Inspection apparatus, method for controlling the same, program, and image forming apparatus

Abstract

To provide an inspection apparatus that reduces waste paper.SOLUTION: An inspection apparatus comprises inspection means configured to inspect a scanned image obtained such that scanning means scans a sheet on which an image is formed, the sheet being conveyed from an image processing apparatus; and control means configured to perform control to cause image formation of second and subsequent sheets to stand by until image formation of a first sheet and inspection according to inspection settings are completed in a job of performing image formation on a plurality of sheets.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to an inspection device for inspecting whether or not an abnormality has occurred in a printed image such as a printed matter output by a printing device, a control method thereof, a program, and an image forming device. [Background technology]

[0002] In recent years, printing systems have become known that allow sheets printed by a printing device (hereinafter referred to as "printed sheets") to be inspected by an inspection device while they are being transported. Inspecting printed sheets involves the inspection device reading an image of the transported printed sheet and analyzing the read image to determine whether the printing on the printed sheet is normal. This inspection to detect abnormalities in printed sheets is called print image inspection. The inspection device can detect, for example, missing barcodes or ruled lines, missing images, printing errors, missing pages, and color misalignment. If a printed sheet is determined to be abnormal, the abnormal sheet can be discharged to a different destination from normal sheets. This prevents abnormal sheets from being mixed in with normal sheets and allows the operator to discard the abnormal sheets.

[0003] In addition, an image may be printed on preprinted paper on which a form format such as an invoice has been printed in advance (hereinafter, the preprinted image will be referred to as a preprinted image), and the image may then be inspected. For example, in the case of an invoice, printing an image on a common preprinted paper requires printing different content on each sheet individually depending on the content of the invoice.

[0004] Patent document 1 proposes an inspection device that generates mask data based on parts that are individually printed on preprinted paper, uses the area surrounding the individually printed parts as an inspection area, compares the images of the individually printed parts, and determines that the product is normal if they are identical. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-310567 Summary of the Invention [Problem to be solved by the invention]

[0006] If preprinted paper is loaded into the printer with the wrong top or bottom or front and back orientation, it will be printed in the wrong position on the form format. When this happens, the inspection device will judge the first sheet to be an "error." All sheets remaining in the machine after the first error sheet (hereafter referred to as "remaining sheets in the machine") will also be judged to be errors, and all remaining sheets will be wasted.

[0007] Although Patent Document 1 can handle cases where printing is skewed, if preprinted paper is set in the wrong direction, the individual printed portions are judged to be normal, so it does not handle detection of incorrect preprinted paper setting. Also, because no consideration is given to sheets remaining in the machine, there is a problem in that all remaining sheets in the machine are wasted. An object of the present invention is to provide an inspection device that reduces paper waste. [Means for solving the problem]

[0008] The inspection device of the present invention is characterized by comprising an inspection means for inspecting a read image read by a reading means from a sheet of paper on which an image has been formed and which is transported from an image processing device, and a control means for controlling image formation on the second sheet and thereafter to wait until image formation on the first sheet and inspection according to the inspection settings have been completed in a job in which images are formed on multiple sheets. [Effects of the Invention]

[0009] According to the present invention, it is possible to reduce the amount of wasted paper that occurs when preprinted paper is set in the wrong orientation, without impairing user convenience. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing an example of the overall configuration of an inspection system according to the present invention. [Figure 2] An example of an internal configuration diagram of an image forming apparatus 100 according to an embodiment. [Figure 3] 1 is a diagram illustrating an example of a hardware configuration of an image forming apparatus 100 according to an embodiment of the present invention; [Figure 4] FIG. 1 is a block diagram showing the functional configuration of an image processing apparatus according to an embodiment. [Figure 5] 10 is a flowchart showing a processing procedure of an inspection process performed in an image processing apparatus according to an embodiment. [Figure 6] 10 is a flowchart showing a processing procedure of an inspection setting process performed in an image processing apparatus according to an embodiment. [Figure 7] 10 is an example of a display screen according to an embodiment. [Figure 8] 10 is a flowchart showing a processing procedure of an inspection execution process according to an embodiment. [Figure 9] 10 is an example of a display screen according to an embodiment. [Figure 10] FIG. 10 is a diagram for explaining an effect according to an embodiment. [Figure 11] 10 is an example of a result display screen according to an embodiment. [Figure 12] 10 is a flowchart showing a processing procedure of an inspection execution process according to an embodiment. [Figure 13] 10 is an example of a display screen according to an embodiment. [Figure 14] 10 is an example of a display screen according to an embodiment. [Figure 15] 10 is a flowchart showing a processing procedure of an inspection execution process according to an embodiment. [Figure 16] 10 is an example of a display screen according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted. [Example]

[0012] <System configuration> 1 is a diagram showing the overall configuration of a system including an inspection device for explaining this embodiment. The system including the inspection device in this embodiment is composed of an image forming device 100, an inspection PC 110, a network 120, and a communication cable 130. The image forming apparatus 100 receives various input data and print job data via a network 120 and performs print output. The image forming apparatus 100 includes an image processing apparatus 101, an inspection apparatus 102, and a finisher 103. The image processing apparatus 101, the inspection apparatus 102, the finisher 103, and the inspection PC 110 are connected via a communication cable 130, which is an internal bus. The image processing device 101 performs image processing on various input data in accordance with print settings, and outputs the processed images as printouts.

[0013] The inspection device 102 receives the printed matter output from the image processing device 101 and acquires image data for inspecting the received printed matter for any abnormal images. Here, an abnormal image is something that reduces the quality of the printed matter. For example, this refers to a round abnormal image (dot) that occurs when coloring material adheres to an unintended location during printing, a color loss that occurs when sufficient coloring material does not adhere to an intended location, or a linear abnormal image (streak). The acquired image data is then transferred from the inspection device 102 to the inspection PC 110 (described later) via the communication cable 130. The inspection PC 110 inspects the printed matter for any abnormal images, and the inspection device 102 acquires the inspection results from the inspection PC 110.

