Inspection apparatus, method for controlling inspection apparatus, and program

Abstract

To make it possible to avoid the shortage of the capacity of a storage device storing reference image data and maintain the convenience to a user in a case of the reuse of a print job.SOLUTION: An inspection apparatus performing an inspection of printed material includes setting means configured to set reference image data generated based on print data on the printed material for the inspection and storing means configured to store the set reference image data according to an inspection method and hold the stored reference image data in order to reuse it for another inspection even after the inspection is performed.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a technique for inspecting printed matter. [Background technology]

[0002] Traditionally, the printing industry has performed inspections to ensure that printed products delivered to clients are free of defects and of satisfactory quality. Printing systems equipped with inline automated inspection functions, which perform this inspection continuously after printing, are widely used. Inspection methods include "scan inspection" and "RIP inspection." In "scan inspection," a defect-free printed product is first scanned using a scanner to obtain and register image data (reference image data) that serves as the inspection standard. Next, printing is performed based on the submitted image data (also called a "print job"), and the printed product is scanned using a scanner to obtain image data to be inspected (inspection image data). The inspected image data is then compared with the previously registered reference image data to determine whether the printed product has defects. In contrast, "RIP inspection" is a method in which the aforementioned reference image data is generated and acquired from the submitted image data. Raster-format image data (print data) obtained by interpreting the PDL included in the print job is used for printing. Since this print data is defect-free, the resolution of the print data is adjusted to create the reference image data. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-049899 Summary of the Invention [Problem to be solved by the invention]

[0004] In preparation for reusing a previously executed print job, the corresponding reference image data may be stored in the printing system along with the print job. In this case, the same number of reference image data is stored as the number of print jobs. However, the greater the number of stored print jobs, the greater the strain on the storage device of the printing system. In this regard, Patent Document 1 describes a technology that automatically deletes reference image data stored in a storage device under certain conditions when the volume of the reference image data exceeds a predetermined amount. However, the method of Patent Document 1 continues to store the data until it reaches a certain volume, so its effectiveness in preventing the storage device from becoming overwhelmed is limited. Furthermore, because the data is automatically deleted once it reaches a certain volume, it is possible that reference image data that the user did not intend to delete is deleted. This disclosure has been made in light of these problems. [Means for solving the problem]

[0005] The inspection device for inspecting printed matter according to the present disclosure is characterized by having a setting means for setting reference image data generated based on printing data of the printed matter for the inspection, and a storage means for storing the set reference image data so that it can be used again for inspection after the inspection is completed, depending on the inspection method. [Effects of the Invention]

[0006] According to the present disclosure, it is possible to maintain user convenience when reusing a print job while avoiding pressure on the capacity of a storage device that stores reference image data. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing an example of the overall configuration of a printing system. [Figure 2] FIG. 1 is a diagram showing an example of the hardware configuration of an image processing apparatus. [Figure 3] FIG. 2 is a diagram showing an example of the hardware configuration of an image forming apparatus, an inspection apparatus, and a post-processing apparatus. [Figure 4]FIG. 2 is a diagram showing an example of the internal hardware configuration of an inspection processing unit. [Figure 5] FIG. 2 is a diagram showing an example of functional blocks of the printing system. [Figure 6] 10 is a flowchart showing the flow of operations of the printing system based on a new job. [Figure 7] An example of a UI screen for selecting an inspection method. [Figure 8] 10 is a flowchart showing details of a printing process. [Figure 9] 10 is a flowchart showing the flow of operations of the printing system based on a saved job. [Figure 10] 10 is an example of a UI screen for configuring settings related to saving reference image data. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, modes for carrying out the present embodiments will be described with reference to the drawings, etc. Note that the following embodiments do not limit the technology of the present disclosure, and all of the configurations described in the following embodiments are not necessarily essential to the means for solving the problems.

[0009] [Embodiment 1] <Overall system configuration> 1 is a diagram showing the overall configuration of a printing system 100 according to this embodiment. The printing system 100 includes an image processing device 101, an image forming device 102, an inspection device 103, and a post-processing device 104, and these devices are interconnected via a communication cable 105.

[0010] The role of each device in realizing the functions of the printing system 100 will be briefly described. The image processing device 101, also known as a DFE (Digital Front End), functions as a printer server. That is, the image processing device 101 performs RIP processing to bitmap PDL data included in an input print job, thereby generating raster image data (print data) used by the image forming device 102 in the print process. The image processing device 101 also controls the print process performed by the image forming device 102 and manages print jobs. The image forming device 102 is a printer that forms an image on a recording medium, i.e., paper, based on the print data generated by the image processing device 101. Image formation methods include offset printing, electrophotography, inkjet, and the like, and are not particularly limited. In this embodiment, the image forming device will be described as an electrophotography-based image forming device. The inspection device 103 inspects the paper (printed material) printed by the image forming device 102 for defects and quality issues. The post-processing device 104 is also called a finisher, and performs post-processing such as sorting, grouping, and stapling in addition to controlling paper discharge based on the results of the inspection performed by the inspection device 103.

