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

Abstract

To provide a technique for reducing cleaning frequencies so as to eliminate defects caused by a reading section.SOLUTION: An image forming apparatus includes: a printed image reading section which reads printed matter printed by a printer by a reading section and generates a first image to be inspected; a first defect discrimination processing section which determines a defect of the printed matter on the basis of a master image generated from printing data of the printed matter and the first image to be inspected; a second defect discrimination processing section which detects a defect and a defect state of a second image to be inspected which is generated by the reading section without passing sheets; an exclusion region setting section which sets the defect portion detected by the second defect discrimination processing section to an inspection exclusion region where the first defect discrimination processing section does not detect a defect; and a user I / F section for notifying a user when the defect state exceeds a threshold.SELECTED DRAWING: Figure 6

Description

[Technical field]

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

[0002] There is known a printing system having a printing device that forms an image on paper based on print data, and an inspection device that reads this image with a reading unit and compares it with a master image generated from the original print data. The inspection device can evaluate the print quality based on the comparison result. To properly evaluate the print quality, it is preferable that the reading unit is free of defects such as dirt.

[0003] There is known a technology for detecting defects caused by a reading unit (see, for example, Patent Document 1). Patent Document 1 discloses a technology that reads only the image of dirt on the contact glass by reading the blank area of ​​a printed document, distinguishes whether the source of the detected dirt is a white reference board or the contact glass, and displays the location of the dirt and instructions for cleaning on the operation unit. Summary of the Invention [Problem to be solved by the invention]

[0004] However, the conventional technology has a problem in that the user needs to clean the reading unit in order to eliminate defects caused by the reading unit. That is, when it is determined that the dirt is on the contact glass or the white reference plate, the user needs to clean the contact glass or the white reference plate in any case.

[0005] In view of the above-mentioned problems, the present invention provides a technique for reducing the frequency of cleaning to eliminate defects caused by a reading unit. [Means for solving the problem]

[0006] In view of the above problems, the present invention is characterized by having a printed image reading unit that reads a printed matter printed by a printing device using a reading unit and generates a first inspection image; a first defect discrimination processing unit that judges defects in the printed matter based on a master image generated from printing data of the printed matter and the first inspection image; a second defect discrimination processing unit that detects defects and defective states in a second inspection image generated by the reading unit without paper passing; an exclusion area setting unit that sets defective locations detected by the second defect discrimination processing unit to an inspection exclusion area in which the first defect discrimination processing unit does not detect defects; and a user I / F unit that notifies a user when the defect state exceeds a threshold value. Effect of the Invention

[0007] The present invention can provide a technique for reducing the frequency of cleaning to eliminate defects caused by the reading unit. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of a schematic system configuration of a printing system. [Diagram 2] 1 is a functional block diagram of a DFE. FIG. [Diagram 3] FIG. 2 is an example of a functional block diagram illustrating functions of a printer. [Figure 4] FIG. 2 is an example of a functional block diagram illustrating functions of an inspection device divided into blocks. [Diagram 5] FIG. 4 illustrates an example of job management information. [Figure 6] FIG. 13 is a flowchart illustrating an example of a flow after a defect detection process in a no-paper-passing detection mode. [Figure 7] FIG. 11 is a diagram showing examples of items that are determined to be in a defective state. [Figure 8] FIG. 13 is a flowchart illustrating an example of a process for registering an inspection exclusion region. [Figure 9] FIG. 13 is a diagram showing an example of a status display screen displayed by the inspection device. [Figure 10]FIG. 13 is a diagram showing another example of an error message displayed on the status display screen. [Figure 11] FIG. 13 is a diagram showing an example of a threshold setting screen displayed by the inspection device. [Figure 12] FIG. 13 is a diagram showing an example of a detailed setting screen displayed as a pop-up. [Figure 13] FIG. 13 is a diagram showing an example of an inspection exclusion region setting screen displayed by the inspection device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An inspection device and an inspection method performed by the inspection device will be described below with reference to the drawings as an example of an embodiment of the present invention.

[0010] <Processing Overview> The printing system of this embodiment reads an actual printed matter with a reading unit to generate an inspection image (an example of a first inspection image), and compares it with a master image generated from the original print data formed on the printed matter, thereby making it possible to determine whether the printed matter has been output with the expected quality. When a difference of a certain amount or more occurs between the inspection image and the master image (defective), there is either a problem with the printing process or a defect such as dirt on the reading unit. However, since the user is uncertain as to whether the detected defect is caused by the printing process or dirt on the reading unit, there are cases where the user is forced to clean the reading unit, which may reduce the productivity of printed matter. When a defect is detected, the printing system needs to distinguish whether the cause of the defect is due to reading or printing in order to present the user with an appropriate maintenance method.

[0011] Therefore, the printing system of this embodiment first detects defects in the reading unit without reading an actual document (hereinafter, referred to as no paper passing), and sets the area in which a defect is detected as an inspection excluded area.

[0012] 1. The printing system generates an inspection image (an example of a second inspection image) without paper passing. The inspection image without paper passing is an image generated by the reading unit reading a predetermined reference surface, and if there are no defects such as dirt, the image will be a uniform image with almost all white or black pixels.

[0013] 2. The printing system detects defects from the inspection image without paper feed.

