Inspection device, inspection method, program, and printing device

Abstract

To solve a problem of a conventional printing device that a slipping occurs in conveyance of a printing sheet according to a loading amount of a toner and a printing image is contracted in a conveyance direction of the printing sheet, and due to this, at the time of inspection of a printed matter, a deviation exceeding a correction allowable range occurs in positioning for defect abnormality detection by comparison between a printing result and a reference image, so that positioning becomes difficult in some cases.SOLUTION: An inspection device of the present invention that performs inspection of a printed matter corrects an RIP image serving as a reference image on the basis of a loading amount of a toner. The inspection is performed by comparing the corrected reference image and a read image obtained by reading the printed matter.SELECTED DRAWING: Figure 7

Description

[Technical field]

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

[0002] In recent years, printing systems have become known that allow inspection of sheets printed by a printing device using an inspection device while they are being transported. In the inspection of printed sheets, the inspection device reads an image of the printed sheet as it is being transported, and determines whether the printed sheet is normal by analyzing the read image. The inspection device can detect, for example, missing barcodes or lines, printing abnormalities, etc.

[0003] When a print sheet is determined to be defective in this way, the defective sheet is discharged to a different destination from the normal sheets, which prevents the defective sheet from being mixed in with the normal sheets and allows the operator to easily discard the defective sheet.

[0004] A method that uses a RIP (Raster Image Processor) image prepared in advance is known as a method for creating a correct image to be used in image analysis. By simulating an image scanned from the RIP image in the actual inspection process, it is possible to reduce inspection erroneous judgments caused by the conveyance accuracy of the print sheet and the accuracy of the sensor reading.

[0005] In this inspection device, the registration of the correct image and the scanned image is performed, and the inspection is performed by taking the difference between the two. The registration between the images is performed by feature amount registration and by detecting the four corners of the sheet, and then fine registration is performed by Free Form Deformation (FFD). Patent Document 1 proposes an image inspection device that aligns and compares the registration image data obtained by reading an original image with the inspection image data obtained by reading a printed sheet on which an image has been formed by an image forming device, checks the difference, and detects abnormalities in the inspection image.

[0006] In addition, in printing devices, the sheet transport speed can cause a small deviation in the print position depending on the device and sheet environment and the print content. Of these deviations, the deviation due to the print content is known to occur when toner is placed on the sheet, making the sheet slippery and making it difficult to transmit the force that transports the sheet, resulting in a delay in sheet transport and shrinking the printed image in the sheet transport direction. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2019-217724 A Summary of the Invention [Problem to be solved by the invention]

[0008] With the above-mentioned conventional technology, when printing an image with a large amount of toner, the image shrinks in the sheet transport direction, which can cause the balance between the image and the margins to be lost. If the amount of misalignment in the print is small, it is possible to correct the alignment using FFD, but for large sheets, the amount of misalignment exceeds the amount that can be corrected by FFD, making alignment difficult. If alignment fails, parts that are not actually abnormal may be judged as abnormal, leading to false detection of an abnormality. [Means for solving the problem]

[0009] The present invention is an inspection device for inspecting printed matter, and includes a print data acquisition unit that acquires print data, a reference image generation unit that generates a reference image from the acquired print data, an image reading unit that reads a printed matter on which the print data has been printed by a printing device and acquires a read image, and an inspection unit that performs inspection by comparing the read image with a reference image, and is characterized in that the reference image generation unit corrects the reference image based on the amount of toner applied to the print data.

[0010] The present invention also provides a printing device equipped with an inspection device for inspecting printed matter, comprising a print data acquisition unit for acquiring print data, a reference image generation unit for generating a reference image from the acquired print data, an image printing unit for printing the acquired print data, an image reading unit for reading the printed matter printed by the image printing unit and acquiring a read image, and an inspection unit for performing inspection by comparing the read image with a reference image, wherein the reference image generation unit corrects the reference image based on the amount of toner applied to the print data. Effect of the Invention

[0011] According to the present invention, even when a pattern with a large amount of toner is printed, highly accurate inspection can be performed. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is an overall view of a printing system. [Diagram 2] FIG. 1 is a block diagram showing a system configuration of a printing system. [Diagram 3] FIG. 2 is a schematic cross-sectional view of the mechanism of the image forming apparatus. [Figure 4] 4 is a flowchart of the entire inspection process. [Diagram 5] 13 is a flowchart of reference image generation. [Figure 6] 11 is a flowchart for obtaining the average amount of a pattern applied. [Figure 7] 11 is a flowchart for correcting an image in accordance with an average toner amount. [Figure 8] 1 is a flow chart for performing an inspection. [Figure 9] A diagram showing the inspection settings UI. [Figure 10] 11 is a graph showing the relationship between the amount of toner applied and the pixel value. [Figure 11] FIG. 13 is a table showing a relationship between a toner amount and a correction amount. [Figure 12] FIG. 13 is a diagram showing an example in which the amount of toner applied varies depending on the location of a pattern. [Figure 13] 11 is a flowchart for acquiring the loading amount for each column image. [Figure 14] 11 is a flowchart showing the process of enlarging or reducing each column image. [Figure 15] 13 is a table showing different correction amounts for different paper types. [Figure 16] 5 is a flowchart showing a process for generating a reference image when correcting a scanned image. [Figure 17] 11 is a flowchart showing an inspection execution process when correcting a scanned image. [Figure 18] 11 is a flowchart showing a procedure for correcting a scanned image. [Figure 19] 13 is a table showing different amounts of correction for the front and back surfaces; FIG. [Figure 20] A diagram showing how the roller speed setting affects the enlargement and reduction of an image. [Figure 21] FIG. 13 is a diagram showing a roller speed setting correction table. [Figure 22] A diagram showing a comparison between a RIP image and a scanned image. [Figure 23] FIG. 13 is a diagram showing an example of a RIP image. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0014] In the following description, the external controller may also be called an image processing controller, a digital front end, a print server, a DFE, etc. The image forming apparatus may also be called a multifunction device, a multifunction peripheral, or an MFP. The scanning direction of the laser beam is sometimes called the main scanning direction, and the direction perpendicular to the main scanning direction is sometimes called the sub-scanning direction. The sub-scanning direction is the sheet transport direction.

[0015] <First embodiment> <System configuration> A first embodiment of the present invention will be described below. First, with reference to FIG. 1, an example of the configuration of an image processing system according to this embodiment will be described. The image processing system includes an image forming apparatus 101 and an external controller 102. The image forming apparatus 101 and the external controller 102 are communicatively connected via an internal LAN 105 and a video cable 106. Note that the video cable 106 is not essential, and the internal LAN 105 may be configured to substitute for its function. The external controller 102 is communicatively connected to a client PC 103 via an external LAN 104, and a print instruction is sent from the client PC 103 to the external controller 102.

[0016] A printer driver having a function of converting print data into a print description language that can be processed by the external controller 102 is installed in the client PC 103. A user who performs printing can issue a print instruction from various applications via the printer driver. The printer driver transmits print data to the external controller 102 based on the print instruction from the user. When the external controller 102 receives a print instruction from the client PC 103, it performs data analysis and rasterization processing, and inputs the print data to the image forming apparatus 101 to issue a print instruction.