[0011] <Hardware configuration of each device> Next, the hardware configuration of each device constituting the printing system 100 will be described. Fig. 2 is a diagram schematically showing the internal configuration of the image processing device 101. The image processing device 101 includes a CPU 201, RAM 202, ROM 203, a storage device 204, a system I / F 205, a network I / F 206, an output I / F 207, a general-purpose I / F 208, and a main bus 209. An output device 210 is connected via the output I / F 207, and an input device 211 and an external storage device 212 are connected via the general-purpose device I / F 208.

[0012] The CPU 201 is a processor that controls each unit of the image processing device 101. In this embodiment, the CPU 201 is described as controlling the entire printing system 100. However, this configuration is not limited to this. Processing may be shared with other CPUs, or a GPU, a processor specialized for high-speed parallel computing, may be responsible for part of the control processing of the CPU 201. Furthermore, part of the control processing of the CPU 201 may be performed by hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). The RAM 202 is a volatile memory that functions as the main memory and work area of ​​the CPU 201. The ROM 203 is a nonvolatile memory that stores programs such as an OS executed by the CPU 201. The storage device 204 refers to a nonvolatile large-capacity storage device such as an HDD or SSD, and stores applications executed by the CPU 201, various data, and the like. The system I / F 205 is a communication interface that connects to each device in the printing system 100, namely, the image forming device 102, the inspection device 103, and the post-processing device 104, and exchanges various data. Each device communicates its operating status with the other devices through the system I / F 205, synchronizes its operation timing, and transmits and receives data with other devices. The network I / F 206 is an interface that connects to a network outside the printing system 100 and transmits and receives data. The output I / F 207 is an image output interface such as HDMI (registered trademark). The output device 210 connected to the image processing device 101 via the output I / F 207 is, for example, an LCD display, and provides a GUI (graphical user interface). The general-purpose I / F 208 is a bus interface such as USB or IEEE 1394. The general-purpose I / F 208 accepts user operation (instruction) information from an input device 211, such as a keyboard or mouse, connected to the image processing device 101 via the general-purpose I / F 208.The image processing device 101 is also connected to an external storage device 212 via a general-purpose I / F 208, allowing a user to store data such as logs in the external storage device 212 or to have the image processing device 101 retrieve desired data from the external storage device 212. A main bus 209 connects the above-mentioned hardware components of the image processing device 101 so that they can communicate with each other. The hardware configuration of the image processing device 101 is not limited to the above-mentioned configuration. For example, a display device such as a liquid crystal display that provides a GUI may be present inside the image processing device 101 via the main bus 209. The output device 210 and the input device 211 may also be integrated as a touch panel display or the like.

[0013] FIG. 3 is a diagram showing a schematic diagram of the hardware configuration of the image forming apparatus 102, the inspection apparatus 103, and the post-processing apparatus 104. As shown in FIG.

[0014] The image forming apparatus 102 is connected to other apparatuses in the printing system 100 via a system I / F 301. The image forming apparatus 102 includes a paper feed unit 302, a transport unit 303, an image forming unit 304, and a touch panel 305. The paper feed unit 302 supplies paper sheets set in a cassette or the like (not shown) into the image forming apparatus 102 via the transport unit 303. The transport unit 303 transports the paper sheets set in the paper feed unit 302 using a rotating roller (not shown) or the like. The transport unit 303 can transport paper sheets from the image forming apparatus 102 to the inspection apparatus 103 and the post-processing apparatus 104. In other words, the transport unit 303 is connected to the inspection apparatus 103 and the post-processing apparatus 104 and is a component common to the three apparatuses. The image forming unit 304 forms an image on the paper sheets transported by the transport unit 303 based on print data sent from the image processing apparatus 101. When the printing method is electrophotography, an image indicated by the printing data is formed as a latent image on a photosensitive drum, developed with color material (toner), transferred to paper, and fixed to form an image on the paper. The touch panel 305 is a combination of a display device (e.g., a liquid crystal display) and a pointing device (e.g., a touch pad), and corresponds to the output device 210 and input device 211 of the image processing device 101.