[0014] 3. The printing system sets defects detected from the inspection image without paper passing in the inspection area. Alternatively, the user can set the inspection exclusion area based on the detected defects. If a defect detected during the inspection of a printed material with paper passing falls within the inspection exclusion area, the printing system will not detect it as a defect. Furthermore, the user can set the system to display defects within the inspection exclusion area as "suspected read failure defects."

[0015] On the other hand, if the amount of dirt adhering to the reading section increases, the inspection excluded area will also increase, and if there are defects in the inspection excluded area that are not caused by the reading section, the risk of missing them increases (if the inspection excluded area is set and the user is not notified).

[0016] In addition, if defects in the inspection excluded area are displayed as "suspected read failure defects," the user will be required to frequently check whether the defect is caused by the reading section and perform cleaning (if a suspected defect caused by the reading section is notified to the user).

[0017] Therefore, in this embodiment, in addition to setting an inspection excluded area, if the defect state exceeds a threshold in the no-paper-passing detection mode, the user is notified and prompted to perform cleaning. This makes it possible to prevent the inspection excluded area from increasing and the risk of overlooking defects from increasing too much in the actual printing detection mode. In addition, it is possible to minimize the user's confirmation and cleaning work (to a degree that does not increase the risk of overlooking defects too much) and to prevent false detections due to reading streaks detected in the inspection excluded area.

[0018] <Terminology> The inspection image is an image used to inspect the print quality, and is generated by optically reading the image using a reading unit. There are two types of inspection images: one generated by reading a printed matter, and the other generated by reading a reference surface without passing a paper through the inspection image.

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

[0020] A defect is a location that does not meet the print quality standard or a failure to meet the standard. There are two types of defects: defects that occur in the test image of the printed matter, and defects that occur in the test image when the reference surface is read without paper passing. In the former case, the print quality has decreased, and this may be due to a malfunction in the printing process or dirt on the reading part. In the latter case, dirt may have occurred on the reading part.

[0021] The inspection excluded area is an area in which, even if a defect is detected in a printed product inspected during execution of a print job, the defect is treated as not being detected.

[0022] The defect status is a status of the defect detected by the inspection, which is indicated by some scale, such as the number of defects, the width of one defect, the length of a defect, the area of ​​a defect, or the brightness value of a defect.

[0023] <System configuration example> Fig. 1 shows a schematic system configuration diagram of a printing system 100. The system configuration in Fig. 1 is just an example, and any configuration capable of performing the defect detection described in this embodiment may be used.

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

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

[0026] The printer 101 receives a print job including an RIP image from an external device such as a DFE (Digital Front End) or a PC (Personal Computer) described later, or receives an instruction to execute a print job stored in the printer 101. In this embodiment, as an example, the RIP image is 8 bit 600 dpi for each of CMYK.

[0027] The printer 101 obtains paper from the paper feed unit 105 according to the contents of the print job instructed to be executed, and conveys the paper along the path indicated by the dotted line in the figure. The printer 101 forms an image on the paper using drums 113, 114, 115, and 116. The drums 113, 114, 115, and 116 respectively superimpose K (black), C (cyan), M (magenta), and Y (yellow) toner images on the belt 111, transfer the color toner images to the paper conveyed to the roller 112, and fix the toner images on the paper by heat and pressure using roller 117. In the case of single-sided printing, the paper is directly discharged to the inspection device 103. In the case of double-sided printing, the paper is reversed by a reversing path 118 and conveyed to the roller 112, where the color toner images are transferred and fixed to the other side of the paper by the drums 113, 114, 115, and 116, and then discharged to the inspection device 103.

[0028] The inspection device 103 is a device that inspects the print quality of a printout output by the printer 101. The inspection device 103 has an operation unit 133 of the inspection device 103. The function of the operation unit 133 may be the same as that of the operation unit 102. The inspection device 103 does not need to have the operation unit 133, and the operation unit 102 of the printer body may also serve as this unit. The operation unit 133 of the inspection device 103 may also be a PC connected via a LAN or the like. In this case, the PC displays the inspection results using, for example, a web browser or a dedicated app.

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

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

[0031] <dfe> The DFE 150 will be described with reference to Fig. 2. The DFE 150 is a general term for a device that processes data to be input to a printer. The DFE 150 creates RIP data (raster data) to be printed by the printer 101 from print data such as PostScript data.

[0032] Fig. 2 is an example of a functional block diagram of the DFE 150. The printer 101 in Fig. 1 and a DFE panel 151 for displaying a user interface are connected to the DFE 150. The DFE panel 151 is a user interface having a display (touch panel) and a keyboard.

[0033] The DFE 150 has a system control unit 501, a network I / F unit 502, a user I / F unit 505, a storage unit 503, and a printer I / F unit 504. Each functional unit of the DFE 150 is a function or means realized by the CPU executing instructions included in one or more programs installed in the DFE 150.

[0034] A user I / F unit 505 included in the DFE 150 generates a screen to be displayed on the DFE panel 151 using the UI display information, and displays it on the DFE panel 151. The UI display information includes a plurality of display components that configure the screen and their layout.

