Image forming apparatus, image forming system, inspection method, program

Abstract

To reduce the frequency of cleaning required to eliminate defects caused by the reading unit. [Solution] The present invention is characterized by comprising: a print image reading unit 307 that reads a printed material printed by a printing device with a reading unit and generates a first image to be inspected; a first defect determination processing unit 355 that determines defects in the printed material based on a master image generated from the print data of the printed material and the first image to be inspected; a second defect determination processing unit 357 that detects the location of defects in a second image to be inspected generated by the reading unit without paper feeding; an exclusion area setting unit 356 that sets an inspection exclusion area in which the first defect determination processing unit does not detect defects based on the defect location detected by the second defect determination processing unit; and a display control unit 358 that displays the defect location in the second image to be inspected or at least one of the inspection exclusion area.

Description

Technical Field

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

Background Art

[0002] There is known a printing system including a printing apparatus that forms an image on a sheet based on print data, and an inspection apparatus that reads the image with a reading unit and compares it with a master image generated from the original print data. The inspection apparatus can evaluate the print quality according to the comparison result. For proper evaluation of the print quality, it is preferable that the reading unit has no defects such as dirt.

[0003] Techniques for assisting a user in cleaning the reading unit have been devised (see, for example, Patent Document 1). Patent Document 1 discloses a technique for outputting a dust adhesion position instruction report that marks a mark indicating the position in the main scanning direction of the reading unit at the dust adhesion position and a positioning mark when it is determined that dust is attached.

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the conventional technology has a problem that it is necessary for the user to clean the reading unit to eliminate defects caused by the reading unit. For example, even if the position of the defect does not affect the print quality, the user needs to clean the reading unit.

[0005] In view of the above problems, the present invention provides a technique for reducing the cleaning frequency for eliminating defects caused by the reading unit.

Means for Solving the Problems

[0006] In view of the above problems, the present invention is characterized by comprising: a print image reading unit that reads a printed material printed by a printing device with a reading unit and generates a first image to be inspected; a first defect determination processing unit that determines defects in the printed material based on a master image generated from the print data of the printed material and the first image to be inspected; a second defect determination processing unit that detects the location of defects in a second image to be inspected generated by the reading unit without paper feeding; an exclusion area setting unit that sets an inspection exclusion area in which the first defect determination processing unit does not detect defects based on the defect location detected by the second defect determination processing unit; and a display control unit that displays at least one of the defect location in the second image to be inspected or the inspection exclusion area. [Effects of the Invention]

[0007] This reduces the frequency of cleaning required to eliminate defects caused by the reading unit. [Brief explanation of the drawing]

[0008] [Figure 1] This diagram illustrates defects detected without paper feeding and defects detected with paper feeding. [Figure 2] This is an example of a system configuration diagram for a printing system. [Figure 3] This is an example of a functional block diagram for DFE. [Figure 4] This is an example of a functional block diagram illustrating the functions of a printer. [Figure 5] This is an example of a functional block diagram that explains the functions of an inspection device by dividing them into blocks. [Figure 6] This figure shows an example of job management information. [Figure 7] This is an example of a flowchart showing the flow after defect detection processing in the no-paper-feed detection mode. [Figure 8] This figure shows examples of items that are judged to be in a defective state. [Figure 9] This is an example of a flowchart illustrating the process of registering areas to be excluded from inspection. [Figure 10]It is a diagram showing an example of a status display screen displayed by an inspection device. [Figure 11] It is a diagram showing another display example of an error message displayed on the status display screen. [Figure 12] It is a diagram showing an example of a threshold setting screen displayed by an inspection device. [Figure 13] It is a diagram showing an example of a detailed setting screen displayed in a pop-up. [Figure 14] It is a diagram showing an example of an inspection exclusion area setting screen displayed by an inspection device. [Figure 15] It is a diagram showing an example of an inspection exclusion area display screen displayed by an inspection device. [Figure 16] It is a diagram showing an example of expanding one inspection exclusion area. [Figure 17] It is a diagram showing an example of an inspection exclusion area display screen displayed according to the authority of the logged-in user. [Figure 18] It is a diagram showing an example of an inspection exclusion area display screen displayed according to the authority of the logged-in user. [Figure 19] It is a diagram showing another display example of inspection exclusion area information. [Figure 20] As another display example of inspection exclusion area information, it is a diagram showing a display example having a paper position. [Figure 21] As another display example of inspection exclusion area information, it is a diagram showing a display example having dimensions. [Figure 22] ]>It is a diagram showing a display example of displaying a test image generated in the actual printing detection mode and inspection exclusion area information on one screen. [Figure 23] It is a diagram showing a display example of an arbitrarily set inspection exclusion area.

Embodiments for Carrying Out the Invention

[0009] Hereinafter, as an example of an embodiment for carrying out the present invention, an image forming apparatus and an inspection method performed by the image forming apparatus will be described with reference to the drawings.

[0010] <Overview of the Process> The printing system of this embodiment reads an actual printed matter with a reading device to generate a test image to be inspected (an example of the first test image to be inspected), and compares it with a master image generated from the original print data formed on the printed matter, so as to determine whether the printed matter has been output with the expected quality. When there are differences greater than or equal to a certain level between the test image to be inspected and the master image (defects exist), there may be a problem in the printing process or a defect such as dirt in the reading device. However, since the user is unclear whether the detected defect is caused by the printing process or by dirt on the reading device, etc., the reading device may have to be cleaned, which may reduce the productivity of the printed matter (increase in downtime). When a defect is detected, in order to present an appropriate maintenance method to the user, the printing system needs to classify the cause of the defect as being due to reading or due to printing.

[0011] The printing system detects defects in the reading device without reading an actual document (hereinafter referred to as "no paper passage"), and sets the area where the defect is detected as an inspection exclusion area. Reading an actual document is referred to as "paper passage".

[0012] 1. The printing system generates a test image to be inspected (an example of the second test image to be inspected) without paper passage. The test image without paper passage is an image generated by the reading device reading a predetermined reference surface, and if there are no defects such as dirt, it will be a uniform image of almost white pixels or black pixels as a whole.

[0013] 2. The printing system detects defects from the test image without paper passage.

[0014] 3. The printing system sets the defects detected from the test image without paper passage as inspection exclusion areas. Alternatively, the user can set the inspection exclusion area based on or arbitrarily referring to the detected defects. When a defect detected during the inspection of a printed matter with paper passage is included in the inspection exclusion area, the printing system does not detect it as a defect. Furthermore, the user can also set to display the defects within the inspection exclusion area as "suspected reading defect".

[0015] Figure 1 illustrates defects detected without paper feeding and defects detected with paper feeding. In Figure 1, defects due to dust adhesion (exclusion areas for inspection, described later) are detected at four locations A to D without paper feeding. Defects A, C, and D are in the margins or outside the paper area, so they do not need to be set as exclusion areas for inspection (however, it is desirable to set them as exclusion areas for inspection because detecting defects with paper feeding will result in unnecessary checking work). Defect B is located in a position that overlaps with the image 951 under inspection, and if an exclusion area for inspection is not set, a false detection will occur in inspection with paper feeding (a defect in the reading device will be mistakenly detected as a defect in the printing process). In Figure 1, three defects 952 are detected in the same position as defect B in the image 951 under inspection.

[0016] Thus, if dust accumulates on the line sensor of the reader, the area excluded from inspection will also increase. If the user needs to check the print quality of the excluded area while paper is being fed, it is preferable to remove reading streaks through cleaning so that it does not become an excluded area. For areas where the inspection requirement is not high and there is no inconvenience even if it becomes an excluded area, the work may be continued without cleaning.

[0017] Therefore, in this embodiment, the printing system notifies the user of the location of the defect or the area to be excluded from inspection. The location of the defect refers to the detected location itself, and the area to be excluded from inspection is the area set to include the location of the defect. By displaying the location of the defect or the area to be excluded from inspection, the user can more reliably determine whether or not cleaning work is necessary.

[0018] <About Terminology> An image under inspection is an image used for inspecting print quality, and is generated by optically reading it with a reading device. Images under inspection can be generated by reading a printed document, or by reading a reference surface without any paper feeding.

