Image forming apparatus, control method thereof, and program

Abstract

The present invention provides a novel mechanism for an image forming apparatus that allows the user to recognize the degree of an impending abnormality when an abnormality is detected in an image. [Solution] The image forming apparatus includes a diagnostic means for detecting abnormalities in an image formed on a sheet and diagnosing whether the detected abnormality is a precursor to an abnormality of an unacceptable level, and an output means for outputting the degree of the abnormality diagnosed as a precursor to an unacceptable level abnormality when the diagnostic means diagnoses the abnormality as a precursor to an unacceptable level abnormality.

Description

Technical Field

[0002] , , , , , , ,

[0004] , , , , , , , ,

[0005] , , ,

[0003] , , , ,

[0001] The present invention relates to an image forming apparatus, a control method thereof, and a program.

Background Art

[0002] There is known an image forming apparatus that detects an abnormality from an image formed and identifies a part of the cause from the detected abnormality (for example, Patent Document 1). In an image forming apparatus having a reading unit, it is possible to read an image formed on a sheet output from the apparatus itself, detect an abnormality included in the image, and identify a part of the cause. Further, according to such an image forming apparatus, in order to perform maintenance work before a failure of the image forming apparatus actually occurs, it is also possible to diagnose a precursor of an unacceptable abnormality by setting a strict detection level of the abnormality. Patent Document 1 proposes an image forming apparatus that repairs an abnormality when the abnormality is detected.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] It is conceivable to display a precursor of an abnormality detected in the image forming apparatus as described above on a screen. However, a user who views such a screen may not recognize the degree of the precursor, and as a result, may not perform part repair, cleaning, etc. In such a case, an abnormality exceeding the standard may be detected in the inspection in the next job, and as a result, there is a possibility of waste such as disposing of the medium on which the image is formed.

[0005] The present invention has been made in view of at least one of the above-mentioned problems, and provides a novel mechanism for an image forming apparatus to allow the user to recognize the degree of an impending abnormality when an abnormality in an image is detected. [Means for solving the problem]

[0006] According to one aspect of the present invention, An image forming apparatus, A diagnostic means for detecting anomalies in the image formed on the sheet and diagnosing whether the detected anomaly is a precursor to an unacceptable level of anomaly, The image forming apparatus is characterized by comprising: an output means that outputs the degree of the abnormality diagnosed as a precursor to an abnormality of an unacceptable level when the diagnostic means diagnoses the abnormality as a precursor to an abnormality of an unacceptable level. [Effects of the Invention]

[0007] According to the present invention, when an image forming apparatus detects an image abnormality, the degree of the precursor to the abnormality can be made known to the user. [Brief explanation of the drawing]

[0008] [Figure 1] Overview diagram of a printing system according to one embodiment. [Figure 2] Cross-sectional view of an image forming apparatus according to one embodiment. [Figure 3] Functional block diagram of a printing system according to one embodiment. [Figure 4] Display screen of an image forming apparatus according to one embodiment [Figure 5] Display screen of an image forming apparatus according to one embodiment [Figure 6] Flowchart of the process according to one embodiment [Figure 7] 1. Diagram illustrating the detection size of the following procedure. [Figure 8] 1. Diagram illustrating the detection size of the following procedure. [Figure 9] Display screen of an image forming apparatus according to one embodiment [Figure 10]Explanatory drawing of repair content according to an embodiment [Figure 11] Display screen of an image forming apparatus according to an embodiment [Figure 12] Display screen of an image forming apparatus according to an embodiment [Figure 13] Display screen of an image forming apparatus according to an embodiment [Figure 14] Display screen of an image forming apparatus according to an embodiment [Figure 15] Display screen of an image forming apparatus according to an embodiment [Figure 16] Flowchart of a process according to an embodiment [Figure 17] Display screen of an image forming apparatus according to an embodiment [Figure 18] Display screen of an image forming apparatus according to an embodiment [Figure 19] Display screen of an image forming apparatus according to an embodiment [Figure 20] Display screen of an image forming apparatus according to an embodiment [Figure 21] Explanatory drawing of an abnormal pattern according to an embodiment [Figure 22] Explanatory drawing of an abnormal pattern according to an embodiment [Figure 23] Explanatory drawing of a counter according to an embodiment

Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims. Although a plurality of features are described in the embodiments, not all of these plurality of features are essential to the invention, and the plurality of features may be arbitrarily combined. Further, in the accompanying drawings, the same or similar configurations are denoted by the same reference numerals, and duplicate explanations are omitted.

[0010] In this specification, the term "image forming apparatus" broadly includes devices that form (record) images on recording materials (also referred to as recording media, sheets, or paper), such as single-function printers, copiers, multifunction printers, and commercial printing presses. The image forming apparatus described below has a maximum sheet size that can be fed that is A3 long side length in the transport direction and A3 short side length in the direction perpendicular to the transport direction (hereinafter also referred to as an A3 machine). Furthermore, in the following, when an image is formed on a sheet, if the long side of the sheet is arranged parallel to the sheet's transport direction, the sheet's transport direction is referred to as horizontal, and when the short side of the sheet is arranged parallel to the sheet's transport direction, the sheet's transport direction is referred to as vertical. As for the sheet, a variety of sheet materials of different sizes and materials can be used, such as plain paper or cardboard, sheet materials with surface treatments such as coated paper, plastic film, cloth, and specially shaped sheet materials such as envelopes and index paper.

[0011] (First Embodiment) <Overall System Configuration> Figure 1 shows an example of a network configuration including a printing system 100 (image processing system) according to this embodiment. As shown in Figure 1, the printing system 100 includes an image forming apparatus 101 and an external controller 102. The image forming apparatus 101 and the external controller 102 are connected to communicate via an internal LAN 105 and a video cable 106. The external controller 102 is also connected to a client PC 103 via an external LAN 104.

[0012] The client PC 103 can issue print commands to the external controller 102 via the external LAN 104. The client PC 103 has a printer driver installed that has the function of converting image data to be printed into a Page Description Language (PDL) that can be processed by the external controller 102. Users who want to print can issue print commands via the printer driver from various applications installed on the client PC 103 by operating the client PC 103. Based on the print command from the user, the printer driver sends the PDL data, which is the print data, to the external controller 102. When the external controller 102 receives the PDL data from the client PC 103, it analyzes and interprets the received PDL data. Based on the result of the interpretation, it performs rasterization processing to generate a bitmap image (print image data) with a resolution matched to the image forming apparatus 101, and issues a print command by submitting a print job to the image forming apparatus 101.

[0013] Next, the image forming apparatus 101 will be described. The image forming apparatus 101 is configured to enable complex printing processes such as bookbinding by connecting multiple devices with different functions. Specifically, the image forming apparatus 101 has a printing unit 107 (image forming unit), a diagnostic unit 108, a stacker 109, and a finisher 110. Each module will be described below. Note that the diagnostic unit 108 is an example of the "diagnostic means" of the present invention.

[0014] The printing unit 107 prints images according to the print job and discharges the printed recording material (sheets). The printed recording material discharged from the printing unit 107 is transported through the diagnostic unit 108, the stacker 109, and the finisher 110 in that order. In this embodiment, the image forming apparatus 101 of the printing system 100 is an example of an image forming apparatus, but the printing unit 107 included in the image forming apparatus 101 may also be referred to as the image forming apparatus. The printing unit 107 forms (prints) images using toner (colorant) on the recording material fed and transported from the paper feed unit located at the bottom of the printing unit 107.