[0035] A network I / F unit 502 included in the DFE 150 is a communication interface that connects the DFE 150 to a LAN. The network I / F unit 502 receives a print job from the LAN and transmits it to the system control unit 501.

[0036] Furthermore, a print job may be stored in storage unit 503, and system control unit 501 may acquire the print job from storage unit 503. That is, system control unit 501 may receive the print job via network I, or may acquire the print job from storage unit 503.

[0037] The DFE 150 includes a system control unit 501. The system control unit 501 controls the entire DFE 150. The system control unit 501 includes a job information processing unit 551, a RIP processing unit 552, a storage unit 553, and a tone correction data generating unit 554.

[0038] The job information processing unit 551 manages the status of the print job, input to the printer 101, progress of the print job (acquired from the printer 101), etc., as job management information related to the print job in the storage unit 553. The job information processing unit 551 combines the job management information and RIP image data to input the print job data to the printer 101. 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 generating unit 554 adjusts the print data so that it is printed with the same gradation, density, and color as the original. For example, the gradation correction data generating unit 554 increases or decreases the gradation, increases or decreases the density, or increases or decreases the warm colors or blue colors.

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

[0041] Furthermore, a printer I / F unit 504 included in the DFE 150 is an interface for communicating with the printer 101. The printer I / F unit 504 transmits to the printer 101 print job data that the system control unit 501 has decided to input.

[0042] <About the printer functions> 3 is a functional block diagram explaining the functions of the printer 101. The printer 101 has 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 the printer 101 is a function or means realized by the CPU executing commands included in one or more programs installed in the printer 101.

[0043] The system control unit 201 controls the entire printer 101. The system control unit 201 is connected to 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.

[0044] The user I / F unit 202 is an interface for connecting the system control unit 201 and the operation unit 102 shown in FIG.

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

[0046] A network I / F unit 203 is an interface for connecting the system control unit 201 to a network such as a LAN and for the printer 101 to communicate with devices on the network.

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

[0048] The storage unit 205 is a storage unit realized by a hard disk drive (HDD), a solid state drive (SSD), etc. The storage unit 205 stores, for example, print job data.

[0049] A mechanism control unit 206 controls each mechanism within the printer 101, such as paper transport within the printer 101, the transfer process, and double-sided / 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 performs overall control of image formation on paper. The image processing control unit 208 processes the image transferred by the mechanism control unit 206.

[0051] The system control unit 201 has a memory 251, a job processing unit 252, a RIP processing unit 253, and a job information generating unit 254. The memory 251 is a working memory for the system control unit 201. When the job information generating unit 254 receives print job data from the DFE 150, it generates a job ID in the printer, the reception date and time, progress, and the like, and stores them in the storage unit 205. When the print job has not been RIP-processed, the RIP processing unit 253 performs RIP processing on the print data. The job processing unit 252 inquires of the printing control unit 209 about the availability of print jobs, and determines the print job to be executed from among the print job data stored in the storage unit 205 according to the priority and the like.

[0052] <Inspection equipment functions> 4 is a functional block diagram explaining the functions of the inspection device 103 by dividing them into blocks. The inspection device 103 has 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 a CPU executing instructions included in one or more programs installed in the inspection device 103.

[0053] The system control unit 301 controls the entire inspection device 103. A master image generating unit 308, a differential image generating 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 are connected to the system control unit 301.

[0054] 1. The user I / F unit 302 displays information of the system control unit 301 on the operation unit 133. When a defect detected in the actual print inspection mode coincides with an area excluded from inspection, the user I / F unit 302 displays the defect as a suspected read error defect, distinguishing it from normal defects.

[0055] The network I / F unit 303 is an interface for connecting the system control unit 301 to a network such as a LAN.

[0056] The external I / F control unit 304 is an interface with other devices (for example, the printer 101, the stacker 104, etc.).

[0057] A 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 discharge.

[0058] The storage unit 305 is a storage means realized by an HDD, an SSD, etc. For example, the storage unit 305 stores an inspection image, a difference image, a master image, an inspection result, etc. The storage unit 305 also stores an inspection excluded region.

[0059] The printed image reading unit 307 reads both sides of the paper conveyed from the printer 101 using the reading devices 131, 132, and outputs an image to be inspected. The printed image reading unit 307 generates an image to be inspected in either an actual printing detection mode or a no-paper-passing detection mode, which will be described later. The actual printing detection mode is a mode in which a printed matter is inspected while a print job is being executed, and the no-paper-passing detection mode is a mode in which defects in the reading devices 131, 132 are detected before execution of the print job is started.

[0060] In the detection-during-actual-printing mode, the master image generating unit 308 generates a master image from the RIP image transmitted by the DFE 150. This RIP image is generated from print data to be formed on paper.

[0061] The difference image generating unit 309 generates a difference image between the master image and the inspection target image in the actual printing detection mode. The difference image is an image that represents the difference in pixel value for each pixel between the master image and the inspection target image. The RIP image is generated from print data formed on paper, and the inspection target image is a scanned printout, so if normal, the pixel value of the difference image will be less than the threshold value.

[0062] The system control unit 301 includes a storage unit 351 , a job management data processing unit 352 , a first defect discrimination processing unit 355 , a second defect discrimination processing unit 357 , and an exclusion area setting unit 356 .

