supplies the specified paper to image forming apparatus 100 based on instructions from image forming apparatus 100.

[0030] The reading unit 300 is disposed between the paper feed unit 200 and the upstream paper discharge unit 600, and is connected to the paper feed unit 200 on the upstream side in the paper transport direction D, and is connected to the image forming apparatus 100 on the downstream side.

[0031] Reading unit 300 has sensors 301 and 302 that read paper transported from paper feed unit 200. Sensor 301 is located above the path along which paper is transported, facing the paper being transported, and is configured to read the front (upper) side of the paper being transported. Sensor 302 is located below the path along which paper is transported, facing the paper being transported, and is configured to read the back (lower) side of the paper being transported.

[0032] For example, CCDs (Charge Coupled Devices) or CISs (Contact Image Sensors) are used as sensors 301 and 302. Furthermore, for sensors 301 and 302, line sensors that extend across a width equal to or greater than the width of the paper (the width in the direction perpendicular to the paper conveyance direction D), such as line scanners or line sensor cameras, are used.

[0033] The sensors 301 and 302 acquire information related to the paper, such as the size of the paper (paper width, paper length, etc.) and the position of the paper.

[0034] Here, as an example, the reading unit 300 is configured to have sensors 301 and 302 that read both sides (front and back) of the paper, but this is not limited to this, and it may also be configured to have, for example, only sensor 301 that reads one side (front) of the paper.

[0035] The upstream discharge unit 600 is connected to the reading unit 300 on the upstream side in the paper transport direction D, and is connected to the image forming device 100 on the downstream side. The upstream discharge unit 600 has a purge tray 601, and based on the results of reading the paper by the reading unit 300, conveys the paper to the image forming device 100 or discharges the paper to the purge tray 601.

[0036] For example, if the paper size satisfies a predetermined condition, the upstream paper ejection unit 600 conveys the paper to the image forming apparatus 100. If the paper size does not satisfy the predetermined condition, the upstream paper ejection unit 600 ejects the paper to the purge tray 601, as indicated by the dashed arrow in Fig. 1. In this embodiment, if the size of the paper read by the reading unit 300 does not fit within the predetermined size, the upstream paper ejection unit 600 ejects the paper to the purge tray 601.

[0037] Note that, here, as an example, image forming system 1 is configured to include upstream paper discharge section 600, but it may also be configured not to include upstream paper discharge section 600. In such a configuration, when the paper size does not satisfy a predetermined condition based on the results of reading the paper by reading section 300, image formation (hereinafter referred to as "printing") is not performed by image forming section 20, and the paper is transported to downstream paper discharge section 400 by paper transport section 40.

[0038] The downstream discharge section 400 is disposed downstream of the image forming apparatus 100 in the paper transport direction D, and is connected to the image forming apparatus 100. The downstream discharge section 400 has a paper output tray 401 and a purge tray 402, and discharges paper transported from the image forming apparatus 100 to the paper output tray 401 or the purge tray 402.

[0039] The paper output tray 401 outputs paper on which an image has been formed by the image forming apparatus 100. The purge tray 402 outputs paper whose paper size does not satisfy predetermined conditions as a result of the paper size being read by the reading unit 300. For example, if the paper size read by the reading unit 300 does not satisfy predetermined conditions, the downstream paper output unit 400 may output paper on which an image has not been formed by the image forming apparatus 100 from the purge tray 402, as indicated by the dashed-dotted arrow in FIG.

[0040] The control unit 500 is connected to the above-mentioned image processing unit 10, image forming unit 20, fixing unit 30, paper transport unit 40, operation display unit 50, communication unit 71, memory unit 72, paper feed unit 200, reading unit 300, upstream paper discharge unit 600, and downstream paper discharge unit 400. The control unit 500 issues various instructions to each of these units and executes predetermined processes.

[0041] In this embodiment, the control unit 500 performs a correction coefficient calculation process to calculate a correction coefficient for correcting the size of the paper read by the reading unit 300. Furthermore, if the size of the paper is not the desired size, the control unit 500 performs a purge process to purge the paper. Details of the correction coefficient calculation process and the purge process will be described later.