[0019] A master image is an image generated from the original print data of a printed material, and it serves as the standard image for print quality.

[0020] A defect refers to a part of a print that does not meet the print quality standards, or a failure to meet the standards. Defects can occur in the inspected image of the printed material, or in the inspected image when the reference surface is read without paper feeding. In the former case, the print quality is reduced, and the cause can be either a malfunction in the printing process or dirt on the reading device. In the latter case, even if there is a defect, the print quality is not affected.

[0021] The defect location is the position where a defect is detected in the image under inspection. This location is in the image under inspection generated without paper feeding, and can be identified by the position in the main scanning direction and the position in the sub-scanning direction. Since the reading device reads using a line sensor, many defects result in streaks parallel to the sub-scanning direction, and in many cases, the defect location can be identified by the position in the main scanning direction alone.

[0022] An inspection exclusion area is an area in a print job that, even if a defect is detected during the execution of the print job, will be treated as if no defect was detected. The defect exclusion area may be set to include the location of the defect, or it may be set manually by the user.

[0023] <Example System Configuration> Figure 2 shows a schematic system configuration diagram of the printing system 100. The system configuration in Figure 2 is just one example; any configuration that enables defect detection as described in this embodiment is acceptable.

[0024] The printing system 100 includes a printer 101, an inspection device 103, and a stacker 104. The printing system 100 may also be called an image forming apparatus, an image forming system, an MFP (Multifunction Peripheral / Printer / Product), or a multifunction device, etc. The printer 101, the inspection device 103, and the stacker 104 may all or two be in an integrated configuration. The printer 101 is a device that receives data such as characters, images, or graphics and prints them on paper or the like. The printer 101 may also be called a printing device, etc.

[0025] A control panel 102 for the printer 101 is located on the top surface of the printer 101. The control panel 102 has a display (touch panel) and a keyboard, and displays an operation screen. The control panel 102 displays the operation screen of the printing system 100 and accepts various operations from the user.

[0026] The printer 101 receives print jobs containing RIP images from external sources such as a DFE (Digital Front End) or PC (Personal Computer), as described later, or receives execution instructions for print jobs stored within the printer 101. In this embodiment, as an example, the RIP image is CMYK 8-bit 600dpi.

[0027] The printer 101 retrieves paper from the paper feed unit 105 according to the contents of the print job it has been instructed to execute, and transports the paper along the path shown by the dotted line in the figure. The printer 101 forms an image on the paper using drums 113, 114, 115, and 116. Drums 113, 114, 115, and 116 each place toner images of K (black), C (cyan), M (magenta), and Y (yellow) onto the belt 111, transfer the color toner image to the paper transported to the roller 112, and fix the toner image on the paper using heat and pressure at the roller 117. In the case of single-sided printing, the paper is ejected directly to the inspection device 103. In the case of double-sided printing, the paper is inverted in the inversion pass 118 and transported to the roller 112, where the color toner image is transferred and fixed to the opposite side of the paper by drums 113, 114, 115, and 116 before being ejected to the inspection device 103.

[0028] The inspection device 103 is a device that inspects the print quality of printed materials output by the printer 101. The inspection device 103 has an operation unit 133. The functions of the operation unit 133 may be the same as those of the operation unit 102. The inspection device 103 does not necessarily have an operation unit 133; the operation unit 102 of the printer itself may serve this purpose. Alternatively, the operation unit 133 of the inspection device 103 may be a PC connected via LAN or the like. In this case, the PC displays the inspection results using, for example, a web browser or a dedicated application.

[0029] The inspection device 103 reads the image on the paper ejected from the printer 101, one side at a time, using the reading devices 131 and 132 (an example of a reading unit), transports the image in the direction of the arrow in the path, and ejects it to the stacker 104. In this embodiment, as an example, the image to be read is RGB 8-bit each, 200 dpi.

[0030] The stacker 104 stacks the paper ejected from the inspection device 103 onto the tray 141.

[0031] <dfe> The DFE150 will be explained with reference to Figure 3. The DFE150 is a general term for a device that processes data for input to a printer. The DFE150 creates RIP data (raster data) for printing on printer 101 from print data such as PostScript data.

[0032] Figure 3 is an example of a functional block diagram of the DFE150. The DFE150 is connected to the printer 101 shown in Figure 2 and the DFE panel 151 for displaying the user interface. The DFE panel 151 is a user interface that has a display (touch panel) and a keyboard.

[0033] The DFE150 includes a system control unit 501, a network interface unit 502, a user interface unit 505, a storage unit 503, and a printer interface unit 504. Each functional unit of the DFE150 is a function or means realized by the CPU executing instructions contained in one or more programs installed on the DFE150.

[0034] The user interface unit 505 of the DFE150 generates a screen for display on the DFE panel 151 using UI display information and displays it on the DFE panel 151. The UI display information includes multiple display components that make up the screen and their arrangement.

[0035] The network interface unit 502 of the DFE150 is a communication interface that connects the DFE150 to a LAN. The network interface unit 502 receives print jobs from the LAN and transmits them to the system control unit 501.

[0036] Furthermore, print jobs may be stored in the storage unit 503, and the system control unit 501 may retrieve print jobs from the storage unit 503. In other words, the system control unit 501 may receive print jobs via the network I, or it may retrieve them from the storage unit 503.

[0037] The DFE150 has a system control unit 501. The system control unit 501 controls the entire DFE150. The system control unit 501 includes a job information processing unit 551, a RIP processing unit 552, a storage unit 553, and a gradation correction data generation unit 554.

[0038] The job information processing unit 551 manages job management information related to print jobs, such as the status of the print job, feeding into the printer 101, and the progress of the print job (obtained from the printer 101), in the storage unit 553. The job information processing unit 551 feeds the print job data into the printer 101, combining the job management information and the RIP image data. The storage unit 553 stores print job data related to the print job (for example, job ID, file name, job registration date and time, job owner, etc.).

[0039] The gradation correction data generation unit 554 adjusts the print data so that it is printed with the same gradation, density, and color as the original document. For example, the gradation correction data generation unit 554 may increase or decrease the gradation, increase or decrease the density, or increase or decrease the amount of warm colors or blues.

[0040] The RIP processing unit 552 creates RIP data for printing print data such as PostScript data on the printer 101. The RIP data is the halftone data (whether or not to print dots) for each color of toner.

[0041] Furthermore, the printer I / F unit 504 of the DFE150 is an interface for communicating with the printer 101. The printer I / F unit 504 transmits the print job data that the system control unit 501 has decided to input to the printer 101.

[0042] <About the printer's functions> Figure 4 is a functional block diagram illustrating the functions of printer 101. Printer 101 includes a system control unit 201, a user I / F unit 202, a DFF I / F unit 207, a network I / F unit 203, an external I / F control unit 204, a storage unit 205, an image processing control unit 208, a printing control unit 209, and a mechanism control unit 206. Each functional unit of printer 101 is a function or means realized by the CPU executing instructions included in one or more programs installed on printer 101.

[0043] The system control unit 201 controls the entire printer 101. The system control unit 201 is connected to the user I / F unit 202, DFF I / F unit 207, network I / F unit 203, external I / F control unit 204, storage unit 205, image processing control unit 208, printing control unit 209, and mechanism control unit 206.

[0044] The user interface unit 202 is an interface for connecting the system control unit 201 and the operation unit 102 shown in Figure 2.

[0045] The DFE I / F unit 207 is an interface that enables communication between the system control unit 201 and the DFE 150 shown in Figure 3 (for example, receiving print job data).

[0046] The network interface unit 203 connects the system control unit 201 to a network such as a LAN, and is an interface for communication between the printer 101 and devices on the network.

[0047] The external I / F control unit 204 is an interface for the printer 101 to communicate with other devices (such as the inspection device 103 and the stacker 104).

[0048] The storage unit 205 is a storage means implemented by an HDD (Hard Disk Drive) or SSD (Solid State Drive), for example. Print job data is stored in the storage unit 205.