[0017] Next, we will explain the image forming apparatus 101. The image forming apparatus 101 is composed of a printer 107, an inserter 108, an inspection device 109, a large-capacity stacker 110, and a finisher 111, which are devices having a plurality of different functions. The image forming apparatus 101 is capable of complex printing processes such as bookbinding.

[0018] The printing device 107 forms an image using toner on a medium (hereinafter referred to as a sheet) conveyed from a paper feed unit located below the printing device 107. The inserter 108 inserts an insertion sheet into a printed material printed by the printing device 107. The inserter 108 can insert an insertion sheet into an arbitrary sheet group position of a sheet group printed and transported by the printing device 107.

[0019] The inspection device 109 is a device for reading an image on the conveyed sheet and comparing it with a correct image registered in advance to determine whether the printed image is normal. The large-capacity stacker 110 is a stacker capable of stacking a large volume of sheets. The finisher 111 performs finishing processing on the transported sheets. The finisher 111 is capable of performing finishing such as stapling, punching, and saddle stitching, and discharges the finished sheets to a paper discharge tray.

[0020] 1 has a configuration in which an external controller 102 is connected to an image forming apparatus 101, but this embodiment is not limited to a configuration in which an external controller 102 is connected. In other words, a configuration in which the image forming apparatus 101 is connected to an external LAN 104 and print data that can be processed by the image forming apparatus 101 is transmitted from a client PC 103 via the external LAN 104 may also be used. In this case, data analysis and rasterization processing are performed in the image forming apparatus 101, and print processing is executed.

[0021] Next, the configurations of the printing apparatus 107, inserter 108, inspection apparatus 109, large-capacity stacker 110, finisher 111, external controller 102, and client PC 103 according to this embodiment will be described with reference to FIG.

[0022] First, the configuration of the printing device 107 of the image forming apparatus 101 will be described. The printing device 107 of the image forming apparatus 101 is composed of a communication I / F 217, a LAN I / F 218, a video I / F 220, a HDD 221, a CPU 222, a memory 223, an operation unit 224, and a display 225. The printing device 107 of the image forming apparatus 101 further includes a document reading unit 226, a latent image unit 227, an image creating unit 228, a fixing unit 229, and a paper feeding unit 230. Each of the components is connected via a system bus 231.

[0023] The communication I / F 217 is connected to the inserter 108, the inspection device 109, the large-capacity stacker 110, and the finisher 111 via a communication cable 256, and is used for communication to control each of the devices. The LAN I / F 218 is connected to the external controller 102 via the internal LAN 105 and is used for communication of print data and the like. The video I / F 220 is connected to the external controller 102 via the video cable 106 and is used for communication of image data and the like.

[0024] The HDD 221 is a storage device in which programs and data are stored. The CPU 222 comprehensively controls image processing and printing based on the programs stored in the HDD 221. The memory 223 stores programs and image data required for the CPU 222 to perform various processes, and operates as a work area. The operation unit 224 accepts various setting inputs and operation instructions from the user. The display 225 displays setting information of the image forming apparatus 101, the processing status of a print job, and the like. The document reading unit 226 performs a process of reading a document when using a copy function or a scan function. The document data is read by photographing an image with a CMOS image sensor while illuminating an exposure lamp on a document sheet placed by a user. The latent image unit 227 is a device that performs primary charging and laser exposure to irradiate a laser beam onto a photosensitive drum to develop a toner image. In the latent image unit 227, primary charging is first performed to charge the surface of the photosensitive drum to a uniform negative potential. Next, the laser driver irradiates the photosensitive drum with a laser beam while adjusting the reflection angle with a polygon mirror, forming an electrostatic latent image. The image forming unit 228 is a device for transferring toner to a sheet, and is composed of a developing unit, a transfer unit, a toner supply unit, etc., and transfers the toner on the photosensitive drum to a sheet. In the developing unit, negatively charged toner from a developing cylinder is attached to the electrostatic latent image on the surface of the photosensitive drum to make it visible. In the transfer unit, 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, and a positive potential is applied to the secondary transfer 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 by heat and pressure, and is composed of a heater, a fixing belt, a pressure belt, etc. The paper feed unit 230 is a device for feeding sheets, and controls the sheet feeding and conveying operations by rollers and various sensors.

[0025] Next, the configuration of the inserter 108 of the image forming apparatus 101 will be described. The inserter 108 of the image forming apparatus 101 is composed of a communication I / F 232, a CPU 233, a memory 234, and a paper feed control unit 235, and each of the components is connected via a system bus 236. The communication I / F 232 is connected to the printing device 107 via a communication cable 256, and communication required for control is performed. The CPU 233 performs various controls required for paper feed according to a control program stored in the memory 234. The memory 234 is a storage device in which the control program is saved. The paper feed control unit 235 controls the paper feed unit of the inserter and the feeding and conveying of sheets conveyed from the printing device 107 while controlling rollers and sensors based on instructions from the CPU 233.

[0026] Next, the configuration of the inspection device 109 of the image forming device 101 will be described. The inspection device 109 of the image forming device 101 is composed of a communication I / F 237, a CPU 238, a memory 239, a photographing unit 240, a display unit 241, an operation unit 242, and a HDD 255, and each of the components is connected via a system bus 243. The communication I / F 237 is connected to the printing device 107 via a communication cable 256, and communication required for control is performed. The CPU 238 performs various controls required for the inspection based on a control program stored in the memory 239. The memory 239 is a storage device in which the control program is saved. The photographing unit 240 takes an image of the conveyed sheet based on an instruction from the CPU 238. The CPU 238 saves the image taken by the photographing unit 240 in the memory 239 as a correct image. Furthermore, the CPU 238 compares the image taken by the photographing unit 240 with the correct image saved in the memory 239 to determine whether the printed image is normal. The display unit 241 displays the inspection results, a setting screen, and the like. The operation unit 242 is operated by the user and receives instructions such as changing the settings of the inspection device 109 and registering a correct image. The HDD 255 stores various setting information and images required for the inspection. The stored various setting information and images can be reused.

[0027] Next, the configuration of the large-capacity stacker 110 of the image forming apparatus 101 will be described. The large-capacity stacker 110 of the image forming apparatus 101 is composed of a communication I / F 244, a CPU 245, a memory 246, and a paper discharge control unit 247, and each of the components is connected via a system bus 248. The communication I / F 244 is connected to the printing apparatus 107 via a communication cable 256, and communication required for control is thereby performed. The CPU 245 performs various controls required for paper discharge based on a control program stored in the memory 246. The memory 246 is a storage device in which the control program is saved. The paper discharge control unit 247 controls the transport of the transported sheet to a stack tray, an escape tray, or a subsequent finisher 111 based on an instruction from the CPU 245.

