Image forming system

Abstract

To solve a problem that adjustment operation cannot be appropriately performed.SOLUTION: When an evaluation unit 304 determines rejection due to an inspection item that can be corrected by image adjustment control, the image adjustment control is executed. When the evaluation unit 304 determines rejection due to an inspection item that cannot be corrected by the image adjustment control, the image adjustment control is not executed.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an imaging system for inspecting documents on sheets. [Background technology]

[0002] Conventionally, in an image forming system that inspects an image on a sheet, if an image defect continues to occur, an adjustment chart is formed on the sheet, and an adjustment operation is performed to adjust the conditions for forming the image based on the reading result of the adjustment chart (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2022-90999 Summary of the Invention [Problem to be solved by the invention]

[0004] Image defects include, for example, an image to be formed on a sheet being shifted from an ideal position (misalignment) or a streak image that is not included in the image to be formed on the sheet being formed on the sheet. While misalignment can be corrected by an adjustment operation, streak images are not necessarily reduced even if an adjustment operation is performed. In other words, with the configuration of Patent Document 1, there is a possibility that an adjustment operation will be performed even if an image defect occurs due to a streak image or the like that cannot be reduced by the adjustment operation.

[0005] In view of the above problems, an object of the present invention is to appropriately perform an adjustment operation. [Means for solving the problem]

[0006] In order to solve the above problems, an image forming system according to the present invention includes an image forming apparatus that forms an image on a sheet, a reading apparatus that reads the image on the sheet conveyed from the image forming apparatus, an inspection means that inspects the image read by the reading apparatus to detect defects in the image, and a control means that controls the image forming apparatus, wherein the control means: before If the inspection means detects a first type defect, before performing an adjustment operation to adjust the quality of an image formed by the image forming apparatus; before When a second type defect different from the first type is detected by the inspection means, A cause of the defect is determined based on which region of the image the second type defect occurs in. It is characterized by: [Effects of the Invention]

[0007] According to the present invention, the adjustment operation can be performed appropriately. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view of an image forming system. [Figure 2] FIG. 2 is a block diagram showing the configuration of a control device. [Figure 3] FIG. 2 is a block diagram showing the configuration of an inspection controller. [Figure 4] FIG. 4 is a diagram showing a print setting screen. [Figure 5] FIG. 10 is a diagram showing an examination setting screen. [Figure 6] FIG. 10 is a diagram illustrating an example of an adjustment chart. [Figure 7] 4 is a flowchart illustrating image inspection control in the first embodiment. [Figure 8] FIG. 10 is a diagram showing a screen for selecting whether or not to execute image adjustment control. [Figure 9] 10 is a flowchart illustrating image inspection control in the second embodiment. [Figure 10] 10 is a flowchart illustrating image inspection control in the third embodiment. [Figure 11]FIG. 2 is a diagram illustrating a configuration of a fixing unit. [Figure 12] FIG. 1 is a diagram illustrating a configuration of an inspection device. [Figure 13] FIG. 10 is a diagram showing a screen for instructing cleaning of dust. [Figure 14] 10A and 10B are diagrams illustrating a method for determining the cause of image streaks. [Figure 15] 10 is a flowchart illustrating image inspection control in the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Preferred embodiments of the present invention will be described below with reference to the drawings. However, the shapes of the components and their relative positions described in the embodiments may be changed as appropriate depending on the configuration of the device to which the present invention is applied and various conditions, and the scope of the present invention is not intended to be limited to the following embodiments.

[0010] [First embodiment] [Image formation system] FIG. 1 is a cross-sectional view of an image forming system 100 used in this embodiment. The image forming system 100 includes an operation unit 20, a color electrophotographic copying machine (hereinafter referred to as the image forming apparatus) 30, a control device 40, an inspection device 50 as a reading device, and stacking devices 60a, 60b, and 60c. The image forming apparatus 30, the inspection device 50, and the stacking devices 60a, 60b, and 60c each have separate housings. The number of stacking devices 60 may be one or more. Note that the recording method of the image forming apparatus 30 is not limited to electrophotography, and may be, for example, inkjet. Furthermore, the image forming apparatus may be either monochrome or color.

[0011] The configuration and functions of the image forming system 100 will be described below with reference to FIG.

[0012] <Image forming device> A sheet storage tray 11 for storing sheets is provided inside the image forming apparatus 30. Note that a sheet is a material on which an image is formed by the image forming apparatus, and includes, for example, paper, resin sheets, cloth, overhead projector sheets, labels, etc.

[0013] The sheets stored in the sheet storage tray 11 are sent out by a pickup roller and conveyed by a conveying roller 12 and the like.

[0014] An image signal input to the image forming device 30 is input for each color component to optical scanning devices 3Y, 3M, 3C, and 3K, each of which includes a semiconductor laser and a polygon mirror. Specifically, an image signal for yellow is input to optical scanning device 3Y, and an image signal for magenta is input to optical scanning device 3M. An image signal for cyan is input to optical scanning device 3C, and an image signal for black is input to optical scanning device 3K. In the following description, a configuration for forming a yellow image will be described, but similar configurations apply to magenta, cyan, and black.

[0015] The outer peripheral surface of the photosensitive drum 1Y is charged by a charger 2Y. After the outer peripheral surface of the photosensitive drum 1Y is charged, a laser beam corresponding to an input image signal is emitted from an optical scanning device 3Y through an optical system including a polygon mirror and other mirrors, and then irradiated onto the outer peripheral surface of the photosensitive drum 1Y. As a result, an electrostatic latent image is formed on the outer peripheral surface of the photosensitive drum 1Y.

[0016] Subsequently, the electrostatic latent image is developed with toner in a developing unit 4Y as a developing section, and a toner image is formed on the outer peripheral surface of the photosensitive drum 1Y. The toner image formed on the photosensitive drum 1Y is transferred to a transfer belt 6 as an intermediate transfer body by a transfer roller 5Y provided at a position facing the photosensitive drum 1Y.

[0017] The yellow, magenta, cyan, and black toner images transferred onto the transfer belt 6 are then transferred onto a sheet by a secondary transfer unit 7 .

[0018] As described above, the sheet onto which the toner image has been transferred is sent to the fixing device 8, where the toner image is fixed to the sheet by heat and pressure applied by the fixing device 8. In this way, an image is formed on the sheet by the image forming device 30.

[0019] <Inspection equipment> The inspection device 50 is a device that reads the image on the sheet conveyed from the image forming device 30 and inspects the quality of the image. In other words, the inspection device 50 is a device that inspects whether or not the image on the sheet meets the inspection standard.