[0049] The mechanism control unit 206 controls various mechanisms within the printer 101, such as paper transport, transfer process, and duplex / single-sided printing control.

[0050] The printing control unit 209 instructs the mechanism control unit 206 to control the timing of each mechanism and also controls the overall image formation on the paper. The image processing control unit 208 processes the image transferred by the mechanism control unit 206.

[0051] The system control unit 201 includes a memory 251, a job processing unit 252, a RIP processing unit 253, and a job information generation unit 254.

[0052] Memory 251 is the working memory for the system control unit 201.

[0053] When the job information generation unit 254 receives print job data from the DFE 150, it generates the job ID, reception date and time, progress, etc., within the printer and stores them in the storage unit 205.

[0054] The RIP processing unit 253 performs RIP processing on the print data if the print job has not been RIP processed.

[0055] The job processing unit 252 queries the print control unit 209 for the availability of print jobs and determines which print job to execute from the print job data stored in the storage unit 205 according to priority and other factors.

[0056] <Functions of the inspection device> Figure 5 is a functional block diagram illustrating the functions of the inspection device 103 in blocks. The inspection device 103 includes a system control unit 301, a master image generation unit 308, a difference image generation unit 309, a print image reading unit 307, an external I / F control unit 304, a user I / F unit 302, a storage unit 305, a network I / F unit 303, and a mechanism control unit 306. Each functional unit of the inspection device 103 is a function or means realized by the CPU executing instructions included in one or more programs installed in the inspection device 103.

[0057] The system control unit 301 controls the entire inspection device 103. The system control unit 301 is connected to the master image generation unit 308, the difference image generation unit 309, the print image reading unit 307, the external I / F control unit 304, the user I / F unit 302, the storage unit 305, the network I / F unit 303, and the mechanism control unit 306.

[0058] The user interface unit 302 is an interface for connecting the system control unit 301 and the operation unit 133 shown in Figure 2. The user interface unit 302 displays information from the system control unit 301 on the operation unit 133. If a defect detected in the actual print inspection mode matches an exclusion area, the user interface unit 302 displays it separately from normal defects as a suspected read failure defect.

[0059] The network interface unit 303 is an interface for connecting the system control unit 301 to a network such as a LAN.

[0060] The external I / F control unit 304 is an interface with other devices (e.g., printer 101, stacker 104, etc.).

[0061] The mechanism control unit 306 controls the operation of each mechanism of the inspection device 103, such as paper transport, double-sided / single-sided reading of paper, and paper ejection.

[0062] The memory unit 305 is a storage means implemented by an HDD or SSD. For example, the memory unit 305 stores the image under inspection, difference images, master images, and inspection results. The memory unit 305 also stores an area excluded from inspection.

[0063] The print image reading unit 307 reads both sides of the paper transported from the printer 101 using the reading devices 131 and 132 and outputs the image to be inspected. The print image reading unit 307 generates the image to be inspected in either the actual printing detection mode or the paper feed failure detection mode, which will be described later. The actual printing detection mode is a mode in which the printed material is inspected while the print job is in execution, and the paper feed failure detection mode is a mode in which defects in the reading devices 131 and 132 are detected before the execution of the print job begins.

[0064] In the actual printing detection mode, the master image generation unit 308 generates a master image from the RIP image transmitted by the DFE 150. This RIP image is generated from the print data formed on the paper.

[0065] The difference image generation unit 309 generates a difference image between the master image and the image to be inspected in the actual printing detection mode. A difference image is an image that represents the difference in pixel values ​​for each pixel between the master image and the image to be inspected. Since the RIP image is generated from the print data formed on the paper, and the image to be inspected is read from the printed material, if normal, the pixel values ​​in the difference image will be below the threshold.

[0066] The system control unit 301 includes a storage unit 351, a job management data processing unit 352, a first defect discrimination processing unit 355, an exclusion area setting unit 356, a second defect discrimination processing unit 357, and a display control unit 358.

[0067] In the actual printing detection mode, the system control unit 301 receives print management information (included in the job management information) via the external I / F control unit 304 and stores it in the storage unit 351 within the system control unit 301. The job management data processing unit 352 extracts post-processing machine information from the job management information shown in Figure 6 and transmits it via the external I / F control unit 304 to the stacker 104, which is a post-processing device downstream of the inspection device 103. The job management data processing unit 352 reads the print management information from the storage unit 351. The job management data processing unit 352 then transfers the print management information to the master image generation unit 308, the difference image generation unit 309, the print image reading unit 307, and the mechanism control unit 306 so that they can process the print job. The print management information transferred is the job management information shown in Figure 6, with the post-processing machine information removed.

[0068] In the actual printing detection mode, the system control unit 301 stores the image under inspection and the difference image in the storage unit 351 and notifies the first defect discrimination processing unit 355. The first defect discrimination processing unit 355 performs defect discrimination on the difference image using a preset defect discrimination threshold. The first defect discrimination processing unit 355 performs edge detection on the difference image, for example, by detecting edges with an intensity greater than the defect discrimination threshold. The detected edges can be of any shape, such as points or lines.

[0069] Furthermore, in the no-paper-feed detection mode, the system control unit 301 stores the image under inspection in the storage unit 351 and notifies the second defect discrimination processing unit 357. The second defect discrimination processing unit 357 performs defect discrimination on the image under inspection using a preset defect discrimination threshold. In the no-paper-feed detection mode, if there are no defects such as dirt, the image under inspection will be a uniform image consisting almost entirely of white or black pixels. When generating a difference image from a master image, the master image is an image consisting entirely of white or black pixels. However, a master image is not required. The second defect discrimination processing unit 357 performs edge detection on the image under inspection, detecting edges with an intensity greater than the threshold. The detected edges can be of any shape, such as points or lines.

[0070] The exclusion area setting unit 356 excludes the defect location detected by the second defect determination processing unit 357 or the defect location set by the user from the area in which the first defect determination processing unit 355 detects defects. In other words, the exclusion area setting unit 356 sets an inspection exclusion area in which the first defect determination processing unit 355 does not detect defects, so as to include the defect location detected by the second defect determination processing unit 357.

[0071] The display control unit 358 causes the operation units 102, 133, etc., to display at least one of the inspection exclusion areas set by the second defect discrimination processing unit 357 or the defect locations that gave rise to the inspection exclusion areas, via the user interface unit 302. Alternatively, the network interface unit 303 may notify the user via email or other means of a URL where the inspection exclusion areas or defect locations are displayed.

[0072] Figure 6 shows an example of job management information. This job management information is for when the printer 101 is performing normal printing (actual printing detection mode). During printing, print data is generated page by page by at least one of the DFE 150 or the printer 101. The processing of print jobs is carried out based on the job management information.

[0073] The job management information includes fields for parameters, remarks, and initial values. The parameter is the field name, the remarks are a description of the parameter, and the initial value indicates the value received by the system control unit 201 of the printer 101.

[0074] The job origin is information indicating the job output source. The job origin includes information on whether the print job was submitted from DFE150 or is internal data from printer 101.

[0075] The generation time is the date and time when the job creator generated the job information.

[0076] The page ID is the identification number for each printed page. The page ID is incremented by 1 for each page processed from the time the power is turned on. A numerical value is assigned to the page ID when printing is initiated.

[0077] The print side identifies whether the print job is single-sided, double-sided (front side), or double-sided (back side).

[0078] The paper ID is the identification information for the paper used for printing. In the case of double-sided printing, pages printed on the same sheet of paper will have the same paper ID. The paper ID is incremented by 1 for each sheet of paper processed from the time the power is turned on. The paper ID is set as a numerical value when printing is initiated.

[0079] The part ID is identification information for each individual part. The part ID is incremented by 1 for each completed print job from the time the power is turned on. The part ID is set as a numerical value when printing is initiated.

[0080] The Job ID is a unique identifier for each job. The Job ID is incremented by 1 for each job completed, starting from when the power is turned on. The Job ID is set numerically when printing is initiated.

[0081] The paper type is information about the type of paper used for printing. The paper size is information about the size of the paper. The job type indicates whether the print job is subject to defect detection, is not subject to defect detection, or is interleaved paper for defect detection identification.

