Inspection apparatus, inspection system, control method for inspection system, and program

Abstract

To realize an adjustment function without impairing an inspection function.SOLUTION: An inspection apparatus for inspecting a printed matter comprises: acquisition means (238) which acquires a read image obtained by reading the printed matter; and setting means (238) which, when the read image includes a pattern image that is not a target of inspection, sets a region including the pattern image in the read image not to be the target of inspection.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a method for setting an inspection target area in an inspection system.

Background Art

[0002] Conventionally, an in-line inspection system for inspecting a sheet (printed matter) printed by linking a printing device and an inspection device has been known. In this inspection system, the inspection device reads the printed matter conveyed from the printing device and inspects the presence or absence of printing defects by comparing the read image with a previously registered correct image.

[0003] In addition, the inspection system also has a function of automatically adjusting, for example, the image position or color tone of the printed matter. At the time of this adjustment, first, the printing device prints a patch image with a dedicated patch at a predetermined interval (for example, every 100 sheets). Then, the inspection device reads the sheet on which the patch image is printed and sends the information to the printing device, and the printing device adjusts the color tone or image position based on the information. In this regard, Patent Document 1 discloses a conventional technique of printing a color adjustment patch and a front / back registration adjustment mark on a sheet according to a printing job and adjusting color or front / back printing misregistration based on the reading result of the printed sheet.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The technology of Patent Document 1 sets the areas of the color adjustment patches and the front-back registration adjustment marks as non-inspection target areas based on the position information of the color adjustment patches and the front-back registration adjustment marks. Specifically, in the above prior art, when the position information of both the color adjustment patches and the front-back registration adjustment marks (corresponding to the pattern image) is included in the print job, during the execution of the print job, all areas of the pattern image are set as non-inspection target areas. For example, every time the number of sheets printed according to the print job reaches 100, even if the setting to print the pattern image is registered in the main body of the printing device, regardless of the count of the number of sheets, all areas where the printing of the pattern image is assumed become non-inspection target areas. That is, the above prior art sets non-inspection target areas for each print job regardless of whether the pattern image is actually printed. Therefore, for a sheet on which the pattern image is not printed, even if an image for comparison with the accurate image is printed in the non-inspection target area, the inspection of the image in the non-inspection target area cannot be performed. For example, when inspecting the images on the sheets while printing 1000 sheets, assume that an operation to make adjustments with the pattern image every 100 sheets is registered in the main body of the printing device so that there is no color tone and positional deviation in the images between the first sheet and the 1000th sheet. Even in such an assumption, in the prior art, regardless of the count of the number of sheets to be printed, all areas where the printing of the pattern image is assumed are set as non-inspection target areas. Therefore, even if the adjustment function by the pattern image can be realized, the inspection of the area where the printing of the pattern image is assumed is not always executed, which may inhibit the inspection function.

[0006] The present disclosure has been made in view of the above problems, and an object thereof is to realize an adjustment function without inhibiting the inspection function.

Means for Solving the Problems

[0007] An information processing apparatus according to one aspect of the present disclosure is an inspection apparatus for inspecting a printed matter, and includes an acquisition unit that acquires a read image obtained by reading the printed matter, and a setting unit that, when the read image includes a pattern image that is not a target of the inspection, sets a region including the pattern image in the read image as not being a target of the inspection.

Effect of the Invention

[0008] According to the present disclosure, an adjustment function can be realized without inhibiting the inspection function.

Brief Description of the Drawings

[0009]

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Mode for Carrying Out the Invention

[0010] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the present disclosure, and the combinations of features described in the following embodiments are not necessarily essential for the solution means of the present disclosure. The same reference numerals are assigned to the same components. In the present embodiment, an image forming apparatus will be used as an example of the information processing apparatus, but the present invention is not limited thereto.

[0011] <<First Embodiment>> (System Configuration) FIG. 1 is a diagram showing a configuration example of an inspection system 100. The inspection system 100 includes, as system components, an image forming apparatus 101, an external controller 102, and a client PC 103. The image forming apparatus 101 and the external controller 102 are communicably connected via an internal LAN 105 and a video cable 106. Further, the external controller 102 is communicably connected to the client PC 103 via an external LAN 104 which is a network. In an example of FIG. 1, the system components include the image forming apparatus 101, the external controller 102, and the client PC 103, but the system components are not limited thereto. For example, a mobile terminal such as a smartphone may be a system component of the inspection system 100. Also, in an example of FIG. 1, the system components are connected by a wired medium such as the internal LAN 105, the video cable 106, or the external LAN 104, but the communication medium is not limited to the wired medium. For example, the system components may be connected by a wireless medium.

[0012] (Client PC 103; External Controller 102) The client PC 103 has a printer driver (print driver) installed. The printer driver has a function of converting image data to be printed into a page description language (PDL). The PDL is, for example, a language that can be processed by the external controller 102. The image data converted into PDL is transmitted as PDL data from the client PC 103 to the external controller 102. A user who uses the inspection system 100 can give a print instruction from various applications installed on the client PC 103 via the printer driver. The printer driver transmits the PDL data to the external controller 102 based on the print instruction from the user. When the external controller 102 receives the PDL data from the client PC 103, it performs PDL analysis (interpreter processing) and rasterization processing to generate print data (hereinafter referred to as "print job"). The print job is composed of a data format that can be processed by the image forming apparatus 101. The print job is input from the external controller 102 to the image forming apparatus 101. Note that the print job may be directly input to the image forming apparatus 101 without going through the external controller 102. In this case, the print job may be generated by the printer driver or may be generated by a web service (not shown). For the print job to be generated by the web service, it is sufficient that each system component can be connected to the Internet composed of the World Wide Web.

[0013] (Image forming apparatus 101) The image forming apparatus 101 will be described. The image forming apparatus 101 includes, as components, a printing module (also referred to as a printing device) 107, an inserter 108, an adjustment module (also referred to as an adjustment device) 112, an inspection module (also referred to as an inspection device) 109, a stacker 110, and a finisher 111. Hereinafter, each component of the image forming apparatus 101 will be described. Note that the components of the image forming apparatus 101 are not limited to these. For example, a trimmer capable of cutting the edge of a sheet may be included.

[0014] (Printing Module 107) The printing module 107 forms an image on a recording medium according to a print job. The print job is received into a print queue by being input from an external controller 102 or the like and is sequentially executed by the printing module 107. The recording medium is a sheet (also referred to as a recording sheet or paper) as the recording medium conveyed from a paper feeding unit 230 described later with reference to FIG. 2. The image is formed by using toner as a recording agent by an electrophotographic method. Specifically, the configuration and operating principle (image forming process by electrophotographic method) of the printing module 107 are as follows. The printing module 107 includes a photosensitive drum (not shown), a transfer drum (not shown), a fixing device (not shown), etc. The photosensitive drum is irradiated with laser light from a laser exposure unit 227 described later with reference to FIG. 2. This laser light is modulated according to the image specified in the print job, reflected by a rotating polygon mirror or the like, and irradiated onto the photosensitive drum as scanning light. An electrostatic latent image is formed on the photosensitive drum by this laser light (scanning light). This electrostatic latent image is developed with toner to become a toner image. This toner image is transferred onto the sheet attached to the transfer drum. The printing module 107 sequentially executes this series of image forming processes for each of the toners of yellow (Y), magenta (M), cyan (C), and black (K). Thereby, a full-color image is formed on the sheet. The sheet on the transfer drum on which the full-color image is formed is conveyed to the fixing device. The fixing device includes rollers, belts, etc. The fixing device incorporates a heat source such as a halogen heater inside the roller. With such a configuration, the fixing device melts the toner on the sheet on which the full-color image is formed by heat and pressure and fixes it to the sheet. Note that the above-described image forming process may be executed for toners of special colors that are pre-toned other than CMYK. Also, in the present embodiment, a sheet subjected to a printing process by the above-described image forming process is referred to as a printed sheet or a printed matter.

[0015] (Inserter 108) The inserter 108 is arranged on the downstream side of the printing module 107. The inserter 108 is a device that inserts, for example, a partition sheet for separating at an arbitrary position, into a sheet group including a plurality of sheets (also referred to as "printed sheets") that have been printed and conveyed by the printing module 107.

[0016] (Adjustment module 112) The adjustment module 112 is arranged between the inserter 108 and the inspection module 109. The adjustment module 112 reads an adjustment patch. Although the details of the adjustment patch will be described later, the adjustment patch is a pattern image for adjusting the color of the printed image or the printing misregistration between the front and back (also referred to as "front-back registration misalignment"). The adjustment patch is generated by the printing module 107 according to an instruction from the external controller 102 or the client PC 103. Specifically, the printing module 107 generates the adjustment patch by printing on the printed sheet that has been conveyed through the above-described image forming process. The adjustment module 112 notifies the printing module 107 of the result of reading the adjustment patch. The printing module 107 adjusts the color of the printed image or the printing misregistration between the front and back by rewriting various settings according to the notification.

[0017] (Inspection module 109) The inspection module 109 is disposed between the adjustment module 112 and the stacker 110. The inspection module 109 reads an image of the printed processed sheet conveyed from the adjustment module 112. The inspection module 109 compares the read image of the printed processed sheet with a previously registered correct image (also referred to as a "reference image"). Thereby, the inspection module 109 determines whether the image formed on the printed processed sheet is normal. That is, the inspection module 109 determines whether there is a printing defect in the image formed on the printed processed sheet. Here, the printing defect corresponds to a defect included in the image when the image is determined to be abnormal. The image is determined to be abnormal when the difference from the correct image exceeds a preset numerical value. The preset numerical value is, for example, within 1%. Assuming this set numerical value, for example, when the difference between the correct image and the image formed on the printed processed sheet exceeds 1%, this image is determined to be abnormal and a printing defect is determined to exist. The above difference will be described later.

[0018] (Stacker 110; Finisher 111) The stacker 110 is disposed between the inspection module 109 and the finisher 111. The stacker 110 is a large-capacity stacking device capable of stacking the printed processed sheets conveyed from the inspection module 109. The finisher 111 is disposed on the downstream side of the stacker 110. The finisher 111 is a post-processing device having a finishing processing function. The finishing processing function is, for example, a function of performing stapling, punching, or saddle stitching. The finisher 111 applies a previously selected and / or set finishing process to the printed processed sheet conveyed from the stacker 110. The sheet after the finishing process is discharged to a paper discharge tray 351 or the like, which will be described later with reference to FIG. 3.

[0019] (Other system components) In the inspection system described with reference to FIG. 1, a printing job is input to the image forming apparatus 101 via the external controller 102. However, the present invention is not limited to this configuration. For example, a configuration in which the external controller 102 is omitted is also possible. That is, the image forming apparatus 101 may be connected to the external LAN 104, and PDL data may be transmitted from the client PC 103 to the image forming apparatus 101. In this case, the image forming apparatus 101 may generate a printing job by performing PDL analysis and rasterization processing, and execute printing processing. In the example of FIG. 1, the external controller 102 and the image forming apparatus 101 are connected by the internal LAN 105, which is a network, and the video cable 106. However, the present invention is not limited to this configuration. Any configuration capable of transmitting and receiving data necessary for printing may be used. For example, the external controller 102 and the image forming apparatus 101 may be connected by only one of the internal LAN 105 and the video cable 106. Alternatively, the external controller 102 and the image forming apparatus 101 may be wirelessly connected.