[0014] The finisher 103 receives the output paper inspected by the inspection device 102, switches the paper output destination based on the inspection results of the inspection PC 110, and performs post-processing (bookbinding, etc.) as necessary. Printed materials with abnormal images are output to a purge tray. The image forming apparatus 100 is connected to an inspection PC 110 via a communication cable 130, and communicates image data and inspection results during inspection.

[0015] 1, the image forming apparatus 100 is described with the image processing apparatus 101 and the inspection apparatus 102 as separate devices, but this is not intended to limit the present invention, and they may be integrated into a single device. For example, the inspection apparatus 102 may be integrated with the image processing apparatus 101 to form the image forming apparatus 100. Furthermore, for example, the inspection PC 110 of the image forming apparatus 100 may be included in the inspection apparatus 102, and may be integrated into the image forming apparatus 100. In this case, the image forming apparatus 100 may be configured as an in-line inspection machine that performs image formation, inspection, post-processing, and paper discharge in an integrated manner. The detailed configuration of the image forming apparatus 100 in this embodiment will be described later.

[0016] The inspection PC 110 is a PC for inspecting images read from printed materials using the inspection device 102, and includes a device control unit 111 and a user interface unit 118 (hereinafter referred to as the "UI unit"). Furthermore, the device control unit 111 is configured from a controller board, and a CPU 112, RAM 113, ROM 114, communication I / F unit 115, storage unit 116, and inspection processing unit 117 are implemented on the device control unit 111. These components are connected to each other via an internal system bus 119, and inter-module communication is performed. The inspection PC 110 may also be configured to be built into the inspection device 102.

[0017] The CPU 112 reads the main program from the storage unit 116 in accordance with the initial program in the ROM 114 and stores it in the RAM 113. The RAM 113 is used as a main memory for storing programs and for working purposes. The RAM 113 is also used to temporarily store data created during program processing. The communication I / F unit 115 is used when communicating with the image forming apparatus 100 or other devices via the network 120 or the communication cable 130. The storage unit 116 is used to store large amounts of data such as programs, image data, and inspection jobs.

[0018] The inspection processing unit 117 obtains a difference value between a reference image stored in the RAM 113 as a correct image and the scanned image to be inspected in order to inspect the image data acquired by the inspection device 102 for defects such as stains or color loss. The inspection processing unit 117 then performs inspection by comparing the obtained difference value with the inspection thresholds (contrast and size) for each inspection item, pixel by pixel. The inspection processing unit 117 then stores the inspection results in the RAM 113. The inspection results include, for example, information on whether or not there are any abnormal images in the printed matter, and position information of the abnormal images when displaying the type of detected abnormal image (such as a dent or streak) on the UI unit 118. The inspection PC 110 then transmits the inspection results to the inspection device 102 and the finisher 103 via the communication I / F unit 115 and the communication cable 130.

[0019] The UI unit 118 is configured by, for example, a keyboard, a mouse, a display, or other input / output devices, and is a device that can input various setting values ​​or designated values ​​and can display settings and inspection results. The above is a description of the overall system configuration including the inspection device 102 in an embodiment of the present invention. Note that in this embodiment, each device in the system communicates with each other regarding image data and inspection results during inspection via the communication cable 130, but any form of communication is acceptable as long as the devices can communicate with each other. Each device may communicate with each other regarding image data and inspection results during inspection via the network 120, for example.

[0020] <Internal Configuration of Image Forming Apparatus 100> The internal configuration of the image forming apparatus 100 according to this embodiment will be described with reference to FIG. The image forming apparatus 100 includes an image processing apparatus 101 , an inspection apparatus 102 , and a finisher 103 . Furthermore, the image processing apparatus 101 includes a device control unit 200, a printer unit 210, a scanner unit 220, a user interface unit (UI unit) 230, and a paper feed unit 250.

[0021] The device control unit 200 receives images and documents from the network 120 and converts them into print data. The device control unit 200 includes a CPU 201, RAM 202, a storage unit 203, a communication I / F unit 204, a ROM 205, and an image processing unit 206. Each component can communicate with each other via an internal system bus 207. Note that the role of each component of the device control unit 200 is the same as that of the inspection PC 110, except for the image processing unit 206, and therefore a description thereof will be omitted.

[0022] The image processing unit 206 acquires the PDL data stored in the RAM 202 and performs image processing to convert it into print data. The image processing to convert it into print data is, for example, as follows: First, the PDL data is subjected to RIP processing to convert it into multi-value bitmap data. Then, the multi-value bitmap data is subjected to well-known screen processing or the like to convert it into binary bitmap data. This binary bitmap data is the print data. The binary bitmap data obtained by the image processing unit 206 is sent from the communication I / F unit 204 to the printer unit 210 via the internal system bus 208.

[0023] The printer unit 210 conveys recording material (paper) from the paper feed unit 250, receives binary bitmap data generated by the device control unit 200, and forms an image on the recording material using color materials. At this time, the CPU 211 issues instructions to the printer unit 210 based on print settings specified by the user. For example, in the case of print settings using coated paper, the CPU 211 issues instructions to the printer unit 210 to print using a paper feed deck in the paper feed unit 250 that stores coated paper.

[0024] Various processes from receiving the PDL data to printing it on the recording material are controlled by the device control unit 200 and the printer unit 210, and a full-color toner image is formed on the recording material. The printer unit 210 includes a CPU 211, a RAM 212, a communication I / F unit 214, and a ROM 215. The components of the printer unit 210 can communicate with each other via an internal system bus 217. The roles of the components of the printer unit 210 are the same as those described for the inspection PC 110, and therefore will not be described here.