[0020] The image on the sheet being conveyed by the conveying rollers 53 is read at a reading position by the image sensors 54 and 55. The image sensors 54 and 55 include a light source that illuminates the sheet and a CMOS sensor. The sheet from which the image has been read is discharged to the stacking device 60a.

[0021] The stacking device 60a receives the sheets discharged from the inspection device 50 at an entrance 64a, and discharges the sheets onto a sheet tray 62a or from an exit 65a.

[0022] Downstream of the entrance 64a, there is a branch point where the conveying paths P1a and P2a branch off. A flapper (not shown) is arranged at the branch point to guide the sheet to either the conveying path P1a or the conveying path P2a. The conveying paths P1a and P2a are each connected to the conveying path P3a.

[0023] The conveying path P3a branches into a conveying path P4a and a conveying path P5a at a branching position where a flapper F2a is installed. A sheet conveyed along the conveying path P3a is guided to the conveying path P4a or the conveying path P5a by the flapper F2a.

[0024] A sheet tray 62a is provided at the exit of the transport path P4a. For example, sheets whose image quality has been determined to be unacceptable (do not meet the inspection standard, which may also be called "failure") by the inspection device 50 are stacked on the sheet tray 62a. Note that sheets whose image quality has been determined to be unacceptable may be discharged from the exit 65a to a device in a subsequent stage. Also, sheets whose image quality has been determined to be OK (meet the inspection standard, which may also be called "pass") may be stacked (discharged) on the sheet tray 62a. The transport path P5a extends to the exit 65a.

[0025] The stacking device 60b receives the sheets discharged from the stacking device 60a at an entrance 64b, stacks (discharges) the sheets onto sheet trays 61b and 62b, and discharges the sheets from an exit 65b.

[0026] A conveying path P1b extending from an entrance 64b branches into a conveying path P2b and a conveying path P3b at a branching position where a flapper F1b is installed. A sheet conveyed along the conveying path P1b is guided to the conveying path P2b or the conveying path P3b by the flapper F1b. A sheet tray 61b is provided at the exit of the conveying path P2b. The sheet tray 61b is a large-capacity sheet stacking means capable of stacking a large number of sheets. For example, sheets that have passed an image inspection (quality inspection) are stacked on the sheet tray 61b.

[0027] The conveying path P3b branches into a conveying path P4b and a conveying path P5b at a branching position where a flapper F2b is installed. A sheet conveyed along the conveying path P3b is guided to the conveying path P4b or the conveying path P5b by the flapper F2b.

[0028] A sheet tray 62b is provided at the exit of the transport path P4b. For example, sheets P whose image quality has been determined to be unacceptable by the inspection device 50 are stacked on the sheet tray 62b. Note that sheets whose image quality has been determined to be unacceptable may be discharged from the exit 65b to a downstream device. Also, sheets whose image quality has been determined to be OK (meet the inspection standards, which may also be called "pass") may be stacked on the sheet tray 62b. The transport path P5b extends to the exit 65b.

[0029] A downstream device may be connected to the exit 65b. Also, like the stacking device 60c, a sheet tray 69 may be provided at the exit 65c. The sheet tray 69 can also hold sheets P whose image quality has been determined to be unacceptable or acceptable. In this way, the types of sheets P to be discharged to the sheet trays 61b, 61c, 62a, 62b, 62c, and 69 are determined in advance based on settings made by the user.

[0030] The sheet trays 61c, 62c, and 69 provided in the stacking device 60c may be referred to as an upper tray, a middle tray, and a lower tray, respectively. The post-processing unit 68 may be provided with a binding processor that bundles the sheets P discharged from the stacking device 60b to create a sheet bundle and staples the sheet bundle. The post-processing unit 68 may be provided with a bookbinding processor that folds the sheet bundle in half. The post-processing unit 68 may be provided with a trimming processor that cuts the sheet bundle.

[0031] Each of the conveying paths P1, P2, P3, P4, and P5 is provided with one or more conveying rollers 63. The conveying rollers 63 convey the sheet P from the upstream side to the downstream side in the conveying direction of the sheet P. The conveying rollers 63 may be a roller pair consisting of two rollers that sandwich and convey the sheet P.

[0032] The number of stacking devices 60 connected downstream of the inspection device 50 may be one or more. The total number of sheet trays 61, 62, 69 provided in the stacking device 60 connected downstream of the inspection device 50 may be two or more. The number of flappers F1, F2 may be one or more.

[0033] [Control configuration] <Control device> 2 is a block diagram showing the configuration of the control device 40. The control device 40 is made up of at least one ASIC, and executes the functions described below.

[0034] The operation unit 20 has a display device 21 as a display unit that outputs information to the user, and an input device 22 (e.g., a touch panel sensor) that receives instructions from the user. The operation unit 20 may also have an audio circuit and a speaker that output messages to the user.

[0035] The setting unit 202 accepts settings such as sheet information, inspection items, and inspection level. The sheet information includes the type of sheet P and the length of sheet P in the conveying direction (which may also be called the longitudinal direction). The inspection level indicates the strictness of the image inspection. The setting unit 202 stores in the memory 210 setting data 212, which is information related to the image inspection such as sheet information, inspection contents, and inspection level set by the user via the display device 21.

[0036] The memory 210 stores reference data 211. The reference data 211 is image data of a reference image used as a reference in image inspection. The reference data 211 may be, for example, original image data (RIP image data) linked to a print job received from a host computer external to the image forming system 100. RIP is an abbreviation for raster image processing. The reference data 211 may also be, for example, image data obtained by reading one or more sheets on which an image corresponding to the reference image is formed.

[0037] The inspection control unit 205 controls the inspection device 50 based on the setting data 212. For example, when the inspection device 50 requests reference data 211, the inspection control unit 205 transmits the reference data 211 to the inspection device 50. The inspection control unit 205 also acquires image inspection result information from the inspection device 50. Based on the inspection result, the inspection control unit 205 controls flappers F1 and F2 to discharge the sheet to one of the sheet trays 61, 62, and 69 designated by the user.

[0038] The job processing unit 206 controls a print job for printing an image on a sheet, a stacking job for stacking a sheet bundle on the stacking devices 60a and 60b, a post-processing job for the sheet bundle in the stacking device 60c, etc. The job processing unit 206 may store job data (job information) required to execute these jobs in the memory 210.