[0020] (Internal Configuration of Inspection System 100) FIG. 2 is a block diagram showing the internal configurations of the image forming apparatus 101, the external controller 102, and the client PC 103 that constitute the inspection system 100 of FIG. 1. The following will describe them in order.

[0021] (Internal Configuration of Image Forming Apparatus) (Printing Module 107) The internal configuration of the printing module 107 of the image forming apparatus 101 will be described. The printing module 107 mainly includes, as components related to control, a communication I / F 217, a LAN I / F 218, a video I / F 220, an HDD 221, a CPU 222, a memory 223, an operation unit 224, and a display 225. The printing module 107 mainly includes, as components related to image formation, a document reading unit 226, a laser exposure unit 227, an image forming unit 228, a fixing unit 229, and a paper feeding unit 230. Each component of the printing module 107 is connected via a system bus 231.

[0022] The communication I / F 217 is connected to the inserter 108, the adjustment module 112, the inspection module 109, the stacker 110, and the finisher 111 via the communication cable 270. According to such a connection configuration, the printing module 107 can perform communication for controlling each of the inserter 108, the adjustment module 112, the inspection module 109, the stacker 110, and the finisher 111. The LAN I / F 218 is connected to the external controller 102 via the internal LAN 105. According to such a connection configuration, communication such as printing data can be performed between the printing module 107 and the external controller 102. The video I / F 220 is connected to the external controller 102 via the video cable 106. According to such a connection configuration, communication such as image data can be performed between the printing module 107 and the external controller 102.

[0023] The HDD 221 is a storage device in which programs and data are stored. The CPU 222 comprehensively controls the printing module 107 based on programs and the like stored in the HDD 221. The memory 223 stores programs and image data required when the CPU 222 performs various processes. The memory 223 operates as at least one work area for programs and image data. The operation unit 224 receives at least one of various setting inputs and operation instructions from the user. The display 225 displays various setting information related to the printing process or the processing status of the printing job. The document reading unit 226 includes an exposure lamp and a CCD camera (both not shown). The document reading unit 226 irradiates light from the exposure lamp toward the document and images the reflected wave with the CCD camera. By optically reading the image on the document through such an operation, the document reading unit 226 functions as a scanner device that realizes a copying function or a scanning function. That is, the document reading unit 226 optically reads the image on the document by imaging the light including the reflected light of the exposure lamp with the CCD camera while illuminating the exposure lamp on the sheet placed on the transparent document table (not shown) by the user, and generates image data.

[0024] The laser exposure unit 227 is a device for performing primary charging or laser exposure to irradiate laser light. The laser exposure unit 227 first performs primary charging to charge the surface of the photosensitive drum to a uniform negative potential. Next, the laser exposure unit 227 irradiates the photosensitive drum with laser light while adjusting the reflection angle with a polygon mirror by a laser driver. According to such an operation, the negative charges in the irradiated portion are neutralized, and an electrostatic latent image is formed. The image forming unit 228 is a device for transferring toner to a sheet. The image forming unit 228 is composed of a developing unit (not shown), a transfer unit, a toner supply unit, etc., and transfers the toner on the photosensitive drum to the sheet.

[0025] The developing unit adheres the negatively charged toner from the developing cylinder to the electrostatic latent image on the surface of the photosensitive drum and visualizes it. The transfer unit performs secondary transfer after performing primary transfer. For primary transfer, a positive potential is applied to the primary transfer roller to transfer the toner on the surface of the photosensitive drum to the transfer belt. For secondary transfer, a positive potential is applied to the secondary transfer outer roller to transfer the toner on the transfer belt to the sheet. The fixing unit 229 is a device for melting and fixing the toner on the sheet to the sheet with heat and pressure. The fixing unit 229 is composed of a heating heater (not shown), a fixing belt, a pressure belt, etc. The paper feeding unit 230 is a device for feeding the sheet to be subjected to the printing process. The paper feeding unit 230 performs the paper feeding operation and the conveying operation of the sheet by rollers (not shown) and various sensors.

[0026] (Inserter 108) The internal configuration of the inserter 108 of the image forming apparatus 101 will be described. The inserter 108 includes, as components, a communication I / F 232, a CPU 233, a memory 234, and a paper feed control unit 235. Each component of the inserter 108 is connected via a system bus 236. The communication I / F 232 is connected to the print module 107 via a communication cable 270. According to such a connection configuration, the inserter 108 can perform communication necessary for sheet insertion control. The CPU 233 controls the entire inserter 108 according to a control program stored in the memory 234. The memory 234 is a storage device in which the control program is stored. The paper feed control unit 235 controls a roller and a sensor (not shown) based on an instruction from the CPU 233, and takes in a sheet placed on a tray 321 of FIG. 3, which will be described later, or controls the conveyance of a sheet conveyed from the print module 107.

[0027] (Adjustment module 112) The internal configuration of the adjustment module 112 of the image forming apparatus 101 will be described. The adjustment module 112 includes, as components, a communication I / F 255, a CPU 256, a memory 257, and a reading unit 258. Each component of the adjustment module 112 is connected via a system bus 259. The communication I / F 255 is connected to the printing module 107 via a communication cable 270. According to such a connection configuration, the adjustment module 112 can perform communication necessary for controlling the reading process of the adjustment patch. The CPU 256 controls the entire adjustment module 112 according to a control program stored in the memory 257. The memory 257 is a storage device that stores various setting information or adjustment patch information in addition to the control program. The reading unit 258 includes a first sensor 323 and a second sensor 324, which will be described later with reference to FIG. 3. The first sensor 323 and the second sensor 324 read the adjustment patch printed on the conveyed printed sheet based on an instruction from the CPU 256. In the present embodiment, the adjustment patch on the sheet is read by an in-line scanner, but the present invention is not limited to this. For example, the adjustment patch on the sheet may be read by an imaging device such as a camera. The adjustment module 112 notifies the printing module 107 of the reading result obtained by the reading unit 258. The printing module 107 adjusts the color to be printed or the deviation between the front and back registrations by rewriting the set value according to the notification.

[0028] (Inspection module 109) The internal configuration of the inspection module 109 of the image forming apparatus 101 will be described. The inspection module 109 includes, as components, a communication I / F 237, a CPU 238, a memory 239, an imaging unit 240, a display unit 241, an operation unit 242, and an HDD 260. Each component of the inspection module 109 is connected via a system bus 243. The communication I / F 237 is connected to the printing module 107 via a communication cable 270. According to such a connection configuration, communication necessary for controlling inspection of a printed sheet and the like can be performed between the printing module 107 and the inspection module 109. The HDD 260 is a storage device that stores various setting information or image data in addition to a control program. The CPU 238 comprehensively controls the inspection module 109 based on a program and the like stored in the HDD 260. The memory 239 stores a program and image data necessary when the CPU 238 performs various processes. The memory 239 operates as a work area for at least one of the program and the image data. The imaging unit 240 reads, by imaging, an image on the printed sheet conveyed from the adjustment module 112 based on an instruction from the CPU 238. In the present embodiment, the image on the sheet is read by imaging with a camera, but it may be read by, for example, an in-line scanner. The CPU 238 compares the captured image to be inspected obtained by the imaging unit 240 with a correct image previously stored in the memory 239, and determines whether there is a defect in the printing result. The display unit 241 displays an inspection result, a setting screen, or the like. The operation unit 242 receives instructions such as changing the settings of the inspection module 109 or registering a correct image when operated by the user.

[0029] (Stacker 110) The internal configuration of the stacker 110 of the image forming apparatus 101 will be described. The stacker 110 has, as components, a communication I / F 244, a CPU 245, a memory 246, and a paper discharge control unit 247. Each component of the stacker 110 is connected via a system bus 248. The communication I / F 244 is connected to the printing module 107 via a communication cable 270. With such a connection configuration, the stacker 110 can perform communication necessary for sheet stacking and paper discharge control. The CPU 245 controls the entire stacker 110 according to a control program stored in the memory 246. The memory 246 is a storage device in which the control program is stored. The paper discharge control unit 247 performs control for transporting the conveyed sheet to the stack tray, the escape tray, or the subsequent finisher 111 based on an instruction from the CPU 245.

[0030] (Finisher 111) The internal configuration of the finisher 111 of the image forming apparatus 101 will be described. The finisher 111 has, as components, a communication I / F 249, a CPU 250, a memory 251, a paper discharge control unit 252, and a finishing processing unit 253. Each component of the finisher 111 is connected via a system bus 254. The communication I / F 249 is connected to the printing module 107 via a communication cable 270. With such a connection configuration, the finisher 111 can perform communication necessary for control of the finishing process. The CPU 250 controls the entire finisher 111 according to a control program stored in the memory 251. The memory 251 is a storage device in which the control program is stored. The paper discharge control unit 252 controls the conveyance and paper discharge of the sheet based on an instruction from the CPU 250. The finishing processing unit 253 executes processes such as stapling, punching, and saddle stitching based on an instruction from the CPU 250.

[0031] (Internal Configuration of External Controller 102) The internal configuration of the external controller 102 will be described. The external controller 102 includes, as components, a CPU 208, a memory 209, an HDD 210, a keyboard 211, a display 212, a LAN I / F 213, a LAN I / F 214, and a video I / F 215. Each component of the external controller 102 is connected via a system bus 216. The CPU 208 executes processes such as receiving PDL data from the client PC 103, RIP (Raster Image Processor) processing, and sending a print job to the image forming apparatus 101 based on programs and data stored in the HDD 210. Here, the RIP process consists of three steps: an interpreter process, a rasterization process, and a screening process. The interpreter process is a process of converting image data to be printed into PDL data. When the external controller 102 receives PDL data from the client PC 103, this step is omitted. The rasterization process is a process of converting vector data called PDL data into image data composed of a set of dots called raster data. The screening process is a process of screening image data composed of a set of dots into printable data for a printer. The memory 209 stores programs and data necessary for the CPU 208 to perform various processes and operates as a work area. The HDD 210 stores programs and data necessary for the operation of the RIP process. The keyboard 211 is an input device for a user to input various operations or instructions to the external controller 102. Information such as applications being executed by the external controller 102 is displayed on the display 212 as a still image or a moving image. The LAN I / F 213 is connected to the client PC 103 via the external LAN 104 and receives PDL data and the like. The LAN I / F 214 is connected to the image forming apparatus 101 via the internal LAN 105 and sends a print job and the like. The video I / F 215 is connected to the image forming apparatus 101 via the video cable 106 and transmits and receives image data and the like.

[0032] (Internal Configuration of Client PC 103) The internal configuration of the client PC 103 will be described. The client PC 103 includes, as components, a CPU 201, a memory 202, an HDD 203, a keyboard 204, a display 205, and a LAN I / F 206. Each component of the client PC 103 is connected via a system bus 207. The CPU 201 executes at least one of creation of image data to be printed and a print instruction based on a document creation program or the like stored in the HDD 203. Also, the CPU 201 comprehensively controls each component connected to the system bus 207. The memory 202 stores programs and image data necessary when the CPU 201 performs various processes. The memory 202 operates as a work area for at least one of programs and image data. The HDD 203 stores programs and image data necessary for operations such as print processing. The keyboard 204 receives at least one of input of various settings by the user and an operation instruction to the client PC 103. Information such as an application being executed by the client PC 103 is displayed on the display 205 as a still image or a moving image. The LAN I / F 206 is connected to the external LAN 104 and transmits PDL data and the like.