[0015] The diagnostic unit 108 is an image diagnostic device that diagnoses the presence or absence of abnormalities in the image forming apparatus 101 based on printed recording material that has been printed by the printing unit 107 and transported through the transport path. Specifically, the diagnostic unit 108 reads the image printed on the transported printed recording material and performs a diagnosis from the obtained read image. The diagnosis of abnormalities is determined by extracting a diagnostic area from the read image and confirming the difference in read signal values ​​within the extracted diagnostic area. The detailed processing of the diagnostic unit will be described later. The diagnostic unit is used during inspection and predictive diagnosis. It is also a device that inspects the presence, size, or degree of defects or abnormalities in image quality of printed recording material based on a comparison between the data on the printed recording material that has been printed by the printing unit 107 and transported through the transport path and the printed data.

[0016] The stacker 109 is a device capable of stacking a large number of printed recording materials. The finisher 110 is a device capable of performing finishing processes such as stapling, punching, and saddle stitching on the transported printed recording materials. After processing by the finisher 110, the recording materials are discharged into a designated output tray.

[0017] In the configuration example shown in Figure 1, an external controller 102 is connected to the image forming apparatus 101, but this embodiment can also be applied to other configurations. For example, the image forming apparatus 101 may be connected to an external LAN 104, and print data may be transmitted from the client PC 103 to the image forming apparatus 101 without going through the external controller 102. In this case, data analysis and rasterization of the print data may be performed by the image forming apparatus 101.

[0018] <Hardware configuration of the image forming apparatus 101> A specific example of the operation of the image forming apparatus 101 will be explained with reference to Figure 2.

[0019] <Explanation of the paper feed deck> The printing unit 107 is equipped with, for example, six types of paper feed decks 361, 362, 363, 364, 365, and 366. Various types of recording material are stored in each paper feed deck. Of the recording material stored in each paper feed deck, the topmost recording material is separated one sheet at a time and fed to the transport path 303. The image forming stations 304 to 307 each include a charging device, an exposure device, and a photosensitive drum (photoreceptor). In the image forming stations 304 to 307, the photosensitive drum is charged by the charging device, exposed by the exposure device, and a toner image of each color is formed on the photosensitive drum using a different color toner for each station. Specifically, the image forming stations 304 to 307 use yellow (Y), magenta (M), cyan (C), and black (K) toners to form toner images of each color.

[0020] The toner images of each color formed in the image forming stations 304 to 307 are sequentially transferred onto the intermediate transfer belt 308 (primary transfer). The toner images transferred to the intermediate transfer belt 308 are transported to the secondary transfer position 309 as the intermediate transfer belt 308 rotates. At the secondary transfer position 309, the toner images are transferred from the intermediate transfer belt 308 to the recording material that has been transported along the transport path 303 (secondary transfer). After the secondary transfer, the recording material is transported to the fixing unit 311. The fixing unit 311 is equipped with a pressure roller and a heating roller. Heat and pressure are applied to the recording material as it passes between these rollers, fixing the toner image onto the recording material. The recording material that has passed through the fixing unit 311 is transported through the transport path 312 to the connection point 315 between the printing unit 107 and the diagnostic unit 108. In this way, a color image is formed (printed) on the recording material.

[0021] If further fixing is required depending on the type of recording material, the recording material that has passed through the fixing unit 311 is guided to the transport path 314 where the fixing unit 313 is located. The fixing unit 313 performs further fixing on the recording material being transported in the transport path 314. The recording material that has passed through the fixing unit 313 is transported to the connection point 315. If the operation mode for double-sided printing is set, the image is printed on the first side, and the recording material that has been transported in the transport path 312 or transport path 314 is guided to the inversion path 316. The recording material that has been inverted in the inversion path 316 is guided to the double-sided transport path 317 and transported to the secondary transfer position 309. As a result, the toner image is transferred to the second side of the recording material, which is opposite to the first side, at the secondary transfer position 309. After that, the recording material passes through the fixing unit 311 (and fixing unit 313), completing the formation of the color image on the second side of the recording material.

[0022] Once the image formation (printing) in the printing unit 107 is complete, the printed recording material, which has been transported to the connection point 315, is transported into the diagnostic unit 108. The diagnostic unit 108 is equipped with image reading units (331, 332) having CIS (Contact Image Sensors) on the transport path 330 through which the printed recording material from the printing unit 107 is transported. The image reading units (331, 332) are positioned opposite each other across the transport path 330. The image reading units (331, 332) are configured to read the upper surface (first surface) and the lower surface (second surface) of the recording material, respectively. Note that the image reading units may be composed of, for example, a CCD (Charge Coupled Device) or a line scan camera instead of a CIS. Note that the image reading units (331, 332) are just one example of the "reading means" of the present invention.

[0023] The diagnostic unit 108 performs various image diagnostic processes on the image forming apparatus 101 based on the image printed on the printed recording material being transported along the transport path 330. Specifically, when the printed recording material being transported reaches a predetermined position, the diagnostic unit 108 uses the image reading units (331, 332) to read the image of the printed recording material. Then, using the read image, it performs inspection diagnostics to check for abnormalities in the output being printed, and precursor diagnostics to diagnose precursors to abnormalities. In this embodiment, "abnormality" refers to an abnormality that is unacceptable in terms of quality level, and "precursor" refers to an abnormality in the preliminary stage that may become an unacceptable abnormality in the future. Image diagnostic methods are employed for these diagnoses. Furthermore, the diagnostic unit 108 identifies the cause of the precursor or abnormality from the diagnostic results of the inspection diagnostic or precursor diagnostic, and causes the printing unit 107 to execute a process to repair the part causing the cause. Inspection and diagnosis involve checking for abnormalities, such as whether there are any defects in the printed materials or whether items not included in the original data have been printed.

[0024] Precursor diagnosis identifies signs that may indicate a future malfunction, and does not require immediate repair after diagnosis. Furthermore, precursor diagnosis is typically performed using printed images while the user is printing. Image diagnosis identifies abnormalities and repairs them immediately. This is generally performed while printing is stopped. When image diagnosis is performed using the image forming apparatus 101 alone, an image diagnosis chart is printed, and the diagnosis is performed using the printed image. Image diagnosis is also used to analyze the cause of abnormalities found on printed materials during quality inspection.

[0025] The recording materials that have passed through the diagnostic unit 108 are sequentially transported to the stacker 109. The stacker 109 is equipped with a stack tray 341. Printed recording materials transported from the diagnostic unit 108, which is located upstream in the transport direction of the printed recording materials, are loaded onto the stack tray 341. The printed recording materials that have passed through the diagnostic unit 108 pass through the transport path 344 inside the stacker 109. As the printed recording materials passing through the transport path 344 are guided to the transport path 345, they are loaded onto the stack tray 341.

[0026] The stacker 109 is further equipped with an escape tray 346 as a paper output tray. In this embodiment, the escape tray 346 is used to discharge recording material containing test charts used for image diagnosis by the diagnostic unit 108. Printed recording material passing through the transport path 344 is guided to the transport path 347 and then transported to the escape tray 346. Printed recording material that is transported without being stacked or discharged in the stacker 109 is transported to the downstream finisher 110 via the transport path 348. The escape tray 346 is also used to discharge printed recording material that has been determined to be defective or abnormal by the inspection diagnosis by the diagnostic unit 108, and to distinguish it from normally printed recording material.

[0027] The stacker 109 further includes a reversal unit 349 for reversing the orientation of the printed recording material being transported. The reversal unit 349 is used, for example, to make the orientation of the recording material input to the stacker 109 the same as the orientation of the printed recording material when it is loaded onto the stack tray 341 and output from the stacker 109. Note that the reversal operation by the reversal unit 349 is not performed on printed recording material that is not loaded into the stacker 109 and is transported to the finisher 110.

