Inspection device, its control method, and program

Abstract

To provide an inspection device which can prevent an inspection result of a printed matter from being unnecessarily determined to be abnormal in the time of an RIP inspection, and provide a control method and program of the same.SOLUTION: An inspection device 108, when performing an inspection of appearance quality of a printed matter printed by a printer 101 by using a reference image and a scan image of the printed matter, compares the scan image with an RIP image used in printing of the printed matter, when a difference is detected, displays a reference image selection screen including the RIP image and the scan image on a display part 245, as well as, receives the user input that determines whether or not the detected difference is a defect, and selects either of the RIP image or the scan image to be the reference image on the basis of the received user input.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to an inspection device, a control method thereof, and a program, and more particularly to an inspection device that inspects the quality of printed matter printed by a printing device, a control method thereof, and a program. [Background technology]

[0002] Inspection devices are known that use scanned images of printed matter produced by a printing device to inspect the quality of printed matter (hereinafter referred to as "printed matter inspection"). Inspection devices can detect image defects such as stains and missing prints, as well as print quality defects such as characters and barcodes, during the inspection of printed matter. It is common for these image defects and print quality defects to be able to detect the type of defect and set a threshold value for each detected defect type. For example, it is common for inspection devices to be able to set a minimum diameter in millimeters that a circular image defect called a "dot" must have to be considered a defect, and to set a minimum length in millimeters that a line defect called a "streak" must have to be considered a defect.

[0003] Inspection of such prints involves using a defect-free image, called a reference image, as the comparison target and comparing it with a scanned image of the print. There are two types of this method: one in which a scanned image of a pre-printed print is used as the reference image (hereafter referred to as "scan inspection"), and one in which an image before printing, such as a RIP image, is used as the reference image (hereafter referred to as "RIP inspection").

[0004] In scan inspection, one or more copies of the print job to be inspected are first printed, and scanned images of the resulting prints are generated. Next, after the user confirms that these prints are free of smudges and typographical errors, these scanned images are used as reference images. For example, out of a print job to print 1,000 copies, the first five copies are printed, and the user visually inspects the resulting prints. These scanned images are then used as reference images for comparison when printing the remaining 995 copies. In this way, scan inspection uses the scanned image of the print that the user visually inspected as the reference image. While this ensures that the reference image meets the print quality desired by the user, it has the disadvantage of taking time to visually inspect the prints.

[0005] In contrast, RIP inspection uses the pre-printed RIP image as a reference image for comparison with the scanned image of the print job being inspected. For example, defects such as smudges and missing prints are present in the print but not in the RIP image. RIP inspection allows for inspection of such defects without the user having to visually check the reference image, thereby increasing productivity. However, some differences between the RIP image and the print result are not due to defects in the print, but rather to the performance of the printing device. For example, when depicting extremely thin lines, the RIP image may faithfully reproduce the print data as a 0.5 pt line, but the print may appear as a 1 pt line depending on the performance of the printing device. Furthermore, moiré, the ripple-like stripes that appear on prints, is not present in the RIP image and is often a result of the performance of the printing device. Conventional RIP inspection cannot resolve these differences between the RIP image and the print due to the performance of the printing device, leading to unnecessary defects in the print inspection results.

[0006] On the other hand, as a method for preventing unnecessary judgment of abnormalities in the inspection results of printed materials, Patent Document 1 describes a technology in which, during scan inspection, images that contain defective images such as paper dust are excluded from the candidates for the reference image. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent Publication No. 2021-37736 Summary of the Invention [Problem to be solved by the invention]

[0008] However, the technique described in Patent Document 1 for preventing unnecessary determination of abnormalities in the inspection results of printed materials is a technology that can be used in scan inspection, but cannot be used in RIP inspection. RIP inspection uses the RIP image, which is the image before printing, as the reference image, so image defects that occur during printing by a printing device cannot be detected from the RIP image. Furthermore, in RIP inspection, even if the print job to be inspected prints multiple copies, one RIP image per page of the print job becomes the reference image. Therefore, if the RIP image of a specific page is inappropriate as a reference image and is excluded, there will be no reference image for the specific page.

[0009] Therefore, an object of the present invention is to provide an inspection device, a control method and a program for the same that can prevent the inspection result of a printed matter from being unnecessarily determined to be abnormal during RIP inspection. [Means for solving the problem]

[0010] In order to solve the above-mentioned problems, an inspection device according to the present invention is an inspection device that inspects the quality of printed matter printed by a printing device using a reference image and a scanned image of the printed matter, and during inspection of the quality of a first copy of the printed matter, using a pre-press image used to print the printed matter as the reference image, the inspection device is equipped with UI means that, if a difference is detected as a result of comparing the pre-press image that functions as the reference image with the scanned image of the first copy of the printed matter, displays a reference image selection screen including the pre-press image and the scanned image and receives user input as to whether the detected difference is a defect, and inspects the quality of second and subsequent copies of the printed matter printed by the printing device based on the user input received by the UI means, using the scanned image of the first copy of the printed matter as the reference image. If the detected difference corresponds to a predetermined defect type, the result of the quality inspection of the first copy of the printed matter is determined to be abnormal without displaying the reference image selection screen. It is characterized by: [Effects of the Invention]

[0011] According to the present invention, it is possible to prevent the inspection result of a printed matter from being unnecessarily determined to be abnormal during RIP inspection. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic diagram illustrating a configuration of an inspection system including an inspection device according to a first embodiment of the present invention. [Figure 2] 2 is a block diagram showing the hardware configurations of a printing device, an inspection device, an inspection unit, a large-capacity stacker, an information processing device, and a client computer in FIG. 1. FIG. [Figure 3] 2A and 2B are diagrams illustrating the internal configurations of a printing device, an inspection unit, and a large-capacity stacker. [Figure 4] 10 shows a setting screen for an operation mode in the inspection device. [Figure 5] 10 shows an inspection status screen displayed on the display unit of the inspection device when the inspection is being performed. [Figure 6] 10 is a flowchart of a reference image registration process executed by the inspection device. [Figure 7] 10 is a flowchart of an inspection process executed by the inspection device. [Figure 8] 8 is a flowchart of a reference image selection process executed in step S706 of FIG. 7 when the inspection method is RIP inspection. [Figure 9] 9 is a diagram showing a reference image selection screen used in the reference image selection process of FIG. 8. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] First Embodiment A first embodiment of the present invention will be described below with reference to the drawings. Unless otherwise specified, the present invention can be applied to an inspection device consisting of a single device or multiple devices, as long as the functions of the present invention are realized. Furthermore, unless otherwise specified, the present invention can be applied to an inspection device that is connected and performs processing via a network such as a LAN or WAN, as long as the functions of the present invention are realized. In other words, the system configuration in which various terminals are connected, as described in the following embodiment, is merely an example, and it goes without saying that there are various configuration examples depending on the application and purpose.