[0063] In the actual printing detection mode, the system control unit 301 receives the 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 in the system control unit 301. The job management data processing unit 352 extracts the post-processing machine information from the job management information shown in FIG. 5 and transmits it via the external I / F control unit 304 to the stacker 104, which is the post-processing device downstream of the inspection device 103. The job management data processing unit 352 reads out the print management information from the storage unit 351. The job management data processing unit 352 transfers the print management information to the master image generating unit 308, the difference image generating unit 309, the print image reading unit 307, and the mechanism control unit 306 so that they can process the print job. The transferred print management information is the job management information shown in FIG. 5 excluding the post-processing machine information.

[0064] In the actual printing detection mode, the system control unit 301 stores the inspection image 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, where the intensity is greater than the defect discrimination threshold. The detected edge may have any shape, such as a point or a line.

[0065] Furthermore, in the no-paper-passing detection mode, the system control unit 301 stores the inspection image 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 inspection image using a preset defect discrimination threshold value. If the inspection image in the no-paper-passing detection mode has no defects such as stains, it will be a uniform image with almost all white or black pixels. Furthermore, the master image is an image with all white or black pixels. Alternatively, there may be no master image. The second defect discrimination processing unit 357 performs edge detection on the inspection image with an intensity greater than the threshold value. The detected edge may be of any shape, such as a point or a line.

[0066] The exclusion area setting unit 356 excludes a defective portion detected by the second defect discrimination processing unit 357 or a defective portion set by the user from an area in which defects are detected by the first defect discrimination processing unit 355. In other words, the exclusion area setting unit 356 sets an inspection exclusion area in which the first defect discrimination processing unit 355 does not detect defects, so as to include the defective portion detected by the second defect discrimination processing unit 357.

[0067] 5 shows an example of job management information. This job management information is for when the printer 101 performs normal print processing (detection during actual printing mode). During print processing, print data is generated for each page by at least one of the DFE 150 and the printer 101. The print job is processed based on the job management information.

[0068] The job management information has the fields of parameter, remarks, and initial value. The parameter is the item name, the remarks is an explanation of the parameter, and the initial value indicates the value when the system control unit 201 of the printer 101 receives it.

[0069] The job creation source is information that indicates the job output source, and includes information on whether the job is a print job input from the DFE 150 or internal data of the printer 101.

[0070] The creation time is information about the date and time when the job creator created the job information.

[0071] The page ID is an identification number for a print page. The page ID is incremented by 1 for each page processed after the power is turned on. A numeric value is set for the page ID when printing is performed.

[0072] The print side identifies whether the print job is single-sided, double-sided, with the front side printed (duplex front), or the back side printed (duplex back).

[0073] The paper ID is identification information for the paper used for printing. In the case of double-sided printing, the page IDs printed on the same paper will have the same paper ID. The paper ID is incremented by +1 for each sheet of paper processed after the power is turned on. A numerical value is set for the paper ID when printing is executed.

[0074] The copy ID is identification information for each copy. The copy ID is incremented by 1 for each copy that is printed after the power is turned on. The copy ID is set to a value when printing is performed.

[0075] The job ID is identification information for each job. The job ID is incremented by 1 for each completed job output after the power is turned on. The job ID is set to a value when printing is performed.

[0076] 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 a print job subject to defect detection, a print job not subject to defect detection, or an interleaf for defect detection and identification.

[0077] <Defect detection processing> Fig. 6 is a flow chart showing the flow after the defect detection process in the no-paper-passing detection mode. The process in Fig. 6 is executed after the no-paper-passing detection mode is executed and the second defect discrimination processing unit 357 performs the defect detection process on the inspection image. In the no-paper-passing detection mode, the print image reading unit 307 generates the inspection image in a state where no paper is being transported. If there is a defect in the inspection image, it is highly likely that the defect (e.g., dirt) is caused by the reading devices 131 and 132.

[0078] First, the second defect discrimination processing unit 357 generates defect discrimination information (S601). The second defect discrimination processing unit 357 discriminates defects in the inspection image using a preset defect discrimination threshold value, and generates the following defect discrimination information. Number of reading defects detected when no paper is fed -Reading defect position when no paper is passed The second defect discrimination processing unit 357 judges the presence or absence of a defect based on the defect discrimination information, and detects the defective state if a defect is present (S602). If no defect is present (No in S602), the processing in FIG.

[0079] If there is a defect (Yes in S602), the second defect determination processor 357 determines whether the detected defect state is less than a threshold value (S603). The defect state is determined based on, for example, the following items. (i) For example, the defect status may be determined based on the number of defects, with the threshold against which the number of defects is compared being user-configurable (e.g., notify when there are more than a dozen defects). (ii) For example, the defect state is determined by a combination of multiple conditions. For example, a notification is sent when there are 10 or more defective areas with a width of 3 pixels or more. In this case, the user can set the width and number thresholds.