[0028] The finisher 110 performs a finishing function specified by the user on the printed recording material transported from the diagnostic unit 108, which is located upstream in the transport direction of the printed recording material. In this embodiment, the finisher 110 has finishing functions such as stapling (single or double stapling), punching (two or three holes), and saddle stitching. The finisher 110 is equipped with two output trays 351 and 352. If no finishing process is performed by the finisher 110, the printed recording material transported to the finisher 110 is discharged to the output tray 351 via the transport path 353. If a finishing process such as stapling is performed by the finisher 110, the printed recording material transported to the finisher 110 is guided to the transport path 354. The finisher 110 uses the finishing processing unit 355 to perform a finishing process specified by the user on the printed recording material being transported along the transport path 354, and then ejects the finished printed recording material to the output tray 352.

[0029] <Functional Configuration Diagram> Figure 3 is a schematic diagram of the functional blocks of the image forming apparatus 101, the external controller 102, and the client PC 103.

[0030] <Image forming apparatus 101> The printing unit 107 of the image forming apparatus 101 includes a communication interface 201, a network interface 204, a video interface 205, a CPU 206, memory 207, an HDD unit 208, a UI display unit 225, and an operation unit 226. The printing unit 107 further includes an image processing unit 202 and a print unit 203. These are connected to each other via a system bus 209, enabling them to send and receive data.

[0031] The communication interface 201 includes a communication module and is connected to the diagnostic unit 108, stacker 109, and finisher 110 via a communication cable 260. The CPU 206 communicates via the communication interface 201 for the control of each device. The network interface 204 includes a communication module such as a Network Interface Card (NIC) and is connected to the external controller 102 via the internal LAN 105 and is used for the communication of control data, etc. The video interface 205 includes a video module, etc. and is connected to the external controller 102 via a video cable 106 and is used for the communication of data such as image data. Note that the printing unit 107 (image forming apparatus 101) and the external controller 102 may be connected only by the video cable 106, provided that the operation of the image forming apparatus 101 can be controlled by the external controller 102.

[0032] The HDD unit 208 stores various programs and data. The CPU 206 controls the operation of the entire printing unit 107 by executing programs stored in the HDD unit 208. The memory 207 stores programs and data necessary for the CPU 206 to perform various processes. The memory 207 operates as the work area for the CPU 206. The UI display unit 225 is configured, for example, to include a touch panel display, and accepts input of various settings and operation instructions from the user, and is used to display print job management. For example, it displays the job management screen shown in Figure 4, allowing the user to perform touch or slide operations to check or change print jobs. The operation unit 226 is configured, for example, to include this touch panel display and buttons, and accepts touch or slide operations to instruct, for example, to change settings of the printing unit 107 and to execute various diagnostics.

[0033] The diagnostic unit 108 comprises a communication interface 211, a CPU 214, a memory 215, an HDD unit 216, image reading units 331 and 332, a UI display unit 241, and an operation unit 242. These devices are connected to each other via a system bus 219, enabling them to send and receive data. The communication interface 211 includes a communication module and is connected to the printing unit 107 via a communication cable 260. The CPU 214 performs the necessary communication for controlling the diagnostic unit 108 via the communication interface 211. The CPU 214 controls the operation of the diagnostic unit 108 by executing a control program stored in the memory 215. The memory 215 stores the control program for the diagnostic unit 108. The image reading units (331, 332) include, for example, a scanner and read images according to instructions from the CPU 214. In various diagnostic tests, the CPU 214 diagnoses whether there are any abnormalities in the image forming apparatus 101 based on the diagnostic images read by the image reading units (331, 332). In particular, during quality control inspection, the CPU 214 reads the recording material printed by the image forming apparatus 101 via the image reading units (331, 332) and inspects the printed recording material for defects (abnormalities) based on the read images.

[0034] The UI display unit 241 is configured, for example, to include a touch panel display and is used to display the results of various diagnoses, the status of automatic repairs based on the diagnoses, and setting screens. The operation unit 242 is also configured to include this touch panel display and accepts touch or slide operations, for example, to change the settings of the diagnostic unit 108 and to instruct the execution of various diagnoses.

[0035] Figure 5 illustrates the diagnostic settings screen displayed on the UI display unit 241 of the diagnostic unit 108. The diagnostic settings screen allows for the setting of the inspection diagnostic level 501 and the predictive diagnostic setting 502. In the example shown in Figure 5, the inspection diagnostic level 501 is set to "normal" and the predictive diagnostic setting 502 is set to "implement," which are the default settings. As the inspection diagnostic level 501 gradually changes from "strict" to "normal" and then to "lenient," the size of the detected anomaly increases. Here, an example of the minimum detectable size at each level is the area shown in Figure 7. While "strict," "normal," and "lenient" are displayed as inspection diagnostic levels, these are just examples, and the inspection diagnostic levels are not limited to these. For example, diagnostic levels may be set between "strict" and "normal," or between "normal" and "lenient."

[0036] The HDD unit 216 stores setting information and image data necessary for various diagnostics. The setting information and image data stored in the HDD unit 216 can be reused. The stacker 109 controls whether the printed recording material that has passed through the transport path is ejected to the stack tray, ejected to the escape tray, or transported to the finisher 110 connected downstream in the transport direction of the printed recording material. The finisher 110 controls the transport and ejection of the printed recording material and performs finishing processes such as stapling, punching, or saddle stitching.

[0037] <External controller 102> The external controller 102 includes a CPU 251, memory 252, HDD unit 253, keyboard 256, display unit 254, network I / F (255, 257), and video I / F 258. These devices are connected to each other via a system bus 259, enabling them to send and receive data.

[0038] The CPU 251 controls the overall operation of the external controller 102, such as receiving print data from the client PC 103, performing RIP processing, and transmitting print data to the image forming apparatus 101, by executing programs stored in the HDD unit 253. The memory 252 stores programs and data necessary for the CPU 251 to perform various processes. The memory 252 operates as the work area for the CPU 251.

[0039] Various programs and data are stored in the HDD unit 253. The keyboard 256 is used to input operation instructions from the user to the external controller 102. The display unit 254 is, for example, a display and is used to display information about the application running on the external controller 102 and the operation screen. The network interface 255 is configured to include communication modules such as a NIC and a wireless circuit, and is connected to the client PC 103 via the external LAN 104 and is used for data communication such as print instructions. The network interface 257 is configured to include communication modules such as a NIC, and is connected to the image forming apparatus 101 via the internal LAN 105 and is used for data communication such as print instructions. The external controller 102 is configured to communicate with the printing unit 107, diagnostic unit 108, stacker 109, and finisher 110 via the internal LAN 105 and communication cable 260. The video interface 258 is configured to include a video module, is connected to the image forming apparatus 101 via video cable 106 and is used for data communication such as image data (print data).

[0040] <Client PC 103> The client PC 103 comprises a CPU 261, memory 262, HDD unit 263, display unit 264, keyboard 265, and network interface 266. These devices are connected to each other via a system bus 269, enabling them to send and receive data. The CPU 261 controls the operation of each device via the system bus 269 by executing programs stored in the HDD unit 263. This enables various processes to be performed by the client PC 103. For example, the CPU 261 generates print data and issues print commands by executing a document processing program stored in the HDD unit 263. The memory 262 stores programs and data necessary for the CPU 261 to perform various processes. The memory 262 operates as the work area of ​​the CPU 261.