[0028] Next, the configuration of the finisher 111 of the image forming apparatus 101 will be described. The finisher 111 of the image forming apparatus 101 is composed of a communication I / F 249, a CPU 250, a memory 251, a paper discharge control unit 252, and a finishing processing unit 253, and each of the components is connected via a system bus 254. The communication I / F 249 is connected to the printing device 107 via a communication cable 256, and communication required for control is performed by this. The CPU 250 performs various controls required for finishing and paper discharge based on a control program stored in the memory 251. The memory 251 is a storage device in which the control program is saved. The paper discharge control unit 252 controls sheet transport and paper discharge based on an instruction from the CPU 250. The finishing processing unit 253 controls finishing processes such as stapling, punching, and saddle stitching based on an instruction from the CPU 250.

[0029] Next, a description will be given of the configuration of the external controller 102. The external controller 102 is composed of a CPU 208, a memory 209, a HDD 210, a keyboard 211, a display 212, a LAN I / F 213, a LAN I / F 214, and a video I / F 215, and each of the components is connected via a system bus 216.

[0030] The CPU 208 comprehensively executes processes such as receiving print data from the client PC 103, RIP (Raster Image Processor) processing, and sending print data to the image forming apparatus 101 based on programs and data stored in the HDD 210. It is also capable of performing RIP processing for correct image data. Specifically, in the RIP processing for correct image data, an image is generated by converting a resolution of, for example, 600 dpi to 300 dpi, and in the RIP processing for print data, an image is generated without reducing the resolution.

[0031] The memory 209 stores programs and data required for the CPU 208 to perform various processes, and operates as a work area. The HDD 210 stores programs and data required for operations such as printing. The keyboard 211 is a device for inputting operation instructions for the external controller 102. The display 212 displays information such as an application executed by the external controller 102 by video signals of still images and moving images. The LAN I / F 213 is connected to the client PC 103 via the external LAN 104, and thereby performs communication such as print instructions. The LAN I / F 214 is connected to the image forming apparatus 101 via the internal LAN 105, and thereby performs communication such as print instructions. The external controller 102 can exchange various data with the printing apparatus 107, the inserter 108, the inspection apparatus 109, the large-capacity stacker 110, and the finisher 111 via the internal LAN 105 and the communication cable 256. The video I / F 215 is connected to the image forming apparatus 101 via a video cable 106, through which communication of print data and the like is carried out.

[0032] Next, the configuration of the client PC 103 will be described. The client PC 103 is composed of a CPU 201, a memory 202, a HDD 203, a keyboard 204, a display 205, and a LAN I / F 206, which are connected via a system bus 207. The CPU 201 creates print data and executes print instructions based on a document processing program stored in the HDD 203. The CPU 201 also comprehensively controls each device connected to the system bus. The memory 202 stores programs and data required for the CPU 201 to perform various processes, and operates as a work area. The HDD 203 stores programs and data required for operations such as print processing. The keyboard 204 is a device for inputting operation instructions for the PC 103. The display 205 displays information such as an application executed by the client PC 103 by video signals of still images and moving images. The LAN I / F 206 is connected to the external LAN 104, and communication such as receiving print instructions and RIP images is performed by this. In this embodiment, the amount of applied toner during printing is obtained by the CPU 238 , but it may also be obtained from the printing device 107 or the external controller 102 via the communication cable 256 .

[0033] In the above description, the external controller 102 and the image forming apparatus 101 are connected via the internal LAN 105 and the video cable 106, but any other configuration is acceptable as long as data necessary for printing can be transmitted and received, and for example, a connection configuration using only a video cable is also acceptable. Also, each of the memories 202, 209, 223, 234, 239, 246, and 251 may be a storage device for holding data and programs. For example, the memories may be replaced by volatile RAM, non-volatile ROM, built-in HDD, external HDD, USB memory, or the like.

[0034] FIG. 3 shows a cross-sectional view of the mechanism of the image forming apparatus 101. With reference to FIG. 3, the conveyance of the sheet in the image forming apparatus 101 will be described. 107 is a printing device that forms an image to be printed on a sheet. 301 and 302 are paper feed decks. Each paper feed deck can store various sheets. Each paper feed deck can separate only the topmost sheet of the stored sheets and convey it to a sheet conveyance path 303. 304 to 307 are development stations that form toner images using color toners of Y, M, C, and K, respectively, to form a color image. The toner image formed here is primarily transferred to an intermediate transfer belt 308, which rotates clockwise in the figure, and the toner image is transferred to a sheet conveyed from the sheet conveyance path 303 at a secondary transfer position 309. At this time, if the amount of toner applied is large, the toner makes the sheet slippery, and the conveyance speed of the sheet decreases. Therefore, the toner image is reduced in size in the sheet transport direction, and a picture reduced in size in the sheet transport direction is printed as shown in the scanned image on the right side of FIG.

[0035] The display 225 displays the printing status and information for setting the image forming apparatus 101. 311 is a fixing unit for fixing a toner image to a sheet. The fixing unit 311 includes a pressure roller and a heating roller, and the toner is melted and pressed by the sheet passing between the rollers, thereby fixing the toner image to the sheet. The sheet that has passed the fixing unit 311 is conveyed to 315 through a sheet conveying path 312. If further melting and pressing is required for fixing depending on the type of sheet, after passing through the fixing unit 311, the sheet is conveyed to a second fixing unit 313 using the upper sheet conveying path, and after additional melting and pressing are performed, it is conveyed to 315 through a sheet conveying path 314. When the image forming mode is double-sided, the sheet is conveyed to a sheet reversing path 316, and after being reversed at 316, the sheet is conveyed to a double-sided conveying path 317, where the image of the second side is transferred at a secondary transfer position 309.

[0036] Reference numeral 108 denotes an inserter for inserting an insertion sheet. The inserter 108 includes an inserter tray 321, and merges an insertion sheet fed through a sheet transport path 322 with the transport path. This makes it possible to insert an insertion sheet at an arbitrary sheet position in a series of sheets transported from the printing device 107 and transport the sheet to a subsequent device.

[0037] The sheet that has passed through the inserter 108 is transported to the inspection device 109. Two photographing units 240 are arranged facing each other inside the inspection device 109. The two photographing units 240 are sensors for reading the upper surface and the lower surface of the sheet, respectively. When the sheet transported to the sheet transport path 333 reaches a predetermined position, the inspection device 109 reads the image of the sheet using the photographing units 240, and can determine whether the image printed on the sheet is normal. The display unit 241 displays the inspection results performed by the inspection device 109, etc.

[0038] Reference numeral 110 denotes a large-capacity stacker capable of stacking a large volume of sheets. The large-capacity stacker 110 has a stack tray 341 as a tray for stacking sheets. A sheet that has passed through the inspection device 109 is transported to the large-capacity stacker 110 through a sheet transport path 344. The sheet is stacked on the stack tray 341 via the sheet transport path 344 and a sheet transport path 345. The large-capacity stacker 110 further has an escape tray 346 as a paper discharge tray. The escape tray 346 is a paper discharge tray used for discharging a sheet determined to be an abnormal sheet by the inspection device 109. When discharging a sheet to the escape tray 346, the sheet is transported from the sheet transport path 344 to the escape tray 346 via a sheet transport path 347. When transporting a sheet to a finisher 111 at the rear of the large-capacity stacker 110, the sheet is transported via a sheet transport path 348. Reference numeral 342 denotes a paper discharge inversion unit for inverting a sheet. This discharge reversal section 342 is used when stacking sheets on the stack tray 341. When stacking on the stack tray 341, the sheet is reversed once by the discharge reversal section 342 so that the orientation of the input sheet is the same as the orientation of the sheet at the time of output. When conveying to the escape tray 346 or the subsequent finisher 111, the sheet is discharged as is, and therefore the reversal operation by the discharge reversal section 342 is not performed.