[0042] The control unit 500 includes a CPU (Central Processing Unit) 501, a ROM (Read Only Memory) 502, and a RAM (Random Access Memory) 503. The CPU 501 reads a program corresponding to the processing content from the ROM 502, loads it into the RAM 503, and centrally controls the operation of each block of the image forming system 1 in cooperation with the loaded program. At this time, various data such as an LUT (Look Up Table) stored in the storage unit 72 is referenced. The storage unit 72 is configured, for example, with a non-volatile semiconductor memory (so-called flash memory) or a hard disk drive.

[0043] The control unit 500 transmits and receives various data to and from an external device (e.g., a personal computer) connected to a communication network such as a LAN (Local Area Network) or a WAN (Wide Area Network) via the communication unit 71. The control unit 500 receives, for example, 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 configured, for example, by a communication control card such as a LAN card.

[0044] The control unit 500 also includes a counter 505. The counter 505 counts the number of sheets of paper that are continuously purged during the purging process.

[0045] Furthermore, the control unit 500 functions as a calculation unit and a comparison unit. The calculation unit performs various calculations performed during the correction coefficient calculation process or the purge process. The comparison unit performs various comparisons performed during the purge process.

[0046] Specifically, for example, during the correction coefficient calculation process, the calculation unit calculates a correction coefficient for correcting the reading size based on the size of the paper read by the reading unit 300 (hereinafter referred to as the "reading size") and a predetermined standard paper size.

[0047] The calculation unit calculates a corrected paper size by correcting the read size based on the read size and the calculated correction coefficient during the purge process. The calculation unit then calculates a size difference value, which is the absolute value of the difference between the calculated corrected paper size and the standard paper size.

[0048] The comparison unit, for example, compares the size difference value calculated by the calculation unit with the difference deviation amount, and determines whether to purge the paper based on the comparison result. The difference deviation amount is an allowable value for the size difference value, and indicates the allowable deviation amount of the corrected paper size from the reference paper size.

[0049] The comparison unit also compares the count value of counter 505 with the number of consecutive NG sheets, and determines whether to cancel the job based on the comparison result. The number of consecutive NG sheets indicates the number of sheets that becomes the criterion for canceling the job when paper is purged consecutively.

[0050] [Operation of image forming system 1] In image forming system 1 according to the present embodiment having the above configuration, when an image is formed on paper as a recording medium, the paper is stored in paper feed trays 201, 202, and 203 of paper feed unit 200. The paper supplied from paper feed unit 200 is then transported to image forming apparatus 100, where printing is performed, and the paper is transported to downstream paper discharge unit 400.

[0051] When forming images on a large amount of paper, the paper feed trays 201, 202, and 203 often contain bundles of paper that have been packaged. In this case, even if the packaged paper is of the same standard, the paper size may differ from the expected size. This is because the paper in the bundle of paper is cut from larger paper, and errors that occur during cutting are the influence of the paper.

[0052] Fig. 3 is a schematic diagram for explaining the paper size of a paper stack. Fig. 3 shows an example of a paper stack when the paper is viewed from a direction perpendicular to the transport direction. This example also shows a state in which two packaged paper stacks are stacked.

[0053] This example shows a situation where there is a discrepancy of about 1 mm between the size of the top and bottom sheets of paper for each stack. This discrepancy occurs when larger sheets are cut at an angle rather than perpendicular to the surface. In this case, the size of the sheets decreases from top to bottom of the stack, and if the top sheet is cut to fit the standard, the bottom sheet will be about 1 mm shorter than the standard size.

[0054] In this way, when an image is printed on paper of a size different from the size specified by the standard, the printing may not be performed properly, and the user may not be able to obtain the quality of the printed matter desired. Also, when outputting a large amount of printed matter using paper from multiple paper stacks, there is a possibility that the ejected paper may be significantly misaligned, and the paper may not be properly aligned.

[0055] Therefore, the image forming system 1 according to the present embodiment reads the paper size using the reading unit 300, and performs a purge process to eject paper that cannot be used for printing based on the reading result. In the purge process, an allowable deviation from the actual paper size is set in advance, and paper whose read paper size has an error larger than the set deviation is purged.

[0056] On the other hand, the paper size read by the reading unit 300 may differ from the actual paper size. This is because the distance between the sensors 301 and 302 and the paper varies from device to device, and a reading error occurs between the actual paper size and the read size, making it impossible to read the paper size accurately.