[0041] The HDD unit 263 stores various applications such as document processing programs, printer drivers and other programs, and various data. The display unit 264 is, for example, a display and is used to display information about applications running on the client PC 103 and the operation screen. The keyboard 265 is used to input operation instructions from the user to the client PC 103. The network interface 266 is configured to include communication modules such as a NIC and a wireless circuit and is connected to the external controller 102 via the external LAN 104 for communication. The CPU 261 communicates with the external controller 102 via the network interface 266.

[0042] <Inspection and diagnostic processes and predictive diagnostic processes> Figure 6 is a flowchart illustrating the procedures for the inspection and diagnostic processes and the predictive diagnostic process performed during printing, which are initiated by a print command from the printing unit 107. The processes in Figure 6 are implemented, for example, by the CPU 206 of the printing unit 107 and the CPU 214 of the diagnostic unit 108 of the image forming apparatus 101 reading and executing programs stored in memory 207 and memory 215. Furthermore, the processes in Figure 6 are implemented, for example, by the CPU 251 of the external controller 102 reading and executing a program stored in memory 252. Also, the processes in Figure 6 are implemented, for example, by the CPU 251 of the client PC 103 reading and executing a program stored in memory 252. Before the start of the processes in Figure 6, the predictive diagnostic is set to "Perform".

[0043] In S601, the CPU 214 of the diagnostic unit 108 displays the diagnostic settings screen shown in Figure 5 in user mode on the UI display unit 241. The CPU 214 then accepts a slide operation of the arrow for the inspection diagnostic level 501 via the operation unit 242. The CPU 214 then sets the level indicated by this arrow as the inspection diagnostic level. Then, according to the setting of the inspection diagnostic level, the CPU 214 sets the detection size K of the abnormality in the inspection, as shown in Figure 7, and sets the maximum size of abnormality to be detected.

[0044] For example, as shown in Figure 5, the arrow for inspection diagnostic level 501 points to "normal". Therefore, CPU 214 sets the inspection diagnostic level to "normal". In this case, the abnormality detection size K in inspection is set to 1.0 mm². Details regarding the relationship between the inspection diagnostic level and the abnormality detection size area shown in Figure 7 will be described later. Note that although this example shows CPU 214 setting the detection size K from the user mode UI settings, the detection size K may also be set from the administrator mode settings or service mode settings.

[0045] In S602, the CPU 214 receives touch operations for the "Perform" and "Do not perform" icons of the precursor diagnosis setting 502 via the operation unit 242. In the example in Figure 5, "Perform" is selected for the precursor diagnosis setting. The CPU 214 then receives a touch operation for the "OK" icon on the diagnosis setting screen shown in Figure 5 and sets the precursor diagnosis to "Perform". The CPU 214 also sets the abnormality detection size Z in the precursor diagnosis to a value smaller than the size K (e.g., 1.0 mm²) (e.g., 0.5 mm²). The setting of size Z to 0.5 mm² is an example of the present invention's principle that "the second criterion is set more strictly than the first criterion and is set within the range of the abnormality detection capability of the diagnostic means."

[0046] Figure 8 illustrates the shape of an abnormal image at the detection size shown in Figure 7. If the abnormality is a small dot, the diagnostic criterion is, for example, the area of ​​the abnormality as shown in Figure 7. A precursor to a dot is the accumulation of toner particles on the drum or transfer belt. These accumulated toner particles then grow into dots, forming the dot. If the abnormality is linear (hereinafter also referred to as a streak), the diagnostic criterion is, for example, the length or thickness of the streak. Different diagnostic criteria are set for this type of abnormality compared to the criteria for a dot.

[0047] The area of ​​the dot changes according to the detection size, as shown in Figure 8. Also, the size of the detection image for a precursor anomaly is smaller than the detection image for an inspection anomaly because it is a dot before the inspection anomaly occurs. Note that the detection size for inspection anomalies and the detection size for precursor anomalies are set separately. That is, the detection size for inspection anomalies can be changed by the user as an inspection diagnostic level, as shown in Figure 5. On the other hand, the detection size for precursor anomalies is automatically determined according to the inspection diagnostic level and may be set so that the user cannot change it in principle. However, exceptionally, a service technician familiar with the device may be allowed to change the detection size for precursor anomalies in service mode. With such a setting, even if the image to be diagnosed is an image formed on a device different from the image forming apparatus 101, the diagnosis can be made in accordance with the differences between devices. In addition, not only service technicians but also experienced users may change the service mode to user mode and make it possible to change in user mode so that users can also cope with the differences between devices. Furthermore, the detection size for precursor anomalies is restricted from being set to larger than the detection size for inspection anomalies, as this is to detect anomalies before they become inspection anomalies.

[0048] In S603, the CPU 214 displays, via the UI display unit 241, whether or not to automatically repair the cause of a detected precursor anomaly on the user mode automatic repair setting screen shown in Figure 19. The CPU 214 then accepts touch input via the operation unit 242, selecting either icon 1901 to indicate automatic repair or icon 1902 to indicate not to automatically repair. The CPU 214 then sets the automatic repair of the precursor anomaly according to the received touch input. Note that the size of the precursor anomaly is not large enough to be judged as abnormal (NG) in the inspection diagnosis. Therefore, it may not be necessary to immediately repair the cause. Accordingly, icon 1902, which indicates not to automatically repair, is displayed as selectable on this setting screen.

[0049] In S604, the CPU 206 of the printing unit 107 displays a job management screen on the UI display unit 225, as shown in Figure 4. The user can input a print job by touching the print instruction 402 on the job management screen. The CPU 206 then accepts this print job via the operation unit 226. The CPU 206 then transmits the print job information to the external controller 102 via the network interface 204.

[0050] In S605, the CPU 251 of the external controller 102 receives print job information from the printing unit 107 via the network interface 257. The CPU 251 then rasterizes the page to be printed and generates a bitmap for printing. In S606, the CPU 251 transmits the rasterized bitmap data to the video interface 205 of the printing unit 107 via the video interface 258 and video cable 106. The CPU 206 of the printing unit 107 receives the bitmap data via the video interface 205 and performs printing.

[0051] In S607, the CPU 214 of the diagnostic unit 108 generates a reference image (an example of the "original image" in this invention) with modified resolution and other properties so that it can perform a difference comparison with the printed image read from the printed material in S608, using the bitmap that has been rasterized for printing. The reference image may be, for example, a normally printed image, and any normally printed image that can compare the difference with the image to be diagnosed and extract differences (abnormalities) in the image to be diagnosed is acceptable. Alternatively, the reference image may be generated from the image read by the image reading unit (331, 332) after reading the normally printed material. In S608, the CPU 214 executes a process to have the image reading unit (331, 332) read the printed material printed in S606. The CPU 214 then saves the read image as a diagnostic image in the HDD unit 216 of the diagnostic unit 108 and proceeds to S609.

[0052] In S609, the CPU 214 compares the reference image and the diagnostic image and generates differential image data to determine an anomaly in the printing unit 107. In S610, the CPU 214 derives the area of ​​the difference from the differential image data in S609 and determines whether this differential area is greater than the size K for anomaly detection in inspection. If the CPU 214 determines that the differential area is greater than the size K, it determines that the inspection result is NG and proceeds to S611. On the other hand, if the CPU 214 determines that the differential area is less than or equal to the size K, it proceeds to S615. If the CPU 214 detects multiple differences in the image, it derives the differential area for each of the differences and determines whether each of the differential areas is greater than the size K. Furthermore, an anomaly that results in an inspection NG is an example of an "unacceptable level anomaly" in this invention.