[0082] <Defect detection process> Figure 7 is a flowchart showing the flow after defect detection processing in the no-paper-feed detection mode. The processing in Figure 7 is executed after the no-paper-feed detection mode is performed and the second defect discrimination processing unit 357 performs defect detection processing on the image under inspection. In the no-paper-feed detection mode, the print image reading unit 307 generates the image under inspection without paper being transported. If there is a defect in the image under inspection, it is highly likely that the defect (e.g., dirt) is caused by the reading devices 131 and 132.

[0083] First, the second defect discrimination processing unit 357 generates defect discrimination information (S601). The second defect discrimination processing unit 357 performs defect discrimination on the image under inspection using a preset defect discrimination threshold and generates the following defect discrimination information. • Number of reading defects detected when no paper is fed through • Reading defect location when no paper is fed through The second defect detection processing unit 357 determines whether a defect exists based on the defect detection information, and if a defect exists, it detects the defect state (S602).

[0084] If there are no defects (No. in S602), the display control unit 358 turns off the notification to the user (S608). Turning it off means that no notification prompting cleaning is sent.

[0085] If a defect is found (Yes in S602), the second defect determination processing unit 357 determines whether the detected defect state is below a threshold (S603). The defect state is determined based on, for example, the following items. (i) For example, the defect status is determined based on the number of defects. The threshold used to compare the number of defects is user-configurable (e.g., notify when there are tens or more defects). (ii) For example, a defect status is determined by a combination of multiple conditions. For example, a notification is issued if there are 10 or more defect areas with a width of 3 pixels or more. In this case, the user can set thresholds for width and number.

[0086] In addition, as shown in Figure 8, the defect state may be determined based on several items. Figure 8 shows examples of items that may be used to determine a defect state. In addition to the number and width mentioned above, length, area, and brightness value may be used to determine the defect state. The number of defects refers to the number of defect regions. Defect regions are mainly streaks, but may include defects of other shapes. The width of a defect is the width of the defect area. The width can be, for example, the length of the circumscribing rectangle of the defect area in the main scanning direction. The defect length is the length of the defect region. The length can be, for example, the length of the circumscribing rectangle of the defect region in the sub-scan direction. The area of ​​a defect is the area of ​​the defect region (width × length). The brightness value of a defect refers to the pixel value (RGB value) of the defect, and can be, for example, its mean, median, or maximum value. Alternatively, the brightness value can be the difference in pixel value between the defect area and a non-defective area.

[0087] If the determination in step S603 is Yes, the display control unit 358 turns OFF the notification to the user (S604). OFF means that no notification prompting cleaning is sent. If the determination in step S603 is No, the display control unit 358 turns ON the notification to the user (S605). ON means that a notification prompting cleaning is sent.

[0088] In step S605, when user notifications are turned ON, the user is notified to prompt cleaning based on a threshold set according to their preferences. This allows for notifications tailored to the user's acceptable risk of overlooking something, thus suppressing an increase in the risk of overlooking something. The display control unit 358 also notifies the user to prompt cleaning, and if the user cleans, the process in Figure 7 (setting the inspection exclusion area) may be executed again. Depending on the printer 101, the "no paper feed detection mode" may also be performed when the cover is closed for cleaning. That is, the sequence is cover open → user cleaning → cover closed, so in such printers 101, the process in Figure 7 is always performed after cleaning. Therefore, since the inspection exclusion area is set after cleaning, it is possible to suppress an increase in the risk of overlooking something due to increased dust accumulation or an increase in the inspection exclusion area after cleaning.

[0089] Steps S603 to S605 minimize user verification and cleaning tasks, and also reduce the risk of overlooking defects. Specifically, since areas where defects are detected are set as inspection exclusion areas, step S603 determines that if there are noticeable defects in the inspection exclusion areas caused by readers 131 and 132, the user can be prompted to clean them in advance. Therefore, the increase in inspection exclusion areas is suppressed, and the risk of overlooking defects that are not caused by readers 131 and 132 but are present in the inspection exclusion areas is reduced. In addition, since defects in the inspection exclusion areas are excluded from inspection, the user's work of frequently checking whether a defect is caused by readers 131 and 132 and cleaning is reduced.

[0090] Next, in step S606, if the pre-set manual adjustment of the inspection exclusion area is invalid, the exclusion area setting unit 356 sets the area where the defect was detected as an inspection exclusion area (S606). By excluding the defect location detected without paper feeding from the defect detection area in the actual printing detection mode, cleaning to resolve defect detection caused by the reading devices 131 and 132 can be made unnecessary or reduced. In addition, false detections due to reading streaks (defects caused by the reading devices 131 and 132) can be suppressed.

[0091] If manual adjustment of the pre-configured inspection exclusion area is enabled, the inspection exclusion area setting screen is displayed (Figure 14). The display control unit 358 displays the inspection exclusion area configured to include the detected defects. The user can adjust the inspection exclusion area by operating the inspection exclusion area setting screen. The user can also choose whether or not to read defects within the inspection exclusion area and display them as suspected defects. The exclusion area setting unit 356 sets the inspection exclusion area configured by the user. Since the location of defects may vary slightly, the user can avoid missing any exclusion areas by allowing some flexibility in the exclusion area.

[0092] Next, in step S607, the display control unit 358 updates the display of the defect location or inspection exclusion area (S607). Examples of the display of the defect location and inspection exclusion area are explained in Figure 15, etc. The user can display the currently set inspection exclusion area and defect location through user operation.

[0093] Note that steps S606 and S607 may be reversed. In this case, the defect location and inspection exclusion area are automatically displayed via a pop-up, and when the user navigates to another screen, the display control unit 358 transitions to the inspection exclusion area setting screen shown in Figure 14. The inspection exclusion area is set when the user performs the save operation on the inspection exclusion area setting screen.

[0094] Figure 9 is a flowchart illustrating the execution process for setting the no-paper-feed detection mode and the inspection exclusion area. The process in Figure 9 is executed, for example, when the power of the inspection device 103 is turned ON and the main unit starts up (S701). In addition, the process in Figure 9 may be executed when the user operates, when power saving is restored, or when the cover of the printer 101 is closed at a predetermined time.

[0095] When the main unit starts up, the system control unit 301 of the inspection device 103 automatically executes the no-paper-feed detection mode operation (S702). In other words, before actual printing using an actual print job begins, the system control unit 301 performs defect detection of the reading devices 131 and 132 without paper feeding.

[0096] After detecting a defect due to no paper feed, the process shown in Figure 7 above is performed. Before displaying the inspection exclusion area setting screen in step S606, the system control unit 301 resets the inspection exclusion areas registered in step S606.

[0097] The display control unit 358 then accepts user input regarding whether to set an exclusion area, that is, whether an exclusion area is permissible (S703). The user displays the exclusion area information shown in Figure 15 and decides whether the exclusion area is permissible. By allowing the user to display the exclusion area information themselves, the input screen is not displayed each time the no-paper-feed detection mode is executed, thus preventing the user from having to input whether or not it is permissible. However, if the exclusion area information to be set has increased since the last execution of the no-paper-feed detection mode, the input screen may be displayed automatically. The exclusion area setting unit 356 compares the area of ​​the exclusion areas already stored in the storage unit 351 with the area of ​​the exclusion areas to be set by the exclusion area setting unit 356. If the latter is larger, the display control unit 358 displays the message "Do you want to set this as an exclusion area in the actual printing detection mode?" on the exclusion area setting screen in step S606. If the user input indicates that the exclusion area is permissible, the exclusion area setting unit 356 registers the exclusion areas displayed or set in step S606.

[0098] The user may be able to set whether to turn notifications ON or OFF according to the area of ​​the inspection exclusion area to be set by the exclusion area setting unit 356, or whether to display an input screen each time the no-paper-feed detection mode is executed.

[0099] If the decision in step S703 is Yes, the process proceeds to step S704; otherwise, the process proceeds to step S707.