[0033] Note that each of the memories 202, 209, 223, 234, 239, 246, 251, and 257 shown in FIG. 2 may be any storage device for holding data or programs. For example, a configuration in which they are replaced with a volatile RAM, a non-volatile ROM, a built-in HDD, an external HDD, a USB memory, or the like may be used. Alternatively, a configuration in which they are replaced with an SSD (Solid State Drive) may be used. Alternatively, based on temporal locality and spatial locality, they may be configured from a combination of the respective replacement configurations. For example, data and programs with an access frequency higher than a certain standard may be stored in a volatile RAM, and data and programs with an access frequency lower than a certain standard may be stored in a built-in HDD, an external HDD, or the like.

[0034] (Transport System of the Image Forming Apparatus) The conveyance system of the image forming apparatus 101 will be described. FIG. 3 is a cross-sectional view along the connection direction of each module of the image forming apparatus 101 in FIG. 1. Hereinafter, description will be made with reference to FIG. 3. Note that FIG. 3 includes content that partly overlaps with the content of each block described in the block diagram for each function in FIG. 2. However, since FIG. 3 is an explanation of the structure focusing on the conveyance system, the explanation of the correspondence with FIG. 2 will be omitted as appropriate for convenience. The printing module 107 includes paper feed decks 301 and 302, and developing stations 304 to 307. The printing module 107 includes an intermediate transfer belt 308, a fixing unit 311, and a second fixing unit 313. The printing module 107 includes sheet conveyance paths 303, 312, 312', 314, 315, a sheet reversing path 316, and a duplex conveyance path 317. The inserter 108 includes a tray 321 on which a separator sheet is placed and a sheet conveyance path 322. The adjustment module 112 includes a first sensor 323, a second sensor 324, and a sheet conveyance path 325. Each of the first sensor 323 and the second sensor 324 functions as an in-line sensor. The first sensor 323 and the second sensor 324 constitute the reading unit 258 in FIG. 2. The inspection module 109 includes a first camera 331, a second camera 332, and a sheet conveyance path 333. The first camera 331 and the second camera 332 constitute the photographing unit 240 in FIG. 2. The stacker 110 includes a stack tray 341 for stacking sheets, sheet conveyance paths 344, 345, 347, 348, an escape tray 346 as a paper discharge tray, and a reversing unit 349. The stack tray 341 includes a lift tray 342 and an eject tray 343. The finisher 111 includes a housing 350. Inside the housing 350, sheet conveyance paths 353, 354, 357, a first processing mechanism 355, and a second processing mechanism 356 are provided. Outside the housing 350, paper discharge trays 351 and 352, and a saddle stitching binding tray 358 are provided.

[0035] Each of the paper feed decks 301 and 302 can accommodate various sheets. Each of the paper feed decks 301 and 302 separates only the topmost one sheet among the accommodated sheets and conveys it to the sheet conveyance path 303. Each of the developing stations 304 to 307 forms a toner image using colored toner of Y, M, C, and K. The formed toner image is first primarily transferred to the intermediate transfer belt 308. Then, the intermediate transfer belt 308 rotates clockwise in FIG. 3, and at the secondary transfer position 309, the toner image is transferred to the sheet conveyed from the sheet conveyance path 303. At least one of the processing status of the print job and information for various settings is displayed on the display (also referred to as a display device) 225. The fixing unit 311 has a pressure roller and a heating roller. A nip is formed between the pressure roller and the heating roller. When the sheet passes through the nip formed between the pressure roller and the heating roller, the toner melts, and the melted toner is pressure-bonded to the sheet. Through such an operation, the toner image is fixed on the sheet. The sheet that has passed through the fixing unit 311 is conveyed through the sheet conveyance path 312 to the sheet conveyance path 315. In the case of a sheet that requires further melting and pressure bonding for fixing, after passing through the fixing unit 311, it is conveyed to the second fixing unit 313 through the sheet conveyance path 312' located above the sheet conveyance path 312. The sheet that has been subjected to additional melting and pressure bonding in the second fixing unit 313 is conveyed through the sheet conveyance path 314 to the sheet conveyance path 315. Here, when the print mode is set to double-sided printing, the sheet is conveyed to the sheet inversion path 316, inverted, and then conveyed to the double-sided conveyance path 317. Then, the second image transfer is performed at the secondary transfer position 309.

[0036] When the number of sheets conveyed to the inserter 108 through the sheet conveyance path 315 reaches a predetermined number, the inserter 108 merges the partition sheet fed from the tray 321 through the sheet conveyance path 322 with the sheets from the sheet conveyance path 315. As a result, it becomes possible to interrupt the partition sheet at an arbitrary timing in a series of sheet groups conveyed from the printing module 107 and convey them to the subsequent adjustment module 112. The sheets that have passed through the inserter 108 are conveyed to the adjustment module 112. Inside the adjustment module 112, a first sensor 323 and a second sensor 324 are arranged to face each other. The first sensor 323 can read the adjustment patch printed on the upper surface of the sheet. The second sensor 324 can read the adjustment patch printed on the lower surface of the sheet. The adjustment module 112 reads the images on both sides of the sheet using the first sensor 323 and the second sensor 324 at the timing when the sheet conveyed to the sheet conveyance path 325 reaches a predetermined position. The sheets that have passed through the adjustment module 112 are conveyed to the inspection module 109.

[0037] Inside the inspection module 109, a first camera 331 and a second camera 332 are arranged to face each other. The first camera 331 can photograph the upper surface of the sheet. The second camera 332 can photograph the lower surface of the sheet. The inspection module 109 reads the images on both sides of the sheet using the first camera 331 and the second camera 332 at the timing when the sheet conveyed to the sheet conveyance path 333 reaches a predetermined position. The inspection module 109 inspects whether there are defects in the read images of the inspection target surfaces. The display unit 241 displays the inspection results and the like performed by the inspection module 109. The sheets that have completed the inspection are conveyed to the stacker 110.

[0038] The sheet that has passed through the inspection module 109 is conveyed to the stacker 110 through the sheet conveyance path 344. The sheet that has been conveyed from the sheet conveyance path 344 via the sheet conveyance path 345 is stacked on the stack tray 341 while being flipped. The escape tray 346 discharges the sheets determined by the inspection module 109 to have printing defects (image defects). When discharging a sheet to the escape tray 346, the sheet is conveyed to the escape tray 346 via the sheet conveyance path 344 and the sheet conveyance path 347. When conveying the sheet to the finisher 111 after the stacker 110, it is conveyed via the sheet conveyance path 348. The inversion unit 349 is used when switching the discharge destination of the sheet according to the inspection result in the inspection module 109. This is to read the image on the sheet by the first camera 331 and the second camera 332, inspect the read image, and gain time to switch the conveyance path to either the sheet conveyance path 345 or 348. When no inspection is performed, the inversion unit 349 may be used only when flipping the sheet during stacking on the stack tray 341. As a result of the inspection in the inspection module 109, the sheets on which no image defects (image defects) are detected are conveyed to the finisher 111.

[0039] In finisher 111, finishing processes such as stapling (stapling at one or two locations), punching (punching two or three holes), and saddle stitching are performed on the conveyed sheets. The sheets conveyed via sheet conveyance path 353 are discharged to discharge tray 351. When performing finishing processes such as stapling, the sheets are conveyed to first processing mechanism 355 via sheet conveyance path 354. Then, after the finishing function specified by the user is executed in first processing mechanism 355, they are discharged to discharge tray 352. Each of discharge trays 351 and 352 is capable of moving up and down. Alternatively, it is also possible to lower discharge tray 351 and operate it to stack the sheets that have been subjected to the finishing process in first processing mechanism 355 onto discharge tray 351. Alternatively, when saddle stitching among the finishing functions is specified, after stapling the sheets at the center in second processing mechanism 356, the sheets are folded in half and discharged to saddle stitching tray 358 via sheet conveyance path 357. Saddle stitching tray 358 has a belt conveyor configuration, and the stack of sheets (saddle stitched stack) loaded on saddle stitching tray 358 is configured to be conveyed to the left side.

[0040] (Details of Adjustment Patch) An example of an adjustment patch read by the adjustment module 112 will be described with reference to FIG. 4. FIG. 4 is a diagram showing an example of the printing result of the adjustment patch. In the present embodiment, the adjustment patch is used as a mark for color measurement or front-back registration adjustment. Such an adjustment patch is used for the adjustment of the printing module 107. The adjustment of the printing module 107 includes the adjustment of various setting values related to printing. For example, it is possible to change various setting values such as the set value of the transfer voltage value or the correction amount of skew by the resist roller. In the present embodiment, at least one of the adjustment patch and the mark for front-back registration adjustment is referred to as a pattern image or pattern image information. Whether to print the pattern image on the sheet can be set by the client PC 103 and the main body of the printing module 107. For example, it is possible to set which pattern image to print on the sheet via a printer driver (print driver) on the client PC 103. Also, for example, it is possible to set at what timing to print the pattern image on the main body of the printing module 107. For example, information related to the pattern image such as the size of the product, the size of the paper to be printed, the presence or absence of the attachment of the adjustment patch, and how many sheets to attach on which page when attaching the adjustment patch can be set. The information related to the pattern image set by the printer driver may be included in the print job and transmitted. With such information related to the pattern image, the information related to the set pattern image can then be transmitted to the printing module 107 and the inspection module 109.

[0041] On page 501 of FIG. 4, different images are formed in region 502 and outside region 502. In region 502, the RIP-processed image data received by the printing module 107 is printed. On the other hand, adjustment patches are printed in the blank areas outside the region of region 502. For example, as adjustment patches, color measurement charts 503 to 506 and registration correction marks 507 to 510 are printed. The color measurement charts 503 to 506 are used for adjusting the printing density or measuring the gradation in the ink or toner used by the printing module 107. To adjust the printing density using the color measurement chart 503 or the like, for example, the transfer voltage value may be changed. The color measurement charts 503 to 506 may be created, for example, in four colors of cyan, magenta, yellow, and black (CMYK). Alternatively, the color measurement charts 503 to 506 are created in four colors of red, blue, green, and black (RGB). The registration correction marks 507 to 510 are used to measure the printing misalignment with respect to the paper surface. The color measurement charts 503 to 506 and the registration correction marks 507 to 510 are pattern images added after the RIP process. Therefore, the pattern images are read by the adjustment module 112. In this embodiment, the adjustment patches are described assuming that they are printed in the blank areas outside the region of region 502, but the same can be implemented for the pattern images applied so as to overlap region 502.