[0039] The stacking device 60 drives the motor M1 to rotate the conveyance roller 63 in accordance with a control command from the job processing unit 206. The stacking device 60 also drives the solenoids SL1 and SL2 to switch the flappers F1 and F2 in accordance with a control command from the job processing unit 206. This allows the sheet to be guided and conveyed to either the sheet tray 61, the sheet tray 62, or the stacking device 60c. For example, if the image inspection result by the inspection device 50 is NG, the job processing unit 206 controls the stacking device 60 to discharge the sheet determined to be NG to the sheet tray 62. The image forming device 30 also includes a solenoid that drives the flapper and a motor that drives the conveyance roller, but these are not shown.

[0040] <Inspection equipment> 3 is a block diagram showing the configuration of the inspection controller 51 provided in the inspection device 50. The inspection controller 51 is made up of at least one ASIC, and executes the functions described below.

[0041] The inspection unit 302 performs image inspection based on the setting data 212 received from the control device 40, and transmits the inspection results to the control device 40. Note that the inspection may be performed by the CPU 201, or by an external PC or the like connected to the image forming system. PC is an abbreviation for personal computer.

[0042] The position correction unit 303 performs position correction on the reading results of the image sensors 54 and 55. If the sheet is read by the image sensors 54 and 55 while it is skewed, the sheet may appear skewed in the read image. Therefore, the position correction unit 303 corrects the position of the sheet in the reading results by rotating the reading results or shifting the coordinates.

[0043] The inspection image data (read image data) 312 is image data created by reading the sheet with the image sensors 54 and 55. The evaluation unit 304 compares the reference data 211 with the inspection image data 312 to determine whether the image formed on the sheet meets the inspection standard. That is, the evaluation unit 304 functions as an inspection means.

[0044] For example, if the inspection item is "positional misalignment," the evaluation unit 304 determines the image as pass (no defects in the image) if the amount of misalignment between the image position of the reference data 211 and the image position of the inspection image data 312 is less than a predetermined value. Also, the evaluation unit 304 determines the image as fail (defects in the image) if the amount of misalignment exceeds the predetermined value. That is, the amount of misalignment between the image position of the reference data 211 and the image position of the inspection image data 312 is less than a predetermined value corresponds to meeting the inspection standard. Also, the amount of misalignment between the image position of the reference data 211 and the image position of the inspection image data 312 is greater than a predetermined value corresponds to not meeting the inspection standard. Note that the absolute position of the image of the inspection image data 312 relative to the edge of the sheet may also be inspected.

[0045] Furthermore, when the inspection item is set to "black dots," the evaluation unit 304 determines that the image is pass if the size of black dots (stains) that are not present in the image of the reference data 211 but are present in the image of the inspection image data 312 is equal to or smaller than the judgment threshold. That is, the black dots correspond to noise images that are not present in the image corresponding to the reference data 211 but are present in the image corresponding to the inspection image data 312 to which reduction processing has been applied. The evaluation unit 304 also determines that the image is fail if the size of the black dots exceeds the judgment threshold. That is, the size of the black dots not exceeding the judgment threshold corresponds to meeting the inspection standard. And the size of the black dots exceeding the judgment threshold corresponds to not meeting the inspection standard.

[0046] Furthermore, when the inspection item is "streaks," the evaluation unit 304 determines that the image is pass if, for example, a streak image extending in the conveying direction that is not present in the image of the reference data 211 but present in the image of the inspection image data 312 is less than a predetermined length. The evaluation unit 304 also determines that the image is fail if a streak image extending in the conveying direction that is not present in the image of the reference data 211 but present in the image of the inspection image data 312 is equal to or longer than a predetermined length. In other words, a streak image extending in the conveying direction that is not present in the image of the reference data 211 but present in the image of the inspection image data 312 and is less than a predetermined length corresponds to satisfying the inspection standard. Furthermore, a streak image extending in the conveying direction that is not present in the image of the reference data 211 but present in the image of the inspection image data 312 and is equal to or longer than a predetermined length corresponds to not satisfying the inspection standard.

[0047] Furthermore, when the inspection item is "color," the evaluation unit 304 inspects the color based on, for example, the difference value between the image data (luminance data) of R (red) in the reference data 211 and the image data (luminance data) of R in the inspection target data. More specifically, the evaluation unit 304 determines that the data is unacceptable if the difference value is equal to or greater than a predetermined value. Furthermore, the evaluation unit 304 determines that the data is acceptable if the difference value is less than the predetermined value. In other words, a difference value less than the predetermined value corresponds to satisfying the inspection standard. Furthermore, a difference value equal to or greater than the predetermined value corresponds to not satisfying the inspection standard. Similar processing is performed for G (green) and B (blue), respectively.

[0048] As described above, in this embodiment, the image sensors 54 and 55 are used to control adjustment of the position of an image formed by the image forming apparatus 300 and to inspect the quality of the image formed by the image forming apparatus 300. For example, if the difference in pixel values ​​between the reference data 211 (reference image data) and the inspection image data 312 is less than a predetermined value, the image is determined to be pass. Furthermore, the evaluation unit 304 determines that the difference in pixel values ​​between the reference data 211 (reference image data) and the inspection image data 312 is not less than a predetermined value, the image is determined to be fail. That is, if the difference in pixel values ​​between the reference data 211 (reference image data) and the inspection image data 312 is less than a predetermined value, the inspection standard is met. Furthermore, if the difference in pixel values ​​between the image data corresponding to the reference data and the inspection image data 312 is not less than a predetermined value, the inspection standard is not met.

[0049] The conveyance control unit 306 drives the motor M2 to rotate the conveyance roller 53. The reading control unit 307 controls the image sensors 54 and 55 to read the sheet P and generate inspection image data 312. The image sensor 54 reads the first side of the sheet P, and the image sensor 55 reads the second side of the sheet P. This allows the inspection device 50 of this embodiment to perform image inspection on both sides of the sheet P.

[0050] [Settings screen] FIG. 4 is a diagram showing the print setting screen SC1. Button 601a is a button for specifying the size, basis weight, and sheet cassette 11 of the sheet to be printed. Button 601b is a button for instructing transition from the print setting screen SC1 to the inspection setting screen SC2. Button 601d is a button for instructing cancellation of the setting contents. When button 601d is operated by the operator (user), transition to a predetermined initial screen occurs. Button 601e is a button for instructing start of printing.

[0051] Fig. 5 is a diagram showing the inspection setting screen SC2. The inspection setting screen SC2 is a screen that accepts instructions from the operator for setting an inspection area 705 where quality inspection is performed by the inspection device 50. In Fig. 5, a display area 700 displays an image 704 to be printed, inspection areas 705a and 705b, an inspection exclusion area 711, and the like.