[0080] In addition, the defect state may be determined based on several items as shown in Fig. 7. Fig. 7 shows examples of items that are determined as a defect state. In addition to the number and width, the length, area, and brightness value may be used to determine the defect state. The number of defects is the number of defective areas. The defective areas are mainly streaks, but may include defects of other shapes. The width of a defect is the width of a defective area. The width may be the length in the main scanning direction of, for example, a circumscribing rectangle of the defective area. The length of the defect is the length of the defective area. The length may be the length of the defective area, for example, the circumscribing rectangle, in the sub-scanning direction. The defect area is the area of ​​the defect region (width x length). The brightness value of a defect refers to the pixel value (RGB value) of the defect, and may be, for example, the average, median, or maximum value. The brightness value may also be the difference in pixel value from a non-defective area.

[0081] If the determination in step S603 is Yes, the user I / F unit 302 turns off notifications to the user (S604). OFF means that no notification of an abnormality is to be made. If the determination in step S603 is No, the user I / F unit 302 turns on notifications to the user (S605). ON means that notification of an abnormality is to be made. Therefore, an abnormality means that a serious abnormality has been detected in the no-paper-passing detection mode.

[0082] In step S605 where the notification to the user is ON, the abnormality is notified based on the threshold value set for the user. This allows the notification to be tailored to the user's acceptable risk of overlooking, and the risk of overlooking can be prevented from increasing. In addition, the user I / F unit 302 notifies the user of the abnormality, and when the user cleans the printer, the process of FIG. 6 (setting of the inspection excluded area) may be executed again. Depending on the printer 101, some printers may execute the "no paper passing detection mode" even when the door is closed for cleaning. In other words, the sequence is door open → user cleaning → door close, so in such printers 101, the process of FIG. 6 is always executed after cleaning. Therefore, the inspection excluded area is set after cleaning, and the increase in the risk of overlooking due to increased adhesion of dust or an increase in the excluded area can be prevented.

[0083] Steps S603 to S605 minimize the checking and cleaning work of the user, and also suppress an increase in the risk of overlooking. That is, since the area where the defect is detected is set as the inspection excluded area, if the judgment in step S603 indicates that there is a noticeable defect caused by the reading devices 131 and 132 in the inspection excluded area, the user can be prompted to clean in advance. Therefore, it is possible to suppress an increase in the inspection excluded area, and suppress the risk of overlooking when a defect not caused by the reading devices 131 and 132 exists in the inspection excluded area. In addition, since defects in the inspection excluded area are excluded from inspection, it is possible to reduce the work of the user frequently checking whether the defect is caused by the reading unit or not and the cleaning work.

[0084] Next, in step S606, if the preset manual adjustment of the inspection exclusion area is invalid, the exclusion area setting unit 356 sets the area where the defect is detected as the inspection exclusion area (S603). By excluding the defective portion detected without paper passing from the defect detection area in the detection during actual printing mode, cleaning for eliminating the detection of defects caused by the reading devices 131 and 132 can be eliminated or reduced. In addition, false detection due to reading streaks (defects caused by the reading devices 131 and 132) can be suppressed.

[0085] When the preset manual adjustment of the inspection exclusion area is enabled, an inspection exclusion area setting screen is displayed. An example of the inspection exclusion area setting screen is shown in FIG. 13. The user I / F unit 302 displays the inspection exclusion area that is set to include the detected defect. The user can adjust the inspection exclusion area by operating the inspection exclusion area setting screen. The user can also select whether or not to display defects in the inspection exclusion area as suspected read defects. The inspection exclusion area set by the user is set by the exclusion area setting unit 356. Since the location where defects occur varies slightly, the user can avoid missing any parts of the inspection exclusion area by giving the exclusion area some width.

[0086] 8 is a flow chart for explaining the process of registering the inspection excluded region. The process of FIG. 8 is executed, for example, when the power of the inspection device 103 is turned on and the main body starts up (S701).

[0087] In response to a user operation or automatically, the system control unit 301 of the inspection device 103 executes a no-paper-passage detection mode operation (S702). That is, before the start of actual printing using an actual print job, the system control unit 301 detects defects in the reading devices 131 and 132 without paper passing.

[0088] After the defect of no paper passing is detected, the process of FIG. 6 is performed. Before displaying the screen of step S606 to the user, the system control unit 301 resets the inspection excluded area registered in step S606. Then, the excluded area setting unit 356 registers the inspection excluded area set in step S606. Note that the no paper passing detection mode operation may be performed after the actual printing is completed.

[0089] When the no-paper-passing detection mode ends, the system control unit 301 executes the actual printing detection mode (S703). In the actual printing detection mode, even if the first defect discrimination processing unit 355 detects a defect in the registered inspection exclusion area, it does not treat it as a defect (deterioration in print quality). In the actual printing detection mode, defects caused by the reading devices 131 and 132 are excluded from detection targets, so cleaning to resolve defect detection is unnecessary or can be reduced.

[0090] In this embodiment, even if a defect is detected in an inspection excluded area, it is not treated as a defect, but if the inspection excluded area stored in the storage unit 351 by the second defect discrimination processing unit 357 matches the location of a defect detected by the first defect discrimination processing unit 355, the first defect discrimination processing unit 355 determines that the defect is suspected to be a read failure. This allows the user to check whether the defect is caused by the readers 131, 132.

[0091] <Example of notification to user regarding defect detection> Next, an example of notifying the user of a defect detection will be described with reference to Fig. 9 and Fig. 10. Fig. 9 shows an example of a status display screen 800 displayed by the inspection device 103. The status display screen 800 in Fig. 9 is displayed in step S604 in Fig. 6.