[0025] The scanner unit 220 is a device for reading an original image and obtaining image data. The scanner unit 220 irradiates the original image with a light source (not shown), and obtains a read signal obtained from a sensor such as a CCD (Charge Coupled Device) sensor, which receives the original image reflected by the original through a lens, as multi-value image data of red, green, and blue.

[0026] The UI unit 230 is a device that is configured with, for example, a keyboard, a mouse, a display, or other input / output devices, and that can input various setting values ​​or specified values ​​and display settings and inspection results. The paper feed unit 250 has one or more cassettes into which the recording material to be printed is set. The paper feed unit 250 feeds the recording material from a cassette that corresponds to the size of the recording material specified in the print settings, and transports the recording material to the printer unit 210. The inspection device 102 includes a device control unit 260 and an image reading unit 270 . The image reading unit 270 is an image reading unit that reads the printed matter conveyed from the printer unit 210 .

[0027] The device control unit 260 controls the transfer of image data acquired by the image reading unit 270 to the inspection PC 110 via the communication cable 130. The inspection PC 110 then inspects the printed matter for any abnormal images based on the transferred image data. The device control unit 260 acquires the inspection results of the printed matter from the inspection PC 110. The device control unit 260 includes a CPU 261, a RAM 262, a communication I / F unit 264, and a ROM 265. The components of the device control unit 260 can communicate with each other via an internal system bus 267. The roles of the components of the device control unit 260 are the same as those described for the inspection PC 110, and therefore will not be described here.

[0028] The finisher 103 includes a device control unit 280 and a paper discharge unit 290 . The device control unit 280 determines the paper discharge control to be performed by the paper discharge unit 290, taking into consideration the print settings and the inspection results. The device control unit 280 includes a CPU 281, a RAM 282, a communication I / F unit 284, and a ROM 285. The components of the device control unit 280 can communicate with each other via an internal system bus 287. The role of each device is the same as that of the device control unit 200, and therefore a description thereof will be omitted.

[0029] The paper discharge unit 290 is a device for switching the discharge destination of printed materials conveyed from the inspection device 102 based on post-processing (e.g., bookbinding) and inspection results according to print settings. For example, it is possible to switch the discharge destination based on whether or not there is an abnormal image in the printed material. When switching the discharge destination based on the inspection results, the finisher 103 uses the inspection results received from the inspection PC 110 to discharge printed materials without abnormal images to a normal discharge tray, and discharge printed materials with abnormal images to a tray other than the normal discharge tray.

[0030] <Hardware Configuration of Image Forming Apparatus 100> 3 is a cross-sectional view showing an example of the hardware configuration of the image forming apparatus 100. A specific example of the operation of the image forming apparatus 100 will be described below with reference to FIG. In the image processing device 101, various recording materials are stored in paper feed decks 301 and 302. Of the recording materials (paper sheets) stored in each paper feed deck, the uppermost recording material is separated one by one and fed to a conveying path 303. The image forming stations 304 to 307 each include a photosensitive drum (photoconductor) and form a toner image on the photosensitive drum using toner of a different color. Specifically, the image forming stations 304 to 307 form a toner image using toner of yellow (Y), magenta (M), cyan (C), and black (K), respectively.

[0031] The toner images of each color formed at the image forming stations 304 to 307 are transferred onto the intermediate transfer belt 308 in order, superimposed on top of each other (primary transfer). The toner images transferred onto the intermediate transfer belt 308 are transported to a secondary transfer position 309 as the intermediate transfer belt 308 rotates. At the secondary transfer position 309, the toner image is transferred from the intermediate transfer belt 308 onto the recording material transported along the transport path 303 (secondary transfer). After the secondary transfer, the recording material is transported to a fixing unit 310. The fixing unit 310 includes a pressure roller and a heating roller. The fixing unit 310 applies heat and pressure to the recording material as it passes between these rollers, thereby fixing the toner image to the recording material. After passing through the fixing unit 310, the recording material is transported along a transport path 311 to a connection point 314 between the image processing device 101 and the inspection device 102. In this manner, a color image is formed (printed) on the recording material (paper).

[0032] If further fixing processing is required depending on the type of recording material, the recording material that has passed through fixing unit 310 is guided to conveyance path 313 provided with fixing unit 312. Fixing unit 312 performs further fixing processing on the recording material conveyed along conveyance path 313. The recording material that has passed through fixing unit 312 is conveyed to connection point 314. Furthermore, if an operating mode for double-sided printing is set, an image is printed on the first side of the recording material, and the recording material conveyed along conveyance path 311 or conveyance path 313 is guided to reversing path 315. The recording material that has been reversed by reversing path 315 is guided to double-sided conveyance path 316 and conveyed to secondary transfer position 309. As a result, a toner image is transferred to the second side of the recording material, which is opposite to the first side, at secondary transfer position 309. Thereafter, the recording material passes through fixing unit 310 (and fixing unit 312), thereby completing the formation of a color image on the second side of the recording material.

[0033] After the image formation (printing) in the image processing device 101 is completed, the printed matter is transported to the connection point 314 and then transported into the inspection device 102. The inspection device 102 includes image reading units 317 and 318 each having a CIS (Contact Image Sensor) on a conveying path 319 along which printed matter is conveyed from the image processing device 101. The image reading units 317 and 318 are disposed in positions facing each other across the conveying path 319. The image reading units 317 and 318 are configured to read the top surface (first surface) and bottom surface (second surface) of the printed matter, respectively. Note that the image reading units 317 and 318 may be configured with a CCD (Charge Coupled Device) or a line scan camera instead of a CIS, for example. The inspection device 102 performs a reading process to read the printed matter conveyed on the conveying path 319 using image reading units 317 and 318. The printed matter that has passed the inspection device 102 is conveyed to the finisher 103 in order.