[0042] (Details of the inspection module 109) Before the start of the inspection process, various setting operations that the user should perform on the inspection module 109 are explained. The inspection module 109 inspects the printed sheets that have been conveyed according to preset inspection items. The inspection is performed by comparing a reading image (hereinafter referred to as the "inspection image") corresponding to the inspection target surface among the reading images of both sides of the sheet obtained by photographing the printed sheet with a registered correct image associated with the page number. Specifically, the inspection module 109 registers the inspection image in association with the page number corresponding to the inspection image. The correct image is also registered in association with the page number. To compare a certain inspection image with the correct image, the inspection module 109 extracts the inspection image and the correct image of the same page. Examples of the comparison method between the extracted inspection image and the correct image include a method of comparing pixel values for corresponding positions in both images. Alternatively, there is a method of comparing the positions of objects by edge detection. Alternatively, there is a method of comparing the recognition results by optical character recognition (OCR). In the present embodiment, the inspection module 109 constituting the image forming apparatus 101 is described as performing the inspection process by comparing the inspection image with the correct image, but an inspection apparatus as an inspection PC communicably connected to the image forming apparatus 101 may be configured to execute the inspection process.

[0043] Next, the preliminary preparation and settings of the inspection module 109 will be described with reference to various UI screens shown in FIGS. 5 to 10. FIG. 5 is a diagram showing an example of a UI screen (hereinafter referred to as the “inspection menu screen 400”) displayed on the display unit 241 when the inspection module 109 is activated. The display control of various UI screens including this inspection menu screen 400 is performed by the CPU 238 in the inspection module 109. In the present embodiment, although an explanation is given of displaying various UI screens such as the inspection menu screen 400 on the display unit 241 of the inspection module 109, the display destination is not limited to the display unit 241 of the inspection module 109. For example, a UI screen such as the inspection menu screen 400 may be displayed on the display 225 of the printing module 107 by the CPU 222 of the printing module 107. That is, the display device for displaying the inspection menu screen 400 is not limited. Further, in FIG. 5, an example of displaying the inspection menu screen 400 over the entire displayable range of the display unit 241 of the inspection module 109 will be described, but it is not particularly limited thereto. The inspection menu screen 400 may be displayed in a part of the displayable range of the display unit 241. That is, the inspection menu screen 400 can be displayed as a sub-window. Alternatively, the inspection menu screen 400 may be displayed across a plurality of display devices. In this case, a part of the inspection menu screen 400 will be displayed on the display unit 241. Alternatively, the inspection menu screen 400 may be simultaneously displayed on each of a plurality of display devices. For example, various UI screens such as the same inspection menu screen 400 may be simultaneously displayed on the display unit 241 and the display 225.

[0044] An example is shown in the inspection menu screen 400 of FIG. 5, where a message column 401, a screen display area 402, and buttons 403 to 406 are displayed. The message column 401 is arranged at the upper left of the inspection menu screen 400. The message column 401 displays "No correct image is registered. Please register the correct image to start the inspection." That is, the message column 401 displays a message indicating that the correct image is not registered and that it is necessary to register the correct image prior to starting the inspection process. If the correct image has been registered at the time of starting the inspection menu screen 400, a message indicating that the inspection process can be started will be displayed. The screen display area 402 is arranged below the message column 401. When the correct image has been registered, the correct image is displayed in the screen display area 402. In the example of FIG. 5, since the correct image is not registered, the string "Unregistered" is displayed in the screen display area 402. The buttons 403 to 406 are arranged vertically side by side on the right side of the inspection menu screen 400. Each of the buttons 403 to 405 is arranged as a button for calling a UI screen. The UI screen called by operating the button 403 is a UI screen for registering the correct image. The correct image is an image that serves as a reference for determining the presence or absence of defects in the inspection image. The UI screen called by operating the button 404 is a UI screen for setting the conditions during inspection. The user can set the inspection items and inspection accuracy according to the inspection purpose. Examples of the inspection items include misalignment of the printing position, color tone of the image, density of the image, streaks or smudges, and printing omission. The inspection accuracy is an index for determining to what extent the difference from the correct image should be considered as having a defect. This index is defined by a numerical value such as within 1%, for example. The UI screen called by operating the button 405 is a UI screen for confirming the inspection result. The user can confirm the past inspection content or inspection result on the inspection result confirmation screen. The button 406 is assigned a function of instructing the start of the inspection. When the pressing (operation) of the button 406 is detected, the inspection module 109 starts the inspection of the sequentially conveyed printed sheets. This will be described in detail using the flowcharts of FIGS. 13 and 14, which will be described later.When the correct image is not registered, buttons 404 to 406 may be displayed in a grayed-out form and may be in a state where they cannot be operated. Alternatively, button 405 may be displayed in a grayed-out form until the inspection is performed and may be in a state where it cannot be operated. By adopting such an interface, it is possible to avoid misoperations.

[0045] Note that the configuration of the inspection menu screen 400 shown in FIG. 5 is an example, and information other than that described above may be included. For example, the inspection menu screen 400 may be configured to display information related to inspection settings such as partition sheet settings. Also, the operation methods of buttons 403 to 406 are not limited to pressing. For example, it may be an interface that accepts operations by clicking. Alternatively, it may be an interface that accepts operations by touching. That is, as long as the inspection menu screen 400 can accept the operation content of the user, the operation form is not limited. Subsequently, for each of the above three UI screen calls, the respective UI screens and their operations that are displayed when buttons 403 to 405 are pressed will be described.

[0046] (Registration of Correct Image) (Image Registration Screen 600) (FIG. 6(a): When "Correct Image Registration" is selected in the Registration Mode Selection Section 601) On the above inspection menu screen 400, when the CPU 238 of the inspection module 109 receives the operation (press) of the button 403 from the operation unit 242, the following operations are performed. That is, a UI screen for registering a correct answer image as shown in Fig. 6(a) (hereinafter referred to as the "image registration screen 600") is displayed on the display unit 241. Here, the registration of the correct answer image will be described using Fig. 6(a) described in this embodiment. In the second embodiment, it will be described using Fig. 6(b). On the image registration screen 600 shown in Fig. 6(a), a registration mode selection section 601, an OK button 602, a cancel button 603, and a setting area 605 are arranged. In the setting area 605, the inspection job name can be set. The inspection job name is a name assigned to the correct answer image to be registered in units of jobs (for each job). The user can set a desired inspection job name (in the example of Fig. 6, "Inspection Job A") in the setting area 605 using an input device such as a keyboard. In the registration mode selection section 601, either "Correct Answer Image Registration" or "Adjustment Patch Image Registration" can be selectively displayed. When the OK button 602 is operated (pressed) with "Correct Answer Image Registration" selected in the registration mode selection section 601, the screen transitions to a UI screen indicating that the image is being received and standby (hereinafter referred to as the "image generation in progress screen") (not shown). Note that when the OK button 602 is operated (pressed) with "Correct Answer Image Registration" selected in the registration mode selection section 604 of Fig. 6(b), the screen also transitions to the image generation in progress screen. It is assumed that by default, "Correct Answer Image Registration" is selected in either the registration mode selection sections 601 and 604 so that the OK button 602 is not operated (pressed) when the registration mode is not selected, but it is not limited to this. Also, the cancel button 603 is a button for canceling the registration of the correct answer image. When the cancel button 603 is operated (pressed), the registration of the correct answer image is aborted, and the display returns from the image registration screen 600 to the inspection menu screen 400.

[0047] (Method for generating the correct answer image) The correct image can be generated by either of two methods: the scanned image and the RIP image. The generation method for each correct image will be described using the flowchart of FIG. 11. FIG. 11 is a flowchart showing the processing of the inspection module 109 at the time of correct image registration. The processing shown in FIG. 11 is realized by the CPU 238 of the inspection module 109 when the button 403 on the inspection menu screen 400 in FIG. 5 is operated and the screen transitions from the inspection menu screen 400 to one of the image registration screens 600 in FIGS. 6(a) and (b). Note that some or all of the functions of the steps in FIG. 11 may be realized by hardware such as an ASIC or an electronic circuit. The symbol "S" in the description of each process means that it is a step in the flowchart diagram. The processing shown in FIG. 11 starts when the operation (press) of the button 403 is received from the operation unit 242 and the screen displayed on the display unit 241 transitions to the image registration screen 600.

[0048] (Operation of generating correct image) In S1101, the CPU 238 of the inspection module 109 (hereinafter, the CPU 238 of the inspection module 109 is appropriately abbreviated as CPU 238) starts accepting the correct image. When generating the correct image from the scanned image, the CPU 222 starts processing the print job to be inspected (hereinafter, referred to as the "inspection job"). When generating the correct image from the RIP image, the CPU 208 of the external controller 102 (hereinafter, the CPU 208 of the external controller 102 is appropriately abbreviated as CPU 208) generates the correct image from the inspection job and transmits it to the print module 107. The CPU 238 proceeds from the process of S1101 to the process of S1102. In S1102, the CPU 238 repeats the processes of S1103 to S1105 until all the sheet images are stored in the HDD 260 of the inspection module 109.

[0049] In S1103, when the CPU 238 generates a correct image from a scanned image, it performs the following operations. That is, a printed matter with an image printed on a sheet by the printing module 107 is photographed by the photographing unit 240 of the inspection module 109. By this operation, a scanned image is generated, and the generated scanned image is received by the inspection module 109 as a correct image. On the other hand, when the CPU 238 generates a correct image from a RIP image, it performs the following operations. That is, a RIP image generated by the printing module 107 before printing is received by the inspection module 109 via the communication I / F 237. Next, in S1104, the CPU 238 stores the correct image received in S1103 in the HDD 260. In S1105, S1102 to S1105 are repeated until the reception of images of all sheets is completed. When the reception of images of all sheets is completed, the processing of S1101 to S1105 ends. When generating a correct image from a scanned image, a plurality of scanned images may be printed by the printing module 107, each scanned image may be photographed by the inspection module 109, and an image obtained by synthesizing the photographed plurality of scanned images may be used as the correct image. Also, if either of the cancel buttons 603 in FIGS. 6(a) and 6(b) is operated, the CPU 238 of the inspection module 109 can instruct to cancel the reading of the correct image. When the cancel button 603 is operated, the inspection module 109 deletes the correct image stored in the HDD 260 in S1104. After that, the image registration screen 600 in FIG. 6 returns to the inspection menu screen 400 in FIG. 5.

[0050] (Registration Processing Screen 800) FIG. 8 is a diagram showing an example of a UI screen for prompting registration of a correct answer image and setting of inspection conditions. In FIG. 8, as a UI screen for prompting registration of a correct answer image and setting of inspection conditions, an example of a registration process screen 800 is shown. The registration process screen 800 is displayed on the display unit 241 of the inspection module 109 after reception of the correct answer image is completed. In the registration process screen 800, an image display area 801 and each of buttons 802 to 805 are arranged. The image display area 801 is arranged on the left side of the registration process screen 800. The button 802 is arranged below the image display area 801. The buttons 803 to 805 are arranged vertically side by side on the right side of the registration process screen 800. A correct answer image is displayed in the image display area 801. The button 802 has a function of switching pages (sheets) to be displayed when a part is composed of a plurality of pages. When the number of sheets per part is one page, the button 802 may not be displayed. The button 803 is a button for displaying an inspection setting screen 901. The inspection setting screen 901 will be described with reference to FIG. 9.