[0053] In S611, the CPU 214 displays a pop-up on the job management screen shown in Figure 4 via the UI display unit 241 indicating that the inspection result was NG (Figure 9). Note that the destination of this pop-up is not limited to the job management screen; any screen where the user can recognize that the inspection result was NG is acceptable. In S612, the stacker 109 discharges the printouts that failed inspection, which have been transported along the transport path, to the escape tray 346. The stacker 109 either discharges the printouts that did not fail inspection to the stack tray 341 or transports them to the finisher 110, which is connected downstream in the transport direction of the printed materials. By discharging only the printouts that failed inspection to the escape tray 346, the stacker 109 can distinguish between printouts that failed inspection and those that passed inspection.

[0054] In S613, the CPU 214 identifies the component causing the inspection defect based on the characteristic information of the difference region. More specifically, it selects combinations of the same color with high similarity within the difference region, and identifies the component causing the difference and the cause of the difference from the periodic information of the selected combination. The characteristics of the difference region may be other than period, such as shape or orientation. For example, the shape can be linear or dotted. The orientation can be vertical or horizontal. The period can be, for example, the period that occurs in the charger, developer, photosensitive drum, ITB unit, and secondary transfer. Figure 10 illustrates the relationship between the component causing the difference and the cause of the difference corresponding to such difference (defect) characteristics, as well as the repair content and whether paper is needed when repairing this difference. Data like that shown in Figure 10 is pre-stored in memory 215. The CPU 214 then refers to this relationship data to identify the component causing the difference, the cause of the difference, the repair content, and whether paper is needed when repairing.

[0055] In S614, CPU214 performs the repair work identified in S613. However, even if the inspection fails in S613, if the cause cannot be identified due to the inability to detect periodicity, etc., the part that needs repair has not been identified, and therefore no repair will be performed.

[0056] In S615, the CPU 214 determines whether the premonitory diagnosis set in S602 is to be "implemented" or "not implemented". If the CPU 214 determines that the premonitory diagnosis setting is to be "implemented", it proceeds to S616; if it determines that it is not to be implemented, it proceeds to S619. In S616, the CPU 214 determines whether the difference area derived from the difference image data generated in S609 is greater than the anomaly detection size Z in the premonitory diagnosis. If the CPU 214 determines that the difference area is greater than size Z, it proceeds to S617. On the other hand, if the CPU 214 determines that the difference area is less than or equal to size Z, it proceeds to S619.

[0057] In S617, the CPU 214 identifies the part that is the cause of the precursor to the difference (anomaly) based on the characteristic information of the difference area. The identification method is the same as the identification of the part causing the inspection anomaly in S613. By referring to the data shown in Figure 10, the CPU 214 identifies the part corresponding to the characteristics of the precursor to the difference, the cause of the precursor to the difference, the repair content of the precursor anomaly, and whether paper is required if repair is to be performed.

[0058] In S618, the CPU 214 saves the component causing the precursor anomaly identified in S617 and the details of the repair for the precursor anomaly to the HDD unit 216. In S619, the CPU 206 determines whether or not printing of all pages instructed to be printed in the print job has been completed. If the CPU 206 determines that printing has been completed, it proceeds to S620; otherwise, it returns to S605. In S620, the CPU 214 determines whether or not the details of the repair for the precursor anomaly are stored in the HDD unit 216. If the CPU 214 determines that the details of the repair for the precursor anomaly are stored, it determines whether or not the repair is actually necessary. If the CPU 214 determines that the repair is actually necessary, it proceeds to S621; otherwise, it terminates the flowchart process.

[0059] In S621, the CPU 214 notifies the printing unit 107 via the communication interface 211 that a precursor anomaly has been found and details of the anomaly repair. The printing unit 107 then receives the information about the found precursor anomaly and the repair details via the communication interface 201, with the CPU 206. The CPU 206 then displays a pop-up on the job management screen shown on the UI display unit 225, indicating that a precursor anomaly has been found and prompting the user to repair the anomaly (Figure 11). The CPU 206 then displays an icon that allows the user to select whether or not to perform the repair. If automatic repair is set in S603, a pop-up indicating that automatic repair will be performed is displayed on the job management screen, as shown in Figure 20. Note that the screen on which these pop-ups are displayed is not limited to the job management screen; any precursor notification screen that can notify the user that a precursor anomaly has been found (e.g., Figure 14) is acceptable. Note that the CPU 206 and the UI display unit 225 are examples of the "output means" of the present invention.

[0060] In S622, CPU206 determines whether the icon indicating that a repair should be performed on the job management screen shown in Figure 11 has been touched. If it determines that this icon has been touched, it proceeds to S623; otherwise, it terminates the flowchart process. Alternatively, CPU206 determines whether the OK icon indicating that automatic repair should be performed on the job management screen shown in Figure 20 has been touched. If it determines that this icon has been touched, it proceeds to S623; otherwise, it terminates the flowchart process. In S623, CPU206 controls the execution of the repair. Then, it terminates the flowchart.

[0061] Incidentally, regarding the repair work, there are cases where the execution and completion of the repair can be automatically detected and cases where it cannot. For example, if the repair work is cleaning the charger wire, there is no change in the wire shape, so it is difficult to determine whether the repair has been performed or not. Also, even if the insertion and removal of the part to be cleaned is detected, it is difficult to determine whether the repair work has actually been performed or not. Therefore, automatic detection by sensors is difficult. However, such repair work can be determined by the user. Therefore, the CPU 206 may display a confirmation screen that allows the user to manually select whether or not cleaning has been performed, as shown in Figure 13. The CPU 206 then accepts touch operations for the "Perform cleaning" icon and the "Do not perform cleaning" icon via the operation unit 226. When the CPU 206 accepts the operation of the "Perform cleaning" icon, it terminates the flowchart.

[0062] On the other hand, if the CPU 206 receives an operation on the confirmation screen shown in Figure 13, it will indicate that a precursory abnormality has been detected and will display a screen recommending cleaning, as shown in Figure 12. The CPU 206 will then receive touch operations on the "Clean" icon and the "Cancel" icon via the operation unit 226. If the CPU 206 receives an operation on the "Clean" icon, it will actually perform the cleaning and terminate the flowchart. On the other hand, if the CPU 206 receives an operation on the "Cancel" icon, it will terminate the flowchart without performing the cleaning.

[0063] <Repair contents> Figure 10 illustrates the relationship between the component causing the difference (abnormality), the cause of the difference, the repair process for fixing the difference, and whether paper is required for the repair. The CPU 214 of the diagnostic unit 108 detects the shape of the difference, the orientation of the shape, and the period of the difference from the difference image. The CPU 214 then identifies the component causing the difference and the cause of the difference corresponding to the difference image by referring to the table information shown in Figure 10.

[0064] More specifically, the CPU 214 detects, for example, that horizontal streaks appear in the difference image and that the period of these streaks indicates they are caused by the photosensitive drum. Such detection is achieved, for example, by using a known image processing technique. Note that streaks refer to linear abnormalities on parts such as drums or belts. The CPU 214 then refers to the table shown in Figure 10 to identify the photosensitive drum as the causative part and the cause as poor cleaning of the photosensitive drum. The CPU 214 then decides that the repair involves cleaning the cleaning blade of the photosensitive drum. As described above, the printing unit 107 then performs the cleaning of the cleaning blade of the photosensitive drum. In this way, the repair of the cleaning blade of the photosensitive drum is carried out.