[0034] The finisher 103 executes a finishing function specified by the user on printed materials conveyed from the inspection device 102. In this embodiment, the finisher 103 has finishing functions such as a function to switch the paper discharge destination based on the inspection results and a bookbinding function. When switching the paper discharge destination based on the inspection results, the finisher 103 uses the inspection results received from the inspection PC 110 to discharge printed materials without abnormal images to a paper discharge tray 321 via a sheet conveyance path 320. The finisher 103 discharges printed materials with abnormal images to a paper discharge tray 323 (purge tray) via a sheet conveyance path 322. When bookbinding is specified, the finisher 103 staples the printed sheets in the center at a processing unit 324, folds the sheets in half, and outputs them to a bookbinding tray 326 via a sheet conveyance path 325.

[0035] The conveying path 327 includes the conveying paths 303, 311, and 313 in the image processing device 101 and the conveying path 319 in the inspection device . The above is a description of the operation of the image forming apparatus 100 according to the embodiment of the present invention. This is not limited to the present embodiment, and any configuration may be used as long as it is possible to print print data on a recording material (paper) and read an image to inspect whether or not there is an abnormal image in the printed matter.

[0036] <Overall inspection flow> Next, the overall flow from the registration work before the start of inspection in the inspection PC 110 to the actual inspection will be described with reference to Figures 4 and 5. The processing described below is realized by, for example, the CPU 112 of the inspection PC 110 reading a program stored in the ROM 114 into the RAM 113 and executing it. Figure 4 is a block diagram showing the functional configuration of the inspection PC 110. Figure 5 is a flowchart showing the processing procedure for the inspection process. In the following, the step number of each process in the flowchart is indicated by a number following "S". The same applies to the subsequent flowcharts.

[0037] In S501, the image acquisition unit 401 registers an image that will be used as a reference image for inspection. The image acquisition unit 401 acquires the reference image (reference image data) from the RAM 113 or the storage unit 116. However, it is assumed that the reference image data has been stored in the RAM 113 or the storage unit 116 in advance. There are two methods for creating the reference image. The first method is to execute a print job and generate a reference image by scanning the printed material with the image reading unit 270. The other method is to use image data after RIP processing, which analyzes the print job and generates image data, as the reference image, rather than using a scanned image.

[0038] Next, in S502, the inspection process selection unit 402 sets various inspection parameters such as the inspection level and whether or not the inspection is to be performed on preprinted paper, in accordance with the user's inspection settings. Details of S502 in this embodiment will be described later. Next, in S503, the image acquisition unit 401 acquires an inspection target image by having the image reading unit 270 read the printed material conveyed from the printer unit 210. Note that the inspection target image may be configured to be read in advance by the image reading unit 270 and to acquire read data stored in the storage unit 116 or RAM 113. Then, the alignment processing unit 404 and the image inspection unit 405 align the inspection target image with the reference image and execute anomaly detection processing. Note that details of S503 in this embodiment will be described later. In S504, the test result output unit 406 generates a display screen for the test results, displays it on the UI unit 118, and ends the process.

[0039] 11 shows an example of an inspection result display screen in this embodiment. An inspection result display screen 1101 displays an entire image 1102 of the inspection target image. Anomaly 1103 is determined to be a point anomaly, and the words "point anomaly" are also displayed near the anomaly 1103. Anomaly 1104 is determined to be a linear anomaly, and the words "linear anomaly" are also displayed near the anomaly 1104. Furthermore, as shown in 1105 and 1106, the coordinates of each detected anomaly may also be displayed. The above is a description of the overall flow from the registration work before the start of inspection by the inspection PC 110 to the execution of inspection in this embodiment.

[0040] <Inspection setting process> Next, the procedure for setting the examination in step S502 according to this embodiment will be described with reference to Fig. 6 and Fig. 7. Fig. 6 is a flowchart showing the procedure for setting the examination. Fig. 7 is a diagram showing an example of an examination setting screen for setting the examination. The inspection setting screen 700 includes buttons 702 to 705, a print image inspection setting UI 706, a preprinted paper setting UI 709, a page view area 710, an OK button 719, and a cancel button 720. The print image inspection setting UI 706 includes an inspection area setting 707 for setting the detection items and detection levels. The page view area 710 is an area for displaying the correct image.

[0041] In S601, the inspection process selection unit 402 sets the detection items and their detection levels for detecting anomalies. The user can set the area to be inspected and the image inspection by operating the print image inspection area setting button 704. Although not shown, the area to be inspected can be specified in the page view area of ​​the correct image. Then, for the specified area, the print image inspection detection items can be set by setting the inspection area 707 in the print image inspection setting UI 706. The print image inspection detection items are items related to the abnormality features to be detected when inspecting printed matter, such as point-like anomalies (dots) and linear anomalies (streaks). The detection level is a parameter set in stages to determine the size of each detected anomaly feature before it is deemed an anomaly. For example, there are five levels, from level 1 to level 5, with level 5 being able to detect thinner and smaller anomalies than level 1. Furthermore, a level can be set for each inspection item, such as inspecting dots at level 5 and streaks at level 4. 7 shows that the user has selected level 4 for the inspection level setting for abnormalities (dots) and level 4 for the inspection level setting for abnormalities (streaks). Detection items can be set for each specified inspection area.

[0042] In S602, the user sets the test paper using a preprinted paper setting UI 709. The test paper setting refers to whether the test paper is preprinted paper on which an image has been printed in advance. If the paper to be tested is preprinted paper, the user can set the test paper to be preprinted paper by selecting a radio button 708. After the user has set the print image inspection and preprint paper settings, if the user operates the OK button 719, the print image inspection settings and preprint paper settings are notified to the inspection process selection unit 402. The above is a description of the inspection setting processing procedure in this embodiment.