[0051] (Inspection Setting Screen 901) FIG. 9 is a diagram showing an example of the UI screen of the inspection setting screen 901. FIG. 9(a) is a diagram showing an example of the inspection setting screen 901 displayed after receiving the operation of the button 803 in FIG. 8 and before further receiving an operation from the user. FIG. 9(b) is a diagram showing an example of the inspection setting screen 901 displayed after receiving the operation of the button 803 in FIG. 8 and after further receiving an operation from the user. For example, when the button 803 in FIG. 8 is operated (pressed), the inspection setting screen 901 in FIG. 9(a) is displayed on the display unit 241 of the inspection module 109. Thereby, it becomes possible to receive a further operation from the user. On the inspection setting screen 901 in FIG. 9(a), a preview area 902, an inspection area setting unit 903, a button 904, an OK button 905, and a cancel button 906 are displayed. The preview area 902 is displayed on the left side of the inspection setting screen 901. In the preview area 902, the correct image saved in S1104 in FIG. 11 is displayed. The inspection area setting unit 903 is displayed on the right side of the inspection setting screen 901. In the inspection area setting unit 903, the inspection level for each inspection area is displayed. The inspection level for each inspection area is an icon that standardizes and displays the accuracy of the inspection and can be changed. As the inspection level is set higher, even a slight difference between the correct image and the inspection image is determined as a defect in the inspection image.

[0052] In an example of FIG. 9(a), it is shown that the inspection area setting unit 903 can set a key inspection area, a standard inspection area, and a non-inspection area. The key inspection area is shown to be specified by the area surrounded by a solid line in the preview area 902. The inspection level of the key inspection area is set to level 5. Level 5 is the default inspection level in the key inspection area. The standard inspection area is shown to be specified by the area surrounded by a dotted line in the preview area 902. The inspection level of the standard inspection area is set to level 3. Level 3 is the default inspection level in the standard inspection area. The non-inspection area is shown to be specified by the area surrounded by a dashed line. Thus, the level of the detected defect can be changed according to the type of inspection area such as the key inspection area and the standard inspection area. Generally, the inspection level of the key inspection area is set higher than that of the standard inspection area, but this setting is not limited. In addition, the non-inspection area includes, for example, the case of variable data printing (VDP) where the printed content is changed for a specific area in the sheet for each copy. Other use cases include the case where a different ID is assigned and printed for each copy, or the case where only the address or name part is changed and printed for each copy.

[0053] Button 904 is displayed below the inspection setting screen 901. Button 904 is a button for switching the page (sheet) to be displayed when one copy is composed of multiple pages. Note that when the number of sheets per copy is one page, the button may not be displayed. The OK button 905 and the cancel button 906 are displayed below the inspection setting screen 901. The OK button 905 is a button for registering the area set for the correct image. The cancel button 906, when operated (pressed), cancels the inspection setting and returns the display to the registration processing screen 800 in FIG. 8. Note that the button 904, the OK button 905, and the cancel button 906 are configured as objects displayed on the screen.

[0054] The defects detected by the inspection module 109 are exemplified in FIGS. 9(a) and 9(b) as, for example, circular defects (stains (dots)) and streak-like defects (stains (streaks)). The state in which a circular defect has occurred means a state in which stains occur circularly only in the inspection image when the correct image and the inspection image are compared. The state in which a streak-like defect has occurred means a state in which stains occur in a streak or linear shape only in the inspection image when the correct image and the inspection image are compared. Note that these defects are just examples, and the types of defects that can be detected by the inspection module 109 are not limited to these.

[0055] Also, when the inspection setting screen 901 in Fig. 9(a) is operated (pressed), the inspection setting screen 901 in Fig. 9(b) is displayed on the display unit 241 of the inspection module 109. For example, if the type of inspection area is selected in the inspection area setting unit 903 and area designation is performed in the preview area 902, the inspection module 109 will perform an inspection on the designated inspection area. In Fig. 9(b), an example is shown where area 907 is set as the key inspection area, area 908 is set as the standard inspection area, and area 909 is set as the non-inspection target area. Note that in Fig. 9(b), an example is shown where the key inspection area, standard inspection area, and non-inspection target area are separated by line types, but it is not particularly limited to this. For example, they may be separated by color or background color. Or, without finely dividing the range in the preview area 902, the same area may be designated for the entire page. For example, by switching the displayed page with button 904, the designation of any one of the key inspection area, standard inspection area, and non-inspection target area can be repeated for each page, and the inspection area can be designated for all pages. Also, the method of area designation may be input by, for example, a mouse cursor, but the input method is not particularly limited. For example, when the display unit 241 and the operation unit 242 are configured by a touch panel display, it is also possible to input by tracing the desired location in the preview area 902 with the pad of the user's finger. Also, the user can change the inspection level in the inspection area setting unit 903. In the example of Fig. 9(b), it is shown that the level of the key inspection area is set to level 7 and the level of the standard inspection area is set to level 5. Note that after the correct image is registered, when button 404 is operated (pressed) on the inspection menu screen 400 in Fig. 5, a screen transition to the inspection setting screens 901 in Figs. 9(a) and (b) also occurs. After the designation of the inspection area is completed, when the OK button 905 is operated (pressed), the inspection setting screen 901 automatically ends and the display returns to the inspection menu screen 400.

[0056] Return to the description of FIG. 8. Button 804 is a button for registering various types of information in association with the correct answer image being displayed in the image display area 801. Examples of the various types of information to be associated include the corresponding page number (e.g., the 1st page out of 10 pages), job name, creation time, and the like. For example, when button 804 is operated (pressed), a screen transition is made from the registration processing screen 800 in FIG. 8 to the inspection menu screen 400 in FIG. 5. Button 805 is a button for canceling the registration of the correct answer image. For example, when button 805 is operated (pressed), the CPU 238 of the inspection module 109 deletes the correct answer image saved in the HDD 260 in S1104 in FIG. 11. Therefore, when button 805 in FIG. 8 is operated (pressed), the CPU 238 of the inspection module 109 aborts the registration process and a screen transition is made to the inspection menu screen 400 in FIG. 5.

[0057] (Registration of Pattern Image) (FIG. 6(a): When "Registration of Adjustment Patch Image" is selected in the Registration Mode Selection Section 601) Return to Fig. 6(a). Next, a case where "Adjustment Patch Image Registration" is selected in the registration mode selection unit 601 will be described. Specifically, the operation when the OK button 602 is pressed in a state where "Adjustment Patch Image Registration" is selected in the registration mode selection unit 601 of the image registration screen 600 will be described with reference to Figs. 7(a) and 12. Fig. 12 is a flowchart showing the processing of the inspection module 109 during adjustment patch image registration. Each process shown in Fig. 12 is realized, for example, by the CPU 238 reading and executing a control program stored in the memory 239 or the HDD 256. Specifically, each process shown in Fig. 11 starts when the OK button 602 is operated in a state where "Adjustment Patch Image Registration" is selected in the registration mode selection unit 601 of the image registration screen 600. First, when the OK button 602 is operated (pressed), the screen transitions to the image generation in progress screen. In S1201, if the registration mode selected in the registration mode selection unit 601 is the "Adjustment Patch Image Registration Mode", the CPU 238 advances the process of S1201 to the process of S1202. In S1202, the CPU 238 receives an image. In the "Adjustment Patch Image Registration Mode", a pattern image is registered separately from the correct image. That is, the correct image and the pattern image are not registered on the same virtual sheet surface. Fig. 7 is a diagram showing an example of an image used for correct image (reference image) registration and inspection. Fig. 7(a) is an example of an image registered in the inspection module 109. In Fig. 7(a), either the scanned image or the RIP image is registered as the correct image, and an example of registering the pattern image held by the printing module 107 is shown. Specifically, the CPU 222 of the printing module 107 (hereinafter, the CPU 222 of the printing module 107 is appropriately abbreviated as CPU 222) sends the pattern image stored in the HDD 221 to the inspection module 109. The CPU 238 receives the sent pattern image as a patch image to be registered. The CPU 238 advances the process of S1202 to the process of S1203. In S1203, the CPU 238 stores the pattern image received in S1202 in the HDD 256. Then, when the storage is completed, the CPU 238 ends this flow.

[0058] In addition, in S1202, the pattern image may not be the image data received from the printing module 107, and the pattern image may be printed by the printing module 107 and the image data captured by the imaging unit 240 may be used. Thus, the method for acquiring the pattern image is not particularly limited. When the storage of the pattern image is completed, the image registration screen 600 in FIG. 6 transitions to the registration processing screen 800. In the case of the "adjustment patch image registration mode", the buttons 802 and 803 are not displayed, and the image display area 801 and the buttons 804 and 805 are displayed. The user checks the pattern image displayed in the image display area 801 and selects (presses) either the button 804 or the button 805. When the button 804 is selected (pressed), the CPU 238 registers the pattern image being displayed in the image display area 801 in the HDD 256 in association with the corresponding inspection job.

[0059] (Confirmation of Inspection Results) On the above inspection menu screen 400, when the user presses button 405, a UI screen for confirming the inspection results as shown in Fig. 10(a) (hereinafter referred to as the "result confirmation screen 1000") is displayed on the display unit 241. On the result confirmation screen 1000, a result display area 1001, a spin button 1002, and an OK button 1003 are arranged. The result display area 1001 is arranged at the center of the result confirmation screen 1000. The spin button 1002 is arranged on the lower left side of the result confirmation screen 1000. The OK button 1003 is arranged on the lower right side of the result confirmation screen 1000. Details of the inspection results are displayed in the result display area 1001. The spin button 1002 has a function of switching the inspection job to be displayed. In Fig. 10(a), an example is shown in which, for the first job out of the 9 inspection jobs whose history is saved, the time, job name, number of inspections, number of OKs, and number of NGs are displayed in the result display area 1001. The time is the inspection execution date and time. The job name is the name of the target inspection job. The number of inspections is the number of times the inspection is executed. The number of OKs is the number of qualified pieces among the number of executions. The number of NGs is the number of unqualified pieces among the number of executions. The user can switch the inspection job to be displayed by operating the left and right spin buttons 1002. When the user who has confirmed the inspection results operates (presses) the OK button 1003, the result confirmation screen 1000 in Fig. 10(a) changes the display screen to the inspection menu screen 400 in Fig. 5.