[0014] FIG. 1 is a schematic diagram showing the configuration of an inspection system including an inspection device 108 according to this embodiment.

[0015] 1, the inspection system includes an information processing device 109, an inspection device 108, a printing device 101, and a client computer 110. In this embodiment, the printing device 101 is an electrophotographic printing device, but the printing device may be an inkjet printing device, an offset printing device, or another type of printing device that uses a different image forming method.

[0016] The printing device 101 is connected to an information processing device 109 via a cable 112 .

[0017] The information processing device 109 is connected to a client computer 110 via a network 113 .

[0018] The printing device 101 includes a UI panel 102, a paper feed deck 103, and a paper feed deck 104. In addition, an optional deck 105 consisting of three paper feed decks is connected to the printing device 101. Note that in this embodiment, the UI panel 102 is a user interface equipped with, for example, a capacitive touch panel, but is not limited to this as long as it is a user interface including a display unit and an operation unit that allows user input.

[0019] The printing device 101 further includes an inspection unit 106 and a large-capacity stacker 107 .

[0020] The inspection unit 106 is connected to the inspection device 108 via a cable 114 .

[0021] Large-capacity stacker 107 includes a main tray 324 (not shown in FIG. 1) and a top tray 320, and several thousand sheets of paper can be stacked at one time on main tray 324. Paper sheets for which defects have been detected by inspection device 108 are ejected onto top tray 320.

[0022] A print job is generated by the client computer 110, transmitted to the information processing device 109 via the network 113, and managed by the information processing device 109. The print job is then transmitted from the information processing device 109 to the printing device 101 via the cable 112, and the printing device 101 performs processing to print on paper based on the print job. Note that the print job may also be generated and managed by the information processing device 109, transmitted directly to the printing device 101 via the cable 112, and managed by the printing device 101.

[0023] The client computer 110, information processing device 109, and inspection device 108 may each be connected to a cable 112 and may communicate with the printing device 101. The inspection device 108 may also be connected to the information processing device 109 and client computer 110 via a network 113. In other words, the connection configuration of the printing device 101, information processing device 109, and client computer 110 shown in this embodiment is just one example, and it goes without saying that there are various other connection configurations besides that shown in this embodiment.

[0024] Furthermore, the printing apparatus 101 may be configured to be connected with a stapleable finisher, a folding machine, a bookbinding machine, and the like in addition to the inspection unit 106 and the large-capacity stacker 107 .

[0025] FIG. 2 is a block diagram showing the hardware configuration of each of the printing device 101, the inspection device 108, the inspection unit 106, the large-capacity stacker 107, the information processing device 109, and the client computer 110.

[0026] The printing device 101 includes a CPU 201, a RAM 202, a UI panel 102, a paper feed deck I / F 204, a storage unit 205, a video I / F 206, a NW I / F 207, an accessory I / F 208, an engine I / F 209, and a printer engine 210. The components of the printing device 101 are connected to one another via a system bus 212.

[0027] The CPU 201 is a central processing unit that controls and performs calculations in each section of the printing apparatus 101 via a system bus 212. The CPU 201 is stored in a storage section 205 and executes programs loaded into a RAM 202.

[0028] The RAM 202 is a random access memory, a type of general volatile storage device that can be directly accessed by the CPU 201, and is used as a work area for the CPU 201 or as other temporary data storage areas.

[0029] The storage unit 205 functions as a temporary storage area and a work memory when the printing device 101 is in operation.

[0030] The engine I / F 209 controls and manages communication between the CPU 201 and the printer engine 210 .

[0031] The paper feed deck I / F 204 controls and manages communication between the CPU 201 and the paper feed deck 211 .

[0032] The sheet feed deck 211 is a general term for the sheet feed deck 103, the sheet feed deck 104, and the option deck 105 in FIG.

[0033] The UI panel 102 is a user interface for performing all operations of the printing device 101 .

[0034] The NW I / F 207 is a network interface, and is connected to a later-described NW I / F 238 of the information processing device 109 via a cable 213, and controls communication between the information processing device 109 and the printing device 101. Note that in this embodiment, the NW I / Fs 207 and 238, which are interfaces connected to the system buses 212 and 239, are directly connected, but they may also be connected via a network, for example, and the connection format is not limited thereto.

[0035] The video I / F 206 is connected to a video I / F 233 (described later) via a video cable 241 , and controls communication of image data between the information processing device 109 and the printing device 101 .

[0036] The connection interface between the information processing device 109 and the printing device 101 may be a combination of the functions of the NW I / F 238 and the video I / F 233. Similarly, the connection interface between the printing device 101 and the information processing device 109 may be a combination of the functions of the NW I / F 207 and the video I / F 206.

[0037] The accessory I / F 208 is connected to the accessory I / Fs 214 and 220 (described later) via a cable 225. That is, the printing device 101 communicates with the inspection unit 106 and the large-capacity stacker 107 via the accessory I / Fs 208, 214, and 220.

[0038] The inspection unit 106 includes an accessory I / F 214, an inspection device I / F 215, a CPU 216, a RAM 217, an imaging unit 218, and a storage unit 247. The components of the inspection unit 106 are connected to each other via a system bus 219.