[0052] Inspection areas 705a, 705b and an inspection exclusion area 711 are set via a mouse or touch panel, which is part of the input device 22. Inspection area 705a is a standard inspection area that is set by operating button 701a. A standard inspection area is, for example, an inspection area where inspection of standard content is carried out. Menu 702a is a pull-down menu for setting the inspection level (inspection accuracy) to be applied to inspection area 705a. In this example, inspection level 1 has the lowest inspection accuracy, and as the inspection level number increases, the inspection accuracy increases (the inspection becomes stricter).

[0053] Inspection area 705b is a priority inspection area that is set by operating button 701b. The priority inspection area is, for example, an inspection area where high-precision inspection is performed. In the example shown in FIG. 5, high-precision inspection is performed on shapes such as circles and crosses.

[0054] Menu 702b is a pull-down menu for setting the inspection level (inspection accuracy) to be applied to inspection area 705b. The pull-down menu may also be called a drop-down list.

[0055] The inspection exclusion area 711 is set by operating button 701c and is an area where inspection is not performed. High-precision inspection is not required for cylindrical or triangular shapes. Therefore, areas containing these shapes may be set as inspection exclusion areas. In this way, the inspection level can be set for each area included in the print target. This allows the user to set appropriate pass criteria. As a result, printed materials of acceptable quality are judged to pass, reducing unnecessary reprinting and improving productivity. It also reduces unnecessary sheet disposal.

[0056] Button 701d is a button for instructing to return to the original screen, print setting screen SC1. Button 701d may be implemented as a cancel button. In this case, when button 701d is pressed, the test settings entered through test setting screen SC2 are discarded. When button 701d is implemented as a cancel button, an OK button is also implemented to validate the test settings and return to print setting screen SC1.

[0057] [Image adjustment control] In this embodiment, control (image adjustment control) is performed to adjust the position and density of the image formed by the image forming apparatus 30 based on the reading results of the image sensors 54 and 55. In the image adjustment control, the CPU 201 controls the image forming apparatus 30 to form a predetermined adjustment chart on a sheet. As a result, the image forming apparatus 30 forms the adjustment chart on the sheet.

[0058] FIG. 6 is a schematic diagram showing an adjustment chart printed on a sheet as a test chart. As shown in FIG. 6, the adjustment chart includes marks 820 provided at the four corners of the sheet. Each mark 820 is provided at a position Y0 away from the edge of the sheet in the conveyance direction (corresponding to the sub-scanning direction) and at a position X0 away from the edge of the sheet in the width direction (corresponding to the main scanning direction, a direction perpendicular to the sub-scanning direction). Note that the adjustment chart shown in FIG. 6 includes marks 820 that are patches for adjusting the position of an image, but known register marks may also be used as marks for adjusting the position of an image. Furthermore, the adjustment chart shown in FIG. 6 includes marks 820 for adjusting the position of an image, but in addition, patches for adjusting the density of the image may also be provided.

[0059] The sheet on which the adjustment chart (FIG. 6) is formed by the image forming device 30 is conveyed to the inspection device 50. The inspection device 500 reads the image of the sheet on which the adjustment chart is formed.

[0060] The CPU 201 calculates the distance between the position of the edge of the sheet and the position of the marks 820 in the image obtained by reading the adjustment chart with the image sensors 54 and 55, and the relative positional relationship of each mark 820. Furthermore, the CPU 201 generates image forming conditions for adjusting the position, tilt angle, and magnification of the image to be formed on the sheet based on the calculated distance (X0, Y0) and the relative positional relationship. That is, the CPU 201 adjusts the misalignment by generating image forming conditions for forming an image on the sheet based on the scanned image of the sheet on which the adjustment chart (FIG. 6) is formed. Note that the image forming conditions for adjusting the misalignment may be generated, for example, by an image processor (not shown) of the image forming apparatus 30 based on the scanned image of the sheet on which the adjustment chart (FIG. 6) is formed. In this configuration, the CPU 201 instructs the formation of the adjustment chart (FIG. 6), acquires the scanned image of the sheet on which the adjustment chart (FIG. 6) is formed, and transmits the scanned image to the image processor (not shown) of the image forming apparatus 30. The CPU 201 functions as a control unit that executes an adjustment operation to form an adjustment chart for adjusting at least the positional deviation.

[0061] Furthermore, when a patch for adjusting the density of an image is formed as a separate adjustment chart, the CPU 201 calculates the difference between the density of the patch and the target density of the patch based on the read image obtained by the image sensors 54 and 55 reading the adjustment chart. Then, the CPU 201 generates image forming conditions for adjusting the density of the image to be formed on the sheet so as to reduce the difference. That is, the CPU 201 adjusts the image density by generating image forming conditions for forming an image on the sheet based on the read image of the sheet on which the patch is formed. Note that the image forming conditions for adjusting the image density may be generated, for example, by an image processor (not shown) of the image forming apparatus 30 based on the read image of the patch. In this configuration, the CPU 201 instructs the formation of a patch, obtains a read image of the patch on the sheet, and transmits the read image to the image processor (not shown) of the image forming apparatus 30. The CPU 201 functions as a control unit that executes an adjustment operation for forming a patch for adjusting at least the image density.

[0062] <Timing for image adjustment control> Next, the timing of performing image adjustment control in this embodiment will be described. In this embodiment, the following configuration is applied to suppress the generation of paper waste.

[0063] FIG. 7 is a flowchart illustrating image inspection control including image adjustment control. The flowchart in FIG. 7 is executed by CPU 201 when an inspection job for inspecting an image on a sheet is executed. In this embodiment, the inspection job is also a print job including image inspection. Note that in the control illustrated in FIG. 7, descriptions of the process in which image forming apparatus 30 forms an image on a sheet and the process in which inspection apparatus 50 reads the image on the sheet are omitted. For example, while image forming apparatus 30 executes a print job (inspection job) for printing multiple images on multiple sheets, inspection apparatus 50 sequentially reads the sheets on which images have been formed by image forming apparatus 30. In the following description, CPU 201 of control apparatus 40 executes image inspection control while image forming apparatus 30 executes a print job (inspection job) for printing multiple images on multiple sheets.

[0064] In S101, if the evaluation unit 304 determines that the image on the sheet is unacceptable, the process proceeds to S102.

[0065] On the other hand, if the evaluation unit 304 does not determine that the image on the sheet is unacceptable in S101, the process proceeds to S107.