[0060] (Details of External Controller) The usage method of the external controller 102 will be described in detail. A user who has performed various pre-settings described above for the inspection module 109 gives an instruction to generate a correct image registration job in which settings are made using the external controller 102 as to whether to perform the above-described inspection job or apply an adjustment patch. The generated inspection job or print job is input into the image forming apparatus 101. FIG. 10(b) is an example of a UI screen (hereinafter referred to as the "job setting screen 1100") for setting operation conditions in the correct image registration job and the inspection job. The job setting screen is displayed on the display 212 of the external controller 102. Note that the display control of this job setting screen 1100 is performed by the CPU 208 in the external controller 102. In the job setting screen 1100, a setting area 1101, a setting area 1102, and buttons 1103 to 1106 are arranged. That is, in the example of FIG. 10(b), the job setting screen 1100 has two setting areas 1101 and 1102 and four buttons 1103 to 1106. The setting area 1101 is an area for setting the number of printed copies in the inspection job. In the example of FIG. 10(b), an inspection job for specifying printing of 1000 copies will be generated. The setting area 1102 is an area for setting the paper discharge destination of the sheet processed according to the registration job or the inspection job. In the example of FIG. 10(b), the stacker 110 is selected as the basic paper discharge destination, and the escape tray 346 is selected as the paper discharge destination when a printing defect is found (that is, when an NG determination is made in the inspection process). The user can select a paper discharge destination according to the application, such as discharging the paper to the stacker 110 during mass printing accompanied by inspection processing. Also, a plurality of paper discharge destinations may be configured to be set for each of the basic and when a defect is found. The button 1103 is a button for setting printing conditions other than the paper discharge destination. By operating (pressing) the button 1103, a pop-up screen (not shown) is displayed, and the user can perform face-up setting, print quality setting, finishing setting, paper discharge surface setting, and the like. Here, the face-up setting is a setting for specifying, for example, double-sided printing or 2in1 printing. The print quality setting is a setting for specifying, for example, which of quality and processing speed is to be prioritized during printing.The finishing settings are settings for specifying post - processing details such as stapling or punching holes. The paper discharge surface settings are settings for specifying whether to discharge the paper in the face - up or face - down form for the selected paper discharge destination. Face - up means discharging the paper with the surface facing upward. Face - down means discharging the paper with the surface facing downward. Button 1104 is a button for instructing to print only one copy of the inspection job. When an instruction to print one copy of the inspection job is given to the external controller 102 by operating (pressing) button 1104, printing processing by the printing module 107 and reading of the correct image by the inspection module 109 are performed. Button 1105 is a button for instructing the start of printing of the inspection job. When the start of printing is instructed by operating (pressing) button 1105, the external controller 102 inputs the inspection job to the printing module 107 based on the settings of the job setting screen 1100 in Fig. 10(b). When the start of printing of the inspection job is instructed to the external controller 102 by operating (pressing) button 1105, the external controller 102 inputs the inspection job to the printing module 107. Thereby, the printing module 107 performs printing based on the inspection job. If the inspection job is a job with settings for applying adjustment patches, the printing is performed with adjustment patches applied to the image after RIP processing by the printing module 107. The printing module 107 is instructed to convey the printed print sheet to the inspection module 109. The inspection module 109 reads the image of the print sheet when the print sheet is conveyed from the printing module 107. Thereby, the inspection process is performed. Note that button 1106 has a function of canceling the currently executing process. Specifically, when button 1106 is operated (pressed), the job setting screen 1100 closes.

[0061] (Details of the inspection operation) Next, with reference to FIGS. 13 and 14, the specific processing flow when performing printing processing with inspection and the processing flow in the case of a job for setting to print a pattern image will be described. FIG. 13 is a flowchart showing the processing of the printing module 107. FIG. 14 is a flowchart showing the processing of the inspection module 109. Each process in the flowchart of FIG. 13 is realized, for example, by the CPU 222 reading and executing a control program stored in the memory 223 or the HDD 221. On the other hand, each process in the flowchart of FIG. 14 is realized, for example, by the CPU 238 reading and executing a control program stored in the memory 239 or the HDD 256. Note that some or all of the functions of the steps in FIGS. 13 and 14 may be realized by hardware such as an ASIC or an electronic circuit. The symbol "S" in the description of each process means that it is a step in the flowchart diagram.

[0062] The user operates (presses) a button 406 for calling the "start inspection" function on the inspection menu screen 400 of the inspection module 109. Thereby, the inspection module 109 detects that the button 406 has been operated (pressed), starts an inspection job, starts the processing of FIG. 13, and starts the processing of FIG. 14 after the processing of FIG. 13 ends.

[0063] In S1301, a print job is received from the external controller 102. When the CPU 222 receives the print job, it advances the processing of S1301 to S1302. In S1302, the CPU 222 determines whether the print job received in S1301 is a print job with a pattern image. That is, it checks whether the print job contains information for printing a pattern image such as an adjustment patch. If it is a print job for printing a pattern image, the CPU 222 advances the processing of S1302 to the processing of S1303. The CPU 222 determines whether to print the pattern image on the sheet to be printed now. If the CPU 222 is to print the pattern image on the sheet, it advances the processing of S1303 to the processing of S1304. In S1304, the CPU 222 adds the pattern image read from the HDD 221 to the RIP-processed image data received from the external controller 102 and causes the sheet to be printed. The CPU 222 advances the processing of S1304 to the processing of S1307. In S1307, the CPU 222 transmits information indicating that it is a "print job with a pattern image" to the inspection module 109. The CPU 222 advances the processing of S1307 to the processing of S1308. Here, the timing of transmitting information to the inspection module 109 in S1307 is not limited. Even if it is a "print job with a pattern image", the printing timing of the pattern image is information that cannot be known in advance, and it may be configured to transmit the information as soon as it is known as long as it is before the processing of FIG. 14 starts. For example, among the jobs for printing 1000 sheets, the RIP image is printed over all pages. On the other hand, the pattern image is included in the print job, but for example, it is printed every 100 sheets. This interval of 100 sheets is not determined by the print job. The printing timing of this pattern image appropriately changes according to the hardware status of the printing module 107, such as the usage status (number of uses) of the printing module 107 of the machine body, the usage status of the toner cartridge, and the usage status of the photosensitive drum.

[0064] In S1303, when the CPU 222 does not print a pattern image on the sheet, it advances the process of S1303 to the process of S1305. In S1305, the CPU 222 prints the image data received from the external controller 102. The CPU 222 advances the process of S1305 to the process of S1307. On the other hand, in S1302, if it is a job that does not print a pattern image, the CPU 222 advances the process of S1302 to S1306. In S1306, the CPU 222 of the printing module 107 generates a RIP image from the image data received from the external controller 102, and causes an image to be printed on the sheet based on the generated RIP image. The CPU 222 advances the process of S1306 to the process of S1308. In S1308, the CPU 222 determines whether the sheets printed in S1304, S1305, and S1306 are the last page of the print job. If it is the last page, the CPU 222 ends the processes of S1302 to S1308. If it is not the last page, the CPU 222 repeats the processes of S1302 to S1308.

[0065] The process of the inspection module 109 in FIG. 14 will be described. In S1309, the CPU 238 receives a sheet image. Specifically, the CPU 238 causes the conveyed sheet to be photographed by the photographing unit 240. The CPU 238 advances the process of S1309 to the process of S1310. In S1310, the CPU 238 reads out the correct image of the page corresponding to the inspection image photographed in S1309 from the memory 239. The CPU 238 advances the process of S1310 to S1311. In S1311, the CPU 238 determines whether it is a "print job with a pattern image". Information on whether it is a "print job with a pattern image" is information received from the printing module 107. If it is a print job with a pattern image, the CPU 238 advances the process of S1311 to S1312.

[0066] In S1312, the CPU 238 reads the pattern image stored in the HDD 256 shown in FIG. 7(a) into the memory 239. The CPU 238 advances the process of S1312 to the process of S1313. In S1313, the CPU 238 determines whether the inspection image captured in S1309 contains the pattern image by any method. That is, the CPU 238 determines whether there is a pattern image on the sheet based on the captured image actually captured of the inspection image. If there is a pattern image on the sheet, the CPU 238 advances the process of S1313 to the process of S1314. The determination of whether there is a pattern image in the inspection image of the sheet may be made, for example, by pattern matching, but is not limited to this method. In S1314, the CPU 238 extracts the area of the pattern image within the inspection image. The area of the pattern image may be an area that includes all of the pattern image. For example, an area that includes only the pattern image may be extracted. Such extraction may be performed based on a predetermined extraction algorithm such as edge detection by an edge filter of the image. Alternatively, an area that includes only the pattern image by the hyperplane of the support vector machine may be extracted. The CPU 238 advances the process of S1314 to the process of S1315. In S1315, the CPU 238 sets the area including the extracted pattern image as an area outside the inspection target. Also, at the time of this setting, the CPU 238 saves the correct image of this sheet in the memory 239 to prepare for the inspection. Subsequently, the process proceeds to S1316.

[0067] On the other hand, in S1311, if it is not a print job without a pattern image, the CPU 238 advances the process of S1311 to S1316. Alternatively, in S1313, if there is no pattern image on the sheet, the CPU 238 advances the process of S1313 to the process of S1316.

[0068] In S1316, the CPU 238 performs an inspection using the correct image read into the memory 239. The inspection will be described with reference to FIG. 7(c). FIG. 7(c) is a diagram showing an example of an inspection image and an inspection area. When no pattern image is printed on the inspection image, such as "Inspection Image 1", a full inspection is performed. On the other hand, when a pattern image is printed on the inspection image, such as "Inspection Image 2", the area including the pattern image is excluded from the inspection target. In S1317, the CPU 238 stores the inspection result in the HDD 260. The CPU 238 proceeds to the process of S1318 from the process of S1317. In S1318, the CPU 238 determines whether the sheet inspected in S1316 is the last page of the job. If it is the last page of the job, the CPU 238 ends the process of S1318. On the other hand, if it is not the last page, the CPU 238 returns the process of S1318 to the process of S1309 and repeats the processes of S1309 to S1318.

[0069] <Effect of the First Embodiment> As described above, according to the present embodiment, even when it is unknown on which sheet of the job the pattern image given by the printing module 107 is printed after the RIP process, the following can be achieved. That is, the presence or absence of the pattern image is determined based on the captured image of the sheet on which the pattern image is printed. By this operation, it is possible to perform an inspection with the pattern image portion excluded from the inspection target for the sheet having the pattern image among a plurality of sheets. Also, for the sheet on which the pattern image is not printed, the inspection can be performed with the maximum inspection area, and the possibility of overlooking defects during the inspection can be reduced.

[0070] Specifically, the CPU 238 acquires a read image obtained by reading a printed matter. When the read image includes a pattern image that is not a subject of inspection, the CPU 238 sets the area including the pattern image in the read image as not being a subject of inspection. According to this operation, the inspection module 109 can set an area that is not a subject of inspection from the read image. The read image is an image obtained by reading from an actual printed matter. Therefore, only the locations where the pattern image is actually printed can be excluded from the inspection target, so the inspection target is not unnecessarily narrowed. Therefore, the adjustment function can be realized without inhibiting the inspection function.

[0071] Also, the CPU 238 may use, as an inspection image, an image that is a read image and corresponds to an inspection target surface that is a subject of inspection. According to this operation, the inspection image is to be selected from the read images. Therefore, the inspection image is to be selected from the images obtained by reading from an actual printed matter. Therefore, it becomes possible to perform the inspection more accurately.

[0072] Also, the pattern image may be an image different from a correct image that is a criterion for determining whether there is a defect in the inspection image. According to this operation, something different from the inspection target can be used as the pattern image. Therefore, it becomes possible to process separately the image for inspection and the image for adjustment.

[0073] Also, the correct image may be an image generated based on a print job for printing another printed matter different from the printed matter. According to this operation, the print job for printing the inspection image and the print job for printing the correct image can be made different. Therefore, since the registration process of the correct image and the inspection process of the inspection image can be separated, it becomes possible to register in advance the correct image that is a criterion for determination.