[0043] <Test execution process> Next, the processing procedure for executing the test in S503 according to this embodiment will be described with reference to Fig. 8. Fig. 8 is a flowchart showing the processing procedure for executing the test in S503. First, in S801, the inspection PC 110 determines whether or not the inspection is to be performed on preprinted paper. Whether or not the inspection is to be performed on preprinted paper is determined based on whether or not the radio button 708 for inspection of preprinted paper was selected in S402. If it is determined that the inspection is to be performed on preprinted paper, the process proceeds to S802, where only the first sheet of the job is printed and the inspection is performed. Printing of the second and subsequent sheets is put on hold. If it is determined that the inspection is not to be performed on preprinted paper, the process proceeds to S810 to start printing and inspecting all sheets in the job.

[0044] In S802, the image processing apparatus 101 receives a notification from the inspection PC 110 and executes printing of the image of the first sheet. In S803, the inspection device 102 detects the conveyance of the printed matter, scans the printed matter with the image reading unit 270, and stores the scanned image in RAM 113. The inspection PC 110 then compares the scanned image of the printed matter with a reference image that is the correct image for inspection and that has been stored in advance in RAM 113, and obtains the difference value. Based on the obtained difference value, the scanned image is inspected for any printing abnormalities.

[0045] In S804, the inspection PC 110 determines whether an alignment error occurred during inspection. <Method for determining alignment errors> The registration error determination method will now be described. The registration processing unit 404 acquires feature points in order to align the reference image and the inspection image. One method for acquiring feature points is to look for pixels in the image that have a large corner feature amount. Various methods have been devised for detecting corner features. One method for detecting corner features is a well-known technique called the Harris corner detection method. In the Harris corner detection method, a corner feature image is detected from a differential image in the main scanning direction and a differential image in the sub-scanning direction. When two edges are both strong, the magnitude of the corner feature is expressed by whether the relatively weaker edge has a strong edge amount.

[0046] Then, the alignment processing unit 404 adopts pixels having a feature amount greater than a predetermined value as feature points. When comparing pixel values ​​at each position of the reference image and the inspection image after alignment, if the difference in pixel values ​​is too large, an alignment error has occurred. Therefore, if the difference in pixel values ​​of pixels at feature points between the reference image and the inspection image after alignment is larger than a preset threshold, the inspection PC 110 determines that alignment processing unit 404 has not performed accurate alignment and an alignment error has occurred.

[0047] Another example is a method of determining whether the total difference between the pixel values ​​of the inspection image and the reference image after alignment is greater than a predetermined threshold value. Another method may be to determine whether the difference between the coordinate positions of the four corners of the paper in the inspection image after alignment and the coordinate positions of the four corners of the paper in the reference image is equal to or greater than a threshold value. In S804, if the inspection PC 110 determines that an alignment error occurred during inspection, the process proceeds to S806. If the inspection PC 110 determines that no alignment error occurred during inspection, the process proceeds to S805.

[0048] In S805, the inspection PC 110 determines whether the preprinted paper and the print direction do not match by comparing the number of detected abnormalities with a predetermined threshold. If the orientation of the preprinted paper and the orientation of the print do not match, the number of abnormalities will be extremely large, making it possible to determine that the print direction does not match. If the number of abnormalities is greater than the threshold, it is determined that the orientation of the preprinted paper and the orientation of the print do not match, and the process proceeds to S806. If the number of abnormalities is equal to or less than the threshold, it is determined that the cause of the abnormality is dirt or the like, and the process proceeds to S809, where printing and inspection of the second and subsequent sheets that have been put on hold is started.

[0049] In S806, the inspection PC 110 displays, for example, a warning display 900 shown in FIG. 9 on the UI unit 118 to notify the user that the orientation of the preprinted paper and the orientation of the print may not match. The warning display 900 is a UI that displays the fact that the orientation of the preprinted paper and the orientation of the print may not match, and allows the user to confirm whether to continue the job as is or to cancel the job. The cancel button 901 is a button for canceling the job. The continue button 902 is a button for continuing the job. The device control unit 111 continues to display the warning display 900 in accordance with the user's operation until either the cancel button 901 or the continue button 902 is operated. The cancel button 901 and the continue button 902 are examples of display objects.

[0050] In S807, the inspection PC 110 determines whether the Stop button 901 or the Continue button 902 is selected according to the user's operation, and if the Stop button 901 is selected, the process proceeds to S808 (if Yes). If the Continue button 902 is selected, the process proceeds to S809 (if No), and starts printing and inspection of the second and subsequent sheets that have been put on hold.

[0051] In S808, the inspection PC 110 notifies the image processing apparatus 101 of the cancellation of the job, and ends the printing and inspection execution process. In S809, the inspection PC 110 notifies the image processing apparatus 101 of permission to print the second and subsequent sheets that have been put on hold in the image processing apparatus 101, executes printing and inspection of all sheets, and ends the inspection execution process. In S810, the inspection PC 110 notifies the image processing apparatus 101 of permission to print all sheets in the job, executes printing and inspection of all sheets, and ends the printing and inspection execution process.

[0052] <Explanation of effect> The effects of the present invention will be described with reference to Fig. 10. Although Fig. 10 shows an example in which single-sided printing is performed, the process is similar when double-sided printing is used.

[0053] Figure 10(a) shows the state of printed matter when the orientation of the preprinted paper and the printing direction are incorrect using a conventional method. Printed matter 1001 is determined to have an error and is discharged to purge tray 323. At the time printed matter 1001 is determined to have an error, printed matters 1002 to 1005 are already being conveyed on conveyance path 327. After an error in printed matter 1001 is detected, printing is temporarily stopped. However, if the orientation of the preprinted paper and the printing direction are incorrect, printed matters 1002 to 1005 will also result in an error, and not only the first sheet but also the remaining sheets in the machine will be wasted.