[0066] In S102, if the failure is "misalignment", the process proceeds to S103.

[0067] On the other hand, if the reason for failure is not "misalignment" in S102, the process proceeds to S107.

[0068] In S103, when a predetermined number of sheets (for example, five sheets) have been found to have a failure status of "misalignment," in S104, the CPU 201 suspends (stops) image formation on the sheets by the image forming apparatus 30 during image formation based on the inspection job. The CPU 201 controls various devices to eject any sheets remaining in the image forming system 100, for example, to the sheet tray 62a.

[0069] On the other hand, if the predetermined number of sheets whose rejection is "misalignment" has not occurred in S103, the process proceeds to S107.

[0070] In S105, CPU 201 executes the image adjustment operation. Specifically, CPU 201 controls image forming apparatus 30 to form an adjustment chart on a sheet, and controls inspection apparatus 50 to read the formed adjustment chart. Image forming apparatus 30 generates image formation conditions using the above-described method based on the reading result of inspection apparatus 50.

[0071] Thereafter, in S106, the CPU 201 resumes the inspection job (resumes forming an image on the sheet).

[0072] If the inspection job is completed in S107, the CPU 201 ends the processing of this flowchart.

[0073] Also, in S107, if the inspection job is not completed, the process returns to S101.

[0074] As described above, in this embodiment, image adjustment control is executed when a predetermined number of sheets fail due to the first defect, "misalignment." On the other hand, image adjustment control is not executed even when a predetermined number of sheets fail due to the second defect, "black dots" or "streak images." That is, image adjustment control is not executed when the failure is due to "black dots" or "streak images." Image adjustment control is executed when "misalignment" is detected as a first type of defect, and is not executed when "black dots" or "streak images" are detected as a second type of defect. That is, in this embodiment, image adjustment control is executed when the evaluation unit 304 determines that a failure is due to an inspection item that can be corrected by image adjustment control. On the other hand, image adjustment control is not executed when the evaluation unit 304 determines that a failure is due to an inspection item that cannot be corrected by image adjustment control. As a result, adjustment operation can be prevented from being executed even when an image defect, such as a streak image, occurs that cannot be reduced by adjustment operation. That is, the generation of waste paper can be suppressed.

[0075] In this embodiment, image adjustment control is executed when a predetermined number of sheets have been rejected because of "misalignment," but this is not limited to this. For example, image adjustment control may be executed when a predetermined number of consecutive sheets have been rejected because of "misalignment." Furthermore, image adjustment control may be executed when a sheet has been rejected because of "misalignment." The predetermined number can be set by the user using the input device 22, for example.

[0076] Second Embodiment The description of the configuration of the image forming system that is the same as that of the first embodiment will be omitted.

[0077] Image adjustment control in this embodiment will be described below. In this embodiment, the following configuration is applied to suppress the generation of paper waste.

[0078] 8 is a diagram showing a screen for selecting whether or not to execute image adjustment control. When button 801 is selected, CPU 201 executes image adjustment control. When button 801 is selected, CPU 201 does not execute image adjustment control.

[0079] FIG. 9 is a flowchart illustrating image inspection control including image adjustment control. The flowchart in FIG. 9 is executed by CPU 201 when an inspection job for inspecting an image on a sheet is executed. In this embodiment, the inspection job is also a print job including image inspection. Note that in the control illustrated in FIG. 9, descriptions of the process in which image forming apparatus 30 forms an image on a sheet and the process in which inspection apparatus 50 reads the image on the sheet are omitted. For example, while image forming apparatus 30 executes a print job (inspection job) for printing multiple images on multiple sheets, inspection apparatus 50 sequentially reads the sheets on which images have been formed by image forming apparatus 30. In the following description, CPU 201 of control apparatus 40 executes image inspection control while image forming apparatus 30 executes a print job (inspection job) for printing multiple images on multiple sheets.

[0080] The processing from S201 to S204 is the same as the processing from S101 to S104 in FIG. 7, and therefore a description thereof will be omitted.

[0081] In S205, the CPU 201 displays a selection screen on the display device 21.

[0082] If button 801 is selected in S206, CPU 201 executes the image adjustment operation in S207. Specifically, CPU 201 controls image forming apparatus 30 to form an adjustment chart on a sheet, and controls inspection apparatus 50 to read the formed adjustment chart. Image forming apparatus 30 generates image formation conditions using the above-described method based on the reading results of inspection apparatus 50.

[0083] On the other hand, if the button 802 is selected in S206, the process proceeds to S208.

[0084] The processes of S208 and S209 are the same as the processes of S106 and S107 in FIG. 7, and therefore the description thereof will be omitted.

[0085] As described above, in this embodiment, when a predetermined number of sheets are rejected due to "misalignment," the CPU 201 displays the screen (selection screen) shown in FIG. 8 . The selection screen is not displayed even when a predetermined number of sheets are rejected due to "black dots" or "streaky images." That is, the selection screen is not displayed when the rejected sheets are rejected due to "black dots" or "streaky images." The selection screen shown in FIG. 8 is displayed when "misalignment" is detected as a first type of defect, whereas the selection screen is not displayed when "black dots" or "streaky images" are detected as a second type of defect. That is, in this embodiment, the selection screen is displayed when the evaluation unit 304 determines that the sheet has failed due to an inspection item that can be corrected by image adjustment control, whereas the selection screen is not displayed when the evaluation unit 304 determines that the sheet has failed due to an inspection item that cannot be corrected by image adjustment control. As a result, it is possible to prevent adjustment operations from being performed even when image defects, such as streaky images, occur that cannot be reduced by adjustment operations. That is, it is possible to prevent waste paper from being generated.

[0086] Third Embodiment The description of the configuration of the image forming system that is the same as that of the first embodiment will be omitted.

[0087] Image adjustment control in this embodiment will be described below. In this embodiment, the following configuration is applied to suppress the generation of paper waste.

[0088] In this embodiment, the CPU 201 counts the number of sheets on which images are formed, and executes image adjustment control, for example, every time images are formed on an adjusted number of sheets (e.g., 100 sheets) in a print job. The adjusted number of sheets is a value greater than a predetermined number of sheets.

[0089] In this embodiment, if a predetermined number of sheets are rejected due to "misalignment" before the number of sheets on which images have been formed reaches the adjusted number, the CPU 201 executes image adjustment control and shortens the interval between executions of the image adjustment control. Specifically, the adjusted number is set to a small number (for example, 95 sheets).