[0015] The inspection device 103 is connected to other devices in the printing system 100 via a system I / F 306. The inspection device 103 includes a reading unit 307, an inspection processing unit 308, and a touch panel 309. The reading unit 307 is a scanner equipped with a light source and a light-receiving sensor (e.g., a CCD) and optically reads the printed material conveyed by the conveying unit 303 to obtain image data. Hereinafter, the image data read by the reading unit 307 will be referred to as "read data." In this embodiment, the read data has an image format in which each pixel has three RGB (Red, Green, Blue) channels, with each channel having 8 bits. The inspection processing unit 308 compares the read data obtained by the reading unit 307 with the reference image data corresponding to the read data to inspect the printed material for defects. Figure 4 is a diagram showing an example of the internal hardware configuration of the inspection processing unit 308. The inspection processing unit 308 includes a CPU 401, RAM 402, ROM 403, a storage device 404, a system I / F 405, and a main bus 406. These pieces of hardware correspond to the CPU 201, RAM 202, ROM 203, storage device 204, system I / F 205, and main bus 209, respectively, described in Fig. 2, and the functions of each piece of hardware have been described above, so description thereof will be omitted. The touch panel 309 is a combination of a display device (e.g., a liquid crystal display) and a pointing device (e.g., a touchpad), and corresponds to the touch panel 305 of the image forming apparatus 102.

[0016] The post-processing device 104 is connected to other devices in the printing system 100 via a system I / F 310. The post-processing device 104 includes a drive control unit 311 and paper output trays 312 / 313. ​​The hardware configuration for realizing functions such as sorting, grouping, and stapling is omitted from FIG. 3. The drive control unit 311 controls switching of the path so that printed materials conveyed by the conveying unit 303 are output to either the paper output tray 312 or 313 depending on the inspection results of the inspection device 103. The drive control unit 311 separates the printed materials, for example, into those that pass inspection and those that fail inspection, and then outputs them.

[0017] <Printing system functional configuration> Next, the functional configuration (software configuration) of each device that constitutes the printing system 100 will be described with reference to the functional block diagram of FIG.

[0018] The image processing device 101 includes a print job acquisition unit 511, a print data generation unit 512, a print job storage unit 513, and a data transmission unit 514. The functions of each unit are briefly described below. The print job acquisition unit 511 acquires a print job, which consists of header information and data describing the image to be printed on a page-by-page basis (PDL data). The header information includes information (print settings) related to printing conditions such as the number of copies to be printed and the type and size of paper, as well as information (save settings) indicating whether the print job should be saved for reuse. The print job is input, for example, along with a print instruction, from a personal computer (not shown) that can communicate with the image processing device 101 via a network. Alternatively, a user may input the above-mentioned printing conditions, etc., for the PDL data via the input device 211, which generates and acquires the print job in the image processing device 101. The print data generation unit 512 performs RIP processing based on the print settings and PDL data included in the header information of the input print job to generate print data. A print job saving unit 513 saves the print job in the storage device 204 if the save setting included in the header information of the input print job specifies that the print job should be saved even after execution. The save setting is, for example, binary flag information in which "1" indicates that the print job should be saved and "0" indicates that the print job should not be saved. A data transmission unit 514 transmits the print data generated by the print data generation unit 512 to the image forming apparatus 102 via the system I / F 205.

[0019] The image forming apparatus 102 has a data acquisition unit 521, an image processing unit 522, a print control unit 523, and a data transmission unit 524. The data acquisition unit 521 receives and acquires print data transmitted by the data transmission unit 514 of the image processing apparatus 101 via the system I / F 301. The image processing unit 522 performs color conversion processing, halftone processing, correction processing, etc. on the print data in accordance with the printing characteristics of the image forming unit 304. Hereinafter, the print data processed in accordance with the printing characteristics will be referred to as "image formation data." The print control unit 523 controls the image forming unit 304 to perform processing (print processing) to form an image on paper based on the image formation data. The data transmission unit 524 transmits the print data (or image formation data) and an end signal indicating that the print processing has been performed to the inspection apparatus 103 via the system I / F 301.