[0039] 111 is a finisher that performs finishing processing on the conveyed sheets according to a function designated by the user. Specifically, the finisher 111 has finishing functions such as stapling (one-point or two-point binding), punching (two-hole or three-hole), and saddle stitching. The finisher 111 has two discharge trays 351 and 352, and discharges sheets to the discharge tray 351 via a sheet conveying path 353. However, the sheet conveying path 353 cannot perform finishing processing such as stapling. When performing finishing processing such as stapling, the sheets are discharged to the discharge tray 352 via a sheet conveying path 354, and a finishing function designated by the user is executed in a processing section 355. The discharge trays 351 and 352 can be raised and lowered, and it is also possible to operate so that the discharge tray 351 is lowered and the sheets that have been subjected to finishing processing in the processing section 355 are stacked on the discharge tray 351. When saddle stitching is specified, the saddle stitching processing unit 356 staples the center of the sheet, folds the sheet in half, and discharges it to a saddle stitching tray 358 via a sheet transport path 357. The saddle stitching tray 358 is configured as a belt conveyor, and the saddle stitched bundle loaded on the saddle stitching tray 358 is transported to the left side.

[0040] The inspection device 109 inspects the sent sheet image according to preset inspection items. The inspection of the sheet image is performed by comparing the sent sheet image with a preset correct image. Image comparison methods include comparing pixel values ​​for each image position, comparing object positions by edge detection, and extracting character data by OCR (Optical Character Recognition). Inspection items include misalignment of print position, image color, image density, streaks, blurring, printing omissions, etc.

[0041] <Overall inspection process flow> Next, an overall flow from the work before starting the inspection in the inspection device 109 to the execution of the inspection will be described with reference to Fig. 4. Each process in Fig. 4 is executed by the inspection device 109 in accordance with a user's operation from the operation unit 242 shown in Fig. 2. The process described below is realized, for example, by the CPU 238 of the inspection device 109 reading and executing a control program stored in the memory 239. In the following, the step numbers of each process included in the flowchart are indicated by numbers beginning with "S". The same applies to the subsequent flowcharts.

[0042] First, in S401, the inspection device 109 registers a reference image that is a correct answer for the inspection. Details will be described later with reference to FIGS. In S402, the inspection device 109 sets detailed inspection area settings such as the inspection level, inspection type, and inspection area of ​​the print image inspection in accordance with the user's operation. This setting is performed using the inspection setting UI in FIG.

[0043] A screen 901 in FIG. 9 shows an inspection setting UI window, from which the user sets four types of inspection areas: a focus area, a standard area, a simple area, and an area not to be inspected. A focus area is an area in which inspection for abnormalities is to be performed with special emphasis compared to other areas such as a person's face. A standard area is an area in which inspection is to be performed as a standard. A simple area is an area in which inspection may be performed more simply than the standard area. An area not to be inspected is an area to be excluded from inspection. In this embodiment, an example of setting four types of inspection areas will be described, but the area names and types are not limited to these.

[0044] Numeral 902 denotes a preview screen. Here, the reference image registered in S401 is displayed. The aforementioned inspection area setting is set by depicting the area on this reference image. Region 903 indicates an inspection region. The type of line surrounding the region in the figure is the same as that of the four types of inspection region settings described above. For example, the region surrounded by a dotted line in region 903 is a priority inspection region.

[0045] When depicting an inspection area, the user operates each of buttons 911, 912, 913, and 914, and then writes the area on the preview screen to select the area. Button 904 is a rotation button. Clicking this button rotates the preview screen by 90 degrees. As shown in Fig. 9, there are two buttons, and clockwise rotation and counterclockwise rotation can be selected. A button 905 is an OK button. By operating the OK button 905, the inspection area setting can be saved. A cancel button 906 is used to cancel the inspection area setting.

[0046] Areas 907 and 908 are UIs for setting the inspection level. The inspection level can be set for each of the priority area, standard area, and simple area settings within the frame of area 907. The dotted lines used in the frames of each inspection area 907 depict the inspection setting areas on the preview screen 902.

[0047] Next, the acceptance of the examination settings in S402 will be described. S402 is a process for accepting detailed settings of the inspection level, inspection type, and inspection area of ​​the print image inspection.

[0048] First, when setting a priority area, the user operates the priority area setting button 911. Next, the user operates the preview screen 902 to specify an area to be inspected with priority, and the inspection device 109 sets the specified area as the priority inspection area. After that, the user can change the inspection level of the priority area in area 908.

[0049] When setting a standard area, the user operates the standard area setting button 912. Next, the user operates the preview screen 902 to specify an area to be inspected as standard, and the inspection device 109 sets the specified area as the standard inspection area. After that, the user can change the inspection level of the standard inspection area in area 908.

[0050] When setting a simple region, the user operates the simple region setting button 913. Next, the user operates to specify an area to be simply inspected on the preview screen 902, and the inspection device 109 sets the specified area as a simple inspection area. After that, the user can change the inspection level of the simple inspection area in area 908.

[0051] When setting an area not to be inspected, the user operates the inspection exclusion area setting button 914. Next, the user specifies an area to be excluded from inspection in the preview screen 904, and the inspection device 109 sets the specified area as an area not to be inspected.

[0052] Thereafter, when the user operates an OK button 905, the inspection device 109 sets the detection items for detecting abnormalities and their inspection levels input in the UI for setting the inspection level in area 908, and saves the inspection settings.

[0053] The detection items of the print image inspection are items related to the features of abnormalities to be detected when inspecting the print, such as round-shaped abnormalities (dots) and linear abnormalities (streaks). The inspection level is a parameter that sets the size of each detected abnormality feature at which it is determined to be abnormal, in stages. For example, there are seven stages from level 1 to level 7, and level 7 can detect thinner and smaller abnormalities than level 1. Also, a different level can be set for each inspection item, such as inspection level 7 for dots and inspection level 4 for streaks. Note that the parameter settings and the number of levels are not limited to these. In the focus area settings in FIG. 9, it is shown that the user has selected level 7 for the inspection level setting for abnormalities (dots) and level 7 for the inspection level setting for abnormalities (streaks). Next, an inspection is performed in S403, the details of which will be described later with reference to FIG.

[0054] <Generation of reference images> The generation of the reference image in S401 in Fig. 4 is a process of correcting image data after RIP processing to obtain a correct image. The generation of the reference image will be described with reference to Figs. 5 to 7. The process described below is realized, for example, by the CPU 238 of the inspection device 109 reading and executing a control program stored in the memory 239.