[0057] Therefore, the image forming system 1 according to the present embodiment performs a correction coefficient calculation process to calculate a correction coefficient for correcting the reading error before the above-described purge process when a job is reserved or executed.

[0058] (Correction coefficient calculation process) FIG. 4 is a flowchart showing an example of the flow of the correction coefficient calculation process by the image forming system 1 according to the present embodiment. First, before the correction coefficient calculation process is performed, the actual size of the paper is measured in advance by the user. The actual size of the paper is measured manually, for example. At this time, the user may, for example, remove the top sheet of paper from a package of papers to be used for printing and measure the size of the removed sheet. However, this is not limiting, and the actual size of the paper may also be stored in advance in the storage unit 72.

[0059] When the actual size of the paper is measured, in step S1, the actual size of the paper measured by the user is input by operating the operation display unit 50. The operation display unit 50 supplies size information including the actual size of the paper input by the user to the control unit 500. The control unit 500 stores the actual size of the paper included in the received size information in the memory unit 72 as a reference paper size.

[0060] Fig. 5 is a schematic diagram showing an example of an actual size setting screen 51 displayed on the operation display unit 50. As shown in Fig. 5, the operation display unit 50 displays the actual size setting screen 51 including a conveying direction size input box 52, a conveying direction intersection size input box 53, and a measurement start button 54.

[0061] The conveying direction size input box 52 is selected by a touch operation or the like by the user when inputting a numerical value indicating the actual size of the paper in the conveying direction. When the conveying direction size input box 52 is selected, for example, numeric input buttons such as a numeric keypad are displayed on the operation display unit 50. Then, the user operates the numeric input buttons to input the actual size of the paper in the conveying direction (conveying direction size). This example shows a state in which "210.0 mm" has been input as the conveying direction size.

[0062] The conveyance direction intersecting size input box 53 is selected by a touch operation or the like by the user when inputting a value indicating the actual size of the paper in a direction intersecting the conveyance direction. When the conveyance direction intersecting size input box 53 is selected, for example, numeric input buttons such as a numeric keypad are displayed on the operation display unit 50. Then, the user operates the numeric input buttons to input the actual size of the paper in a direction intersecting the conveyance direction (conveyance direction intersecting size). This example shows a state in which "297.0 mm" has been input as the conveyance direction intersecting size.

[0063] The measurement start button 54 is selected by the user when reading the paper size by the reading unit 300. By operating the measurement start button 54, the reading unit 300 starts measuring the paper size.

[0064] When the measurement start button 54 displayed on the actual size setting screen 51 of the operation display unit 50 is selected, in step S2 of Fig. 4, the control unit 500 reads the paper size using the sensors 301 and 302 of the reading unit 300 and obtains the read size. The sensors 301 and 302 supply information including the read size to the control unit 500.

[0065] In step S3, the control unit 500 reads out the standard paper size stored in the storage unit 72. Then, the calculation unit of the control unit 500 calculates the reading error based on the standard paper size, which is the actual measured size of the paper, and the size read by the reading unit 300.

[0066] Specifically, when the read size is "X" and the reference paper size (actual size) is "Y", the control unit 500 calculates the read error as "Y / X" by dividing the reference paper size Y by the read size X. For example, when the reference paper size X of the paper in the transport direction is 210 mm and the read size Y is 209.5 mm, the read error is "Y / X = 210 / 209.5 (≈ 1.0024)".

[0067] Therefore, when the size of the paper on which an image is to be printed read by the reading unit 300 is 209.5 mm, the actual paper size is "209.5 x 210 / 209.5 = 210 mm," and it is found that the actual paper size is 210 mm.

[0068] In step S4, the control unit 500 stores the calculated reading error as a correction coefficient in the storage unit 72. Then, a series of correction coefficient calculation processes ends.

[0069] This correction coefficient calculation process is performed for each paper type classified by standard, and a correction coefficient is calculated according to the paper type. As a result, the corrected paper size is calculated using the correction coefficient corresponding to each paper type, so the size of the scanned paper can be appropriately corrected.

[0070] Furthermore, depending on the job reserved or executed, there may be a mixture of multiple types of paper, such as A4 size and A3 size, etc. In such a case, the control unit 500 calculates a correction coefficient (reading error) for each type, based on the size of the first sheet of paper of each type in the job.