[0090] FIG. 10 is a flowchart illustrating image inspection control including image adjustment control. The flowchart in FIG. 10 is executed by the CPU 201 when an inspection job for inspecting an image on a sheet is executed. In this embodiment, the inspection job is also a print job including image inspection. Note that in the control illustrated in FIG. 10, the process in which the image forming apparatus 30 forms an image on a sheet and the process in which the inspection apparatus 50 reads the image on the sheet are omitted. For example, while the image forming apparatus 30 executes a print job (inspection job) in which multiple images are printed on multiple sheets, the inspection apparatus 50 sequentially reads the sheets on which images have been formed by the image forming apparatus 30. In this embodiment, image adjustment control is executed each time an image is formed on an adjusted number of sheets. In the following description, the CPU 201 of the control apparatus 40 executes image inspection control while the image forming apparatus 30 executes a print job (inspection job) in which multiple images are printed on multiple sheets.

[0091] In S301, when the count value of the CPU 201 reaches the adjusted number, the process proceeds to S305.

[0092] On the other hand, in S301, if the count value of the CPU 201 has not reached the adjusted number, the process proceeds to S302.

[0093] In S302, if the evaluation unit 304 determines that the image on the sheet is unacceptable, the process proceeds to S303.

[0094] In S303, if the failure is "misalignment", the process proceeds to S304.

[0095] On the other hand, if the reason for failure is not "misalignment" in S303, the process proceeds to S309.

[0096] In S304, if a predetermined number of sheets (for example, five sheets) are found to have a failure status of "misalignment," in S305, the CPU 201 suspends image formation on the sheets by the image forming apparatus 30 during image formation based on the inspection job. Note that the CPU 201 controls various devices to eject any sheets remaining in the image forming system 100, for example, to the sheet tray 62a.

[0097] On the other hand, if the predetermined number of sheets whose rejection is "misalignment" has not occurred in S304, the process proceeds to S309.

[0098] In S306, CPU 201 executes the image adjustment operation. Specifically, CPU 201 controls image forming apparatus 30 to form an adjustment chart on a sheet, and controls inspection apparatus 50 to read the formed adjustment chart. Image forming apparatus 30 generates image formation conditions using the above-described method based on the reading result of inspection apparatus 50.

[0099] In S307, the CPU 201 sets the adjustment number to a number that is smaller than the currently set number. Note that the CPU 201 sets the adjustment number to a number obtained by subtracting a predetermined number from the currently set number.

[0100] Thereafter, in S308, the CPU 201 resumes the inspection job (resumes forming an image on the sheet).

[0101] If the inspection job is completed in S309, the CPU 201 ends the processing of this flowchart.

[0102] Also, in S309, if the inspection job has not been completed, the process returns to S301.

[0103] As described above, in this embodiment, if a predetermined number of sheets are rejected due to "misalignment" before the number of sheets on which images have been formed reaches the adjusted number, the CPU 201 executes image adjustment control and shortens the interval between executions of image adjustment control. As a result, it is possible to prevent image defects from occurring. Furthermore, according to this embodiment, it is possible to prevent the generation of waste paper.

[0104] Note that image adjustment control may be performed every time a predetermined number of pages of images are formed in a print job.

[0105] [Fourth embodiment] The description of the configuration of the image forming system that is the same as that of the first embodiment will be omitted.

[0106] Image adjustment control in this embodiment will be described below. In this embodiment, the following configuration is applied to suppress the generation of paper waste.

[0107] Fig. 11 is a diagram showing the configuration of the fixing unit 8 in this embodiment. As shown in Fig. 11, the fixing unit 8 includes a heating roller 8a, a pressure roller 8b, and a refreshing roller 8c. Note that a heater for heating the heating roller 8a is omitted in Fig. 11.

[0108] The heating roller 8a and the pressure roller 8b nip the sheet while transporting the sheet, and fix the toner image transferred onto the sheet onto the sheet.

[0109] <Refreshing roller> The refreshing roller 8c can come into contact with and separate from the heating roller 8a. The refreshing roller 8c will be described below.

[0110] When a sheet is nipped and conveyed by the heating roller 8a and the pressure roller 8b, the edges of the sheet in the width direction may cause edges to form on the heating roller 8a and the pressure roller 8b, which are elastic members. If a toner image is fixed to the sheet with these edges, streaks may appear in the fixed image.

[0111] Therefore, in this embodiment, the refreshing roller 8c and the heating roller 8a rotate while the refreshing roller 8c is in contact with the heating roller 8a, thereby smoothing out the unevenness of the edge portion, thereby preventing the occurrence of streaky images.

[0112] <Cleaning the image sensor glass> FIG. 12 is a schematic cross-sectional view showing the configuration near the image sensors 54 and 55 in the inspection device 50. The transport roller 53 transports the sheet received from the image forming device 30 to the transport path 56. The image sensor 54 has a glass surface 54a between the image sensor 54 and the transport path 56, through which reflected light from the sheet passes. A backing roller 54b is provided on the opposite side of the glass surface 54a with respect to the transport path 56. The image sensor 54 reads the side of the sheet transported along the transport path 56 that faces the glass surface 54a. Similarly, the image sensor 55 has a glass surface 55a between the image sensor 55 and the transport path 56, through which reflected light from the sheet passes. A backing roller 55b is provided on the opposite side of the glass surface 55a with respect to the transport path 56. The image sensor 55 reads the side of the sheet transported along the transport path 56 that faces the glass surface 55a. In this embodiment, the backing rollers 54b and 55b are white rollers.

[0113] Here, dust (g in the figure) such as paper dust from the sheet being conveyed along the conveying path 56 may adhere to the glass surfaces 54a and 55a. If dust adheres to at least one of the glass surfaces 54a and 55a, a streak image will appear in the image read by the image sensors 54 and 55, even though no streak image has actually occurred on the sheet. This will prevent the inspection device 50 (or the control device 40) from performing image inspection correctly.

[0114] The housing of inspection device 50 of this embodiment has a mechanical mechanism that enables a portion (upper portion) above transport path 56 in the direction of gravity to be separated from a portion (lower portion) below transport path 56 in the direction of gravity. This allows, for example, when dust adheres to glass surface 54a (glass surface 55a), the user to separate the upper and lower portions and clean glass surface 54a (glass surface 55a). When a streaky image occurs due to adhered dust, CPU 201 of control device 40 of this embodiment displays a screen ( FIG. 13 ) on display device 21 to prompt the user to clean the glass surface.