[0020] The inspection device 103 includes an inspection job setting unit 531, a data acquisition unit 532, a reading control unit 533, a defect detection unit 534, an inspection job storage unit 535, an inspection result transmission unit 536, and a report creation unit 537. A user who wants to inspect a printed material using the automatic inspection function specifies the target print job and then sets up the inspection job. At this time, reference image data for defect detection (also called "correct image data") is generated according to the inspection method. If the inspection method is "RIP inspection," the inspection job setting unit 531 performs predetermined image processing on the print data sent from the image forming device 102 to generate the reference image data. On the other hand, if the inspection method is "scan inspection," the inspection job setting unit 531 prints only one copy of the print data, acquires scanned data of the resulting product (printed material), and uses this data as the reference image data. The inspection job setting unit 531 associates header information including the inspection conditions entered by the user (described below) with the reference image data acquired according to the inspection method and sets it as an "inspection job." The data acquisition unit 532 receives and acquires print data and an end signal transmitted by the data transmission unit 524 of the image forming apparatus 102 via the system I / F 306. Based on the acquired end signal, the reading control unit 533 causes the reading unit 307 to read (scan) the printed material conveyed by the conveyance unit 303 and acquires the read data. The defect detection unit 534 compares the read data with the reference image data and performs a process (inspection process) to detect defects in the printed material in accordance with the inspection settings in the set inspection job. If a print job linked to the inspection job is saved after its execution, the inspection job saving unit 535 saves the inspection job in the storage device 404, linking it to the print job. At this time, if the inspection method specified in the inspection settings is "scan inspection," all data including the reference image data is saved, but if it is "RIP inspection," the remaining data excluding the reference image data is saved. For example, if the image to be printed is A3 size, has a resolution of 600 DPI, and each pixel has an RGB 8-bit pixel value, the data size per page of the corresponding reference image will be approximately 200 MB. In bookbinding printing, for example, there are cases where more than 1,000 pages are inspected per copy, in which case the data size will exceed 200 GB by simple calculation.Storing all of this reference image data with such a huge data size in preparation for reuse would put a strain on the capacity of the storage device 404, so in this embodiment, whether to store the data is determined depending on the inspection method. Details of the method for storing reference image data will be described later. An inspection result transmission unit 536 transmits the results of the inspection processing performed by the defect detection unit 534 to the post-processing device 104 via the system I / F 306. A report creation unit 537 creates an inspection report summarizing the results of the inspection processing performed by the defect detection unit 532.

[0021] The post-processing device 104 has an inspection result acquisition unit 541 and an output control unit 542. The inspection result acquisition unit 541 receives and acquires the inspection results transmitted by the inspection result transmission unit 537 of the inspection device 103 via the system I / F 310. The output control unit 542 issues instructions based on the acquired inspection results to the drive control unit 311, and controls the drive control unit 311 so that the printed matter is discharged to the appropriate paper discharge tray (either 312 or 313).

[0022] <Printing system operation flow> Next, the operational flow of the printing system 100 according to this embodiment will be described with reference to the flowcharts shown in FIGS. 6, 8, and 9. FIG. 6 is a flowchart showing the flow of printing and inspection processing based on new print jobs and inspection jobs, and FIG. 8 is a flowchart showing details of the printing processing. FIG. 9 is a flowchart showing the flow of printing and inspection processing based on saved print jobs and inspection jobs. Of the series of processes shown in the flowcharts of FIGS. 6 and 9, those related to the printing processing are mainly performed by the CPU 201 of the image processing device 101, and those related to the inspection processing are mainly performed by the CPU 401 of the inspection processing unit 313 of the inspection device 103. In the following description, the symbol "S" means step.

[0023] <<Operation flow based on a new job>> First, the printing and inspection process based on newly submitted print jobs and inspection jobs will be described with reference to the flowchart in Figure 6. In this embodiment, attention is focused on the fact that reference image data for RIP inspection can be easily regenerated by converting print data, and the reference image data is not saved even in the case of an inspection job that is planned to be reused. On the other hand, since obtaining reference image data for scan inspection requires printing and reading processes, which take more time and cost, the reference image data is saved in the case of an inspection job that is planned to be reused.

[0024] In S601, the print job and inspection job to be processed are acquired. As described above, the print job is acquired by receiving it from, for example, a PC (not shown). The inspection job is acquired by the user setting it via the UI of the inspection device 103. When setting the inspection job, the user specifies which print job the inspection job corresponds to on the touch panel 309, and then inputs inspection conditions such as the inspection method ("RIP inspection" or "scan inspection"), inspection items, and inspection level via the touch panel 309. Here, the inspection method is specified, for example, via the UI screen 700 shown in FIG. 7. The inspection items specify the type of defect to be detected. Defects in printed matter occur when color material adheres to unintended locations during printing processing, or when sufficient color material does not adhere to intended locations. Types of defects include point defects, linear defects, color loss, and color unevenness.

[0025] In S602, the print data generation unit 512 performs RIP processing based on the header information and image data (PDL data) included in the print job acquired in S601. This RIP processing generates print data that is image data in a raster format that can be handled by the image forming device 102 and reflects the various printing conditions defined in the header information.

[0026] In S603, the print job saving unit 513 refers to the header information of the print job acquired in S601, and saves the print job in the storage device 204 if saving is instructed in the save setting.

[0027] In S604, the inspection job setting unit 531 determines whether the inspection method is RIP inspection or scan inspection based on the header information of the inspection job acquired in S601. If it is RIP inspection, S605 is executed next, and if it is scan inspection, S607 is executed next.