[0055] In S501, the CPU 238 receives a RIP image from the printing device 107 via the communication cable 256. In this embodiment, the RIP image is received from the printing device 107, but the method of receiving the RIP image is not limited to this, and the RIP image can also be received by connecting the external controller 102 with a LAN cable. The RIP image includes, for example, the components shown in Fig. 23. A picture portion 2301 indicates the area of ​​the picture to be printed on the sheet, and a sheet portion 2302 indicates the entire surface of the sheet when printed. A margin portion 2303 indicates the area between the picture portion 2301 and the sheet portion 2302, and is a margin area on which nothing is printed when printed.

[0056] Next, in S502, the CPU 238 acquires the color material usage (toner application amount) of the picture portion 2301 from the received RIP image. Here, the toner application amount refers to the amount of toner applied on the paper surface, expressed in % units. For each color, the state in which the toner is applied solidly over the entire surface is taken as 100%, and it is the percentage indicating what percentage of toner is applied. The method of acquiring the toner application amount will be described later with reference to FIG. 6.

[0057] In S503, the CPU 238 uses a threshold value to determine whether the amount of applied toner is an amount that requires correction of the RIP image. For example, in this embodiment, if the amount of applied toner is 10% or more, it is determined that correction is necessary. If correction is necessary, in S504, the RIP image correction process described in FIG. 7 is executed, and the process proceeds to S505. If correction is not necessary, the process proceeds to S505.

[0058] In S505, the CPU 238 performs a scan simulation process on the pre-simulation image after correction or on the pre-simulation image on which no correction has been performed. In this process, the pre-simulation image is enlarged or reduced so that the image size matches the size at the time of scanning, color conversion is performed on the margins to make the margins closer to the sheet color, glare at the time of scanning is reproduced, and a black border is added, which is a shadow that appears when the edge of the document is read during scanning. In this way, a simulation of the scanned image can be performed and an inspection reference image can be created from the RIP image.

[0059] <Getting the average amount of image loading> Next, the acquisition of the average applied amount in S502 described above will be described with reference to Fig. 6. In acquiring the average applied amount in S502, the amount of area printed is acquired in order to estimate the amount of shrinkage of the image due to sheet slippage. The process described below is realized, for example, by the CPU 238 of the inspection device 109 reading and executing a control program stored in the memory 239.

[0060] In S601, the CPU 238 divides the RIP image into color channels, specifically, into channels for each single color of cyan (C), magenta (M), yellow (Y), and black (K).

[0061] In S602, the CPU 238 converts pixel values ​​into toner application amounts for the RIP image that has been divided into channels for each CMYK color in S601. Specifically, the pixel values ​​of the pixels that form the RIP image are converted into toner application amount information using a relationship table of pixel values ​​(0 to 255) and toner application amounts (0 to 100%) in FIG. 10. The relationship between pixel values ​​and toner application amounts is determined in advance based on the gradation of the printer and the color development of the color material (toner), and is shown in FIG. 10. Note that, although the present invention uses the same pixel value-to-toner application amount relationship table for each CMYK color, it is preferable to use an individual pixel value-to-toner application amount relationship table for each color when the maximum toner application amount or gradation target differs for each color.

[0062] Next, in S603, the CPU 238 converts the image converted into toner amount information in S602 into an average toner amount. Specifically, the average toner amount of each single color C, M, Y, and K can be obtained by the formula (total of all pixel values ​​after toner amount conversion / total number of pixels in the RIP image×100).

[0063] In S604, the CPU 238 calculates the average amount of toner applied of each single color acquired in S603. For example, when the amount of toner applied of cyan is 50%, magenta is 0%, yellow is 50%, and black is 0% in S603, the average amount of toner applied of each of the four colors acquired in S604 is 25%. The total number of pixels of the RIP image is the total number of pixels when printing the entire surface of the sheet size to be printed at a specified resolution.

[0064] <Image correction according to average loading amount> Next, the RIP image correction process performed in S504 described above will be described with reference to Fig. 7. The process described below is realized, for example, by the CPU 238 of the inspection device 109 reading and executing a control program stored in the memory 239. In S701, the CPU 238 reads out a table shown in Fig. 11 for correcting an image from the HDD 255. This table defines an example of a pattern enlargement / reduction ratio according to the amount of application, and for example, the table in Fig. 11 indicates that if the average amount of application is 40 to 100%, a reduction of 0.20% is performed.

[0065] In S702, the CPU 238 obtains the amount of application of the RIP image to the picture portion 2301 from the table obtained in S701 and the amount of correction from the amount of application obtained in S502, and performs enlargement / reduction processing in the sheet conveyance direction (sub-scanning direction). In this embodiment, reduction processing is performed, but enlargement may also be possible depending on the size of the reference image.

[0066] In S703, it is determined whether the correction was enlargement or reduction, and if it was enlargement, the process proceeds to S704, and if it was reduction, the process proceeds to S705. In S704, if the image protrudes into the margin portion 2303 due to enlargement, the image is retained by overwriting the margin portion 2303. If it protrudes beyond the sheet portion 2302, those pixels are discarded. In S705, the margin created by reduction is padded with pixels from the margin portion 2303 (a process of filling in missing pixels with substitute pixels).

[0067] <Testing> In S403, the scanned image is inspected based on the reference data generated in S401 and the inspection settings set in S402. The flow of scanning an image and inspecting it will be described with reference to FIG.

[0068] 8 is a flowchart showing the flow of the process performed by the inspection device 109 when performing the inspection process. The process in FIG. 8 is realized, for example, by the CPU 238 of the inspection device 109 executing a control program stored in the memory 239.

[0069] In S801, the inspection device 109 acquires print settings and a reference image. In S802, the inspection device 109 transitions to a scan standby state. In the scan standby state, two types of external inputs are accepted: image scanning and an instruction to end inspection. In S803, if an instruction to end inspection is received, the inspection process ends. On the other hand, if an input to scan an image is received, the process proceeds to S809. In S809, the image read using the photographing unit 240 is stored in the memory 239 of the inspection device 109. When the CPU 238 is in a scan standby state, the photographing unit 240 waits in a state in which it can always scan a sheet. When the printing device 107 executes printing and the sheet passes the photographing unit 240, the scanned image scanned by the photographing unit 240 is sent to the CPU 238.

[0070] In S804, alignment is performed between the reference image and the scanned image stored in the memory 239. In the alignment, first, rigid body alignment is performed by affine transformation using feature points of each image, and then misalignment due to sheet distortion is removed by FFD.

[0071] In S805, the reference image after alignment is compared with the scanned image to obtain the difference. In S806, it is determined whether the difference is less than a specified value, and if so, the inspection result is determined to be a normal image, and the process proceeds to S807. In S807, the inspection device 109 instructs the large-capacity stacker 110 to discharge the sheet determined to be a normal image onto the stack tray 341. If the difference is equal to or greater than the specified value, the process proceeds to S808, where the inspection device 109 instructs the large-capacity stacker 110 to discharge the sheet onto the escape tray 346 as an abnormal sheet. As described above, when registering the reference image, the inspection device 109 corrects the amount of toner applied to the RIP image to match the pattern of the reference image, thereby absorbing the difference in enlargement or reduction caused by the amount of toner applied. This allows for highly accurate size adjustment and inspection to be performed regardless of the amount of toner applied.