[0100] Since the no-paper-feed detection mode has ended, in step S704, the system control unit 301 executes the actual printing detection mode (S704). In the actual printing detection mode, even if the first defect discrimination processing unit 355 detects a defect in a registered inspection exclusion area, it does not treat it as a defect (decreased print quality). In the actual printing detection mode, defects caused by the reading devices 131 and 132 are excluded from detection, so cleaning to resolve defect detection can be made unnecessary or reduced.

[0101] In this embodiment, not only is a defect detected in an exclusion area not treated as a defect, but if the location of the defect detected by the first defect determination processing unit 355 matches the location of the exclusion area stored in the storage unit 351 by the second defect determination processing unit 357, the first defect determination processing unit 355 may determine that there is a suspected reading defect. The area suspected of being a reading defect is highlighted in the image under inspection. This allows the user to confirm whether the defect is caused by the reading devices 131 and 132.

[0102] Next, in step S705, since the actual printing has finished, the system control unit 301 of the inspection device 103 executes the no-paper-feed detection mode operation again (S705). The system control unit 301 of the inspection device 103 executes the no-paper-feed detection mode operation when the print job is finished.

[0103] Similar to step S702, after detecting a defect due to no paper feed, the process shown in Figure 7 above is performed. Before displaying the inspection exclusion area setting screen in step S606 to the user, the system control unit 301 resets the inspection exclusion areas registered in step S606.

[0104] Then, the display control unit 358 receives user input on the inspection exclusion area setting screen displayed in step S606, indicating whether or not an inspection exclusion area should be set, that is, whether or not an inspection exclusion area is permissible (S706). The method of user input may be the same as in step S703. If the user input indicates that an inspection exclusion area is permissible, the exclusion area setting unit 356 registers the inspection exclusion area displayed or set in step S606.

[0105] If the decision in step S706 is Yes, the process ends; if it is No, the process proceeds to step S707.

[0106] In step S707, the user opens the cover and cleans the readers 131 and 132 (S707). That is, the user cleans the readers 131 and 132 because an unacceptable number or size of defects (inspection exclusion areas) have occurred. Once cleaning is complete, the no-paper-feed detection mode is activated by closing the cover (for example, notification from a sensor that detects a change from the open state to the closed state of the cover) (S702).

[0107] <Example of a defect detection notification to the user> Next, an example of a defect detection notification to the user will be explained with reference to Figures 10 and 11. Figure 10 shows an example of a status display screen 800 displayed by the inspection device 103. The status display screen 800 in Figure 10 is displayed in step S605 of Figure 7.

[0108] First, the status column 801 of the status display screen 800 shows the status of the printing system 100 (e.g., adjusting, printing). Area 802 is an area that displays the machine configuration of the printing system 100 along with the external model 802a. The machine configuration refers to the connection status of peripheral devices such as finishers. When an event such as a paper jam occurs, the location where the event occurred is highlighted in the external model. For example, the location where a paper jam occurred turns red, and when the user taps that location, the procedure for resolving the paper jam is displayed. Also, the remaining amount of toner for each color is displayed in area 802. When the toner is near end, an icon prompting replacement of the toner cartridge is displayed. When the user taps the icon, a message prompting to check the stock of toner cartridges may be displayed, or the procedure for replacing the toner cartridge may be displayed.

[0109] Area 803 is an area that shows the status of a running job. The job status includes status, number of copies, number of pages, paper size, etc. Area 804 shows the paper settings set for each tray. The paper settings are information about the paper stored in the tray, and for each tray, they include remaining amount, paper name, basis weight, and size.

[0110] Area 805 is a notification area for the user. Area 805 displays error and maintenance notifications, including when a defect has been detected in the no-paper-feed detection mode. Figure 10 shows the case where it is determined that "the defect condition has exceeded the threshold," and error message 805a, "Cleaning Required: Line Sensor," prompting the user to clean any dirt attached to the sensor, is displayed in area 805. Furthermore, a message such as "Suspected reading defect" may be displayed to notify the user of the possibility of false detection by the readers 131 and 132.

[0111] Figure 11 shows another example of how error messages are displayed on the status display screen 800. Figure 11 shows how a defect notification is displayed as a pop-up. In Figure 11, a message box 806 pops up on the status display screen 800 when the "defect condition exceeds the threshold". The message box 806 has the title "Cleaning Required: Line Sensor" and the message 808 says "The line sensor is dirty. Please clean it if you are using image defect detection." The user can then understand that the line sensor needs to be cleaned.

[0112] Furthermore, the message box 806 has a procedure button 807, which allows the user to display specific cleaning procedures. For example, pressing the procedure button 807 will display a video demonstrating the cleaning procedure for the line sensor.

[0113] Furthermore, if an error message is pressed in area 805 of Figure 10, the message box shown in Figure 11 may pop up.

[0114] Furthermore, the inspection device 103 may notify the user's smartphone or wearable device (watch-type, glasses-type, neckband-type, etc.) of error messages via email, wireless communication, or other means.

[0115] <Threshold for whether or not to notify the user of a defect> Next, with reference to Figure 12, the method for setting thresholds for detecting defect states will be explained. Figure 12 is an example of the threshold setting screen 900 displayed by the inspection device 103. The threshold setting screen 900 has a threshold type selection field 901 and a threshold setting field 902. In the threshold type selection field 901, the user can select a threshold setting 901a for detecting contamination of the reading devices 131 and 132, and a threshold setting 901b for whether or not to notify the user to clean. In Figure 12, it is assumed that the threshold setting 901b for whether or not to notify the user has been selected. As a result, the items in the threshold setting field 902 switch, and the current settings for the threshold setting 901b for whether or not to notify the user are displayed.

[0116] The threshold setting section 902 displays a setting value field 911, a minus button 912, a plus button 913, and a slider 914 for each of the following items: number of defective areas 903, width of defective areas 904, length of defective areas 905, area of ​​defective areas 906, and brightness value of defective areas 907. Users can adjust the setting values ​​by moving the slider 914 or pressing the minus button 912 or plus button 913 using a mouse or touch panel. Users can also directly input numerical values ​​into the setting value field 911.

[0117] The threshold setting field 902 has an advanced settings button 908. The advanced settings button 908 is a button that displays an advanced settings screen 920 in which the defects to be detected are set during the defect detection process in the inspection exclusion area. The advanced settings screen 920 accepts settings for the types of defects that will be detected even in the inspection exclusion area.

[0118] Figure 13 shows the pop-up detailed settings screen 920. The detailed settings screen 920 has checkboxes 922 to 924 corresponding to "Detect vertical streaks," "Detect horizontal streaks," and "Detect dots," respectively. A "dot" is a point-like defect. The user can set the defects they want to detect within the inspection exclusion area. For example, if the user excludes "vertical streaks" from detection (does not check) and does not exclude "horizontal streaks" and "dots" (checks), the first defect discrimination processing unit 355 can ignore defects that are likely to occur due to dirt on the reading devices 131 and 132, such as vertical streaks, as reading streaks. On the other hand, defects that are different from reading streaks, such as "horizontal streaks" and "dots," which are likely to occur due to dirt on the reading devices 131 and 132, can be detected without being missed, even if they are defects within the inspection exclusion area.

[0119] <Screen Exclusion Area Settings> Figure 14 shows the inspection exclusion area setting screen 930 displayed by the inspection device 103. The inspection exclusion area setting screen 930 is displayed in step S606 of Figure 7.

[0120] The inspection exclusion area setting screen 930 displays the defect detection result 931. The defect detection result 931 is part or all of the image under inspection without paper feed. The detected defect is surrounded by a red frame 936. The inspection exclusion area is also set within this red frame 936 (for example, the red frame 936 becomes the inspection exclusion area). In Figure 14, the three streaky lines 937 represent defects (representing the defect location). Since there are defects in the image under inspection without paper feed, it is presumed that there are defects such as dirt in the reading devices 131 and 132.

[0121] The inspection exclusion area setting screen 930 also displays a cleaning recommendation message 932. The cleaning recommendation message 932 is, for example, "Please clean the reading area." If the answer is No in step S603 in Figure 7, this message will be displayed.