[0028] In S605, the inspection job setting unit 531 acquires the print data generated in S602 from the image forming apparatus 102 and performs predetermined image processing on the print data to generate reference image data. Specifically, image processing such as resolution conversion and color conversion is performed on the print data. Because the print data does not contain defects, it is suitable as reference image data, but it cannot be compared with the scanned data as is. For example, the image resolution of the scanned data is determined by the conveying speed of the conveying unit 303 and the reading frequency of the reading unit 307. However, since this is unrelated to the printing processing system, the image resolution of the scanned data and the print data may not necessarily be the same. Therefore, a process of adjusting the resolution is required to create reference image data for comparison. Note that the resolution conversion may not be adjusted to one of the image resolutions, but may be converted to any resolution that adequately captures defects and does not result in an excessively large image size. Furthermore, when printing is performed using four-color CMYK toner, the print data has pixel values ​​in four CMYK channels, but the scanned data often has pixel values ​​in three RGB channels, so it must be adjusted to one of the two. Therefore, color conversion processing is performed using an LUT that describes the correspondence between pixel values ​​of the print data and pixel values ​​of the read data. The LUT is created in advance by determining the correspondence between the print data and the read data, i.e., which pixel values ​​correspond to which pixel values ​​in the print data. Furthermore, since the read data includes the printing characteristics of the image forming unit 304 and the reading characteristics of the reading unit 307, correction processing may be performed to simulate these characteristics and add them to the print data. In this manner, reference image data is generated from the print data. Note that if the data sent from the image forming device 102 is image formation data rather than print data, the necessary image processing may be performed on the image formation data to generate reference image data. The reference image data generated in this manner is set (stored in RAM 402) as reference image data for the inspection job acquired in S601.

[0029] In S606, the inspection job storage unit 535 associates the inspection job acquired in S601 with the corresponding print job and stores it in the storage device 404. At this time, the inspection job storage unit 535 stores the data excluding the reference image data set in S605. In this embodiment, when reusing an inspection job for RIP inspection, control is performed to perform RIP processing again based on the print job to generate reference image data. When storing the inspection job, information such as a hash value that can uniquely identify the corresponding print job is acquired from the image processing device 101, and the inspection job is stored together with the received hash value, etc., thereby associating the print job with the inspection job.

[0030] In S607, the inspection job setting unit 531 causes the image forming apparatus 102 to execute a print process using the print data generated in S602 in order to obtain scan data for a reference image. As a result, only one printout is output to obtain the reference image data. Details of the print process will be described later.

[0031] In S608, when the inspection job setting unit 531 receives a printing completion signal from the CPU 201 of the image forming apparatus 102, it instructs the reading control unit 533 to read the conveyed printed matter. The reading control unit 533 that has received the instruction reads the conveyed printed matter and acquires read data. The inspection job setting unit 531 sets (stores in RAM 402) the read data thus acquired as reference image data for the inspection job acquired in S601.

[0032] In S609, the inspection job storage unit 535 associates the inspection job acquired in S601 with the corresponding print job and stores them in the storage device 404. At this time, the inspection job storage unit 535 also stores the reference image data set in S608. In this embodiment, when reusing an inspection job for scan inspection, the stored reference image data is read and used, and control is performed so that the generation process is not performed again.

[0033] In S610, printing processing according to the print job acquired in S601 is executed in the image forming apparatus 102. This printing processing is the same as the processing in S607 described above, and is repeated for the number of copies specified in the print settings included in the header information of the print job.

[0034] In S611, the reading control unit 533 reads the conveyed printed matter with the reading unit 307, and acquires read data (inspection image data) of the inspection target.

[0035] In S612, the defect detection unit 534 compares the inspection image data acquired in S611 with the reference image data set in S605 or S608 to check for defects for each item specified in the inspection settings within the inspection job. The defect detection unit 534 performs preprocessing as necessary prior to the comparison. Preprocessing here includes, for example, a resolution conversion process to match the image resolution of the inspection image data with that of the reference image data, and a registration process to align the two images. The inspection image data obtained by scanning a printed material may contain misalignment or tilt due to printing accuracy or conveyance accuracy. Comparing an inspection image containing such misalignment or tilt with the reference image may result in inaccurate defect detection. Therefore, a registration process is required to correct the misalignment or tilt that may be present in the inspection image. Specifically, feature points are extracted from both images to determine corresponding points between the two images, and a conversion is performed to match the corresponding points to correct the misalignment. Note that feature point extraction can be performed using, for example, the well-known AKAZE (Accelerated KAZE) method, and transformation can be performed using a well-known affine transformation. Furthermore, preprocessing can be performed appropriately for both scan inspection and RIP inspection. For example, in the case of scan inspection, the inspection image and reference image have the same resolution, so resolution conversion is not necessary. After the preprocessing is complete, the defect detection unit 534 compares the inspection image data and reference image data pixel by pixel and calculates the difference for each pixel. If the print is defect-free and the degree of match between the inspection image and the reference image is high, the difference for each pixel will be "0" or will remain within a range of small absolute values. On the other hand, if the print has a defect, a mismatch will occur between the inspection image and the reference image, and a large absolute difference will be calculated for the pixel corresponding to the defect. If a defect exists in the print, pixels with large absolute difference values ​​will occur in clusters to a certain extent for each defect type. Therefore, a spatial filter process of a predetermined shape is applied to the calculated difference to identify areas where defects are suspected, and the response value of the spatial filter is compared with a predetermined threshold to determine whether or not the area is considered to be defective. In this way, the presence or absence of defects in the printed matter can be determined. The determination results (inspection results) obtained in this way are stored in RAM 402.After the inspection, the printed matter is conveyed to the post-processing device 104, and is output to a paper output tray according to the inspection result by the output control unit 542 of the post-processing device 104.