[0065] Alternatively, the CPU 214 may detect, for example, that a dot has appeared in the differential image, and that its period indicates it is caused by the photosensitive drum. The CPU 214 then refers to the table shown in Figure 12 and identifies the photosensitive drum as the causative component, and that the cause is dust adhering to the photosensitive drum. The CPU 214 then decides to clean the photosensitive drum as the repair procedure. As described above, the printing unit 107 then performs the cleaning of the photosensitive drum. In this way, the repair of the photosensitive drum is carried out.

[0066] In this way, the cause of the anomaly is identified from the shape, direction, or period of the difference (anomaly) observed in the difference image, and a repair method appropriate to the cause is selected and the repair is carried out. Note that the contents of the table in Figure 10 are only a part of the repair methods, and the repair methods are not limited to these.

[0067] <Patterns of inspection abnormalities and warning signs> Figures 21(A) through (F) illustrate the patterns of inspection defects and precursor defects formed on printed materials. Figure 21(A) shows printed material produced by a printing press in its initial state. Such printed material is diagnosed as having no defects in inspection and also as having no precursor defects in precursor diagnosis. Figure 21(B) shows printed material that has no defects in inspection but has precursor defects detected in precursor diagnosis. Two precursor defects are formed on this printed material by the photosensitive drum at predetermined intervals. If the precursor defects of the photosensitive drum are repaired, printed materials produced by the printing press afterward will basically be in the state shown in Figure 21(A). On the other hand, if the precursor defects of the photosensitive drum are not repaired, these precursor defects will grow as shown in Figure 21(C).

[0068] If no preliminary repair is performed after the printed material shown in Figure 21(C) is printed, the abnormalities formed on the printed material will further increase, as shown in Figure 21(D), and it will be diagnosed as having a defect in the inspection diagnosis. The CPU 214 of the diagnostic unit 108 then calculates the period of the abnormality and identifies the problematic part by referring to data such as that shown in Figure 10. Then, the repair of the part is performed.

[0069] Figure 21(E) shows an example of a printed document that has no defects and no warning signs in the inspection diagnosis. However, unlike the printed document shown in Figure 21(A), this document is not in its initial state, and one warning anomaly has formed. When one warning anomaly is formed in this way, the periodicity of the anomaly cannot be identified. Therefore, even if the CPU 214 refers to the data shown in Figure 10, the cause of the warning cannot be identified. Therefore, no notification of a warning anomaly is given, and it is judged that there are no warning signs. Figure 21(F) shows an example of a printed document that has defects and no warning signs in the inspection diagnosis. Unlike the printed document shown in Figure 21(A), this document is not in its initial state, and an anomaly has formed that is larger than the area set in the inspection diagnosis level. However, since there is only one anomaly, the periodicity cannot be identified. Therefore, even if the CPU 214 refers to the data shown in Figure 10, the cause of the inspection anomaly cannot be identified. Therefore, no repair is performed after the inspection diagnosis.

[0070] Figure 22 illustrates a printed document that was diagnosed as having both a defect and a precursor during inspection. This document contains both an inspection defect and a precursor defect on a single page. Thus, defects are not limited to one per page. Furthermore, inspection defect 2201 is larger than the area set for the inspection diagnosis level, but since there is only one inspection defect 2201, its periodicity cannot be determined. Therefore, even by referring to the data shown in Figure 10, the cause of the inspection defect cannot be determined. Consequently, no repair is performed after the inspection diagnosis. On the other hand, the factor parts corresponding to the period of the precursor defects (2202, 2203) formed on the printed document can be identified by referring to the data shown in Figure 10. Therefore, repair of the factor parts of the precursor defects (2202, 2203) can be performed. Note that when multiple defects exist on a single page, they are not limited to defects caused by the photosensitive drum. For example, multiple defects can also be formed by the operation of the charger or developer. Even in such cases, the same processing as in the case of the photosensitive drum can be performed.

[0071] <Precursor notification> Figures 11, 12, 14, and 15 illustrate example notification screens displayed when an abnormality is detected during a precursor diagnosis. The precursor notification screen shown in Figure 11 is displayed when the area of ​​the abnormality formed on the printed material changes from less than the detection size of the precursor abnormality to greater than or equal to the detection size. The screen in Figure 12 recommends manual cleaning when a precursor abnormality due to charger contamination is detected. As another example, Figure 14 calculates the area of ​​the precursor abnormality when an abnormality is found during a precursor diagnosis and displays the position of the symbol 1401 (×) according to the calculated area. The area of ​​the precursor abnormality may be calculated using a known image processing method. As yet another example, the screen in Figure 15 displays the abnormality image 1501 actually detected in the precursor diagnosis, and also displays the abnormality image 1502 detected in the inspection diagnosis next to it, informing the user that the precursor abnormality is approaching the size of the inspection abnormality. The precursor notification screens in Figures 14 and 15 are examples of displaying the "degree of abnormality" according to the present invention. Furthermore, the warning notification screen in Figure 14 is an example of the present invention's "quantitative display of abnormalities" and "display of the area of ​​abnormalities." Also, the warning notification screen in Figure 15 is an example of the present invention's "display of the shape of abnormalities."

[0072] <Effects and Actions> According to the image forming system 1 described above, by displaying a warning notification screen as shown in Figure 14, the user can quantitatively grasp the magnitude of the warning abnormality. Alternatively, according to the image forming system 1 described above, by displaying a warning notification screen as shown in Figure 15, the user can relatively grasp the magnitude of the warning abnormality by comparing it with the magnitude of the inspection abnormality displayed on the same screen. Therefore, the user can recognize the extent of the warning and perform repairs or cleaning of parts in a timely manner. Thus, the detection of abnormalities exceeding the standard in inspections of the next job after diagnosis is suppressed. Therefore, it is prevented that inspections will fail, and that sheets with images that fail will not be disposed of, nor that toner will be wasted in forming these images.

[0073] (Second Embodiment) Using Figure 16, a flowchart of the process that displays the previous and current early warning abnormalities on the early warning notification screen when an abnormality is detected in the next early warning diagnosis, if the component causing the early warning abnormality was not repaired, will be used. Processes common to Figure 6 are given the same reference number and their explanations are omitted. Furthermore, the process in Figure 16 is realized, for example, by the CPU 206 of the printing unit 107 and the CPU 214 of the diagnostic unit 108 of the image forming apparatus 101 reading and executing programs stored in memory 207 and memory 215. Furthermore, the process in Figure 16 is realized, for example, by the CPU 251 of the external controller 102 reading and executing a program stored in memory 252. Furthermore, the process in Figure 16 is realized, for example, by the CPU 251 of the client PC 103 reading and executing a program stored in memory 252. Note that before the start of the process in Figure 16, the early warning diagnosis setting is set to "Execute". Furthermore, before the flow shown in Figure 16 begins, the counter for the precursor of the dots formed by the photosensitive drum is initialized to N=1.

[0074] In S613, the CPU 214 of the diagnostic unit 108 uses data as shown in Figure 10 to determine whether it is possible to identify the part causing the abnormality in the inspection diagnosis. Here, the CPU 214 identifies the abnormal shape formed on the printed material in the inspection diagnosis as a "dot" and the part causing it as the photosensitive drum. In S614, the CPU 214 performs the repair work on the photosensitive drum that formed the dot, which was identified in S613. More specifically, the CPU 214 notifies the printing unit 107 of the repair work via the communication interface 211. The CPU 206 of the printing unit 107 then receives and performs this repair work via the communication interface 201. As a result, the cause of dot formation in the photosensitive drum is eliminated, and dots exceeding the inspection diagnosis level and the precursor diagnosis level no longer occur. The process then proceeds to S1601. In S1601, the CPU 214 of the diagnostic unit 108 initializes counter N to 1 and proceeds to S619.