[0054] 10B shows the state of the printed matter when the orientation of the preprinted paper and the printing orientation are incorrect in this embodiment. The printed matter 1006 is determined to be an error and is discharged to the purge tray 323. In this embodiment, if the inspection of the first sheet is not completed successfully, printing of the second and subsequent sheets is not performed, and therefore subsequent printed matter is not transported on the transport path 327. If the orientation of the preprinted paper and the printing direction are incorrect, five sheets will be wasted using conventional methods, but if the present invention is used, only one sheet will be wasted, making it possible to reduce paper waste.

[0055] <Effects of this embodiment> According to the present invention, it is possible to reduce the amount of wasted paper that occurs when preprinted paper is set in the wrong orientation, without impairing user convenience. [Example]

[0056] In addition to print image inspection, inspection of print images using preprinted paper also inspects variable area portions of variable printing, such as text strings and barcodes. Variable printing refers to printing in which the content printed on the paper can be changed based on data. In variable printing, different text strings or barcodes are printed on each sheet of preprinted paper based on the data. Inspections of variable area portions include, for example, a data readability inspection, which checks whether the text strings or barcodes are readable, and a data verification inspection, which compares the results of reading the text strings or barcodes with the correct data. Data readability inspection and data verification inspection are referred to as data inspection. The correct data is prepared in advance, for example, by specifying a CSV file.

[0057] In Example 1, a case where the orientation of the preprinted paper and the orientation of the printing are incorrect is described. In Example 2, a case where correct answer data for comparison is incorrectly specified during data inspection is described. In this embodiment, it is possible to reduce paper waste when incorrect correct answer data is specified.

[0058] Only the differences from the first embodiment will be described in detail below. <Data inspection overview> An overview of the data inspection performed by the inspection PC 110 will be described. The inspection PC 110 uses the image reading unit 270 to read the printed material conveyed from the image forming apparatus 100 and acquire a scanned image of the inspection target. The acquired scanned image of the inspection target is stored in the RAM 113 or the storage unit 116. Next, the inspection PC 110 uses the inspection processing unit 117 to inspect whether the character string or barcode is readable using preset font information for optical character recognition (OCR) and barcode specifications. The inspection PC 110 can also perform data inspection to verify whether the read character string or barcode matches the correct data. The inspection PC 110 stores the inspection results in the RAM 113. The inspection results include, for example, the results of the character string or barcode read from the printed material, the result of matching the correct data, and position information of the read character or barcode when displayed on the UI unit 118. The correct data is stored in advance in the RAM 113 or the storage unit 116 of the inspection PC 110.

[0059] <About the inspection settings UI> Next, an example of a UI related to test settings will be described with reference to FIG. The data inspection setting screen 1300 in Fig. 13 is a screen displayed in the inspection setting in S502, and corresponds to the setting screen 700 in Fig. 7. In Fig. 7, the area setting button 1303 for print image inspection is selected, but in Fig. 13, the data inspection setting screen 1300 is displayed when the area setting button 1302 for data inspection is operated. The page preview 1340 is a display area that displays the correct image.

[0060] The method for setting a data inspection area in this embodiment is as follows: First, a user selects a data inspection area setting button 1302. Then, the user specifies an area in the page preview 1340 where data inspection is to be performed, and the inspection PC 110 sets the corresponding specified range as a data inspection area 1341 and a data inspection area 1342. The data inspection area is an inspection area that reads the type of data that has been set (character string or barcode) and determines whether it is correct or not.

[0061] A button 1304 is a button for rotating the image displayed in the page preview 1340. A button 1305 is a button for selecting an inspection area, and is a button operated by the user when the user wishes to change the setting information of an area that has already been set. The data inspection setting UI 1320 is a group of UIs for setting the data file to be referenced when comparing detected data, the type of data inspection, and detailed information when performing a data inspection.The data inspection area is an inspection area where the set data type (character string or barcode) is read and judged to be correct or incorrect. The data UI 1321 for the verification test is a UI for setting, by file selection, a variable data file to be used as the correct character information when determining whether data is correct or incorrect in the data test.

[0062] In this embodiment, variable data refers to a reference CSV file for data inspection, which is compared as the correct answer when performing data inspection. The reference CSV file is a file that lists correct strings for string inspection and barcode inspection, separated by commas. The reference CSV file is also used as data to input into the variable area when generating manuscript data for variable printing. Because the manuscript data is generated by referencing the reference CSV file, the data order of the manuscript data and the reference CSV file is consistent. Therefore, when performing data inspection, the correctness of the data can be determined by comparing the string inspection area and barcode reading results with the correct strings listed in the reference CSV file.

[0063] If the printing order of the manuscript data is changed, the order of the data in the referenced CSV file will no longer match, and the correct character strings will no longer match those listed in the reference CSV file. Here, the data UI 1321 for the verification test in Figure 13 indicates that data with the file name abc.csv has been selected as the data for the verification test. The CSV file is assumed to be stored in advance in the storage unit 116 or RAM 113.

[0064] Next, a data inspection type setting UI 1322 is a UI for setting the type of character string inspection or barcode inspection selected by the user using a radio button method and a pull-down method. In this embodiment, the type of character string refers to a set of font data that associates character glyph images with character codes for character recognition (OCR). The font data set must be saved in advance. The user can print character glyph images and perform a registration process to associate them with character codes. Alternatively, the corresponding font data set can be saved in advance as a factory default. In the data inspection type setting UI 1322 in FIG. 13, both character string inspection and barcode inspection are selected using radio buttons. The example in FIG. 13 indicates that OCRB 12pt is selected as the glyph font for character string inspection, and CODE39 is selected as the barcode standard for barcode inspection.