[0036] In S613, the image forming apparatus 102 determines whether printing of the number of copies specified in the print job has been completed, and if not, the process returns to S610 to continue printing and inspecting the results. On the other hand, if printing has been completed, the process proceeds to S614.

[0037] In S614, the report creation unit 537 creates an inspection report based on the inspection results stored in RAM 402. The inspection report contains information such as the total number of prints, the number of passed products, and the number of rejected products. For rejected products, the report may also contain the location and type of defects detected. The created inspection report is linked to the inspection job saved in S606 or S609 and saved in the storage device 404. Note that the inspection report is created as needed, for example, when an instruction to create an inspection report is included in the print job or inspection job.

[0038] The above is the content of the printing and inspection process based on a newly submitted print job.

[0039] Next, the print processing in S607 and S610 will be described in detail with reference to the flowchart in Fig. 8. The series of processes shown in the flowchart in Fig. 8 are realized under the control of the CPU 201 of the image processing apparatus 101.

[0040] In step S801, the image processing unit 522 of the image forming apparatus 102 performs predetermined image processing on the print data received by the data acquisition unit 521 to generate image formation data suited to the characteristics of the image forming unit 304. The predetermined image processing includes, for example, color conversion processing, halftone processing, and the like. Image forming devices generally have various image formation characteristics due to the color materials and device characteristics used, depending on the model or model. The image formation data generated in this step absorbs these differences in characteristics and is directly referenced by the image forming unit 304 when executing print processing. Here, a brief description of the predetermined image processing will be given. Color conversion processing is a process of converting the colors represented by the image in the print data into the amounts of color materials used in image formation. In this embodiment, the image forming unit 304 forms images using four colors of toner: C (cyan), M (magenta), Y (yellow), and K (black), and the conversion is performed using a three-dimensional, four-dimensional, or one-dimensional LUT that indicates the conversion relationship between various colors and the amounts of the color materials for the four colors. Halftoning is a process of quantizing the multilevel pixel values ​​of each pixel that makes up the printing data into smaller values ​​that can be directly represented by the image forming unit 304 (for example, a binary value representing the presence or absence of toner), and uses methods such as dithering and error diffusion. The predetermined image processing is not limited to these. For example, if the image forming unit 304 has the characteristic of being unable to fully reproduce sharp edges and dulling them, an edge enhancement filter may be used to enhance the edges. In this way, image formation data is generated from the printing data.

[0041] In S802, the print control unit 523 drives the image forming unit 304 to form an image on the conveyed paper based on the image formation data. In the electrophotographic method, a toner image is formed on a photosensitive drum using a latent image and a developing process using the amount of toner specified in the image formation data, and the toner image is then transferred to the paper, after which the toner on the paper is fixed to create a printed matter.

[0042] The above is the content of the printing process in S607 and S610. When the execution of the flow shown in Fig. 8 is completed, printing data or image formation data is transmitted and received between the data transmission unit 524 and the data acquisition unit 532. In addition, a completion signal indicating that printing has been performed is transmitted from the image forming device 102 to the inspection device 103.

[0043] <<Operation flow based on saved jobs>> Printing and inspection processing based on a saved job is performed when additional printing becomes necessary for some reason. When additional printing is expected, the user can include a save instruction in the header information of the print job to be generated and submit the print job, and as described above, the print job and its corresponding inspection job will continue to be saved even after execution. Then, when additional printing is actually required, the user will instruct the image processing apparatus 101 to start execution of the saved print job via the input device 211. Below, we will explain the printing and inspection processing based on the print job and inspection job that continue to be saved even after execution, with reference to the flowchart in Figure 9.

[0044] In S901, information about the print job saved in the storage device 204 is read, and a list of saved jobs (not shown) is presented to the user on a display device serving as the output device 210. When the user finds a desired print job in the list of saved jobs, the user performs an operation to select the print job via the input device 211.