[0075] In S617, the CPU 214 of the diagnostic unit 108 determines whether it is possible to identify the causative part of the abnormality in the precursor diagnosis using the data shown in Figure 10. Here, the CPU 214 identifies the abnormal shape formed on the printed material in the precursor diagnosis as a dot, and the causative part as the photosensitive drum. The process then proceeds in the order of S168 and S1602. In S1602, if the first precursor abnormality of a dot shape caused by the photosensitive drum is found after the previous repair (replacement) of the photosensitive drum, the counter N is set to 1. Therefore, the CPU 214 of the diagnostic unit 108 sets the size S of the precursor abnormality of a dot shape caused by the photosensitive drum (1) to, for example, 0.6 mm2. The process then proceeds in the order of S619, S620 and S621.

[0076] In S621, the CPU 214 of the diagnostic unit 108 notifies the printing unit 107 of the precursor via the communication interface 211. The CPU 206 of the printing unit 107 receives this precursor via the communication interface 201. The CPU 206 then displays the precursor notification screen shown in Figure 17 on the job management screen shown in Figure 4, informing the user that a precursor has been found. The precursor notification screen shown in Figure 17 displays a graph with the number of detected precursor abnormalities on the horizontal axis and the area of ​​the precursor abnormality on the vertical axis. This graph also displays dotted lines representing the diagnostic level at which an inspection diagnosis results in a "NG" and the level at which a precursor abnormality is detected in the precursor diagnosis. Here, in S1602, N is set to 1. Therefore, the number of detections is 1, and an X mark is plotted at position 1701, which corresponds to the size S (0.6 mm2) of the precursor abnormality (1). While this warning notification screen is currently displayed on the job management screen, it may be displayed on other screens as long as it informs the user that a warning has been detected.

[0077] Furthermore, the CPU 206 displays icons for "Perform" and "Do not perform" cleaning of the photosensitive drum on the warning notification screen shown in Figure 17. Then, in S622, if the CPU 206 receives a touch operation for the "Perform" icon for cleaning the photosensitive drum via the operation unit 226, it transmits this information to the diagnostic unit 108. The CPU 214 of the diagnostic unit 108 then determines that the warning detection level is at its initial stage if the value of counter N is less than a predetermined value, and proceeds to S1603. Similarly, if the CPU 206 receives a touch operation for the "Do not perform" icon for cleaning the photosensitive drum via the operation unit 226, it also proceeds to S1603. On the other hand, if the value of counter N is greater than a predetermined value, or if the CPU 206 receives a touch operation for the "Perform" icon for cleaning the photosensitive drum via the operation unit 226, the CPU 214 proceeds to S623.

[0078] In S1603, the CPU 214 of the diagnostic unit 108 increments counter N by one so that it can store the size of the next dot-shaped precursor anomaly caused by the photosensitive drum, and reserves a memory area in memory 215 or the like for the size S of the N+1th precursor anomaly. Then it terminates the flow shown in Figure 16. Meanwhile, in S623, the CPU 214 of the diagnostic unit 108 notifies the printing unit 107 of the repair details for the precursor anomaly set in S615. Then, the CPU 206 in the printing unit 107 implements these repair details and proceeds to S1604. In S1604, the CPU 214 of the diagnostic unit 108 initializes counter N to 1 because the repair of the photosensitive drum was performed in S623 and the cause of the dot-shaped precursor anomaly has been removed, and terminates the flow shown in Figure 16.

[0079] Furthermore, if the part causing the precursor anomaly is not repaired and S623 is not executed, counter N is set to 2 in S1603. In such cases, if a dot-shaped precursor anomaly caused by the photosensitive drum is found during a second diagnosis, the CPU 214 of the diagnostic unit 108 sets the size S of the precursor anomaly (2) to, for example, 0.7 mm2 in S1602. Then, in S621, the CPU 214 of the diagnostic unit 108 notifies the printing unit 107 of the precursor via the communication I / F 211. The CPU 206 of the printing unit 107 receives this precursor via the communication I / F 201. The CPU 206 then displays the precursor notification screen shown in Figure 18 on the job management screen shown in Figure 4 to inform the user that a second precursor has been found.

[0080] Here, in the warning notification screen shown in Figure 18, since N is set to 2, in addition to the screen shown in Figure 17, an X mark is plotted at position 1801, which corresponds to the size S (0.7 mm2) of the warning anomaly (2) when the detection count is 2. Position 1801 is located above the position 1701 shown in Figure 17. Therefore, the user can recognize that the size of the second warning anomaly is larger than that of the first. They can also recognize that the size of the second warning anomaly is approaching the level at which it will fail the inspection diagnosis. As a result, the user is more likely to repair the photosensitive drum that caused the warning anomaly than with the first warning notification. Therefore, by repairing the photosensitive drum before it fails the inspection diagnosis, the cause of the warning anomaly can be eliminated. Thus, it is possible to prevent it from failing the inspection diagnosis, and as a result, the disposal of sheets with images that failed inspection and the wasteful use of toner to form these images are prevented. The warning notification screen in Figures 17-18 is an example of the present invention's display of the "degree of abnormality," the "quantitative display of abnormality," the "time-series display of abnormality," and the "area of ​​abnormality."

[0081] In the warning notification screen displayed in S621, the number of detections is used as a parameter, but any parameter that shows the time-series change of size S can be used instead of the number of detections, for example, the number of printed pages on which the part to be repaired was used. Alternatively, for each detection count, the number of pages that will fail the inspection diagnosis can be predicted using the number of printed pages on which the part was used, and this predicted number can be used as a parameter.

[0082] Furthermore, in the flowchart shown in Figure 16, for dot-shaped precursor anomalies caused by the photosensitive drum, the size transitions according to the number of detections in the precursor diagnosis are shown in Figures 17 and 18. However, for parts other than the photosensitive drum, the size transitions according to the number of detections for each dot-shaped and streak-shaped precursor anomaly may also be shown. That is, for each dot-shaped or streak-shaped precursor anomaly, a counter N may be provided for each cause. Then, a judgment process may be performed for each precursor anomaly in the flowchart of Figure 16. Then, in the precursor notification screen shown in Figure 17, symbols corresponding to the area of ​​each precursor anomaly may be plotted. Also, Figure 23 is a table showing that the photosensitive drum, ITB, and secondary transfer unit are identified as the parts causing dot-shaped precursor anomalies, and a counter N is provided for each. With such an invention, the user can decide whether or not to perform repairs on individual parts by referring to the repairability status of each part.

[0083] <Effects and Actions> According to the image forming system 1 of the second embodiment, by displaying a warning notification screen as shown in Figures 17 and 18, the user can recognize the magnitude of the warning abnormality for each detection count. The user can also recognize that as the magnitude of the warning abnormality changes over time, it approaches the diagnostic level that will result in a "NG" (fail) in the inspection diagnosis. Therefore, the user can recognize the degree of the warning and perform repairs or cleaning of parts in a timely manner. Thus, the detection of abnormalities exceeding the standard in the inspection of the next job after the diagnosis is suppressed. Therefore, the disposal of sheets with images that result in a "NG" in the inspection diagnosis and the wasteful use of toner to form these images are prevented.

[0084] <Variation> In S607, the image forming apparatus 101 may receive a reference image generated outside the image forming apparatus 101 via the external LAN 104 and the internal LAN 105. Also, in S608, the CPU 214 may receive a diagnostic image read outside the image forming apparatus 101 via the external LAN 104 and the internal LAN 105. Also, in S618, the CPU 206 may transmit the identified part and repair details to the client PC 103 via the external LAN 104 and the internal LAN 105. The client PC 103 may then transmit a repair instruction including these repair details to another image forming apparatus 101 via the network.