[0039] The CPU 216 is a central processing unit (Central Processing Unit) that controls and performs calculations in each section within the inspection unit 106 via a system bus 219 , and executes programs stored in the storage section 247 and loaded into the RAM 217 .

[0040] The RAM 217 is a random access memory, a type of general volatile storage device that can be directly accessed by the CPU 216, and is used as a work area for the CPU 216 or as other temporary data storage areas.

[0041] The storage unit 247 functions as a temporary storage area and a work memory when the inspection unit 106 is in operation.

[0042] The inspection device I / F 215 is connected to an inspection device unit I / F 231 (described later) via a cable 249. That is, the inspection unit 106 communicates with the inspection device 108 via the inspection device I / F 215 and the inspection device unit I / F 231.

[0043] The photographing unit 218 has a photographing function equipped with, for example, a conduct image sensor (hereinafter, CIS), photographs a sheet passing through the inspection unit 106, generates a scanned image, and transmits the scanned image to the inspection device 108 via the inspection device I / F 215. In this embodiment, a case where the sensor equipped in the photographing function of the photographing unit 218 is a CIS is described. However, other sensors, such as a CCD image sensor, may also be used, and the photographing method is not limited. There are two purposes for transmitting the image photographed by the photographing unit 218 to the inspection device 108. One is to photograph the printed matter of the print job to be inspected, regardless of the inspection method, and transmit it to the inspection device 108 for inspection of the quality of the printed matter (hereinafter, referred to as "inspection of the printed matter"). The other is to print and photograph one or more copies of the print job to be inspected before executing the print job to be inspected, if the inspection method is scan inspection, and transmit the photographed image to the inspection device 108 as a reference image. For the latter purpose, the image captured by the imaging unit 218 and transmitted to the inspection device 108 is stored as a reference image in the storage unit 228, which will be described later.

[0044] The large-capacity stacker 107 includes an accessory I / F 220, a CPU 221, a RAM 222, a paper discharge unit 223, and a storage unit 248. The components of the large-capacity stacker 107 are connected to one another via a system bus 224.

[0045] The CPU 220 is a central processing unit (Central Processing Unit) that controls and performs calculations in each section within the large-capacity stacker 107 via a system bus 224. The CPU 220 is stored in a storage section 248 and is responsible for executing programs loaded into a RAM 222.

[0046] The RAM 222 is a random access memory, a type of general volatile storage device that can be directly accessed by the CPU 221, and is used as a work area for the CPU 221 or as other temporary data storage areas.

[0047] The storage unit 248 functions as a temporary storage area and a work memory when the large-capacity stacker 107 is in operation.

[0048] Paper discharge unit 223 is responsible for discharging paper onto main tray 324 and top tray 320 (described later), and for monitoring and controlling the loading status of main tray 324 and top tray 320.

[0049] The inspection device 108 includes a CPU 226, a RAM 227, a storage unit 228, a PDL analysis unit 229, an inspection unit I / F 231, and a display unit 245. The components of the inspection device 108 are connected to one another via a system bus 230.

[0050] The CPU 226 is a central processing unit that controls and performs calculations in each section of the inspection device 108 via a system bus 230 , and executes programs stored in a storage section 228 and loaded into a RAM 227 .

[0051] The RAM 227 is a random access memory, a type of general volatile storage device that can be directly accessed by the CPU 226, and is used as a work area for the CPU 226 or as other temporary data storage areas.

[0052] The storage unit 228 functions as a temporary storage area and a work memory when the inspection device 108 is in operation.

[0053] The PDL analysis unit 229 reads PDL data such as PDF, PostScript, or PCL received from the client computer 110 or the information processing device 109 via the printing device 101 and the inspection unit 106, and performs interpretation processing.

[0054] The display unit 245 (UI means) is, for example, a liquid crystal display connected to the inspection device 108, and receives input from the user to the inspection device 108 and displays the status of the inspection device 108.

[0055] The information processing device 109 includes a video I / F 233, a CPU 234, a RAM 235, a storage unit 236, and NW I / Fs 237 and 238. The units of the information processing device 109 are connected to one another via a system bus 239.

[0056] The CPU 234 is a central processing unit that controls and performs calculations in each section of the information processing device 109 via a system bus 239 , and executes programs stored in a storage section 236 and loaded into a RAM 235 .

[0057] The RAM 235 is a random access memory, a type of general volatile storage device that can be directly accessed by the CPU 234, and is used as a work area for the CPU 234 or as other temporary data storage areas.

[0058] The storage unit 236 functions as a temporary storage area and a work memory when the information processing device 109 is in operation.

[0059] The NW I / F 237 is a network interface, and is connected to the NW I / F 240 via the network 113. The information processing device 109 also communicates with the client computer 110 via the NW I / Fs 237 and 240.

[0060] Alternatively, the inspection device 108 may have a network interface, and the information processing device 109 may communicate with the inspection device 108 via the network interface and the network interface 237. For example, consider a case where RIP inspection is used as the inspection method, and an image before printing by the printing device 101, such as a RIP image (image before printing), is used as the reference image. In this case, the reference image may be transmitted to the inspection device 108 via the inspection device interface 215, or may be transmitted to the inspection device 108 from a network interface provided in the inspection device 108 via the network interfaces 207 and 237. In this embodiment, a RIP image generated by the printing device 101 before printing is used as the reference image used during RIP inspection, but a RIP image generated by a RIP device other than the printing device 101, such as RIP software, may also be used.

[0061] The client computer 110 includes a network interface (NW) 240, a CPU 243, a RAM 242, and a storage unit 244. The components of the client computer 110 are connected to one another via a system bus 246.

[0062] The CPU 243 is a central processing unit (Central Processing Unit) that controls and performs calculations in each section of the client computer 110 via a system bus 246, and is stored in a storage section 244. The CPU 243 also controls the execution of programs loaded into the RAM 242.

[0063] The RAM 242 is a random access memory, a type of general volatile storage device that can be directly accessed by the CPU 243, and is used as a work area for the CPU 243 or as other temporary data storage areas.

[0064] The storage unit 244 functions as a temporary storage area and a work memory when the client computer 110 is in operation.