[0045] In S902, a print job selection operation by the user is accepted, and the job acquisition unit 511 reads and acquires the print job related to the selection operation from the storage device 204. Then, based on the header information of the acquired print job, information such as a hash value that can uniquely identify the print job is sent to the inspection device 103. Note that in S603 in the flow of FIG. 6 described above, not only the print job but also the print data may be saved, and in this step the print data may be read and acquired together with the print job. In this case, the next step S903 is unnecessary and is therefore skipped.

[0046] In S903, similar to S602 described above, the print data generation unit 512 performs RIP processing based on the header information and image data (PDL data) included in the print job acquired in S902, and generates print data.

[0047] In S904, the inspection job setting unit 531 reads and acquires the inspection job that is stored in association with the print job acquired in S902 from the storage device 404 based on the hash value etc. received from the image processing device 101. At this time, if the inspection method of the inspection job is scan inspection, the reference image data is also stored, and therefore the reference image data is also read.

[0048] In S905, the inspection job setting unit 531 determines whether the inspection method is RIP inspection or scan inspection based on the header information of the inspection job acquired in S904. If RIP inspection is specified, S906 is executed next, and if scan inspection is specified, S907 is executed next.

[0049] In S906, similar to S605 described above, the inspection job setting unit 531 acquires the printing data generated in S903 from the image forming device 102, performs predetermined image processing on the printing data, and generates and sets reference image data.

[0050] In S907, the inspection job setting unit 531 sets the reference image data read in S904 as the reference image data for the inspection job read in S904. The reference image data used in scan inspection is analog data obtained by scanning a printed material, and once deleted, it is necessary to start over from creating the printed material. Therefore, when the inspection method for an inspection job that is scheduled to be reused is scan inspection, convenience is prioritized, and the reference image data is saved so that printing to obtain the reference image data again is not required. Note that the user manually deletes the reference image data for scan inspection from the storage device 404, for example, when there is no longer any prospect of reuse.

[0051] Steps S908 to S912 correspond to steps S610 to S614 in the flow of Fig. 6, respectively, and there is no particular difference, so a description thereof will be omitted. The above is the content of the printing and inspection process based on a saved job.

[0052] <Variation 1> In the above-described embodiment, the print job and the inspection job are generated and saved separately, but the contents of the inspection job may be included in the print job, for example. That is, the header information of the print job may include information about the printing process, such as the number of copies to be printed and the type and size of paper, as well as information about the inspection process, such as the inspection method, inspection items, and level, and may also include reference image data in addition to the PDL data. In this case, as in the above-described embodiment, when saving the print job, the inspection settings in the header information may be referenced to determine whether the inspection method is "RIP inspection" or "scan inspection," and whether the reference image data should be saved.

[0053] <Variation 2> The inspection report created after the inspection may also include image information that allows visual confirmation of the location and shape of detected defects. In this case, for example, the report creation unit 537 creates an inspection report that includes information such as the total number of prints, the number of passed products, and the number of failed products, as well as the reference image used in the inspection and / or the inspection image in which the defect was detected. The inspection report created in this manner is linked to the inspection job by the inspection job storage unit 535 and stored in the storage device 404. However, to avoid overloading the storage device 404, it is desirable to reduce the data volume of the image information included in the inspection report. In this regard, since the inspection report only needs to show the general appearance of the defect, images with reduced data volume, such as by reducing or shrinking the resolution, are used instead of the reference image and / or inspection image themselves. In the case of the A3 size, 600 DPI, RGB 8-bit mentioned above, by converting the resolution to 150 DPI, for example, the storage device 404's capacity usage can be reduced to 1 / 16 of the capacity required for 600 DPI.

[0054] As described above, according to this embodiment including the modified example, whether to save the reference image data of an inspection job that is scheduled to be reused is determined depending on the inspection method, which makes it possible to achieve both a reduction in the capacity of the storage device used to save the reference image data and user convenience.

[0055] [Embodiment 2] In the first embodiment, when the inspection method is RIP inspection, generating reference image data is relatively easy, so even if it is expected to be reused, the data is not saved, thereby avoiding storage capacity pressure. However, for example, there are cases where printing and inspection to obtain the same printed matter are performed in several separate jobs. When the same printing and inspection are performed repeatedly in a short period of time, it is inefficient to repeatedly generate reference image data each time. Therefore, in the second embodiment, when the inspection method is RIP inspection, the user can choose whether or not to save the data, and if it is saved, the data is saved for a limited period of time.

[0056] The configuration and operation flow of the printing system are basically the same as those of the first embodiment, so the following will only explain the difference regarding the storage of reference image data for RIP inspection.