[0092] First, a status column 801 of the status display screen 800 indicates the status of the printing system 100 (adjusting, printing, etc.). An area 802 is an area that displays the machine configuration of the printing system 100 together with an appearance model 802a. The machine configuration is the connection state of peripheral devices such as a finisher. When an event such as a paper jam occurs, the location where the event occurred is highlighted in the appearance model. For example, the location where the paper jam occurred turns red, and when the user taps on that location, the procedure for clearing the paper jam, etc. is displayed. Furthermore, the remaining amount of toner of each color is displayed in the area 802. When the toner is near the end, an icon or the like is displayed to encourage the replacement of the toner cartridge. When the user taps on the icon, etc., a message urging the user to check the toner cartridge stock, or the procedure for replacing the toner cartridge, etc. may be displayed.

[0093] An area 803 indicates the status of a job being executed. The job status includes the status, number of copies, number of pages, and paper size. An area 804 indicates the paper settings set for each tray. The paper settings include the remaining amount, paper name, basis weight, and size for each tray as information about the paper stored in the tray.

[0094] Area 805 is a notification area for the user. Area 805 displays notifications of errors and maintenance, including the detection of a defect in the no-paper-passing detection mode. FIG. 9 shows a case where it is determined that the "defective state has exceeded the threshold," and area 805 displays an error message 805a, "Cleaning Required: Line Sensor," which prompts the user to clean dirt adhering to the sensor side. Furthermore, a message such as "Reading failure, suspected defect" may be displayed to notify the user of the possibility of erroneous detection by the reading devices 131 and 132.

[0095] Fig. 10 shows another example of an error message displayed on the status display screen 800. Fig. 10 shows a case where a defect notification is displayed as a pop-up. In Fig. 10, a message box 806 pops up on the status display screen 800 when "the defect state exceeds the threshold value". The message box 806 displays a title "Cleaning Required: Line Sensor" and a message 808 saying "The line sensor is dirty. If you want to use image defect detection, please clean it." The user can see that the line sensor needs to be cleaned.

[0096] The message box 806 also has a procedure button 807, which allows the user to display specific cleaning procedures. For example, pressing the procedure button 807 displays a video showing the procedure for cleaning the line sensor.

[0097] When an error message is pressed in area 805 in FIG. 9, a message box in FIG. 10 may be displayed as a pop-up.

[0098] Furthermore, the inspection device 103 may notify an error message to the user's smartphone or wearable device (watch type, glasses type, neck type, etc.) via email, wireless communication, or the like.

[0099] <Threshold for notifying the user of a defect> Next, a method of setting a threshold for determining whether or not the user I / F unit 302 notifies the user of a defect state will be described with reference to FIG. 11. FIG. 11 is an example of a 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 dirt on the reading devices 131 and 132, and a threshold setting 901b for whether or not to notify the user. In FIG. 11, it is assumed that the threshold setting 901b for whether or not to notify the user is selected. As a result, the items in the threshold setting field 902 are switched, and the current setting values ​​for the threshold setting 901b for whether or not to notify the user are displayed.

[0100] In the threshold setting field 902, a setting value field 911, a minus button 912, a plus button 913, and a slider 914 are displayed for each of the items of defective area count 903, defective area width 904, defective area length 905, defective area area 906, and defect brightness value 907. The user can adjust the setting value by operating the mouse or touch panel to move the slider 914 or press the minus button 912 or the plus button 913. The user can also directly input a numerical value into the setting value field 911.

[0101] The threshold setting field 902 has a detailed setting button 908. The detailed setting button 908 is a button for displaying a detailed setting screen 920 for setting defects to be detected in a defect discrimination process in an inspection excluded area. The detailed setting screen 920 accepts settings for types of defects to be detected in the inspection excluded area even in the inspection excluded area.

[0102] FIG. 12 shows a detailed setting screen 920 that is displayed as a pop-up. The detailed setting screen 920 has check boxes 922 to 924 that correspond to "detect vertical streaks," "detect horizontal streaks," and "detect dots," respectively. "Dots" are point-like defects. The user can set defects that he or she wants to detect within the inspection exclusion area. For example, if the user excludes "vertical streaks" from the detection target (unchecks them) and does not exclude "horizontal streaks" and "dots" (checks them), the primary 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 read streaks. On the other hand, defects that are different from read streaks, which are likely to occur due to dirt on the reading devices 131 and 132, such as "horizontal streaks" and "dots," can be detected without being overlooked even if they are defects within the inspection exclusion area.

[0103] <Cleaning recommendation message, inspection exclusion area setting screen> 13 shows an inspection exclusion region setting screen 930 displayed by the inspection device 103. The inspection exclusion region setting screen is displayed in step S606 in FIG.

[0104] The inspection excluded area setting screen 930 displays a defect detection result 931. The defect detection result 931 is a part or the whole of the inspection image without paper passing. The location where the defect is detected is surrounded by a red frame 936. The inspection excluded area is also set within this red frame 936 (for example, the red frame 936 becomes the inspection excluded area). In FIG. 13, three streak-like lines 937 are defects. Since there is a defect in the inspection image without paper passing, it is presumed that the reading devices 131, 132 have a defect such as dirt.