[0065] FIG. 3 is a diagram showing the internal configuration of each of the printing device 101, the inspection unit 106, and the large-capacity stacker 107.

[0066] 1, the printing apparatus 101 includes a UI panel 102 and paper feed decks 103 and 104. The printing apparatus 101 further includes development stations 301 to 304, paper transport paths 305, 309, 311, and 312, an intermediate transfer belt 306, a secondary transfer position 307, a fixing unit 308, a second fixing unit 310, a paper reversing path 313, and a duplex transport path 314.

[0067] The UI panel 102 receives input from the user and displays the status of the printing device 101 .

[0068] Each of the paper feed decks 103 and 104 is a deck that can accommodate various types of paper, and can separate only the topmost sheet of the accommodated sheets and transport it to a paper transport path 305.

[0069] To form a color image, the developing stations 301 to 304 form toner images using color toners of Y, M, C, and K, respectively. The toner images formed here are primarily transferred onto an intermediate transfer belt 306.

[0070] The intermediate transfer belt 306 rotates clockwise in FIG. 3, and the toner image is secondarily transferred to a sheet of paper conveyed from a paper conveyance path 305 at a secondary transfer position 307 .

[0071] The fixing unit 308 includes a pressure roller and a heating roller. As the paper passes between these rollers, the toner is melted and pressed to fix the toner image to the paper. After passing through the fixing unit 308, the paper is transported to a paper transport path 312 via a paper transport path 309. Note that depending on the type of paper, further melting and pressing may be required to fix the toner image. In such cases, the paper passing through the fixing unit 308 is transported to a second fixing unit 310 via a paper transport path 311 above the paper transport path 309, where it is subjected to additional melting and pressing before being transported to the paper transport path 312. Furthermore, when the image formation mode is double-sided, the paper that has passed through the paper transport paths 309 and 311 is transported to a paper inversion path 313, where it is inverted, and then transported to a double-sided transport path 314, where the image on the second side is transferred to the secondary transfer position 307.

[0072] The inspection unit 106 includes therein a paper transport path 317 and CISs 315 and 316 that are arranged opposite the paper transport path 317 .

[0073] The CIS315 is a sensor for reading the top surface of the paper.

[0074] The CIS316 is a sensor for reading the bottom surface of the paper.

[0075] When the paper transported on paper transport path 317 reaches a predetermined position, inspection unit 106 scans the paper using CIS 315, 316. The scanned image is sent to inspection device 108 via inspection device I / F 215 and inspection unit I / F 231. CPU 226 of inspection device 108 determines whether the image received from inspection unit 106 has any defects and notifies inspection unit 106 of the determination result via inspection unit I / F 231 and inspection device I / F 215. CPU 216 of inspection unit 106 notifies large capacity stacker 107 of the determination result received from inspection device 108 via accessory I / Fs 214, 220.

[0076] The large-capacity stacker 107 is a stacker capable of stacking a large amount of paper, and includes paper transport paths 319, 321, and 322, a top tray 320, a reversing unit 323, and a main tray 324 as a tray for stacking paper.

[0077] The paper that has passed through inspection unit 106 enters large-capacity stacker 107 via paper transport path 319. The paper travels from paper transport path 319 to paper transport path 322 and is loaded onto main tray 324.

[0078] CPU 221 of large-capacity stacker 107 discharges to top tray 320 any sheet of paper for which a defect has been detected by inspection device 108. When discharging a sheet of paper to top tray 320, the sheet is transported from sheet transport path 319 to top tray 320 via sheet transport path 321. Reversing unit 323 is a transport path for reversing the sheet of paper, and is used when stacking the sheet of paper on main tray 324. When stacking the sheet on main tray 324, the sheet of paper is reversed once by reversing unit 323 so that the orientation of the sheet entering large-capacity stacker 107 is the same as the orientation of the sheet when stacked on main tray 324. When transporting a sheet of paper to top tray 320, the sheet of paper is discharged as is without being flipped when stacked, and therefore no reversing operation is performed by reversing unit 323.

[0079] FIG. 4(a) shows a setting screen for the operation mode of the inspection device 108.

[0080] The operation mode setting screen 401 is displayed on the display unit 245 of the inspection device 108 and is a screen for accepting operation mode settings from the user, and includes an operation mode selection section 402 and an inspection method selection section 404 .

[0081] The operation mode selection unit 402 is a selection unit that allows the user to select one of the operation modes, "log mode" and "purge mode." When the user selects "log mode" in the operation mode selection unit 402, the printing device 101 ejects the inspected paper to a paper ejection destination that is specified in advance in the properties of the print job, regardless of the inspection result by the inspection device 108. On the other hand, when the user selects "purge mode" in the operation mode selection unit 402, the printing device 101 ejects paper that has been inspected by the inspection device 108 as NG (hereinafter referred to as "paper with an NG inspection result") to the top tray 320.

[0082] The inspection method selection unit 404 is a selection unit that allows the user to select one of the inspection methods, "scan inspection" and "RIP inspection." When the user selects "scan inspection" in the inspection method selection unit 404, the inspection device 108 uses the scanned image of the printed material as the reference image. On the other hand, when the user selects "RIP inspection," the inspection device 108 uses the RIP image used by the printing device 101 for printing as the reference image. The generation and storage process of the reference image will be described with reference to the flowchart in FIG. 6.

[0083] FIG. 4(b) shows a recovery setting screen for the purge mode in the inspection device 108.

[0084] When the user selects "purge mode" in the operation mode selection section 402, the recovery mode setting set by the user is reflected on the recovery mode setting screen 403.

[0085] The recovery mode setting screen 403 is displayed on the display unit 245 and is a screen that accepts one of the "non-recovery mode" and "recovery mode" as a recovery mode setting from the user. If the user selects the "non-recovery mode" on the recovery mode setting screen 403, only sheets that have failed the inspection are ejected to the top tray 320. The inspection device 108 continues the same inspection on subsequent sheets, and the printing device 101 ejects only sheets that have failed the inspection to the top tray 320. On the other hand, if the user selects the "recovery mode" on the recovery mode setting screen 403, not only sheets that have failed the inspection are ejected to the top tray 320, but also all sheets that are in any of the transport paths shown in FIG. 3 at the time the inspection device 108 determines that the inspection result is NG. Thereafter, when all the transport paths shown in FIG. 3 have run out of paper, the printing device 101 and the inspection device 108 resume printing and inspection from the image that was printed on the sheet that has failed the inspection.