[0122] If the pre-configured manual adjustment of the inspection exclusion area is enabled, the inspection exclusion area setting field 933 is displayed. The inspection exclusion area setting field 933 is a setting field for the user to set inspection exclusion areas that will not be treated as defects even if defects are detected in the actual printing detection mode. The inspection exclusion area setting field 933 displays a button 934 for adjusting the width of the inspection exclusion area and an inspection exclusion area setting completion button 935. When the user adjusts the width of the inspection exclusion area by pressing button 934, the range of the red frame 936 also changes accordingly. That is, the red frame 936 surrounding the streak-like defect becomes narrower or wider in conjunction with the operation of button 934. When the user presses the inspection exclusion area setting completion button 935, the inspection exclusion area setting screen 930 is closed. The exclusion area setting unit 356 registers the range of the red frame 936 at the time of closing as the inspection exclusion area.

[0123] Furthermore, it would be beneficial if the user could configure the location and size of the exclusion area according to the paper settings. For example, the user could specify the exclusion area for each paper size, such as A4 or A3, and for each paper type, such as plain paper or coated paper. Since the area where an image is formed differs depending on the paper size and type, the user could set the area where no image is formed as the exclusion area according to the paper settings.

[0124] Furthermore, users may set inspection exclusion areas at any location, regardless of the detected defect location. For example, a user can drag the mouse pointer in defect detection result 931 to generate a rectangular frame. This rectangular frame becomes the inspection exclusion area.

[0125] Furthermore, the inspection exclusion area setting screen 930 has an inspection exclusion area setting acceptance field 941. The inspection exclusion area setting acceptance field 941 displays the message "Do you want to set this as an inspection exclusion area in the actual printing detection mode?" and a Yes button 942 and a No button 943. In steps S703 and S706 of Figure 9, if the Yes button 942 is pressed, it is determined to be Yes, and the inspection exclusion area is set.

[0126] <Screen showing areas excluded from inspection> Figure 15 shows the inspection exclusion area display screen 1000 displayed by the inspection device 103. The inspection exclusion area display screen 1000 is displayed in step S607 of Figure 7. That is, the inspection exclusion areas and defect locations set in S606 are displayed.

[0127] The inspection exclusion area display screen 1000 has a menu bar 1001 and an information display bar 1002. The menu bar 1001 displays options for the user to select the information to be displayed in the information display bar 1002. In Figure 15, inspection exclusion area information 1006 has been selected, so inspection exclusion area information 1006 is highlighted. In the information display bar 1002, inspection exclusion area information 1003 is displayed.

[0128] The horizontal direction of the inspection exclusion area information 1003 represents the main scanning direction, and the vertical direction of the inspection exclusion area information 1003 represents the sub-scanning direction. The width of the inspection exclusion area information 1003 is the total length of the line sensors, which are the reading devices 131 and 132, i.e., the reading width. In Figure 15, a portion of the sub-scanning direction is omitted, but the entire image under inspection generated in the no-paper-feed detection mode may be displayed. Alternatively, the display control unit 358 may scan for defects in the sub-scanning direction, and if there are defects in a different position in the main scanning direction, it may display the entire image under inspection, or a portion of the sub-scanning direction where the defects are located.

[0129] Furthermore, the inspection exclusion area information 1003 may be expandable or contractible. The inspection exclusion area 1004 may be color-coded, for example, according to the size or degree of the defect.

[0130] The inspection exclusion area information 1003 is displayed based on the defect discrimination information from step S601 in Figure 7, which was created in the no-paper-feed detection mode. In the example in Figure 15, inspection exclusion areas 1004 are detected at three locations in the main scanning direction. Each inspection exclusion area 1004 has a width, which is indicated by two lines.

[0131] Note that the inspection exclusion area display screen 1000 in Figure 15 may be displayed before the start of the print job. In this case, it may be possible to transition from the inspection exclusion area display screen 1000 to the inspection exclusion area setting screen 930 in Figure 14.

[0132] Figure 16 is an enlarged view of one inspection exclusion area 1004. A reading streak 1005 is located in the center of the inspection exclusion area 1004. The reading streak 1005 is the location of a defect in the main scanning direction. The inspection exclusion area 1004 is the area enclosed by two straight lines that are equidistant from the reading streak 1005 to the right and left. This distance is preset, but may be adjustable by the user. The display control unit 358 displays at least one of the reading streak 1005 (defect location) and the inspection exclusion area 1004.

[0133] Users can check the location of the exclusion area 1004 and determine whether it overlaps with the image in the print data. This allows for a more reliable determination of whether cleaning is necessary, reducing downtime due to cleaning.

[0134] Furthermore, as shown in Figures 17 and 18, the printing system 100 may grant the authority to display the inspection exclusion area information 1003 only to the administrator. Figure 17 is the inspection exclusion area display screen 1000 with the same configuration as Figure 15, but the permissions of the logged-in user are displayed in the upper right corner. That is, in Figure 17, the equipment administrator has logged into the printing system 100, so equipment administrator 1007 is displayed as the logged-in user's permission. Since equipment administrator 1007 has the authority to display the inspection exclusion area information 1003, the inspection exclusion area display screen 1000 with the same configuration as Figure 15 is displayed.

[0135] On the other hand, in Figure 18, a general operator 1008 is logged into the printing system 100. In Figure 18, operator 1008 is displayed as the user with the necessary privileges. Therefore, the exclusion area information 1006 is not displayed in the menu bar 1001 of the exclusion area display screen 1000 in Figure 18. The exclusion area information 1006 could be displayed, but for example, it is not selectable. Because the exclusion area information 1006 is not available, operator 1008 cannot display the exclusion area information 1003.

[0136] In this way, by switching whether or not the inspection exclusion area information 1003 can be displayed based on the user's permissions, unnecessary information can be prevented from being shown to the operator. This is because even when the cleaning prompt message, as explained in Figure 10, is not displayed, the user can still view the inspection exclusion area information 1003. If a user who is not familiar with the functions of the printing system 100, or a user whose job it is to clean in response to a cleaning prompt message, sees this inspection exclusion area information 1003, they may mistake it for an abnormality or perform unnecessary cleaning. By restricting the permissions to display the inspection exclusion area information 1003, such problems can be avoided.

[0137] Furthermore, the person authorized to display the inspection exclusion area information 1003 may be changed by, for example, the equipment administrator through settings, or individual operators may be given the authority to display the inspection exclusion area information 1003.

[0138] <<Example of displaying exclusion area information>> Figure 19 shows another example of displaying inspection exclusion area information. In Figure 19, the information display area 1002 simultaneously displays past inspection exclusion area information 1101 and the latest inspection exclusion area information 1102. This allows the user who performed the cleaning to confirm whether or not the dirt in the area they wanted to remove has been removed. In the example in Figure 19, it can be confirmed that one exclusion area 1106 (reading streak) has been removed by cleaning.

[0139] The past exclusion area information 1101 and the latest exclusion area information 1102 are displayed with corresponding dates and times 1103 and 1104, respectively, indicating when the exclusion area information 1101 and 1102 were set. The dates and times 1103 and 1104 indicate when the exclusion area information 1101, which is being compared with the latest exclusion area information 1102, was set.

[0140] To achieve this display, the exclusion area setting unit 356 stores the date and time of past inspections and the information of areas excluded from inspection in the storage unit 351. In this way, the storage unit 351 stores a history of the information of areas excluded from inspection.

[0141] Additionally, a pull-down button 1105 is displayed at date and time 1103. When the user presses the pull-down button 1105, a list of dates and times of inspection exclusion area information stored in the memory unit 351 is displayed. The user can check any past exclusion area information by selecting a date and time. If the date and time the user inspected the image under inspection in actual printing detection mode is known, the inspection exclusion area information that was set at that date and time can be checked.

[0142] Figure 20 shows another example of how the inspection exclusion area information is displayed, specifically an example that includes the paper position. In explaining Figure 20, we will mainly explain the differences from Figure 19. First, the width of the inspection exclusion area information 1201 represents the total length of the line sensors, which are the reading devices 131 and 132. In Figure 20, the area where the printed material overlaps with the line sensors when the line sensors read the actual printed material is shown as the paper position 1202. That is, the paper position 1202 is displayed as the area of ​​the width of the inspection exclusion area information 1201 that overlaps with the printed material.