[0105] The inspection exclusion region setting screen 930 also displays a cleaning recommendation message 932. The cleaning recommendation message 932 is, for example, "Please clean the reading section." If a preset cleaning recommendation message display is enabled, such a message is displayed.

[0106] When the preset manual adjustment of the inspection-exclusion area is enabled, an inspection-exclusion area setting field 933 is displayed. The inspection-exclusion area setting field 933 is a setting field for the user to set an inspection-exclusion area in which a defect is not treated as a defect even if it is detected in the detection-during-actual-printing 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 the button 934, the range of the red frame 936 is changed accordingly. That is, the red frame 936 surrounding the streak-like defect narrows or widens in conjunction with the operation of the button 934. When the user presses the inspection-exclusion area setting completion button 935, the inspection-exclusion area setting screen 930 is closed. The range of the red frame 936 when closed is registered by the exclusion area setting unit 356 as the inspection-exclusion area.

[0107] It is also advisable for the user to be able to set the position and size of the inspection exclusion area according to the paper settings. For example, the user can specify the inspection exclusion area for each paper size (A4, A3, etc.) and each paper type (plain paper, coated paper, etc.). Since the area on which an image is formed differs depending on the size and type of paper, the user can set the area on which an image is not formed as the inspection exclusion area according to the paper settings.

[0108] <Major Effects> The printing system 100 of this embodiment can set a defect location detected without paper passing as a defect detection area in the detection mode during actual printing. In addition to setting an inspection excluded area, if a defect state exceeds a threshold in the detection mode without paper passing, the user is notified and prompted to perform cleaning. This makes it possible to prevent the inspection excluded area from increasing and the risk of overlooking a defect from increasing too much in the detection mode during actual printing. In addition, it is possible to minimize the user's confirmation and cleaning work (to a degree that does not increase the risk of overlooking too much) and to prevent erroneous detection due to reading streaks detected in the inspection excluded area.

[0109] <Other application examples> The above describes the best mode for carrying out the present invention using an embodiment, but the present invention is not limited to such an embodiment, and various modifications and substitutions can be made within the scope that does not deviate from the gist of the present invention.

[0110] Moreover, the configuration example in Fig. 4 and the like is divided according to main functions in order to facilitate understanding of the processing by the inspection device 103. The present invention is not limited by the manner in which the processing units are divided or the names of the processing units. The processing by the inspection device 103 can be divided into more processing units according to the processing contents. Also, it can be divided so that one processing unit includes more processes.

[0111] Furthermore, the printer 101 does not have to be one that prints by electrophotography, but may be one that prints by inkjet, thermal transfer, letterpress, lithographic, intaglio, stencil, or other methods.

[0112] Furthermore, the inspection device 103 may be separate from the printer 101. The user causes the inspection device 103 to read the printed matter, and the inspection excluded area determined by the inspection device 103 is stored in the device itself.

[0113] Furthermore, the printing system 100 is not limited to being used for commercial printing, but may also be used in offices, factories, ordinary homes, convenience stores, and the like.

[0114] Furthermore, the processing of the inspection device 103 described in this embodiment may be executed 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 the inspection excluded area and registers it in its own device or the server device.

[0115] Each function of the above-described embodiments can be realized by one or more processing circuits. Here, the term "processing circuit" in this specification includes a processor programmed to execute each function by software, such as a processor implemented by an electronic circuit, and a device such as an ASIC (Application Specific Integrated Circuit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), or a conventional circuit module designed to execute each function described above.

[0116] <Additional Notes> [Claim 1] a print image reading unit that reads a printed matter printed by a printing device with a reading unit and generates a first inspection image; a first defect determination processing unit that determines a defect in the printed matter based on a master image generated from print data of the printed matter and the first inspection image; a second defect discrimination processing unit that detects defects and a defective state of a second inspection image generated by the reading unit without passing a paper; an exclusion area setting unit that sets a defect location detected by the second defect discrimination processing unit to an inspection exclusion area in which the first defect discrimination processing unit does not detect defects; a user I / F unit that notifies a user when the defect state exceeds a threshold; An image forming apparatus comprising: [Claim 2] the user I / F unit displays a threshold setting screen for accepting settings of the threshold; 2. The image forming apparatus according to claim 1, wherein when the defect state exceeds the threshold value set on the threshold value setting screen, a user is notified of the abnormality. [Claim 3] the defect status being the number of defects; 3. The image forming apparatus according to claim 2, wherein the user I / F unit accepts a setting of the threshold value related to the number of defects. [Claim 4] the defect state is a width of the defect; 3. The image forming apparatus according to claim 2, wherein the user I / F unit accepts a setting of the threshold value related to a width of the defect. [Claim 5] the defect condition is the length of the defect; 3. The image forming apparatus according to claim 2, wherein the user I / F unit accepts a setting of the threshold value related to a length of the defect. [Claim 6] the defect state is an area of ​​the defect; 3. The image forming apparatus according to claim 2, wherein the user I / F unit accepts a setting of the threshold value related to an area of ​​the defect. [Claim 7] the defect status being a brightness value of the defect; 3. The image forming apparatus according to claim 2, wherein the user I / F unit accepts a setting of the threshold value related to a luminance value of the defect. [Claim 8] 8. The image forming apparatus according to claim 1, wherein, when the second defect discrimination processing section detects a defect in the second inspection image, the user I / F section displays the location of the detected defect. [Claim 9] 9. The image forming apparatus according to claim 8, wherein the user I / F unit, when displaying the detected defective portion, displays a display component that accepts a change of the inspection exclusion area that is excluded from inspection by the first defect determination processing unit. [Claim 10] 10. The image forming apparatus according to claim 9, wherein the inspection exclusion area excluded from inspection by the first defect discrimination processing section is changeable in accordance with a paper setting. [Claim 11] 11. The image forming apparatus according to claim 1, wherein the user I / F unit receives, in the non-inspection area, a setting for a type of defect that is to be detected even in the non-inspection area. [Explanation of symbols]