[0086] In this embodiment, the inspection device 108 inspects the sheets printed by the printing device 101 by capturing images of the images printed on the sheets using the CISs 315 and 316 of the inspection unit 106. Therefore, when the inspection device 108 determines that a certain sheet has failed the inspection, there is a possibility that subsequent sheets have already reached the sheet transport paths 309 and 311, etc. However, unless all sheets in all transport paths shown in FIG. 3 are ejected, the image printed on the sheet with the failed inspection result cannot be printed again and the sheet cannot be stacked in the correct output order at the sheet ejection destination specified in advance in the print job. Therefore, this type of operation is performed in the "with recovery mode."

[0087] The CPU 226 of the inspection device 108 notifies the inspection unit 106 of the operation mode, recovery mode, and inspection method set on the operation mode setting screen 401 and recovery mode setting screen 403 via the inspection unit I / F 231 and inspection device I / F 215. The operation mode, recovery mode, and inspection method set on the operation mode setting screen 401 and recovery mode setting screen 403 are stored in the RAM 227 by the CPU 226 of the inspection device 108 and in the RAM 217 by the CPU 216 of the inspection unit 106, respectively.

[0088] FIG. 5 shows an examination status screen 501 that is displayed on the display unit 245 of the examination device 108 when the examination is being performed.

[0089] The inspection status screen 501 is displayed on the display unit 245 of the inspection device 108, and receives instructions from the user to start or stop an inspection, and displays the inspection status.

[0090] The test status screen 501 is a screen that displays a test button 502, a test status 503, and a list of test failures 504.

[0091] The inspection button 502 receives instructions from the user to execute or stop an inspection by the inspection device 108. When the user presses the inspection button 502, which displays "Start inspection," to instruct the user to execute an inspection, the text on the inspection button 502 changes to "Stop inspection," and the inspection status 503 changes to "Inspection."

[0092] Thereafter, when the user presses the test button 502 that displays "Stop test" to instruct the test to stop, the text on the test button 502 returns to "Start test," while the test status 503 changes to "Stopped."

[0093] Thereafter, the character string on the inspection button 502 and the inspection status 503 change in a toggle manner every time the inspection button 502 is pressed.

[0094] The inspection status screen 501 further displays in real time during the inspection the number of inspected sheets, the number of sheets for which the inspection result was NG, the defect rate, and the number of occurrences of each cause of the inspection result being NG. Note that the number of occurrences of "errors" displayed on the inspection status screen 501 as one of the causes of the inspection result being NG is the number of sheets for which the inspection device 108 timed out and determined that an error occurred because the inspection was not completed within the specified inspection time, and therefore the inspection result was determined to be equivalent to NG.

[0095] Each time an NG test result occurs, the NG test list 504 is updated with the sheet number indicating the order in which the paper that resulted in the NG test result was fed, information on whether it was the front or back, the cause of the NG test result, the time of the test, and a link to the NG details screen described below.

[0096] When one of the links to the NG details screen (for example, link 505) in the NG inspection list 504 is pressed, the display unit 245 displays the NG details screen (not shown). The NG details screen displays a scanned image of the paper captured by either one of the CISs 315 and 316 that resulted in the NG inspection result, and the location of defects in the scanned image.

[0097] In addition, the inspection NG list 504 displays misalignment, circular defects (dots), line defects (streaks), and errors as causes of the inspection result NG.

[0098] A positional deviation is a defect (causing an NG inspection result) in which all or part of an image is misaligned when a scanned image is compared with a reference image.

[0099] A circular defect is a defect in which a circular stain appears only on the scanned image side (which can cause an NG inspection result).

[0100] A streak defect is a defect in which dirt appears in the form of streaks or lines only on the scanned image (which can cause an NG inspection result).

[0101] In this way, the inspection device 108 identifies the type of the detected defect from the characteristics of each defect and displays it in the inspection failure list 504.

[0102] The defects displayed as causes of an NG inspection result in the NG inspection list 504 are just examples, and the types of defects that can be detected by the inspection device 108 are not limited to these. For example, when an image is drawn only on the reference image side and all or part of it is not drawn on the scanned image side, a cause of an NG inspection result determined to be a missing image may be added to the NG inspection list 504.

[0103] The characteristic processes of this embodiment will be described below with reference to the flowcharts described later.

[0104] FIG. 6 is a flowchart of the reference image registration process executed by the inspection device 108.

[0105] The program for this processing is stored in the storage unit 228 in the inspection device 108, read into the RAM 227, and executed by the CPU 226.

[0106] As described above, if the inspection method is scan inspection, the reference image is a scanned image of the printed matter, and if the inspection method is RIP inspection, the reference image is a RIP image used for printing by the printing device 101. The reference image registration process in Fig. 6 is common to both the scan inspection and RIP inspection methods.

[0107] First, in step S601, when the user presses the inspection button 502 on the display unit 245 of the inspection device 108, the CPU 226 starts reading an image.

[0108] In step S602, the CPU 226 repeats the processes of steps S603 and S604 until the reference images for all sheets to be printed on paper by the print job have been registered.

[0109] In step S603, if the inspection method is scan inspection, the CPU 226 receives, as the reference image, the image scanned by the CIS 315, 316 via the inspection unit I / F 231 and the inspection device I / F 215. On the other hand, if the inspection method is RIP inspection, the CPU 226 (first acquisition means) receives, as the reference image, the RIP image generated by the printing device 101 before printing, from the inspection device I / F 215. Note that the inspection method here is the method selected by the inspection method selection unit 404 in FIG. 4(a) described above.

[0110] In step S604, the CPU 226 registers the reference image received in step S603 in the RAM 227.