[0074] Also, the correct image may be an image obtained by reading another printed matter. According to this operation, the process of obtaining the correct image can be performed in a series of processes as the inspection system 100, so it is possible to provide a highly productive process.

[0075] Also, the correct image may be an image generated based on a RIP image composed of raster images generated based on a print job. According to this operation, the correct image itself is obtained from the RIP image. Therefore, resources allocated for generating the correct image (print module 107) and resources allocated for inspection (inspection module 109 and adjustment module 112) can be distributed, so that processing considering the overall load balance can be performed. Accordingly, it is possible to avoid a local increase in the power consumption of each of the CPUs 222, 238, and 256.

[0076] Also, the pattern image may be composed of adjustment patches for adjusting the color tone of the pattern image. According to this operation, an adjustment patch and an inspection target can be included in the read image. Therefore, it is possible to appropriately print the adjustment patch while printing the inspection target. Accordingly, it is possible to improve the productivity of inspection.

[0077] Also, the pattern image may be composed of front-back registration for adjusting the relative positional relationship between the inspection image and the printed matter. According to this operation, the front-back registration and the inspection target can be included in the read image. Therefore, it is possible to appropriately print the front-back registration while printing the inspection target. Accordingly, it is possible to improve the productivity of inspection.

[0078] <<Second Embodiment>> In the first embodiment, the process of registering a correct image without a pattern image has been described. In the second embodiment, the process of registering a correct image with a pattern image will be described. Note that the functional configuration in this embodiment is the same as that of the first embodiment for the functional configuration not described in this embodiment.

[0079] (Registration of Correct Image) (Fig. 6(b): When "Correct Image Registration with Adjustment Patch" is selected in the Registration Mode Selection Unit 601) The case where "Correct Answer Image Registration with Adjustment Patch" is selected in the registration mode selection unit 604 will be described. Specifically, the operation when the OK button 602 is pressed with "Correct Answer Image Registration with Adjustment Patch" selected in the registration mode selection unit 604 of the image registration screen 600 will be described with reference to FIG. 7(b) and FIG. 15. FIG. 15 is a flowchart showing the processing of the inspection module 109 at the time of correct answer image registration with an adjustment patch. Each process shown in FIG. 15 is realized, for example, by the CPU 238 reading and executing a control program stored in the memory 239 or the HDD 256. Specifically, each process shown in FIG. 15 starts when the OK button 602 is operated (pressed) with "Correct Answer Image Registration with Adjustment Patch" selected in the registration mode selection unit 604 of the image registration screen 600. First, when the OK button 602 is operated (pressed), the screen transitions to the image generation in progress screen. In S1204, if the registration mode selected in the registration mode selection unit 604 is "Correct Answer Image Registration with Adjustment Patch", the CPU 238 advances the process of S1204 to the process of S1205. In S1205, the CPU 238 reads an image. FIG. 7(b) is an example of an image registered in the inspection module 109 as a correct answer image. Separate from the correct answer image without a pattern image described in FIG. 11 for the registration method, a correct answer image with a pattern image printed thereon, such as a "correct answer image with a pattern image", is registered. That is, the correct answer image and the pattern image are registered on the same side of one side of a virtual sheet. In S1205, the CPU 222 executes printing with a pattern image such as an adjustment patch added to the image after the RIP process of the print job. The printed matter with the pattern image added to the image after the RIP process is photographed by the photographing unit 240 of the inspection module 109. The CPU 238 of the inspection module 109 saves the photographed image data in the memory 239. The CPU 238 advances the process of S1205 to the process of S1206. In S1206, the CPU 238 displays the inspection setting screen 901 on the display unit 241. By this operation, the image data stored in the memory 239 is displayed in the preview area 902 as shown in FIG. 9(a). The CPU 238 advances the process of S1206 to the process of S1207.In S1207, the CPU 238 receives a user operation and, as shown in FIG. 9(b), sets the area including the pattern image in the image data as an area outside the inspection target. When the setting is completed and the OK button 905 is pressed, the CPU 238 advances the process of S1207 to the process of S1208. In S1208, the CPU 238 associates the inspection settings received on the inspection setting screen 901 with the image data generated in S1205 and stores them in the HDD 256.

[0080] Note that in S1205, the correct image may be generated by a method of receiving, from the printing module 107, image data in a state where a pattern image is added to the image after RIP image processing. Thus, the method for generating the correct image is not particularly limited. Also, in S1207, although an example of receiving a user operation is described, it is not particularly limited thereto. For example, a machine learning model may be generated by using image data repeatedly captured by machine learning, and the area outside the inspection target may be automatically selected by the generated machine learning model.

[0081] (Details of the inspection operation) Using FIGS. 16 and 17, the specific process flow when performing a printing process involving inspection and the process flow in the case of a job for setting to print a pattern image will be described. FIG. 16 is a flowchart showing the process of the printing module 107. FIG. 17 is a flowchart showing the process of the inspection module 109. Each process in the flowchart of FIG. 16 is realized, for example, by the CPU 222 reading and executing a control program stored in the memory 223 or the HDD 221. On the other hand, each process in the flowchart of FIG. 17 is realized, for example, by the CPU 238 reading and executing a control program stored in the memory 239 or the HDD 256. Note that some or all of the functions of the steps in FIGS. 16 and 17 may be realized by hardware such as an ASIC or an electronic circuit. The symbol "S" in the description of each process means that it is a step in the flowchart diagram.

[0082] The user operates (presses) a button 406 that calls the "Inspection Start" function on the inspection menu screen 400 of the inspection module 109. As a result, the inspection module 109 detects that the button 406 has been operated (pressed), starts an inspection job, starts the process of FIG. 16, and starts the process of FIG. 17 after the process of FIG. 16 ends.

[0083] In S1401, the CPU 222 receives a print job from the external controller 102. When the CPU 222 receives the print job, it advances the process of S1401 to the process of S1402. In S1402, the CPU 222 determines whether the print job received in S1401 is a print job with a pattern image. That is, it checks whether the print job contains information for printing a pattern image such as an adjustment patch. If it is a print job for printing a pattern image, the CPU 222 advances the process of S1402 to the process of S1403. The CPU 222 determines whether to print a pattern image on the sheet to be printed now. If the CPU 222 is to print a pattern image on the sheet, it advances the process of S1403 to S1404. In S1404, the CPU 222 adds the pattern image read from the HDD 221 to the RIP-processed image data received from the external controller 102 and causes the sheet to be printed. The CPU 222 advances the process of S1404 to the process of S1407. In S1407, the CPU 222 transmits information indicating that it is a "sheet with a pattern image" to the inspection module 109. The CPU 222 advances the process of S1407 to the process of S1408.

[0084] In S1403, when the CPU 222 does not print a pattern image on the sheet, it advances the process of S1403 to the process of S1405. In S1405, the CPU 222 prints the image data received from the external controller 102. The CPU 222 advances the process of S1405 to the process of S1408. In S1408, the CPU 222 transmits information indicating that it is a "print job with a pattern image" to the inspection module 109. The CPU 222 advances the process of S1408 to the process of S1409. On the other hand, in S1402, when the CPU 222 is a job that does not print a pattern image, it advances the process of S1402 to the process of S1406. In S1406, the CPU 222 prints the image data received from the external controller 102. The CPU 222 advances the process of S1406 to the process of S1409. In S1409, the CPU 222 determines whether the sheet printed in S1404, S1405, and S1406 is the last page of the print job. If it is the last page, the CPU 222 ends the processes of S1402 to S1409. If it is not the last page, the CPU 222 repeats the processes of S1402 to S1409.

[0085] The process of the inspection module 109 in FIG. 17 will be described. In S1410, the CPU 238 receives a sheet image. Specifically, the CPU 238 causes the conveyed sheet to be photographed by the photographing unit 240. The CPU 238 advances the process of S1410 to the process of S1411. In S1411, the CPU 238 determines whether it is a "print job with a pattern image". Information indicating whether it is a "print job with a pattern image" is information received from the printing module 107. If it is a print job with a pattern image, the CPU 238 advances S1411 to S1412. In S1412, the CPU 238 determines whether it is a "sheet with a pattern image". If it is a sheet with a pattern image, the CPU 238 advances the process of S1412 to the process of S1413.

[0086] In S1413, the CPU 238 reads out the "correct image with pattern image" from the memory 239 and performs an inspection. The "correct image with pattern image" is stored in, for example, the HDD 256. As shown in FIG. 7(b), the "correct image with pattern image" is a state in which not only the correct image but also the pattern image is given on one sheet. That is, the correct image with pattern image means a case where the correct image and the pattern image are registered on the same side of one side of a virtual sheet. Therefore, if an inspection is performed in this state, since the pattern image is associated with the correct image, an inspection including the pattern image becomes possible. In other words, the area outside the inspection target is released, and it becomes possible to set the entire surface of the sheet as the inspection target. That is, when the correct image and the pattern image are registered on the same side of one side of a virtual sheet, the surface of the printed matter corresponding to the same side is set as the inspection target. On the other hand, in S1411, when the CPU 238 is a print job without a pattern image, the CPU 238 advances the process of S1411 to S1414. Alternatively, in S1412, when the CPU 238 is a sheet without a pattern image, the CPU 238 advances the process of S1412 to the process of S1414. In S1414, the CPU 238 reads out the "correct image without pattern image" from the memory 239 and performs an inspection. The "correct image without pattern image" is stored in, for example, the HDD 256. As shown in FIG. 7(b), the "correct image without pattern image" is a state in which the correct image is given on one sheet but the pattern image is not given. Here, the "correct image without pattern image" refers to the correct image registered without printing the pattern image, as described in the flowchart of correct image registration in FIG. 11. When the pattern image is not printed on the inspection image as in "inspection image 1" in FIG. 7(c), the CPU 238 performs a full-surface inspection using the "correct image without pattern image" in FIG. 7(b). On the other hand, when the pattern image is printed on the inspection image as in "inspection image 2" in FIG. 7(c), the CPU 238 performs an inspection with only the area including the pattern image excluded from the inspection target using the "correct image without pattern image" in FIG. 7(b). When the processes of S1413 and S1414 are completed, the CPU 238 advances to the process of S1415 and saves the inspection result in the HDD 256.The CPU 238 advances the process of S1415 to the process of S1416. The CPU 238 determines whether the sheet inspected in S1413 and S1414 is the last page of the inspection job. If it is the last page of the inspection job, the CPU 238 ends the process. On the other hand, if it is not the last page, the CPU 238 repeats the processes of S1410 to S1416.

[0087] <Effect of the Second Embodiment> As described above, according to this embodiment, even when it is unclear on which sheet of the job the image applied by the printing device after the RIP process is printed, the following effects can be obtained. That is, when inspecting the sheet on which the pattern image is printed, the inspection can be performed using the correct image with the pattern image portion excluded from the inspection target. For the sheet on which the pattern image is not printed, the inspection area can be maximized, and the possibility of overlooking defects during inspection can be reduced. In other words, according to this embodiment, the area outside the inspection target can be minimized, so that more printing defects due to deterioration or malfunction of the printer engine of the printing module 107 can be detected.