[0071] (Purge process) Next, the purging process will be described with reference to a flowchart of FIG 6, which shows an example of the flow of the purging process performed by the image forming system 1 according to the present embodiment.

[0072] First, in step S11, the differential deviation amount and the number of consecutive NG sheets are input by the user operating the operation display unit 50. The operation display unit 50 supplies information including the differential deviation amount and the number of consecutive NG sheets input by the user to the control unit 500. The control unit 500 stores and sets the differential deviation amount and the number of consecutive NG sheets included in the received information in the storage unit 72.

[0073] The reason for setting the number of consecutive NG sheets is to prevent a large number of sheets from being purged. This is because, for example, if the size of the sheets in a stack of sheets changes from top to bottom as shown in Figure 3, if a certain number of sheets are purged in succession, there is a high possibility that subsequent sheets will also be purged.

[0074] 7 is a schematic diagram showing an example of a purge setting screen 55 for setting the difference deviation amount and the number of consecutive NG sheets, which is displayed on the operation and display unit 50. As shown in FIG. 7, the operation and display unit 50 displays the purge setting screen 55 including a difference deviation amount input box 56 and a consecutive NG sheet number input box 57.

[0075] The differential deviation amount input box 56 is selected by a touch operation or the like by the user when inputting the differential deviation amount. When the differential deviation amount input box 56 is selected, for example, numeric input buttons such as a numeric keypad are displayed on the operation display unit 50. Then, the user operates the numeric input buttons to input the differential deviation amount. In this example, a state in which "0.5 mm" has been input as the differential deviation amount is shown.

[0076] The continuous NG sheet count input box 57 is selected by a touch operation or the like by the user when inputting the continuous NG sheet count. When the continuous NG sheet count input box 57 is selected, for example, numeric input buttons such as a numeric keypad are displayed on the operation display unit 50. Then, the user operates the numeric input buttons to input the allowable continuous NG sheet count. In this example, a state in which "5 sheets" has been input as the continuous NG sheet count is shown.

[0077] 6, in step S12, control unit 500 initializes the value of counter 505, which counts the number of consecutive NG sheets. Then, in step S13, control unit 500 starts paper feeding. As a result, paper is discharged from paper feeding unit 200 and supplied to reading unit 300.

[0078] Next, in step S14, the control unit 500 uses the sensors 301 and 302 of the reading unit 300 to read the size of the paper conveyed to the reading unit 300. The sensors 301 and 302 supply the control unit 500 with information including the read size of the paper that has been read.

[0079] In step S15, the control unit 500 reads out the correction coefficient stored in the storage unit 72. Then, the calculation unit of the control unit 500 uses the correction coefficient to calculate a corrected paper size by correcting the read size received from the sensors 301 and 302. Specifically, for example, the calculation unit calculates the corrected paper size by multiplying the read size by the correction coefficient.

[0080] In step S16, the calculation unit reads the standard paper size stored in memory unit 72 and calculates a size difference value, which is the absolute value of the difference between the standard paper size and the corrected paper size. Next, the comparison unit of control unit 500 compares the size difference value with the differential deviation amount set in step S11. If the comparison results in the size difference value being equal to or less than the differential deviation amount (step S16: NO), the process proceeds to step S17.

[0081] In step S17, the paper sheet whose size difference value is determined to be equal to or less than the differential deviation amount is transported from the reading unit 300 to the image forming apparatus 100 via the upstream paper ejection unit 600. The control unit 500 forms an image on the paper sheet transported to the image forming apparatus 100. The paper sheet on which the image has been formed is transported to the downstream paper ejection unit 400 and ejected from the paper ejection tray 401.

[0082] In step S18, the control unit 500 resets the count of the number of consecutive NG sheets by the counter 505.

[0083] In step S19, the control unit 500 determines whether the sheet discharged to the discharge tray 401 in step S17 is the last sheet of the job. If the determination result indicates that the sheet is the last sheet (step S19: YES), the process ends. On the other hand, if the sheet is not the last sheet (step S19: NO), the process returns to step S13.