[0111] In step S605, if the CPU 226 has completed registration of the reference images for all sheets, the process proceeds to step S606, otherwise the process returns to step S603.

[0112] In step S606, when the user presses the inspection button 502 on the display unit 245 of the inspection device 108, the CPU 226 ends image reading and ends this process.

[0113] The reference image registration process in FIG. 6 is an example of the reference image registration process of the present invention.

[0114] For example, the start of image reading in step S601 is executed when the user presses the inspection button 502 on the display unit 245, but this is not limited to this. For example, the start of image reading in step S601 may be executed in conjunction with a print start instruction from the user of any of the printing device 101, the information processing device 109, and the client computer 110.

[0115] Similarly, the image reading in step S606 is also terminated when the user presses the inspection button 502 on the display unit 245, but this is not limiting. For example, the image reading in step S606 may be terminated in conjunction with the completion of printing in the printing device 101.

[0116] Furthermore, when the inspection method is scan inspection, the inspection device 108 may read a plurality of images for the same page, and register the composite image as a reference image.

[0117] FIG. 7 is a flowchart of the inspection process executed by the inspection device 108.

[0118] The program for this processing is stored in the storage unit 228 in the inspection device 108, read into the RAM 227, and executed by the CPU 226.

[0119] In step S701, the CPU 226 acquires the operation mode selected by the user in the operation mode selection unit 402, and if the user-selected operation mode is the "purge mode," the recovery mode setting selected by the user in the recovery mode setting screen 403. The CPU 226 also acquires the inspection method selected by the user in the inspection method selection unit 404.

[0120] In step S702, when the user presses the inspection button 502 on the display unit 245 of the inspection device 108, the CPU 226 starts reading an image.

[0121] In step S703, CPU 226 repeats the processes of steps S704 to S715 until inspection of all sheets printed on paper by the print job is completed (until there are no more sheets to be inspected).

[0122] In step S704, the CPU 226 (second acquisition means) receives the image scanned by the CIS 315, 316 via the inspection unit I / F 231 and the inspection device I / F 215. This image is a scanned image of the inspection target obtained by scanning the print result of the print job that will be the deliverable, and the inspection device 108 performs inspection by comparing this scanned image with a reference image that has been registered in advance in the reference image registration process of FIG.

[0123] In step S705, the CPU 226 reads out the reference image of the corresponding page registered in step S604 from the RAM 227. Note that if the inspection method is RIP inspection, the reference image (the correct image for the second copy and subsequent copies) may change due to the reference image selection process described later in Fig. 8. Therefore, after the reference image selection process for all pages of the first copy is completed and the correct images for the second copy and subsequent copies are determined, the first page of the second copy is printed.

[0124] In step S706, the CPU 226 inspects the scanned image of the inspection target received in step S704 using the reference image read in step S705. Then, based on the inspection results, the reference image and the scanned image are compared to determine whether there are any differences. In this determination operation, first, characteristic points on both images are used as alignment reference points to align the image positions of the reference image and the scanned image of the inspection target. Next, in the scanned image of the inspection target, the four corners of the paper and the alignment reference points on the scanned image are analyzed to detect any misalignment of the image relative to the paper. Next, the density values of the reference image and the scanned image of the inspection target are compared pixel by pixel. If the above determination operation determines that there is no difference between the scanned image of the inspection target and the reference image, the inspection result is determined to be OK (no abnormality in the printed material). On the other hand, if a difference is determined to exist, the inspection result is determined to be NG (no abnormality in the printed material), and the details of the NG inspection result described in FIG. 5 are recorded depending on the type of defect. Note that, in order to explain the basic inspection operation, the inspection method used here is scan inspection, in which the inspection result is always NG when a difference is determined to exist. However, unlike scan inspection, when the inspection method is RIP inspection, the inspection result is not always NG even if a discrepancy is determined. Specifically, in RIP inspection during printing of the first copy, even if a discrepancy is determined, if the defect type cannot be identified and the discrepancy is not within the tolerance, a reference image selection process is executed, at the user's option, to replace the reference image with the scanned image of the inspection target. Details of this reference image selection process will be described later using the flowchart in Figure 8.

[0125] In step S707, CPU 226 determines whether the inspection was completed within a specified time. If the result of the determination is that the inspection was completed within the specified time (YES in step S707), the process proceeds to step S708. If not (NO in step S707), the process proceeds to step S709. The determination in step S707 is made because if it takes a long time to inspect one scanned image, CPU 226 will not be able to inspect the scanned images of subsequent sheets that are subsequently transmitted. Furthermore, when purge mode is selected in operation mode selection unit 402, CPU 221 switches the destination of sheets that have been inspected by inspection device 108 as NG so that they are discharged to top tray 320. That is, CPU 226 needs to notify CPU 221 of the NG inspection result before the sheet that has been inspected as NG reaches a point where CPU 221 can no longer switch the destination of the sheet.

[0126] Therefore, if the inspection cannot be completed within the specified time (NO in step S707), the inspection result of the scanned image to be inspected cannot be determined to be OK, so the CPU 226 determines the inspection result to be NG and proceeds to step S709.

[0127] In step S708, CPU 226 determines whether the test result is NG as a result of the comparison in step S706. If the test result is NG (YES in step S708), the process proceeds to step S709, and if the test result is OK (NO in step S708), the process proceeds to step S716.

[0128] In step S709, CPU 226 reads the operation mode from RAM 227 and determines whether the operation mode is the purge mode. If the operation mode is the purge mode (YES in step S709), the process proceeds to step S710. If the operation mode is the log mode (NO in step S709), the process proceeds to step S715.

[0129] In step S710, the CPU 226 notifies the CPU 216 via the inspection unit I / F 231 and the inspection device I / F 215 that the inspection result is NG.

[0130] In step S711, CPU 226 reads the recovery mode setting from RAM 227 and determines whether the read recovery mode setting is the “mode with recovery.” If the result of this determination is the “mode with recovery” (YES in step S711), the process proceeds to step S712; if the result is the “mode without recovery” (NO in step S711), the process proceeds to step S715.