[0088] Specifically, the CPU 238 may register at least one of the correct image and the pattern image on one side of a virtual sheet. Further, when the correct image and the pattern image are registered on the same side of one side, the CPU 238 may cancel the setting of not making the area including the pattern image the inspection target and set the surface of the printed matter corresponding to the same side as the inspection target. According to this operation, if the correct image with the pattern image is registered, the area outside the inspection target is canceled, so that the entire surface of one side of the printed matter can be expanded as the inspection target. Therefore, it is possible to perform the inspection more reliably.

[0089] <<Modification Example>> Here, the additional effects achieved by executing Embodiments 1 and 2 will be described. In the inspection system, when NG judgments continue continuously, there is a function to stop printing when the number of NG judgment sheets exceeds a predetermined number. The case where this function and the configurations of Embodiments 1 and 2 exist will be described. In the parts not described in this example, they are the same as those in Embodiment 2.

[0090] (Registration of correct image) Regarding the registration of the correct image, a user operation is received at S1207 in the flowchart of FIG. 15, and the entire range including the pattern image area in the image data is set as the inspection target area. In the inspection settings described in FIG. 9, for example, a threshold for stopping printing may be set when the discovery of printing defects (that is, when an NG judgment is made in the inspection process) continues. It is a setting to stop printing when NG judgments continue continuously for more than this number. Note that when set to 0, it means that printing is not stopped even if an NG judgment is made. For example, if there are scratches or damages on the parts of the image forming unit 228 or the fixing unit 229 of the printing module 107, printing defects such as streaks or smudges will occur. The inspection device is used to detect such defects, but if the setting to stop printing is not performed when NG judgments continue continuously, printing will continue with the defects, resulting in a large amount of wasted paper. To prevent such inconveniences, it is beneficial to stop printing when NG judgments continue continuously, which leads to a reduction in wasted paper.

[0091] (Details of inspection operation) The inspection operation is as described using the flowchart of FIG. 17 in Embodiment 2. When it is determined at S1412 that it is a "sheet with a pattern image", at S1413, a full inspection including the pattern image area is performed using the correct image with the pattern image. With such a configuration, it is possible to detect printing defects in the pattern image area. When a setting is made to stop printing when consecutive NG determinations continue, if printing defects continuously occur in the pattern image area and it is excluded from the inspection target, it is not determined as NG, and printing continues thereafter. For example, there is a printing defect in the upper left corner of the paper, and a pattern image is printed in this area. For example, assuming that the threshold value of this setting is set to 5 times and the 4th sheet with a pattern image is printed. When the pattern image area is excluded from the inspection target, even if there is a printing defect in the pattern image area, the 4th sheet is determined as OK. In reality, it should be determined as NG for 5 consecutive sheets, but the 1st to 3rd sheets are NG, the 4th sheet which is excluded from the inspection target is OK, the 5th sheet is determined as NG, and the consecutive NG count is reset during the inspection of the 4th sheet. That is, by excluding the location of the pattern image from the inspection target, when a sheet with a pattern image appears during the inspection, the accumulation of the consecutive NG count cannot be achieved, and there is a risk of delay in discovering printing defects.

[0092] On the other hand, when the pattern image area is included in the inspection target, the 4th sheet with a defect in the pattern image area is also determined as NG, and when the 5th sheet is inspected, the NG count reaches 5 consecutive times and printing stops. That is, since the inspection is performed including the location of the pattern image, the accumulation of the consecutive NG count can be achieved during the inspection. According to this operation, it is possible to detect printing defects at an early stage. As a result, the user can quickly notice engine deterioration or malfunction and prevent an increase in waste paper.

[0093] In other words, when the cumulative number of consecutive determinations that there is a defect in the inspection image reaches a preset threshold number of times with the setting in which the CPU 238 does not target the area including the pattern image for inspection being cancelled, the determination as to whether there is a defect in the inspection image may be interrupted. According to this operation, since it is possible to shift to the verification work as to whether there is a malfunction in the printing module 107 assumed when the determination that there is a defect in the inspection image continues continuously, it is possible to suppress the generation of waste paper.

[0094] <<Other Embodiments>> In each of the above-described embodiments, the description has been made based on an example in which the correct image is generated from the scan image or the RIP image. However, it is not limited to this example. For example, a part of the correct image may be generated from the scan image and the rest of the correct image may be generated from the RIP image. The division between the scan image and the RIP image may be made, for example, such that a simple figure is generated from the scan image and a complex figure is generated from the RIP image.

[0095] As described above, various examples and embodiments of the present disclosure have been shown and described. However, the gist and scope of the present disclosure are not limited to the specific description in this specification.

[0096] The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium and causing one or more processors in a computer of the system or device to read and execute the program. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

[0097] The disclosure of the present embodiment includes configurations represented by the following inspection device, inspection system, control method of the inspection system, and program.

[0098] <Configuration 1> An inspection device for inspecting a printed matter, acquisition means for acquiring a read image obtained by reading the printed matter; When the read image includes a pattern image that is not the object of the inspection, setting means for setting the area including the pattern image in the read image as not being the object of the inspection; An inspection apparatus, characterized by comprising the same.

[0099] <Configuration 2> The inspection apparatus according to Configuration 1, wherein the setting means uses, as an inspection image, an image in the read image that corresponds to an inspection target surface that is the object of the inspection.

[0100] <Configuration 3> The inspection apparatus according to Configuration 2, wherein the pattern image is an image different from a correct image that serves as a criterion for determining whether there is a defect in the inspection image.

[0101] <Configuration 4> The inspection apparatus according to Configuration 3, wherein the correct image is an image generated based on a printing job for printing another printed matter different from the printed matter.

[0102] <Configuration 5> The inspection apparatus according to Configuration 4, wherein the correct image is an image generated based on an image obtained by reading the other printed matter.

[0103] <Configuration 6> The inspection apparatus according to Configuration 4, wherein the correct image is an image generated based on a RIP image composed of a raster image generated based on the printing job.

[0104] <Configuration 7> The inspection apparatus according to any one of Configurations 1 to 6, wherein the pattern image is composed of an adjustment patch for adjusting the color tone of the pattern image.

[0105] <Configuration 8> The inspection apparatus according to Configuration 5, wherein the pattern image is composed of a front-back registration for adjusting the relative positional relationship between the inspection image and the printed matter.

[0106] <Configuration 9> Further comprising registration means for registering at least one of the correct image and the pattern image on one side of a virtual sheet. When the correct image and the pattern image are registered on the same side of the one side by the registration means, the setting means cancels the setting of not subjecting the area including the pattern image to the inspection, and sets the surface of the printed matter corresponding to the same side as the inspection target. The inspection apparatus according to any one of Aspects 3 to 6.

[0107] <Configuration 10> When the cumulative number of times continuously determined that there is a defect in the inspection image reaches a preset threshold number of times in a state where the setting of not subjecting the area including the pattern image to the inspection is canceled, further comprising inspection means for interrupting the determination of whether there is a defect in the inspection image. The inspection apparatus according to Configuration 9.

[0108] <Configuration 11> An inspection system including a printing apparatus and an inspection apparatus, The printing apparatus prints at least one of an inspection image corresponding to an inspection target surface to be inspected, a correct image serving as a determination criterion for whether there is a defect in the inspection image, and a pattern image different from the correct image on a sheet. The inspection apparatus Acquisition means for acquiring a read image obtained by reading a printed matter, Setting means for setting an area including the pattern image in the read image as not subject to the inspection when the read image includes a pattern image that is not the inspection target. An inspection system characterized by having.

[0109] <Configuration 12> A control method for an inspection system, A step of printing at least one of an inspection image corresponding to an inspection target surface to be inspected, a correct answer image serving as a determination criterion for whether there is a defect in the inspection image, and a pattern image that is an image different from the correct answer image on a sheet; A step of acquiring a read image obtained by reading a printed matter; When the read image includes a pattern image that is not the inspection target, a step of setting a region including the pattern image in the read image as not being the inspection target; A control method for an inspection system, characterized by including the above.

[0110] <Configuration 13> A program for causing a computer to execute each step of the control method according to claim 12.

Explanation of Signs

[0111] Printing module 107 Inspection module 109 Adjustment module 112

Claims

Claim 1 An inspection apparatus for inspecting a printed matter, comprising: an acquisition means for acquiring a read image obtained by reading the printed matter; a setting means for setting, when a pattern image that is not an inspection target is included in the read image, an area including the pattern image in the read image as not being an inspection target; An inspection apparatus characterized by comprising the above. Claim 2 The inspection apparatus according to claim 1, wherein the setting means sets, as an inspection image, an image that is the read image and corresponds to an inspection target surface that is an inspection target. Claim 3 The inspection apparatus according to claim 2, wherein the pattern image is an image different from a correct image that is a criterion for determining whether there is a defect in the inspection image. Claim 4 The inspection apparatus according to claim 3, wherein the correct image is an image generated based on a print job for printing another printed matter different from the printed matter. Claim 5 The inspection apparatus according to claim 4, wherein the correct image is an image generated based on an image obtained by reading the other printed matter. Claim 6 The inspection apparatus according to claim 4, wherein the correct image is an image generated based on a RIP image composed of a raster image generated based on the print job. Claim 7 The inspection apparatus according to any one of claims 1 to 6, wherein the pattern image is composed of an adjustment patch for adjusting the color tone of the pattern image. Claim 8 The inspection apparatus according to claim 5, wherein the pattern image is composed of a front-back registration for adjusting the relative positional relationship between the inspection image and the printed matter. Claim 9 The inspection apparatus further comprises a registration means for registering at least one of the correct image and the pattern image with respect to one surface of a virtual sheet, When the correct image and the pattern image are registered with respect to the same surface of the one surface by the registration means, the setting means cancels the setting of the area including the pattern image as not being an inspection target, and sets the surface of the printed matter corresponding to the same surface as an inspection target. The inspection apparatus according to any one of claims 3 to 6, characterized in that Claim 10 In a state where the setting that excludes the area including the pattern image from the inspection target is canceled, when the cumulative number of consecutive determinations that there is a defect in the inspection image reaches a preset threshold number of times, the inspection device according to claim 9, further comprising inspection means for interrupting the determination as to whether there is a defect in the inspection image.

11. An inspection system including a printing device and an inspection device, wherein the printing device prints at least one of an inspection image corresponding to an inspection target surface to be inspected, a correct image serving as a determination criterion for whether there is a defect in the inspection image, and a pattern image that is an image different from the correct image on a sheet, and the inspection device comprises acquisition means for acquiring a read image obtained by reading a printed matter, and setting means for setting an area including the pattern image in the read image as not being an inspection target when the read image includes a pattern image that is not an inspection target. An inspection system characterized by comprising the above.

12. A control method for an inspection system, comprising: printing at least one of an inspection image corresponding to an inspection target surface to be inspected, a correct image serving as a determination criterion for whether there is a defect in the inspection image, and a pattern image that is an image different from the correct image on a sheet; acquiring a read image obtained by reading a printed matter; and when the read image includes a pattern image that is not an inspection target, setting an area including the pattern image in the read image as not being an inspection target. A control method for an inspection system, characterized by comprising the above.

13. A program for causing a computer to execute each step of the control method according to claim 12.

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