[0085] <Other Embodiments> The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0086] The invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, claims are attached to disclose the scope of the invention.

[0087] The disclosures herein include the following image forming apparatus, control method thereof, and program. (Item 1) An image forming apparatus, A diagnostic means for detecting anomalies in the image formed on the sheet and diagnosing whether the detected anomaly is a precursor to an unacceptable level of anomaly, An image forming apparatus characterized by comprising: an output means that outputs the degree of the abnormality diagnosed as a precursor to an abnormality of an unacceptable level when the diagnostic means diagnoses the abnormality as a precursor to an abnormality of an unacceptable level. (Item 2) The image forming apparatus according to item 1, characterized in that the output means quantitatively displays the abnormality diagnosed as a precursor on the screen. (Item 3) The image forming apparatus according to item 1 or 2, characterized in that the output means displays the abnormality diagnosed as a precursor on the screen over time. (Item 4) The image forming apparatus according to any one of items 1 to 3, characterized in that the output means displays the area or shape of the abnormality diagnosed as a precursor on a screen. (Item 5) The diagnostic means further diagnoses whether the detected abnormality is at an unacceptable level. The image forming apparatus according to any one of items 1 to 4, characterized in that the output means displays on the screen a first criterion for diagnosing an abnormality at an unacceptable level and a second criterion for diagnosing an abnormality that has been diagnosed as a precursor. (Item 6) The second criterion mentioned above is: Set more strictly than the first standard, The image forming apparatus according to item 5, characterized in that it is set within the range of the abnormality detection capability of the diagnostic means. (Item 7) The image forming apparatus according to any one of items 1 to 6, further characterized in that the output means outputs whether or not to automatically perform the removal of the abnormality diagnosed as a precursor. (Item 8) There are multiple types of abnormalities formed on the aforementioned sheet. The image forming apparatus according to any one of items 1 to 7, characterized in that the output means displays on a screen the degree of the abnormality diagnosed as a precursor for each of the multiple types of causes of the abnormality. (Item 9) The system further comprises a reading means for reading the image formed on the sheet, The image forming apparatus according to any one of items 1 to 8, characterized in that the diagnostic means diagnoses whether or not there is an abnormality of an unacceptable level and an abnormality diagnosed as a precursor in the image read by the reading means, using the difference between the original image of the image before it is formed on the sheet and the image read by the reading means. (Item 10) The image forming apparatus according to any one of items 1 to 9, wherein the output means further outputs content indicating that, if there is an abnormality diagnosed as a precursor, the cause of the abnormality diagnosed as a precursor is removed. (Item 11) A method for controlling an image forming apparatus, A diagnostic means includes a diagnostic step of detecting an abnormality in an image formed on a sheet and diagnosing whether the detected abnormality is a precursor to an abnormality of an unacceptable level, A control method for an image forming apparatus, characterized in that the output means includes an output step of outputting the degree of the abnormality diagnosed as a precursor to an abnormality of an unacceptable level when the abnormality is diagnosed by the diagnostic means as a precursor to an abnormality of an unacceptable level. (Item 12) A program for causing a computer to execute each step in a control method for an image forming apparatus, wherein the control method is: A diagnostic means includes a diagnostic step of detecting an abnormality in an image formed on a sheet and diagnosing whether the detected abnormality is a precursor to an abnormality of an unacceptable level, A program characterized in that the output means includes an output step of outputting the degree of the abnormality diagnosed as a precursor to an abnormality of an unacceptable level when the diagnostic means diagnoses the abnormality as a precursor to an abnormality of an unacceptable level. [Explanation of symbols]

[0088] 1: Image forming system, 100: Printing system, 101: Image forming apparatus, 102: External controller, 103: Client PC, 107: Printing unit, 108: Diagnostic unit, 206, 214, 251, 261: CPU, 207, 215, 252, 262: Memory, 208, 216, 253, 263: HDD unit, 225, 241: UI display unit, 226, 242: Operation unit, 331: Image reading unit, 501: Inspection diagnostic level, 502: Precursor diagnostic setting, 1401: Code, 1501, 1502: Abnormal image, 1701, 1801: Position, 1901, 1902: Icon, 2201: Inspection abnormality

Claims

1. An image forming apparatus, A diagnostic means for detecting anomalies in the image formed on the sheet and diagnosing whether the detected anomaly is a precursor to an unacceptable level of anomaly, An image forming apparatus characterized by comprising: an output means that outputs the degree of the abnormality diagnosed as a precursor to an abnormality of an unacceptable level when the diagnostic means diagnoses the abnormality as a precursor to an abnormality of an unacceptable level.

2. The image forming apparatus according to claim 1, characterized in that the output means quantitatively displays the abnormality diagnosed as a precursor on the screen.

3. The image forming apparatus according to claim 1, characterized in that the output means displays the abnormality diagnosed as a precursor on the screen over time.

4. The image forming apparatus according to claim 1, characterized in that the output means displays the area or shape of the abnormality diagnosed as a precursor on a screen.

5. The diagnostic means further diagnoses whether the detected abnormality is at an unacceptable level. The image forming apparatus according to claim 1, characterized in that the output means displays on the screen a first criterion for diagnosing the abnormality at an unacceptable level and a second criterion for diagnosing the abnormality that has been diagnosed as a precursor.

6. The second criterion mentioned above is, It is set more strictly than the first standard, The image forming apparatus according to claim 5, characterized in that it is set within the range of the abnormality detection capability of the diagnostic means.

7. The image forming apparatus according to claim 1, further characterized in that the output means outputs in a way that allows the user to select whether or not to automatically perform the removal of the abnormality diagnosed as a precursor.

8. There are multiple types of abnormalities formed on the aforementioned sheet. The image forming apparatus according to claim 1, characterized in that the output means displays on the screen the degree of the abnormality diagnosed as a precursor for each of the multiple types of causes of the abnormality.

9. The system further comprises a reading means for reading the image formed on the sheet, The image forming apparatus according to claim 1, characterized in that the diagnostic means diagnoses whether or not there are abnormalities of an unacceptable level and abnormalities diagnosed as precursors in the image read by the reading means, using the difference between the original image of the image before it is formed on the sheet and the image read by the reading means.

10. The image forming apparatus according to any one of claims 1 to 9, further characterized in that the output means outputs content indicating that, if there is an abnormality diagnosed as a precursor, the cause of the abnormality diagnosed as a precursor is removed.

11. A method for controlling an image forming apparatus, A diagnostic means includes a diagnostic step of detecting an abnormality in an image formed on a sheet and diagnosing whether the detected abnormality is a precursor to an abnormality of an unacceptable level, A control method for an image forming apparatus, characterized in that the output means includes an output step of outputting the degree of the abnormality diagnosed as a precursor to an abnormality of an unacceptable level when the abnormality is diagnosed by the diagnostic means as a precursor to an abnormality of an unacceptable level.

12. A program for causing a computer to execute each step in a control method for an image forming apparatus, wherein the control method is: A diagnostic means includes a diagnostic step of detecting an abnormality in an image formed on a sheet and diagnosing whether the detected abnormality is a precursor to an abnormality of an unacceptable level, A program characterized in that the output means includes an output step of outputting the degree of the abnormality diagnosed as a precursor to an abnormality of an unacceptable level when the diagnostic means diagnoses the abnormality as a precursor to an abnormality of an unacceptable level.

Images