[0072] <Second embodiment> The second embodiment of the present invention will be described below. In the first embodiment, the average toner amount is defined for the entire sheet, but in actual printing, as shown in FIG. 12, some parts of the sheet are dense and some parts are sparse, and density varies even within the sheet.

[0073] Therefore, in this embodiment, the process of acquiring the average amount of toner applied to the pattern is divided into smaller units to acquire the amount of toner applied, thereby enabling more accurate alignment. Therefore, in this embodiment, the method of acquiring the average amount of toner applied to the pattern described in S502 above and the method of correcting the pattern according to the average amount of toner applied in S504 are described. In the following, differences from the first embodiment are described in detail.

[0074] <Getting the average amount of image loading> A process for acquiring the average amount of a pattern applied in the second embodiment will be described with reference to Fig. 12 and Fig. 13. The process described below is realized by, for example, the CPU 238 of the inspection device 109 executing a control program stored in the memory 239.

[0075] In S1301, the CPU 238 acquires the column width. Here, the column width means the length of the RIP image in the sub-scanning direction divided by a predetermined division number, and corresponds to the horizontal length of the portion indicated by the dotted line in Fig. 12. In this embodiment, it is defined as a constant of 30 mm, but it may be defined as a variable according to the sheet size and conveying speed.

[0076] In S1302, the CPU 238 divides the RIP image by the column width length acquired in S1301. The divided images are referred to as column images. The portion surrounded by the dotted line in FIG. 12 is the column image.

[0077] In S1303, the CPU 238 divides the column image into color channels. Next, in S1304, the CPU 238 acquires toner amount information for each row image by the same method as in the first embodiment, and in S1305 acquires the average toner amount of each single color of the row images. In S1306, the CPU 238 obtains the average toner application amount of the four colors for each row image, and obtains the average toner application amount for each row image. In this way, the average toner application amount for each row image can be obtained.

[0078] <Image correction according to average loading amount> The process procedure for correcting a pattern in accordance with the average toner amount in this embodiment will be described with reference to Fig. 12 and Fig. 14. The process described below is realized, for example, by the CPU 238 of the inspection device 109 executing a control program stored in the memory 239. In S1401, the CPU 238 sets the index i to 0. This index is the index of the column image cut out in S1302.

[0079] In S1402, the CPU 238 acquires the i-th row image and its average application amount. In S1403, the CPU 238 acquires an appropriate correction amount for the i-th column image using the average applied amount acquired in S1402 and the table in FIG. In S1404, the CPU 238 corrects the i-th column image with the calculated correction amount.

[0080] In S1405, the CPU 238 determines whether the i-th image is the last image in the column, and if it is the last image, the process proceeds to S1407, and if it is not the last image, the process proceeds to S1406. In S1406, the CPU 238 adds 1 to i and returns the process to S1402. This completes the process from S1402 to S1405 for all column images.

[0081] In S1407, the CPU 238 joins together all of the column images after correction, thereby obtaining a picture that has been corrected with different amounts of correction for each portion. In S1408, the CPU 238 determines whether the stitched image generated in S1407 is enlarged or reduced from the original image. If it is enlarged, the process proceeds to S1409, where the CPU 238 deletes all image portion 2301 that extends outside the print area. On the other hand, if it is reduced, the process proceeds to S1410, where the CPU 238 pads the margins created by the reduction with the same color as the surrounding background. As a result, it is possible to reflect the difference in the amount of toner applied to each location of the pattern, and it is possible to correct the pattern more precisely and improve the accuracy of size adjustment.

[0082] <Third embodiment> The third embodiment of the present invention will be described below. In the first embodiment, the table shown in Fig. 11 was used to use different correction parameters depending on the amount of toner applied, but the amount of misalignment of the image during printing also differs depending on the type of sheet. For example, the amount of misalignment is small on a sheet with low smoothness, and large on a sheet with high smoothness.

[0083] In this embodiment, the correction rate acquired in S701 is set as a parameter for each sheet type by using a table for performing different position adjustment for each sheet type as shown in Fig. 15. Information regarding the sheet type is received from the printing device 107 via the communication cable 256 when the RIP image is acquired in S501. In this manner, the slippage amount, which differs for each sheet type, can be accurately corrected.

[0084] <Fourth embodiment> A fourth embodiment of the present invention will be described below. In the above first embodiment, size adjustment is performed by correcting the reference image according to the amount of applied to the toner, but size adjustment can also be performed by correcting the scanned image. A fourth embodiment in which correction is performed on the scanned image will be described with reference to Figs. 16 to 18. Note that only differences from the first embodiment will be described in detail below. In this embodiment, as shown in Fig. 16, no correction process is performed on the reference image in S401 in Fig. 4 and S504 in Fig. 5. Figs. 17 and 18 show a process of performing an inspection corresponding to S403 in Fig. 4.

[0085] Fig. 17 shows processing according to this embodiment, which corresponds to Fig. 8 of the first embodiment. In this embodiment, S1701 after executing scanning is added to the first embodiment. In S1701, the CPU 238 executes correction of the scanned image as described in Fig. 18.

[0086] In S1801, the CPU 238 refers to the table based on the average applied amount acquired in S502, and acquires a necessary correction amount. Next, in S1802, the CPU 238 identifies the pattern portion of the scanned image based on pixel values. In S1803, the CPU 238 performs enlargement / reduction correction on the picture portion with the correction amount obtained from the table.

[0087] In S1804, the CPU 238 determines whether the correction performed in S1803 was enlargement or reduction, and if it was enlargement, the process proceeds to S1805, where the CPU 238 discards any image that protrudes from the sheet, and if it was reduction, the process proceeds to S1806, where the CPU 238 pads the space created by the reduction of the image with pixels from the margins of the sheet.

[0088] In this way, the scanned image is corrected and the size is adjusted. In this embodiment, the correction is applied only to the scanned image, but it is also possible to combine the first and fourth embodiments to perform correction on both the scanned image and the RIP image.

[0089] <Fifth embodiment> The fifth embodiment of the present invention will be described below. In the first embodiment, the amount of correction is set according to the amount of the reference image on the page, but the amount of correction required may change due to differences in the amount of misalignment between the front and back patterns.

[0090] When the first side is printed first and the second side is printed last, if the amount of toner applied to the first side is dense, the first side is likely to slip when printing on the second side. This causes a larger amount of misalignment to occur at the secondary transfer position 309 compared to when the amount of toner applied to the first side is sparse. For this reason, a table that takes the first and second sides into consideration is required to make more precise corrections.

[0091] In this embodiment, as shown in FIG. 19, different tables are used for the first and second surfaces to obtain the correction factor to be used in S701 of FIG. As described above, by creating a table taking into account the amount of slippage on the first and second surfaces, the difference in the amount of misalignment between the first and second surfaces can be absorbed, allowing for more accurate correction.