[0143] In addition, the paper size 1203 is displayed along with the paper position 1202. This allows the user to determine whether the paper size 1203 of the printed document and its paper position 1202 overlap with the exclusion areas 1205 and 1206, enabling them to quickly and reliably determine whether it will have an impact on them. This makes it possible to more reliably determine whether cleaning is necessary and reduces downtime due to cleaning.

[0144] Figure 20 also displays the tray name 1207 and the pull-down button 1208. When the user presses the pull-down button 1208, a list of the tray names installed in the printer 101 and the paper sizes contained in each tray are displayed. When the user selects a tray name from the list of tray names, the paper position 1202 and paper size 1203 switch to those of the selected paper size.

[0145] The tray names and paper sizes contained in each tray may be obtained by the external I / F control unit 304 from the printer 101, or they may be stored in the storage unit 305.

[0146] Figure 21 shows another example of displaying inspection exclusion area information, specifically an example with a scale 1302 representing dimensions. In Figure 21, the display control unit 358 uses the center of the inspection exclusion area information 1301 in the width direction as the reference point 1305 (zero point), and represents the distance from the reference point 1305 using the scale 1302. Note that the left side represents negative dimensions, and the right side represents positive dimensions (the positive and negative can be reversed). This scale 1302 corresponds to the dimensions of the line sensor as well as the paper size. The scale 1302 may be in inches or millimeters only.

[0147] Since the locations of inspection exclusion areas 1303 and 1304 are represented by numerical values ​​(scale 1302), the location of defects can be determined more quantitatively. For example, since A4 size is 210mm x 297mm, it is possible to quantitatively determine whether inspection exclusion areas 1303 and 1304 are within 210 / 2 or 297 / 2 from the reference point 1305. Therefore, it is possible to quickly and reliably determine whether or not it will have an impact on the user. It becomes possible to more reliably determine whether or not cleaning work is necessary, and downtime due to cleaning can be reduced.

[0148] In Figure 21, the reference point 1305 of scale 1302 is set as the center of the line sensor, but the left or right edge of the line sensor may also be used as the reference point.

[0149] <Simultaneous display of the image under examination and information on areas excluded from examination> Figure 22 shows an example of a display that shows the image under inspection 1402 generated in the actual printing detection mode and the inspection exclusion area information 1401 on a single screen. Users may want to check past images under inspection and the inspection exclusion areas that were set when the images under inspection were inspected. In this case, the display control unit 358 receives a specification of a past image under inspection from the user and retrieves the past image under inspection and the date and time the inspection was performed from the storage unit 351. The date and time the inspection was performed may be the timestamp of the file storing the image under inspection, or the image under inspection may be stored in association with a date and time (for example, when the print job was executed).

[0150] The display control unit 358 retrieves the exclusion area information set for the date and time the image under inspection was inspected from the storage unit 351. For example, if the image under inspection was inspected on March 5th, and the exclusion area information for March 4th and March 6th is stored in the storage unit 351, the exclusion area information for March 4th is the exclusion area information set at the time the image under inspection was inspected. The display control unit 358 displays the past image under inspection and the exclusion area information on a single screen.

[0151] In Figure 22(a), the display control unit 358 aligns the main scanning direction of the exclusion area information 1401 with the main scanning direction of the image under inspection 1402, and displays the exclusion area information 1401 and the image under inspection 1402 adjacent to each other. The user can determine whether or not there is a pattern in the area extended in the sub-scanning direction from the exclusion areas 1401a to 1401c.

[0152] The exclusion area display button 1403 is a button used to toggle the display of the inspection exclusion area information 1401 on and off.

[0153] In Figure 22(b), the inspection exclusion region 1405 is displayed superimposed on the image under inspection 1402. The inspection exclusion region 1405 is the area extended from the inspection exclusion region 1401b in the sub-scan direction. The defect location may be displayed instead of, or together with, the inspection exclusion region 1405.

[0154] In this way, by overlaying the exclusion area 1405 onto the image 1402 under inspection, the user can determine whether the exclusion area 1405 overlaps with the image. Therefore, the user can quickly and reliably determine whether or not it will have an impact. This makes it possible to more reliably determine whether or not cleaning work is necessary, and reduces downtime due to cleaning.

[0155] The exclusion area display button 1404 is used to toggle the display of the inspection exclusion area 1405. When hidden, the inspection exclusion area 1405 is removed, making it easier for the user to check the quality of the image under inspection 1402. For example, it can be used to check whether the print quality of the inspection exclusion area 1405 has actually deteriorated.

[0156] <User settings for areas excluded from inspection> The inspection device 103 has a function that allows users to arbitrarily set exclusion areas for each print job and paper size. Users can set areas without images as exclusion areas, or variable areas where the areas without images change depending on the print job as exclusion areas.

[0157] The exclusion area setting unit 356 stores in the storage unit 351 that the system has been set to the no-paper-feed detection mode, associating it with the inspection exclusion area information, and also stores in the storage unit 351 that the system has been arbitrarily set, associating it with the inspection exclusion area.

[0158] Figure 23 shows an example of the display of an arbitrarily set inspection exclusion area 1406. As shown in Figure 23, when the display control unit 358 checks the inspection exclusion area 1405, it displays the arbitrarily set inspection exclusion area 1406 and the inspection exclusion area 1405 set by the no-paper-feed detection mode in different colors. In Figure 23, the area without a pattern in the sub-scanning direction is set as the inspection exclusion area 1406. This makes it easier for the user to distinguish between the inspection exclusion area 1405 due to defects and the arbitrarily set inspection exclusion area 1406.

[0159] <Main effects> In this embodiment, the user can check the inspection exclusion area set in the no-paper-feed detection mode via the screen, allowing for a quick and reliable determination of whether or not it will affect the user. Therefore, it becomes possible to more reliably determine whether or not cleaning is necessary, and downtime due to cleaning can be reduced.

[0160] <Other application examples> Although the best mode for carrying out the present invention has been described above using embodiments, the present invention is not limited in any way to these embodiments, and various modifications and substitutions can be made without departing from the spirit of the present invention.

[0161] Furthermore, the configuration examples shown in Figure 5 and other figures are divided according to their main functions to facilitate understanding of the processing performed by the inspection device 103. The present invention is not limited by the way the processing units are divided or their names. The processing of the inspection device 103 can be further divided into many more processing units depending on the processing content. Also, one processing unit can be further divided to include many more processes.

[0162] Furthermore, the printer 101 does not need to print using an electrophotographic method; any printer capable of printing using inkjet, thermal transfer, letterpress, lithographic, intaglio, or stencil printing methods is acceptable.

[0163] Furthermore, the inspection device 103 and the printer 101 may be separate units. The user has the inspection device 103 read the printed material, and the inspection exclusion areas determined by the inspection device 103 are saved on the user's own device.

[0164] Furthermore, the printing system 100 is not limited to commercial printing; it may also be used in offices, factories, homes, convenience stores, and other similar locations.

[0165] Alternatively, the processing performed by the inspection device 103 described in this embodiment may be performed by a server device connected via a network. The inspection device 103 transmits the image to be inspected to the server device, and the server device transmits the inspection results to the inspection device 103. The inspection device 103 accepts the setting of areas to be excluded from inspection and registers it with itself or the server device.

[0166] Furthermore, defect detection may be performed by a model generated through the learning effect of machine learning. Here, machine learning is a technique for enabling computers to acquire human-like learning abilities, in which a computer autonomously generates algorithms necessary for judgments such as data identification from pre-incorporated training data, and applies these algorithms to new data to make predictions. The learning method for machine learning may be supervised learning, unsupervised learning, semi-supervised learning, reinforcement learning, or deep learning, or a combination of these learning methods; the learning method for machine learning is not restricted.

[0167] Each of the functions of the embodiments described above can be realized by one or more processing circuits. Hereinafter, "processing circuit" as used herein includes processors programmed to execute each function by software, such as processors implemented by electronic circuits, as well as devices such as ASICs (Application Specific Integrated Circuits), DSPs (Digital Signal Processors), FPGAs (Field Programmable Gate Arrays), and conventional circuit modules designed to execute each of the functions described above.