[0115] <Identifying the cause of image streaks> FIG. 14 is a diagram illustrating a streak image in an image read by the image sensor 54. The area rect1 is the area corresponding to the sheet in the read image read by the image sensor 54, and the area rect2 represents the read image read by the image sensor 54. The read image includes the sheet and an area outside the outer edge of the sheet. In the figure, the streak image line1 appears within the sheet, and the streak image line2 appears beyond the sheet. In other words, the streak image line1, which is caused by the edge portions of the heating roller 8a and the pressure roller 8b, appears only on the sheet and therefore appears within the sheet. On the other hand, the streak image line2, which is caused by dust adhered to the glass surface 54a, appears beyond the sheet. Therefore, the evaluation unit 304 determines that the streak image line1 that appears within the area rect1 is a streak image caused by the edge portions of the heating roller 8a and the pressure roller 8b. Furthermore, the evaluation unit 304 determines that the streak image line2 that appears in the range rect2 beyond the range rect1 is a streak image caused by adhered dust.

[0116] <Timing for image adjustment control> FIG. 15 is a flowchart illustrating image inspection control including image adjustment control. The flowchart in FIG. 15 is executed by CPU 201 when a job for inspecting an image on a sheet is executed. The inspection job in this embodiment is also a print job including image inspection. Note that in the control illustrated in FIG. 15, descriptions of the process in which image forming apparatus 30 forms an image on a sheet and the process in which inspection apparatus 50 reads the image on the sheet are omitted. For example, while image forming apparatus 30 executes a print job (inspection job) for printing multiple images on multiple sheets, inspection apparatus 50 sequentially reads the sheets on which images have been formed by image forming apparatus 30. In the following description, CPU 201 of control apparatus 40 executes image inspection control while image forming apparatus 30 executes a print job (inspection job) for printing multiple images on multiple sheets.

[0117] When the image sensors 54 and 55 acquire images of one page of sheets, the CPU 201 determines whether the evaluation unit 304 has determined that the sheet has failed (S401). If the evaluation unit 304 determines that the sheet has failed in step S401, the CPU 201 determines whether the failure is due to "misregistration" (S402). If the failure is due to "misregistration" in step S402, the CPU 201 determines whether a predetermined number of sheets (e.g., five sheets) have failed due to "misregistration" (S403). If the predetermined number of sheets have failed due to "misregistration" as a result of the evaluation unit 304's inspection in step S403, the CPU 201 suspends the image forming operation (S404). In step S404, the CPU 201 controls the image forming apparatus 30 to suspend image formation on subsequent sheets based on the inspection job (print job) during image formation based on the inspection job. Then, in order to execute image adjustment control, CPU 201 controls image forming device 30 to print an adjustment chart (FIG. 6) different from the print job described above (S405). The formed adjustment chart is read by inspection device 50. CPU 201 generates image formation conditions for adjusting the position, inclination angle, and magnification of the image to be formed on the sheet based on the reading result of the adjustment chart.

[0118] Furthermore, if the rejection is not determined to be "misalignment" in step S402, CPU 201 determines whether the rejection is "image streaks caused by unevenness in the edge" (S407). If the rejection is determined to be "image streaks caused by unevenness in the edge" in step S407, CPU 201 determines whether a predetermined number of sheets (e.g., five sheets) have been rejected due to "image streaks caused by unevenness in the edge" (S408). If a predetermined number of sheets have been rejected in step S408 based on the inspection result of evaluation unit 304 indicating "image streaks caused by unevenness in the edge," CPU 201 suspends the image forming operation (S409). In step S409, CPU 201 controls image forming apparatus 30 to suspend image formation on subsequent sheets based on the inspection job (print job) during image formation based on the inspection job. Then, CPU 201 controls image forming apparatus 30 to perform a refresh operation (S410). Specifically, the CPU 201 brings the refreshing roller 8c into contact with the heating roller 8a, rotates it for a predetermined time (for example, 10 seconds), and then separates it from the heating roller 8a.

[0119] Furthermore, if the predetermined number of sheets failing the inspection by the evaluation unit 304 due to "misalignment" has not occurred in step S403, the CPU 201 also proceeds to step S407. After the image adjustment operation is performed in step S405, the CPU 201 proceeds to step S407.

[0120] Furthermore, if the rejection content in step S407 is not "image streaks caused by unevenness in the edge portion," the CPU 201 determines whether the rejection content is "image streaks caused by dust adhesion on the glass surface" (S411). If the rejection content is "image streaks caused by dust adhesion on the glass surface" in step S411, the CPU 201 determines whether a predetermined number of sheets (e.g., five sheets) have been rejected due to "image streaks caused by dust adhesion on the glass surface" (S412). If the evaluation unit 304 has detected a predetermined number of sheets that have failed the inspection due to "image streaks caused by dust adhesion on the glass surface" in step S412, the CPU 201 displays a screen ( FIG. 13 ) on the display device 21 to prompt the user to clean the glass (S413). In step S413, the CPU 201 displays a screen ( FIG. 13 ) on the display device 21 to prompt the user to clean the glass without interrupting image formation on subsequent sheets based on the inspection job (print job).

[0121] Furthermore, if the evaluation unit 304 does not find a predetermined number of sheets that have failed the inspection due to "image streaks caused by unevenness in the edge" in step S408, the CPU 201 also proceeds to step S411. After the refresh operation is performed in step S410, the CPU 201 proceeds to step S411.

[0122] Furthermore, if the rejection content in step S411 is not "image streaks caused by dust adhesion to the glass surface," the CPU 201 determines whether the rejection content is "rejection due to identifiable component defects" (S414). For example, if "black dots" appear in the scanned image at circumferential intervals around the transfer roller 5Y, the "black dots" are thought to be caused by contamination or aging of the transfer roller 5Y. In this case, replacing the transfer roller 5Y may improve the rejection content. Therefore, if the rejection content in step S414 is "rejection due to identifiable component defects," the CPU 201 determines whether a predetermined number of sheets (e.g., five sheets) have been rejected due to "rejection due to identifiable component defects" (S415). If a predetermined number of sheets (e.g., five sheets) have been rejected due to "rejection due to identifiable component defects" in step S415, the CPU 201 displays a screen on the display device 21 prompting the user to replace the component (S416).

[0123] Furthermore, if the evaluation unit 304 determines in step S412 that the number of sheets that have failed the inspection for "image streaks caused by dust on the glass surface" is not the predetermined number, the CPU 201 also proceeds to step S414. Furthermore, after displaying a screen (FIG. 13) on the display device 21 to prompt the user to clean the glass in step S413, the CPU 201 proceeds to step S414.