[0065] <Test execution process> Next, the processing procedure for executing the test in S503 according to this embodiment will be described with reference to Fig. 12. Fig. 12 is a flowchart showing the processing procedure for executing the test in S503. First, in S1201, the inspection PC 110 determines whether or not the inspection is a data inspection based on the inspection settings. Whether or not the inspection is a data inspection is determined based on whether or not inspection settings have been made in the data inspection area setting UI 1340 or the data inspection setting UI 1320. If it is determined that the inspection is a data inspection, the process proceeds to S1202 (if YES), and only the first sheet of the job is printed and inspected. If it is determined that the inspection is not a data inspection, the process proceeds to S1209 (if NO) to start printing and inspecting all sheets in the job.

[0066] In S1202, the image processing apparatus 101 receives a notification from the apparatus control unit 111 of the inspection PC 110 and executes printing of the image of the first sheet. In S1203, the inspection device 102 extracts a data inspection area from the inspection image, decodes it into a character string according to the inspection settings, performs a comparison inspection between the read character string and the correct data, and proceeds to S1204.

[0067] In S1204, the inspection PC 110 determines whether the inspection was correct (OK) or whether an error (NG) occurred during the data inspection. If the read result of the character string or barcode does not match the correct data, it determines that there is a data inspection error (NG) and proceeds to S1205 (if NO). If they match (if OK), proceeds to S1208 (if YES) and executes printing and inspection of the subsequent sheets that have been put on hold.

[0068] In S1205, the inspection PC 110 displays a warning display screen, for example, as shown in FIG. 14 on the UI unit 118, to notify the user that incorrect correct answer data may have been specified in the verification inspection data UI 1321. The warning display screen 1400 is a UI that displays the fact that incorrect correct answer data may have been specified and allows the user to confirm whether to continue the job as is or to cancel the job. The cancel button 1401 is a button for canceling the job. The continue button 1402 is a button for continuing the job. The device control unit 111 continues to display the warning display screen 1400 in accordance with a user operation until either the cancel button 1401 or the continue button 1402 is selected. The cancel button 1401 and the continue button 1402 are examples of display objects.

[0069] In S1206, the inspection PC 110 determines whether the stop button 1401 or the continue button 1402 is selected according to the user's operation, and if the stop button 1401 is selected, the process proceeds to S1207 (if YES). If the continue button 1402 is selected, the process proceeds to S1208, and the printing and inspection of the second and subsequent sheets that have been put on hold is executed (if NO).

[0070] In S1207, the inspection PC 110 notifies the image processing apparatus 101 of the interruption of the job, and ends the printing and inspection execution process. In S1208, the inspection PC 110 notifies the image processing apparatus 101 of permission to print the second and subsequent sheets that have been put on hold, executes printing and inspection of all sheets, and ends the inspection execution process. In S1209, the inspection PC 110 notifies the image processing apparatus 101 of permission to print all sheets in the job, executes printing and inspection of all sheets, and ends the inspection execution process.

[0071] <Effects of this embodiment> According to this embodiment, if correct data for comparison is mistakenly specified during data inspection, it is possible to reduce paper waste by waiting to print and inspect the second and subsequent sheets until the inspection of the first sheet is completed successfully. If the correct data for comparison is incorrectly specified during data matching inspection using conventional methods, printing of the second and subsequent sheets will begin before inspection of the first sheet begins, resulting in all printed sheets being wasted. [Example]

[0072] In the second embodiment, a case where correct data for comparison is mistakenly designated during data inspection is described. In the third embodiment, a case where an incorrect image is set as the reference image is described. In this embodiment, it is possible to reduce wasted paper when an incorrect reference image is specified.

[0073] Only the differences from the first embodiment will be described in detail below. <Test execution process> The processing procedure for executing the test in S503 according to this embodiment will be described with reference to Fig. 15. Fig. 15 is a flowchart showing the processing procedure for executing the test in S503.

[0074] First, in S1501, the inspection PC 110 determines whether or not a print image inspection is being performed. Whether or not a print image inspection is being performed is determined based on whether or not an inspection level has been set in the print image inspection setting UI 706. If it is determined that a print image inspection is being performed, the process proceeds to S1502 (if YES), and only the first sheet of the job is printed and inspected. If it is determined that the inspection is not for print image inspection, the process proceeds to S1510 (if NO) to start printing and inspecting all sheets in the job. In S1502, the image processing apparatus 101 receives the notification from the inspection PC 110 and executes printing of the image of the first sheet.

[0075] In S1503, the inspection device 102 detects the transport of the printed matter, scans the printed matter with the image reading unit 270, and transmits the scanned image to the inspection PC 110. The inspection PC 110 stores the transmitted scanned image of the printed matter in RAM 113. The inspection PC 110 then compares the scanned image of the printed matter with a reference image that is a correct image for inspection and that has been stored in advance in RAM 113, and obtains a difference value between them. Based on the obtained difference value, the scanned image is inspected for any printing abnormalities.

[0076] In S1504, the inspection PC 110 determines whether an alignment error occurred during inspection. If an incorrect reference image is selected, corresponding points for alignment may not be found, and the alignment parameters (e.g., affine matrix) may become extremely large or extremely small. By comparing each element of the affine matrix with a predetermined threshold, it is possible to determine whether an alignment error occurred.

[0077] In S1504, if the inspection PC 110 determines that an alignment error occurred during inspection, the process proceeds to S1506 (if YES). If the inspection PC 110 determines that an alignment error did not occur during inspection, the process proceeds to S1505 (if NO).

[0078] In S1505, the inspection PC 110 compares the number of detected abnormalities with a predetermined threshold to determine whether an incorrect reference image was set. If the number of abnormalities becomes extremely large when the reference image and the inspection image are different, it can be determined that an incorrect reference image was set. If the number of abnormalities is greater than the threshold, it is determined that an incorrect reference image was set, and the process proceeds to S1506 (if YES). If the number of abnormalities is equal to or less than the threshold, it is determined that the cause of the abnormalities is dirt or the like, and the process proceeds to S1509 (if NO), where printing and inspection of the second and subsequent sheets that have been put on hold is started.