[0131] In step S712, the CPU 226 waits until it receives print stop information from the CPU 216 via the inspection unit I / F 231 and the inspection device I / F 215. When the CPU 226 receives the print stop information (Yes in step S712), the process proceeds to step S713.

[0132] In step S713, the CPU 226 reads out from the RAM 227 the reference image corresponding to the sheet for which the inspection result is NG, and stores it as the reference image for the image to be inspected next.

[0133] In step S714, the CPU 226 notifies the CPU 216 via the inspection unit I / F 231 and the inspection device I / F 215 of the resumption of inspection.

[0134] In step S715, the CPU 226 adds information about the paper sheet with the NG inspection result to the NG inspection list 504.

[0135] In step S716, if the CPU 226 has finished inspecting all the sheets, the process proceeds to step S717; otherwise, the process returns to step S704.

[0136] In step S717, when the user presses the inspection button 502 on the display unit 245 of the inspection device 108, the CPU 226 ends image reading and ends this process.

[0137] The inspection process of FIG. 7 is an example of the inspection process of the present invention.

[0138] For example, the start of image reading in step S701 is executed when the user presses the inspection button 502 on the display unit 245, but this is not limited to this. For example, the start of image reading in step S701 may be executed in conjunction with a print start instruction from the user of any of the printing device 101, the information processing device 109, and the client computer 110.

[0139] Similarly, the image reading in step S717 is also terminated when the user presses the inspection button 502 on the display unit 245, but this is not limiting. For example, the image reading in step S717 may be terminated in conjunction with the completion of printing in the printing device 101.

[0140] Fig. 8 is a flowchart of the reference image selection process executed in step S706 in Fig. 7 when the inspection method is RIP inspection. Fig. 9 is a diagram showing a reference image selection screen used in the reference image selection process in Fig. 8.

[0141] The program for this processing is stored in the storage unit 228 in the inspection device 108, read into the RAM 227, and executed by the CPU 226.

[0142] In step S801, the CPU 226 inspects the scanned image of the printout using the RIP image as a reference image.

[0143] In step S802, CPU 226 compares the reference image with the scanned image as a result of the inspection in step S801 to determine whether there is a difference, i.e., whether a difference has been detected. This determination operation is as described above in step S706 of FIG. 7. If it is determined that there is no difference as a result of this determination operation (NO in step S802), the process proceeds to step S810, the inspection result is set to OK, and this process ends. On the other hand, if it is determined that there is a difference (YES in step S802), the process from step S803 onwards, which is the characteristic process of FIG. 8, is executed.

[0144] In step S803, the CPU 226 determines whether the defect type of the detected difference has been identified. In this embodiment, if the defect corresponds to any of misalignment, circular defect, and line defect described in FIG. 5, it is determined that the defect type has been identified. If the result of the determination is that the defect type has been identified (YES in step S803), the process proceeds to step S808, the corresponding page is determined to have an NG inspection result, and this process ends. On the other hand, if the defect type cannot be identified (NO in step S803), the process proceeds to step S804.

[0145] In step S804, the CPU 226 determines whether the magnitude of the detected difference is within the tolerance. In RIP inspection, a RIP image, which is a reference image, is compared with a scanned image of the print product based on that RIP image, so slight differences may occur due to factors such as paper shrinkage. However, if such slight differences are within the tolerance range that does not affect the quality of the print product, it is desirable to determine the inspection result for the corresponding page as OK. Therefore, if the determined magnitude of the difference is within the tolerance (YES in step S804), the CPU 226 proceeds to step S810, as if it were determined in step S802 that there was no difference, determines the inspection result as OK, and terminates this processing. Specifically, the tolerance in this embodiment is "within 3 pixels," but the tolerance can be set arbitrarily depending on the inspection device 108. On the other hand, if the detected difference is outside the tolerance range (NO in step S804), the CPU 226 proceeds to step S805. In this embodiment, if it is determined that the defect type cannot be identified (NO in step S803), the process proceeds to step S804, but the order may be reversed. That is, if the magnitude of the detected difference is not within the allowable range (NO in step S804), the process may proceed to step S803.

[0146] In step S805, CPU 226 determines whether the page in question is the first copy of the printout. If it is not the first copy (if it is the second or subsequent copy) (NO in step S805), the process proceeds to step S808, where the inspection result for the page in question is determined to be NG, and the process ends. On the other hand, if it is the first copy (YES in step S805), the process proceeds to step S806.

[0147] In step S806, the CPU 226 displays on the display unit 245 a reference image selection screen 901 (FIG. 9) including the RIP image that is the current reference image and the scanned image of the page in question.

[0148] When the inspection method is RIP inspection, the difference between the reference image and the print result may not be a defect but may be due to the characteristics of the printing device, and the page may not necessarily be inspected as NG. Therefore, in step S806, a reference image selection screen 901 is displayed to receive an instruction from the user as to whether the difference between the reference image and the print result is a defect.

[0149] As shown in FIG. 9, a reference image selection screen 901 (display means / reception means) has a display frame 902 for the RIP image that is the current reference image, a display frame 903 for the scanned image of the corresponding page, an OK button 904, and an NG button 905.

[0150] In each of the display frames 902 and 903, the locations where differences are detected are indicated by dotted rectangles to make them easier to see.

[0151] 8, in step S807, the CPU 226 determines whether the user has determined that the inspection result of the corresponding page is NG based on the user's operation on the reference image selection screen 901. Specifically, the user compares the images displayed in the display frames 902 and 903, and if the user determines that the scanned image of the corresponding page displayed in the display frame 903 meets the quality of the print product (the print result is acceptable), the user presses the OK button 904. If such a user input is present on the reference image selection screen 901, the CPU 226 determines that the inspection result of the corresponding page is OK (NO in step S807), and proceeds to step S809. Examples of such a user determination include poor reproducibility of thin lines or the occurrence of moire images due to the performance of the printing device 101.