[0092] Sixth embodiment The sixth embodiment of the present invention will be described below. In the first embodiment, the amount of misalignment was reduced by measuring the amount of loading and correcting the reference image using a table. However, as shown in FIG. 20, it is considered that the amount of correction may change depending on the roller speed of the secondary transfer unit. When the speed difference between the upper roller and the lower roller is large, the sheet slippage is large and the amount of misalignment of the image also increases. On the other hand, when the speed difference between the rollers is small, the sheet slippage is small and the image is less likely to be misaligned. The roller speed of the secondary transfer unit is generally operable, and the correction accuracy can be improved by adjusting the correction amount of the table according to this speed. Therefore, it is considered to adjust the correction amount by multiplying the correction amount by a magnification according to the speed difference of the rollers using the table shown in FIG. 21. In this embodiment, the inspection device 109 needs to acquire the speed setting between the rollers in advance, and acquires the setting in the imaging unit 228 when acquiring the RIP image in S501. As described above, by changing the amount of correction using the settings of the image forming unit 228, the speed change due to the settings of the image forming unit 228 can be absorbed, and more precise size matching becomes possible.

[0093] <Modification> The present invention is not limited to the above-mentioned embodiment, and various modifications are possible. In the above-mentioned explanations of the first to sixth embodiments, the single color application amount is expressed as 0 to 100%, or the CMYK average application amount is expressed as 0 to 100%. This is standardized to simplify acquisition in the processing flow, but it is also possible to use mg, which is the absolute weight of the toner, for the determination.

[0094] For example, A4 size, full surface, pixel value 255, monochrome maximum density loading amount (absolute value) 0.40 mg / cm 2 In this case, the 100% monochrome toner amount can be obtained by multiplying the area of ​​A4 size by the monochrome toner amount at maximum density, which is 21cm x 29.7cm x 0.40mg / cm 2 = 8.4 mg. Therefore, if the toner application amounts shown in Figures 11, 12, 15, and 19 are specified for A4 size, the toner application amounts can be specified as 100% = 8.4 mg, 40% = 3.4 mg, and 25% = 2.1 mg. If an absolute value standard is adopted, a specified range can be defined, such as the entire page or 30 mm in the sub-scanning direction, and a table can be created showing what the magnification should be set to when the toner application amount is a certain amount in that specified range.

[0095] <Other embodiments> The present invention can also be realized by a process in which a program for implementing one or more of the functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) that implements one or more of the functions.

[0096] The present invention is not limited to the above-described embodiments, and various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, the following claims are appended to apprise the public of the scope of the invention.

[0097] The disclosure of this specification includes the following inspection apparatus, inspection method, program, and printing apparatus. (Item 1) An inspection device for inspecting printed matter, An acquisition unit that acquires print data; a reference image generating unit that generates a reference image from the acquired print data; an image reading unit that reads a printed matter on which the print data is printed by a printing device and obtains a read image; an inspection unit that performs an inspection by comparing the read image with the reference image; The inspection device, wherein the reference image generating unit corrects the reference image based on an amount of toner applied in the print data. (Item 2) The correction process in the reference image generating unit is characterized in that the reference image is corrected by adding a margin or by enlarging or reducing the reference image, or by both of these processes. Item 1. The inspection device according to item 1. (Item 3) the inspection unit compares the read image with the reference image after aligning the two images. 3. The inspection device according to item 1 or 2. (Item 4) The correction process in the reference image generating unit further modifies the amount of correction depending on the type of print medium to be printed. The inspection device according to any one of items 1 to 3. (Item 5) The correction process in the reference image generating unit is characterized in that the image is divided finer than the print medium in the sub-scanning direction and correction is performed for each division unit. The inspection device according to any one of items 1 to 4. (Item 6) The correction process in the reference image generating unit further includes modifying a correction amount based on information about a paper conveying force when transferring toner to a print medium. 6. The inspection device according to any one of items 1 to 5. (Item 7) the toner comprises a plurality of colors; The correction process in the reference image generating unit is performed based on the amount of toner applied for each color. The inspection device according to any one of items 1 to 6. (Item 8) The correction process in the reference image generating unit is performed based on the amount of toner applied on the first and second sides of a double-sided print job. 8. The inspection device according to any one of items 1 to 7. (Item 9) The present invention is characterized in that the setting means is provided for setting a priority area, a standard area, and a simplified area, and the setting means is capable of setting a detection level for each type of abnormality in each area. The inspection device according to any one of items 1 to 8. (Item 10) a read image correction unit that corrects the read image based on the toner amount of the print data; 10. The inspection device according to any one of items 1 to 9. (Item 11) An inspection device for inspecting printed matter An acquisition unit that acquires print data; a reference image generating unit that generates a reference image from the acquired print data; an image reading unit that reads a printed matter on which the print data is printed by a printing device and obtains a read image; an inspection unit that performs an inspection by comparing the read image with a reference image; The inspection device includes a read image correction unit that corrects the read image based on the amount of toner applied in the print data. (Item 12) The correction process in the read image correction unit is characterized in that a margin addition process or an enlargement / reduction process or both of the processes are performed on the reference image. Item 12. The inspection device according to item 11. (Item 13) the inspection unit compares the read image with the reference image after aligning the two images. Item 13. The inspection device according to item 11 or 12. (Item 14) The correction process in the read image correction unit further modifies the amount of correction depending on the type of print medium to be printed. The inspection device according to any one of items 11 to 13. (Item 15) The correction process in the read image correction unit is characterized in that the sub-scanning direction is divided finer than the print medium, and correction is performed for each division unit. The inspection device according to any one of items 11 to 14. (Item 16) The correction process in the read image correction unit further includes modifying a correction amount based on information about a paper conveying force when the toner is transferred to a print medium. 16. The inspection device according to any one of items 11 to 15. (Item 17) the toner comprises a plurality of colors; The correction process in the read image correction unit is performed based on the amount of toner applied for each color. 17. The inspection device according to any one of items 11 to 16. (Item 18) The correction process in the read image correction unit is performed based on the amount of toner applied on the first and second sides of a double-sided print job. Item 18. The inspection device according to any one of items 11 to 17. (Item 19) The present invention is characterized in that the setting means is provided for setting a priority area, a standard area, and a simplified area, and the setting means is capable of setting a detection level for each type of abnormality in each area. 19. The inspection device according to any one of items 11 to 18. (Item 20) An inspection method for inspecting a printed matter, comprising: an acquisition step in which an acquisition unit acquires print data; a reference image generating step in which a reference image generating unit generates a reference image from the acquired print data; an image reading step in which an image reading unit reads a printed matter on which the print data is printed by a printing device to obtain a read image; an inspection step in which an inspection unit performs an inspection by comparing the read image with the reference image; The inspection method, wherein the reference image generating step corrects the reference image based on an amount of toner applied in the print data. (Item 21) A program for operating a computer to inspect printed matter, comprising: Computer, A print data acquisition unit that acquires print data; a reference image generating unit that generates a reference image from the acquired print data; an image reading unit that reads a printed matter on which the print data is printed by a printing device and obtains a read image; functioning as an inspection unit that performs inspection by comparing the read image with a reference image; The reference image generating unit corrects the reference image based on an amount of toner applied in the print data. (Item 22) A printing device equipped with an inspection device for inspecting printed matter, A print data acquisition unit that acquires print data; a reference image generating unit that generates a reference image from the print data; an image printing unit that prints the acquired print data; an image reading unit that reads the printed matter printed by the image printing unit and obtains a scanned image; An inspection unit that performs an inspection by comparing the scanned image with a reference image, The printing apparatus, wherein the reference image generating unit corrects the reference image based on an amount of toner applied in the print data. (Item 23) A method for inspecting a printed matter in a printing device, comprising: an acquisition step in which an acquisition unit acquires print data; a reference image generating step in which a reference image generating unit generates a reference image from the acquired print data; an image printing step in which an image printing unit prints the print data; an image reading step in which an image reading unit reads the printed matter printed in the image printing step to obtain a read image; an inspection step in which an inspection unit performs an inspection by comparing the read image with the reference image; The inspection method, wherein the reference image generating step corrects the reference image based on an amount of toner applied in the print data. (Item 24) A program for causing a computer to function as a printing device, Computer, An acquisition unit that acquires print data; a reference image generating unit that generates a reference image from the print data; an image printing unit that prints the acquired print data; an image reading unit that reads a printed matter printed by the image printing unit and obtains a read image; functioning as an inspection unit that performs an inspection by comparing the read image with the reference image; The reference image generating unit corrects the reference image based on an amount of toner applied in the print data. [Explanation of symbols]