[0117] 101 Printer 103 Inspection Equipment 104 Stacker 131,132 Reader [Prior art documents] [Patent documents]

[0118] [Patent Document 1] JP 2013-132042 A< / dfe>

Claims

1. a print image reading unit that reads a printed matter printed by a printing device with a reading unit and generates a first inspection image; a first defect determination processing unit that determines a defect of the printed matter based on a master image generated from print data of the printed matter and the first inspection image; a second defect discrimination processing unit that detects defects and a defective state of a second inspection image generated by the reading unit without passing a paper; an exclusion area setting unit that sets a defect location detected by the second defect discrimination processing unit to an inspection exclusion area in which the first defect discrimination processing unit does not detect defects; a user I / F unit that notifies a user when the defect state exceeds a threshold; An image forming apparatus comprising:

2. the user I / F unit displays a threshold setting screen for accepting settings of the threshold; 2. The image forming apparatus according to claim 1, wherein when the defect state exceeds the threshold value set on the threshold setting screen, a user is notified of the abnormality.

3. the defect status being the number of defects; The image forming apparatus according to claim 2 , wherein the user I / F unit accepts a setting of the threshold value related to the number of defects.

4. the defect state is a width of the defect; The image forming apparatus according to claim 2 , wherein the user I / F unit accepts a setting of the threshold value related to a width of the defect.

5. the defect condition is the length of the defect; The image forming apparatus according to claim 2 , wherein the user I / F unit accepts a setting of the threshold value related to the length of the defect.

6. the defect state is an area of ​​the defect; The image forming apparatus according to claim 2 , wherein the user I / F unit accepts a setting of the threshold value related to an area of ​​the defect.

7. the defect status being a brightness value of the defect; The image forming apparatus according to claim 2 , wherein the user I / F unit accepts a setting of the threshold value related to a luminance value of the defect.

8. The image forming apparatus according to any one of claims 1 to 7, wherein the user I / F unit displays the detected defective location when the second defect discrimination processing unit detects a defect in the second inspection image.

9. 9. The image forming apparatus according to claim 8, wherein the user I / F unit, when displaying the detected defective portion, displays a display component that accepts a change of the inspection exclusion area that is excluded from inspection by the first defect determination processing unit.

10. The image forming apparatus according to claim 9 , wherein the inspection exclusion area excluded from inspection by the first defect determination processing section is changeable in accordance with a paper setting.

11. The image forming apparatus according to claim 1 , wherein the user I / F unit receives a setting for a type of defect that is to be detected in the inspection excluded area even in the inspection excluded area.

12. a print image reading unit that reads a printed matter printed by a printing device with a reading unit and generates a first inspection image; a first defect determination processing unit that determines a defect in the printed matter based on a master image generated from print data of the printed matter and the first inspection image; a second defect discrimination processing unit that detects defects and a defective state of a second inspection image generated by the reading unit without passing a paper; an exclusion area setting unit that sets a defect location detected by the second defect discrimination processing unit to an inspection exclusion area in which the first defect discrimination processing unit does not detect defects; a user I / F unit that notifies a user when the defect state exceeds a threshold; An image forming system comprising:

13. A process in which a print image reading unit reads a printed matter printed by a printing device with a reading unit to generate a first inspection image; a process in which a first defect discrimination processing unit judges a defect of the printed matter based on a master image generated from print data of the printed matter and the first inspection image; A process in which a second defect discrimination processing unit detects defects and defective states of a second inspection image generated by the reading unit without passing a paper; a process in which an exclusion area setting unit sets a defect location detected by the second defect discrimination processing unit to an inspection exclusion area in which the first defect discrimination processing unit does not detect defects; A process in which a user I / F unit notifies a user of an abnormality when the defect state exceeds a threshold value; An inspection method comprising the steps of:

14. An image forming apparatus, a print image reading unit that reads a printed matter printed by a printing device with a reading unit and generates a first inspection image; a first defect determination processing unit that determines a defect in the printed matter based on a master image generated from print data of the printed matter and the first inspection image; a second defect discrimination processing unit that detects defects and a defective state of a second inspection image generated by the reading unit without passing a paper; an exclusion area setting unit that sets a defect location detected by the second defect discrimination processing unit to an inspection exclusion area in which the first defect discrimination processing unit does not detect defects; a user I / F unit that notifies a user when the defect state exceeds a threshold; A program to function as a

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