[0124] If the rejection content is not "rejection due to identifiable component defects" in step S414, CPU 201 determines whether the image forming operation has been interrupted (S417). If the number of sheets whose rejection content is "rejection due to identifiable component defects" has not reached a predetermined number (e.g., five sheets) in step S415, CPU 201 also proceeds to step S417. CPU 201 also proceeds to step S417 after displaying a screen on display device 21 in step S416 that prompts the user to replace a component. If image formation has been interrupted in step S417, CPU 201 controls image forming apparatus 30 to resume image formation based on the print job (inspection job), and determines whether inspection of all images included in the inspection job has been completed (S406).

[0125] Furthermore, if it is determined in step S401 that the image on the sheet is not a failure, the CPU 201 determines whether inspection of all images included in the inspection job has been completed (S406). If it is determined in step S406 that inspection of all images included in the inspection job has not been completed, the CPU 201 shifts the process to step S401. On the other hand, when inspection of all images included in the inspection job has been completed, the CPU 201 ends image inspection control.

[0126] In this embodiment, when a predetermined number of sheets have failed due to "streaked images," the above-described refresh operation is performed. That is, in this embodiment, image adjustment control is executed if the evaluation unit 304 determines that the failure is due to an inspection item that can be corrected by image adjustment control. On the other hand, if the evaluation unit 304 determines that the failure is due to an inspection item that can be corrected by the refresh operation, the refresh operation is executed. The refresh operation can also be considered a part of the image adjustment control. As a result, the generation of waste paper can be suppressed. Furthermore, the frequency of failures can be reduced, and the generation of failed sheets (waste paper) can also be suppressed.

[0127] In this embodiment, when the same type of failure occurs on a predetermined number of sheets (scanned images), countermeasures including image adjustment control and refresh operation are executed, but this is not limited to this. For example, image adjustment control may be executed when a predetermined number of consecutive sheets have failed due to "streaked images." Also, for example, image adjustment control may be executed when a sheet has failed due to "streaked images." The predetermined number can be set by the user using the input device 22, for example.

[0128] The image forming system of this embodiment interrupts the image forming operation during execution of a print job (inspection job), executes a recovery process for the abnormality, and then resumes the image forming operation. Therefore, the image forming system of this embodiment can suppress the occurrence of a large number of abnormal images while suppressing a decrease in productivity of the image forming apparatus 30. [Explanation of symbols]

[0129] 30 Image forming device 50 Inspection equipment 201 CPU 510 Inspection Controller

Claims

1. an image forming device that forms an image on a sheet; a reading device that reads an image on the sheet conveyed from the image forming device; an inspection means for inspecting the image read by the reading device to detect defects in the image; a control unit for controlling the image forming apparatus, The control means When the inspection means detects a first type of defect, an adjustment operation is performed to adjust the quality of an image formed by the image forming apparatus; an image forming system characterized in that, when a second type defect different from the first type is detected by the inspection means, the cause of the defect is determined based on which area of ​​the image the second type defect occurs in.

2. the image forming apparatus is controlled based on image forming conditions, The image forming system according to claim 1, characterized in that the adjustment operation adjusts the quality of the image formed by the image forming device by generating the image forming conditions based on the reading results by the reading device of a test chart formed on a sheet by the image forming device.

3. The image forming system according to claim 1, characterized in that, when a predetermined number of sheets in which the first type of defect is detected by the inspection means during the formation of multiple images by the image forming device are successively formed, the control means controls the image forming device to stop the formation of the images and executes the adjustment operation.

4. 2. The image forming system according to claim 1, wherein the first type of defect is a positional deviation between a reference image and the image read by the reading device.

5. 5. The image forming system according to claim 4, wherein the inspection means detects the first type of defect when a positional deviation between the reference image and the image read by the reading device is equal to or greater than a predetermined value.

6. 2. The image forming system according to claim 1, wherein the second type of defect is a black spot that appears in the image read by the reading device and that does not exist in the reference image.

7. 2. The image forming system according to claim 1, wherein the second type of defect is a streak image that is not present in the reference image and that appears in the image read by the reading device.

8. A heating roller for heating the sheet; a refresh roller that can be brought into contact with and separated from the heating roller, 2. The image forming system according to claim 1, wherein the control means determines that the cause of the defect is a heating roller when the control means determines that the second type defect is a streak image that has occurred within an area of ​​the sheet.

9. The image forming system described in Claim 8, characterized in that the control means brings the refresh roller into contact with the heating roller and rotates it for a predetermined period of time, and then separates the refresh roller from the heating roller.

10. The reading device reads the image on the sheet through a glass surface, 2. The image forming system according to claim 1, wherein the control means determines that the cause of the defect is a glass surface when the control means determines that the second type defect is a streak image that has occurred outside the area of ​​the sheet.

11. The image forming system described in Claim 10, characterized in that the control means displays a screen on a display device to prompt cleaning of the glass surface.

12. A transfer roller for transferring an image onto a sheet, 2. The image forming system according to claim 1, wherein the control means determines that the cause is the transfer roller when it determines that the second type of defect is black spots occurring at circumferential intervals on the transfer roller.

13. The image forming system according to claim 12, wherein the control means displays a screen on a display device to prompt the user to replace the transfer roller.

14. an image forming device that forms an image on a sheet; a reading device that reads an image on the sheet conveyed from the image forming device; an inspection means for inspecting the image to be inspected based on first image data obtained by the reading device reading the image to be inspected formed on the sheet by the image forming device and reference data; a generating unit that generates image forming conditions when the image forming device forms the image to be inspected on the sheet based on second image data obtained by the reading device reading the test chart formed on the sheet by the image forming device; and a display unit that displays a selection screen for selecting whether or not to form the test chart; a control unit for controlling the image forming apparatus, and The control means When a first type defect is detected by the inspection means, the selection screen is displayed on the display unit; an image forming system characterized in that, when a second type defect different from the first type is detected by the inspection means, the component causing the defect is determined based on which area of ​​the image the second type defect occurs in.

15. The image forming system described in Claim 14, characterized in that the control means does not display the selection screen on the display unit when the second type of defect is detected.

16. The image forming system according to claim 14, wherein the inspection means determines that the image to be inspected has the first type of defect when the amount of positional deviation of the image to be inspected from the image corresponding to the reference data is equal to or greater than a predetermined value.

17. The image forming system according to claim 14, wherein the inspection means determines that the image to be inspected contains the second type of defect when the image to be inspected contains a noise image that is not present in the image corresponding to the reference data.

Images