[0098] 101: image forming device, 102: external controller, 103: client PC, 107: printing device, 108: inserter, 109: inspection device, 110: large capacity stacker, 111: finisher

Claims

1. An inspection device for inspecting printed matter, An acquisition unit that acquires print data; a reference image generating unit that generates a reference image from the acquired print data; an image reading unit that reads a printed matter on which the print data is printed by a printing device and obtains a read image; an inspection unit that performs an inspection by comparing the read image with the reference image; The inspection device, wherein the reference image generating unit corrects the reference image based on an amount of toner applied in the print data.

2. The correction process in the reference image generating unit is characterized in that the reference image is corrected by adding a margin or by enlarging or reducing the reference image, or by both of these processes.

2. The inspection device according to claim 1.

3. the inspection unit compares the read image with the reference image after aligning the two images.

2. The inspection device according to claim 1.

4. The correction process in the reference image generating unit further modifies the amount of correction depending on the type of print medium to be printed.

2. The inspection device according to claim 1.

5. The correction process in the reference image generating unit is characterized in that the image is divided finer than the print medium in the sub-scanning direction and correction is performed for each division unit.

2. The inspection device according to claim 1.

6. The correction process in the reference image generating unit further includes modifying a correction amount based on information about a paper conveying force when transferring toner to a print medium.

2. The inspection device according to claim 1.

7. the toner comprises a plurality of colors; The correction process in the reference image generating unit is performed based on the amount of toner applied for each color.

2. The inspection device according to claim 1.

8. The correction process in the reference image generating unit is performed based on the amount of toner applied on a first side and a second side of a double-sided printing sheet.

2. The inspection device according to claim 1.

9. The present invention is characterized in that the setting means is provided for setting a priority area, a standard area, and a simplified area, and the setting means is capable of setting a detection level for each type of abnormality in each area.

2. The inspection device according to claim 1.

10. a read image correction unit that corrects the read image based on the toner amount of the print data; 2. The inspection device according to claim 1.

11. An inspection device for inspecting printed matter An acquisition unit that acquires print data; a reference image generating unit that generates a reference image from the acquired print data; an image reading unit that reads a printed matter on which the print data is printed by a printing device and obtains a read image; an inspection unit that performs an inspection by comparing the read image with a reference image; The inspection device includes a read image correction unit that corrects the read image based on the amount of toner applied in the print data.

12. The read image correction unit performs a margin addition process or an enlargement / reduction process on the reference image, or both of these processes. The inspection apparatus according to claim 11.

13. the inspection unit compares the read image with the reference image after aligning the two images. The inspection apparatus according to claim 11.

14. The correction process in the read image correction unit further modifies the amount of correction depending on the type of print medium to be printed. The inspection apparatus according to claim 11.

15. The correction process in the read image correction unit is characterized in that the sub-scanning direction is divided finer than the print medium, and correction is performed for each division unit. The inspection apparatus according to claim 11.

16. The correction process in the read image correction unit further includes modifying a correction amount based on information about a paper conveying force when the toner is transferred to a print medium. The inspection apparatus according to claim 11.

17. the toner comprises a plurality of colors; The correction process in the read image correction unit is performed based on the amount of toner applied for each color. The inspection apparatus according to claim 11.

18. The correction process in the read image correction unit is performed based on the amount of toner applied on the first and second sides of a double-sided print sheet. The inspection apparatus according to claim 11.

19. The present invention is characterized in that the setting means is provided for setting a priority area, a standard area, and a simplified area, and the setting means is capable of setting a detection level for each type of abnormality in each area. The inspection apparatus according to claim 11.

20. An inspection method for inspecting a printed matter, comprising: an acquisition step in which an acquisition unit acquires print data; a reference image generating step in which a reference image generating unit generates a reference image from the acquired print data; an image reading step in which an image reading unit reads a printed matter on which the print data is printed by a printing device to obtain a read image; an inspection step in which an inspection unit performs an inspection by comparing the read image with a reference image; The inspection method, wherein the reference image generating step corrects the reference image based on an amount of toner applied in the print data.

21. A program for operating a computer to inspect printed matter, comprising: Computer, An acquisition unit that acquires print data; a reference image generating unit that generates a reference image from the acquired print data; an image reading unit that reads a printed matter on which the print data is printed by a printing device and obtains a read image; functioning as an inspection unit that performs inspection by comparing the read image with a reference image; The reference image generating unit corrects the reference image based on an amount of toner applied in the print data.

22. A printing device equipped with an inspection device for inspecting printed matter, An acquisition unit that acquires print data; a reference image generating unit that generates a reference image from the acquired print data; an image printing unit that prints the acquired print data; an image reading unit that reads a printed matter printed by the image printing unit and obtains a read image; an inspection unit that performs an inspection by comparing the read image with the reference image; The printing apparatus, wherein the reference image generating unit corrects the reference image based on an amount of toner applied in the print data.

23. A method for inspecting a printed matter in a printing device, comprising: an acquisition step in which an acquisition unit acquires print data; a reference image generating step in which a reference image generating unit generates a reference image from the acquired print data; an image printing step in which an image printing unit prints the print data; an image reading step in which an image reading unit reads the printed matter printed in the image printing step to obtain a read image; an inspection step in which an inspection unit performs an inspection by comparing the read image with the reference image; The inspection method, wherein the reference image generating step corrects the reference image based on an amount of toner applied in the print data.

24. A program for causing a computer to function as a printing device, Computer, An acquisition unit that acquires print data; a reference image generating unit that generates a reference image from the print data; an image printing unit that prints the acquired print data; an image reading unit that reads a printed matter printed by the image printing unit and obtains a read image; functioning as an inspection unit that performs an inspection by comparing the read image with the reference image; The reference image generating unit corrects the reference image based on an amount of toner applied in the print data.

Images