[0079] In S1506, the inspection PC 110 displays, for example, a warning display 1600 shown in FIG. 16 on the UI unit 118 to notify the user that an incorrect reference image may have been specified. The warning display 1600 is a UI that displays the fact that an incorrect reference image may have been specified and allows the user to confirm whether to continue the job as is or to cancel the job. The cancel button 1601 is a button for canceling the job. The continue button 1602 is a button for continuing the job. The device control unit 111 continues to display the warning display 1600 in accordance with a user operation until either the cancel button 1601 or the continue button 1602 is selected. The cancel button 1601 and the continue button 1602 are examples of display objects. The subsequent processing is the same as in the first embodiment and will therefore be omitted.

[0080] <Effects of this embodiment> According to this embodiment, if an incorrect image is set as the reference image, it is possible to reduce wasted paper by waiting to print and inspect the second and subsequent sheets until the inspection of the first sheet is completed successfully. In conventional methods, if an incorrect image is specified as the reference image, printing of the second and subsequent sheets will begin before inspection of the first sheet begins, resulting in all printed sheets being wasted.

[0081] <Other embodiments> The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0082] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention.

[0083] The disclosure of this specification includes the following inspection device, its control method, program, and image forming device. (Item 1) An inspection device, an inspection means for inspecting a read image obtained by reading a sheet of paper on which an image is formed and which is conveyed from the image processing device; a control means for controlling the image formation of the second and subsequent sheets to wait until the image formation of the first sheet and the inspection according to the inspection setting are completed in a job in which images are formed on a plurality of sheets; An inspection device comprising: (Item 2) the inspection setting is a setting for inspecting image formation on preprinted paper; Item 1. The inspection device according to item 1. (Item 3) The inspection setting is a setting related to data included in the read image. Item 1 or 2. The inspection device according to item 1 or 2. (Item 4) The inspection setting is a setting for an image inspection using a registered reference image. 4. The inspection device according to any one of items 1 to 3. (Item 5) the inspection means displays a setting screen for setting the inspection settings; 5. The inspection device according to any one of items 1 to 4. (Item 6) the inspection means determines sheet registration errors; 6. The inspection device according to any one of items 1 to 5. (Item 7) the inspection means determines the alignment error based on a difference between pixel values ​​of corresponding pixels in the reference image and the read image. Item 6. The inspection device according to item 6. (Item 8) The inspection means detects whether the number of detected abnormalities is greater than a predetermined threshold value. 8. The inspection device according to any one of items 1 to 7. (Item 9) When the number of abnormalities detected by the inspection means is less than a predetermined threshold, the control means starts image formation on the second and subsequent sheets that have been put on hold. Item 8. The inspection device according to item 8. (Item 10) the control means controls the display means to display a warning message when the inspection means detects an abnormality in the read image. 10. The inspection device according to any one of items 1 to 9. (Item 11) The warning display is a display object capable of receiving an instruction to stop or continue the image formation of the second and subsequent sheets that have been put on hold; Item 11. The inspection device according to item 10. (Item 12) An image forming apparatus, an image processing means for forming an image on a sheet; a reading means for reading the paper on which an image is formed; The inspection device according to any one of items 1 to 11, An image forming apparatus comprising: (Item 13) The inspection means inspects the read image read by the reading means from the paper on which the image is formed and which is conveyed from the image processing device; The control means controls the job of forming images on a plurality of sheets so that image formation on the second and subsequent sheets is put on hold until image formation on the first sheet and inspection according to the inspection setting are completed. A method for controlling an inspection device. (Item 4) 12. A program for causing a computer to function as the inspection device according to claim 1. [Explanation of symbols]

[0084] 100: Image forming device, 101: Image processing device, 102: Inspection device, 103: Finisher

Claims

1. An inspection device, an inspection means for inspecting a read image obtained by reading a sheet of paper on which an image is formed and which is conveyed from the image processing device; a control means for controlling the image formation of the second and subsequent sheets to wait until the image formation of the first sheet and the inspection according to the inspection setting are completed in a job in which images are formed on a plurality of sheets; An inspection device comprising:

2. the inspection setting is a setting for inspecting image formation on preprinted paper; The inspection device according to claim 1 .

3. The inspection setting is a setting related to data included in the read image. The inspection device according to claim 1 .

4. The inspection setting is a setting for an image inspection using a registered reference image. The inspection device according to claim 1 .

5. the inspection means displays a setting screen for setting the inspection settings; The inspection device according to claim 1 .

6. the inspection means determines sheet registration errors; The inspection device according to claim 1 .

7. the inspection means determines the alignment error based on a difference between pixel values ​​of corresponding pixels in the reference image and the read image. The inspection device according to claim 6.

8. The inspection means detects whether the number of detected abnormalities is greater than a predetermined threshold value. The inspection device according to claim 1 .

9. When the number of abnormalities detected by the inspection means is less than a predetermined threshold, the control means starts image formation on the second and subsequent sheets that have been put on hold. The inspection device according to claim 8.

10. the control means controls the display means to display a warning message when the inspection means detects an abnormality in the read image. The inspection device according to claim 1 .

11. The warning display is a display object capable of receiving an instruction to stop or continue the image formation of the second and subsequent sheets that have been put on hold; The inspection device according to claim 10.

12. An image forming apparatus, an image processing means for forming an image on a sheet; a reading means for reading the paper on which an image is formed; The inspection device according to any one of claims 1 to 11, An image forming apparatus comprising:

13. The inspection means inspects the read image read by the reading means from the paper on which the image is formed and which is conveyed from the image processing device; The control means controls the job of forming images on a plurality of sheets so that image formation on the second and subsequent sheets is put on hold until image formation on the first sheet and inspection according to the inspection setting are completed. A method for controlling an inspection device.

14. A program for causing a computer to function as the inspection device according to any one of claims 1 to 11.

Images