[0084] On the other hand, if the size difference value is greater than the differential deviation amount in step S16 (step S16: YES), the process proceeds to step S20. If the size difference value is determined to be greater than the differential deviation amount in step S20, the paper is transported from the reading unit 300 to the upstream paper ejection unit 600 and purged by being ejected from the purge tray 601.

[0085] If the image forming system 1 is not provided with the upstream paper discharge unit 600, a sheet of paper whose size difference value is determined to be larger than the differential deviation amount may be discharged from the downstream paper discharge unit 400. In this case, the sheet of paper is transported from the reading unit 300 to the image forming apparatus 100, but is transported to the downstream paper discharge unit 400 without an image being formed on the sheet in the image forming apparatus 100. The sheet of paper transported to the downstream paper discharge unit 400 is then purged by being discharged from the purge tray 402.

[0086] In step S21, the control unit 500 increments the count value of the counter 505 for the number of consecutive NG sheets by one.

[0087] In step S22, the control unit 500 compares the count value of the counter 505, which indicates the number of consecutive NG sheets, with the set value for the number of consecutive NG sheets, and determines whether the count value is greater than the set value. If the comparison result shows that the count value for the number of consecutive NG sheets is greater than the set value (step S22: YES), the control unit 500 determines that the number of consecutive NG sheets has exceeded the allowable number. In this case, the control unit 500 cancels the current job. Then, the series of processes ends.

[0088] On the other hand, if the count value is equal to or less than the set value (step S22: NO), the control unit 500 determines that the number of consecutive NG sheets does not exceed the allowable number, and the process returns to step S13.

[0089] The purging process is performed after the correction coefficients have been calculated by the above-described correction coefficient calculation process. However, if it is not necessary to correct the paper size, the purging process may be performed without performing the correction coefficient calculation process. In this case, after the paper size is read in step S14, the calculation unit of the control unit 500 calculates the absolute value of the difference between the standard paper size and the read size as a size difference value in step S16.

[0090] As described above, in the image forming system 1 according to the present embodiment, paper sheets whose size difference, which is the difference between the scanned size of the paper and the reference paper size, is greater than a predetermined difference deviation amount are purged. As a result, only paper sheets whose size deviation amount is within a predetermined range are used for image formation. Therefore, even when a large amount of paper is output, deviations in paper size are tolerable, and the size of the output paper sheets can be properly aligned.

[0091] Furthermore, the calculation unit of the control unit 500 calculates a correction coefficient for correcting the size of the paper read by the reading unit 300, and calculates a corrected paper size by correcting the read size using the correction coefficient. As a result, the read size read by the reading unit 300 is corrected to match the actual paper size. Therefore, the image forming system 1 can accurately obtain the paper size. [Explanation of symbols]

[0092] 1. Image forming system 50 Operation display section 51 Actual size setting screen 52 Conveying direction size input box 53 Conveyance direction cross size input box 54 Measurement start button 55 Purge setting screen 56 Differential deviation input box 57 Continuous NG count input box 100 Image forming device 200 Paper feed section 201, 202, 203 paper trays 300 Reading unit 301, 302 sensors 400 Downstream paper output section 401 Paper output tray 402, 601 Purge tray 500 control section 505 Counter 600 Upstream paper delivery section

Claims

1. An acquisition unit that acquires information regarding the size of a recording medium; a control unit that compares the acquired size information with information about a reference size stored in a storage unit and distinguishes the recording medium based on the comparison result; an input unit for inputting information regarding a difference between the information regarding the size and the information regarding the reference size; An image forming system comprising:

2. Further comprising a display unit that displays information about the input difference. The image forming system according to claim 1 .

3. The information about the difference is a threshold value, the control unit determines whether the recording medium satisfies a predetermined condition based on the threshold value. The image forming system according to claim 1 .

4. The information about the difference is a threshold value, the control unit distinguishes and ejects the recording medium based on a result of comparing the difference between the information about the size and the information about the reference size with the threshold value. The image forming system according to claim 1 .

5. A second input unit for inputting information regarding the reference size; a display unit that displays information about the input reference size; Further provided with The image forming system according to claim 1 .

6. A method performed in an imaging system, comprising: obtaining information about the size of the recording medium; a step of comparing the acquired size information with information on a reference size stored in a storage unit, and distinguishing the recording medium based on the comparison result; inputting information about a difference between the information about the size and the information about the reference size; A method for providing

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