[0168] <Mode> [Claim 1] A print image reading unit reads a printed document from a printing device and generates a first image to be inspected, A first defect determination processing unit that determines defects in the printed material based on a master image generated from the print data of the printed material and the first image to be inspected, A second defect discrimination processing unit that detects the location of defects in the second image under inspection generated by the reading unit without paper feeding, An exclusion area setting unit sets an inspection exclusion area in which the first defect determination processing unit does not detect defects, based on the defect location detected by the second defect determination processing unit. A display control unit that displays at least one of the defect location in the second image under inspection, or the inspection exclusion area, An image forming apparatus characterized by having the following features. [Claim 2] The exclusion area setting unit has a storage unit that stores at least one of the inspection exclusion areas or defect locations set in the past, and the set date and time. The display control unit uses the past inspection exclusion area or defect location stored in the storage unit and the date and time to determine the date and time. The latest inspection exclusion area or defect location set by the exclusion area setting unit is displayed simultaneously with the following: The image forming apparatus according to claim 1. [Claim 3] The display control unit displays at least one of the inspection exclusion area or the defect location in correspondence with the main scanning direction. The paper position of the paper on which the first image to be inspected is formed is displayed, along with at least one of the inspection exclusion area or the defect location. The image forming apparatus according to claim 1 or 2. [Claim 4] The display control unit displays at least one of the inspection exclusion area or the defect location in correspondence with the main scanning direction. The scale for the dimensions in the main scanning direction is displayed in correspondence with the main scanning direction, along with at least one of the inspection exclusion area or the defect location. An image forming apparatus according to any one of claims 1 to 3. [Claim 5] The display control unit, according to the permissions of the user identified through login, Switching between displaying and hiding at least one of the inspection exclusion area or the defect location, An image forming apparatus according to any one of claims 1 to 4. [Claim 6] The memory unit stores the date and time the first image under inspection was inspected and the first image under inspection. When the display control unit displays the first image to be inspected, which was received at the user's request, it displays at least one of the past inspection exclusion areas or defect locations that were set at the date and time the first image to be inspected was set. The image forming apparatus according to claim 2. [Claim 7] The display control unit superimposes on the first image under inspection the past inspection exclusion areas or defect locations that were set for the first image under inspection at the set date and time. The image forming apparatus according to claim 6. [Claim 8] The exclusion area setting unit receives the setting of the inspection exclusion area arbitrarily set by the user, When the display control unit overlays the previously excluded inspection area onto the first image under inspection, it displays the arbitrarily set excluded inspection area and the previously excluded inspection area in different colors. The image forming apparatus according to claim 7. [Claim 9] The second defect detection processing unit detects the defect location of the second inspected image generated by the reading unit without paper feeding, The process by which the exclusion area setting unit sets the defect location detected by the second defect discrimination processing unit to the inspection exclusion area is as follows: The following actions are performed when the image forming apparatus is powered on, when it returns to a power-saving state, when a print job is completed, or when a predetermined cover of the image forming apparatus is closed: The image forming apparatus according to any one of claims 1 to 8. [Explanation of Symbols]

[0169] 101 Printer 103 Inspection device 104 Stacker 131,132 Reading device [Prior art documents] [Patent Documents]

[0170] [Patent Document 1] Patent No. 3853583< / dfe>

Claims

1. A print image reading unit reads a printed document from a printing device and generates a first image to be inspected, A first defect determination processing unit that determines defects in the printed material based on a master image generated from the print data of the printed material and the first image to be inspected, A second defect discrimination processing unit that detects the location of defects in the second image under inspection generated by the reading unit without paper feeding, An exclusion area setting unit sets an inspection exclusion area in which the first defect determination processing unit does not detect defects, based on the defect location detected by the second defect determination processing unit. A display control unit that displays at least one of the defect location in the second image under inspection, or the inspection exclusion area, An image forming apparatus characterized by having the following features.

2. The exclusion area setting unit has a storage unit that stores at least one of the inspection exclusion areas or defect locations set in the past, and the set date and time. The display control unit uses the past inspection exclusion area or defect location stored in the storage unit and the date and time to determine the date and time. The latest inspection exclusion area or defect location set by the exclusion area setting unit is displayed simultaneously with the following: The image forming apparatus according to claim 1.

3. The display control unit displays at least one of the inspection exclusion area or the defect location in correspondence with the main scanning direction. The paper position of the paper on which the first image to be inspected is formed is displayed, along with at least one of the inspection exclusion area or the defect location. The image forming apparatus according to claim 1 or 2.

4. The display control unit displays at least one of the inspection exclusion area or the defect location in correspondence with the main scanning direction. The scale for the dimensions in the main scanning direction is displayed in correspondence with the main scanning direction, along with at least one of the inspection exclusion area or the defect location. The image forming apparatus according to claim 1.

5. The display control unit, according to the permissions of the user identified through login, Switching between displaying and hiding at least one of the inspection exclusion area or the defect location, The image forming apparatus according to claim 1.

6. The storage unit stores the date and time the first image under inspection was inspected and the first image under inspection. When the display control unit displays the first image to be inspected, which was received at the user's request, it displays at least one of the past inspection exclusion areas or defect locations that were set at the date and time the first image to be inspected was set. The image forming apparatus according to claim 2.

7. The display control unit superimposes on the first image under inspection the past inspection exclusion areas or defect locations that were set for the first image under inspection at the set date and time. The image forming apparatus according to claim 6.

8. The exclusion area setting unit receives the setting of the inspection exclusion area arbitrarily set by the user, When the display control unit overlays the previously excluded inspection area onto the first image under inspection, it displays the arbitrarily set excluded inspection area and the previously excluded inspection area in different colors. The image forming apparatus according to claim 7.

9. The second defect detection processing unit detects the defect location of the second inspected image generated by the reading unit without paper feeding, The process by which the exclusion area setting unit sets the defect location detected by the second defect discrimination processing unit to the inspection exclusion area is as follows: The following actions are performed when the power of the image forming apparatus is turned ON, when it returns to an energy-saving state, when a print job is completed, or when a predetermined cover of the image forming apparatus is closed: The image forming apparatus according to claim 1.

10. A print image reading unit reads a printed document from a printing device and generates a first image to be inspected, A first defect determination processing unit that determines defects in the printed material based on a master image generated from the print data of the printed material and the first image to be inspected, A second defect discrimination processing unit that detects the location of defects in the second image under inspection generated by the reading unit without paper feeding, An exclusion area setting unit sets an inspection exclusion area in which the first defect determination processing unit does not detect defects, based on the defect location detected by the second defect determination processing unit. A display control unit that displays at least one of the defect location in the second image under inspection, or the inspection exclusion area, An image forming system characterized by having the following features.

11. The print image reading unit reads the printed material from the printing device using the reading unit and generates a first image to be inspected. The first defect detection processing unit performs a process to determine defects in the printed material based on the master image generated from the print data of the printed material and the first image to be inspected. The second defect detection processing unit performs a process to detect the defect location of the second inspected image generated by the reading unit without paper feeding, The exclusion area setting unit performs the process of setting an inspection exclusion area in which the first defect determination processing unit does not detect defects, based on the defect location detected by the second defect determination processing unit. The display control unit performs a process to display at least one of the defect location in the second image under inspection, or the area excluded from inspection. An inspection method characterized by performing the following.

12. Image forming apparatus, A print image reading unit reads a printed document from a printing device and generates a first image to be inspected, A first defect determination processing unit that determines defects in the printed material based on a master image generated from the print data of the printed material and the first image to be inspected, A second defect discrimination processing unit that detects the location of defects in the second image under inspection generated by the reading unit without paper feeding, An exclusion area setting unit sets an inspection exclusion area in which the first defect determination processing unit does not detect defects, based on the defect location detected by the second defect determination processing unit. A display control unit that displays at least one of the defect location in the second image under inspection, or the area excluded from inspection. A program designed to function as such.

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