[0152] In step S809, the CPU 226 (selection means) selects and registers the scanned image of the corresponding page as the reference image (the correct image for the second or subsequent copies). This is because, even if there are differences between the RIP image and the scanned image of the corresponding page, if the user determines that the scanned image of the corresponding page satisfies the quality of the print product, it is desirable to use this as the reference image for subsequent copies or when reprinting the same job at a later date. Otherwise, the reference image selection screen 901 in FIG. 9 would be displayed every time the corresponding page is inspected for subsequent copies or reprints, which would impair user convenience. Therefore, in this embodiment, the RIP image registered in the processing of FIG. 6 becomes the reference image except when the scanned image of the corresponding page is registered as the reference image in step S809.

[0153] Then, in step S810, the CPU 226 determines that the inspection result for the page is OK, and ends this process. As a result, even if the reproducibility of thin lines is poor or moire images occur due to the performance of the printing device 101, it will be determined that there are no similar differences when inspecting the scanned image of the page from the next time onwards.

[0154] 9, if the user determines that the scanned image of the page displayed in the display frame 903 does not meet the quality requirements for the printout, the user presses the NG button 905. If such a user input is made on the reference image selection screen 901, the CPU 226 determines in step S807 that the inspection result for the page is NG, and the process proceeds to step S808.

[0155] In step S808, the CPU 226 determines that the page has been inspected as NG, and the process ends. An example of such a user judgment is when the performance of the printing device 101 causes poor reproducibility of thin lines or moiré images, and the user determines that the scanned image of the page does not meet the quality requirements of the printed output. In this case, the user reviews the print settings and print data as necessary, or adjusts the printing device 101. Another example is when a printing defect occurs, but the defect type cannot be identified in step S803. For example, this may occur when the difference determined in step S802 is a print stain, but the difference does not meet the conditions for determining a circular defect or a line defect.

[0156] As described above, according to this embodiment, even if a difference occurs between the RIP image and the scanned image due to the performance of the printing device 101 during RIP inspection, if the user determines that the difference satisfies the quality of the printed output, the reference image of the relevant page is replaced with the scanned image. This makes it possible to avoid unnecessary NG judgments of the inspection results. Furthermore, it is possible to prevent the same difference from being detected in subsequent copies or reprints of the same job, thereby improving inspection and printing productivity.

[0157] Although the first embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and various modifications and changes are possible within the scope of the gist of the present invention.

[0158] (Other embodiments) The present invention can also be realized by performing the following process: a program that implements one or more functions is supplied to a computer of a system or device via a network or storage medium, and the program is read and executed by a system controller of the system or device. The system controller has one or more processors or circuits, and may include multiple separate system controllers or a network of multiple separate processors or circuits to read and execute executable instructions.

[0159] The processor or circuitry may include a central processing unit (CPU), a microprocessing unit (MPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP), a data flow processor (DFP), or a neural processing unit (NPU).

[0160] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0161] 101 Printing device 106 Inspection Unit 107 Large Capacity Stacker 108 Inspection Equipment 109 Information processing equipment 110 client computers 226 CPU 228 Memory section 245 Display section 315,316 CIS

Claims

1. An inspection device that inspects the quality of a printed matter printed by a printing device using a reference image and a scanned image of the printed matter, a UI means for, when a difference is detected as a result of comparing the pre-press image that functions as the reference image with a scanned image of the first printed matter during an inspection of the quality of the first printed matter, using the pre-press image used for printing the printed matter as the reference image, displaying a reference image selection screen including the pre-press image and the scanned image, and receiving user input as to whether the detected difference is a defect, based on the user input received by the UI means, inspecting the quality of the second and subsequent copies of the printed matter printed by the printing device using the scanned image of the first copy of the printed matter as the reference image; An inspection device characterized in that, if the detected difference corresponds to a predetermined defect type, the result of the quality inspection of the first copy of the printed material is determined to be abnormal without displaying the reference image selection screen.

2. The inspection device according to claim 1, characterized in that, when the received user input indicates that the detected difference is not a defect, the quality of the second and subsequent copies of the printed matter printed by the printing device is inspected using a scanned image of the first copy of the printed matter as the reference image.

3. The inspection device according to claim 2, characterized in that when a scanned image of the first printed matter is set as a reference image for the second or subsequent printed matter printed by the printing device, the result of the quality inspection of the first printed matter is found to be normal.

4. The inspection device according to claim 1, characterized in that, if the detected difference is within a predetermined tolerance range, the result of the quality inspection of the first copy of the printed material is deemed to be normal without displaying the reference image selection screen.

5. The inspection device according to claim 1, characterized in that if the detected difference is detected as a result of comparing the reference image with the scanned image of the nth copy of the printed material while the nth copy (n is a number greater than or equal to 2) is being printed by the printing device, the inspection device determines that the quality of the nth copy of the printed material is abnormal without displaying the reference image selection screen.

6. The inspection device according to any one of claims 1 to 5, characterized in that printing of the first page of the second copy by the printing device begins when inspection of the quality of the first copy of the printed material by the printing device is completed and user input is received regarding whether the detected differences are defects for all pages of the first copy of the printed material.

7. 7. The inspection device according to claim 1, wherein if the inspection of the quality of the first copy of the printed matter is not completed within a specified time, the result of the inspection of the quality of the first copy of the printed matter is determined to be abnormal.

8. A control method for an inspection device that inspects the quality of a printed matter printed by a printing device using a reference image and a scanned image of the printed matter, comprising: a UI step of, when a difference is detected as a result of comparing the pre-press image that functions as the reference image with a scanned image of the first printed matter during an inspection of the quality of the first printed matter, using the pre-press image used for printing the printed matter as the reference image, displaying a reference image selection screen including the pre-press image and the scanned image, and receiving user input as to whether the detected difference is a defect; based on the user input received in the UI step, inspecting the quality of the second and subsequent copies of the printed matter printed by the printing device using the scanned image of the first copy of the printed matter as the reference image; A control method characterized in that, if the detected difference corresponds to a predetermined defect type, the result of the quality inspection of the first copy of the printed material is determined to be abnormal without displaying the reference image selection screen.

9. A program for causing a computer to function as each of the means of the inspection apparatus according to any one of claims 1 to 7.

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