[0057] In this embodiment, in S606 in the flow of FIG. 6 described above, the inspection job storage unit 535 associates the reference image data with the print job and the inspection job and stores them in the storage device 404 after adding information indicating the storage period (storage period information). The user can specify the storage period via, for example, a UI screen 1000 shown in FIG. 10 displayed on the touch panel 309. In this case, as exemplified by the UI screen 1000 of FIG. 10, relatively short-term options such as when the printing system (or each component device) is powered off, a few hours, or one day (24 hours) are prepared in advance. The user may select from the displayed options or specify an arbitrary time. The inspection job storage unit 535 then deletes the reference image data from the storage device 404 when the period indicated by the storage period information has elapsed.

[0058] The above is the flow of control in this embodiment when the reference image data is saved even in the case of RIP inspection.

[0059] <Modification> 6, a UI screen (not shown) may be presented to the user to select whether or not to save the reference image data, and if the user selects "save," the reference image data may be saved for a predetermined period of time. The predetermined period is set to be shorter for reference image data for RIP inspection than for reference image data for scan inspection.

[0060] As described above, according to this embodiment, it is possible to reduce the capacity pressure on the storage device that stores the inspection jobs, while improving user convenience in cases where the same printing and inspection are repeated within a short period of time.

[0061] <Other embodiments> The present disclosure 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.

[0062] The present disclosure also includes the following configurations and methods. [Configuration 1] An inspection device for inspecting printed matter, a setting means for setting reference image data generated based on the printing data of the printed matter for the inspection; a storage means for storing the set reference image data so that the set reference image data can be used again for the inspection according to the inspection method even after the inspection is completed; An inspection device comprising: [Configuration 2] The inspection method includes a first method in which the reference image data is obtained by reading a printed matter obtained by a printing process using the printing data, and a second method in which the reference image data is obtained by performing a predetermined image processing on the printing data. the storage means performs the storage when the inspection method is the first method, and does not perform the storage when the inspection method is the second method; 2. The inspection device according to configuration 1, [Configuration 3] The inspection device described in configuration 2, wherein the storage means stores information indicating the conditions of the inspection, including the inspection method, so that the information continues to be stored even after the inspection is performed, regardless of whether the inspection method is the first method or the second method. [Configuration 4] a creation means for creating an inspection report showing the results of the inspection; The inspection report includes an image in which the volume of the reference image data used in the inspection is reduced, or an image in which the volume of the read data obtained by reading the printout in which the defect was detected is reduced, The storage means stores the inspection report in association with information indicating the inspection conditions. 4. The inspection device according to configuration 3. [Configuration 5] 5. The inspection device according to any one of configurations 2 to 4, wherein the storage means determines whether to continue to store the reference image data after the inspection is performed based on an instruction from a user. [Configuration 6] 6. The inspection device according to configuration 5, further comprising a display means for displaying a UI screen for receiving instructions from a user. [Configuration 7] The inspection device described in configuration 6, characterized in that the UI screen displays possible storage periods in the case where the reference image data used in the second method is selected to continue to be stored even after the inspection is performed. [Configuration 8] The inspection device described in configuration 6, characterized in that when a user selects via the UI screen to continue saving the reference image data used in the second method even after the inspection is performed, the saving means saves the reference image data used in the second method so that it continues to be saved for a certain period of time even after the inspection is performed. [Configuration 9] 9. The inspection device according to any one of configurations 1 to 8, wherein the storage device used for storage by the storage means is a non-volatile storage device. [Configuration 10] The inspection device according to any one of configurations 1 to 9, characterized in that, when a print job instructing printing of the printed matter is saved so as to continue to be saved even after the print job is executed, the saving means saves the set reference image data so as to continue to be saved even after the execution of the inspection according to the inspection method. [Method 1] A control method for an inspection device that inspects printed matter, comprising: a setting step of setting reference image data generated according to an inspection method based on the printing data of the printed matter for the inspection; a storing step of storing the set reference image data so that the reference image data continues to be stored even after the execution of the inspection in accordance with the inspection method; A control method comprising: [Configuration 11] A program for causing a computer to operate as the inspection device according to any one of configurations 1 to 10.

Claims

1. An inspection device for inspecting printed matter, a setting means for setting reference image data generated based on the printing data of the printed matter for the inspection; a storage means for storing the set reference image data so that the set reference image data can be used again for the inspection according to the inspection method even after the inspection is completed; An inspection device comprising:

2. The inspection method includes a first method in which the reference image data is obtained by reading a printed matter obtained by a printing process using the printing data, and a second method in which the reference image data is obtained by performing a predetermined image processing on the printing data. the storage means performs the storage when the inspection method is the first method, and does not perform the storage when the inspection method is the second method; 2. The inspection device according to claim 1.

3. The inspection device according to claim 2, characterized in that the storage means stores information indicating the conditions of the inspection, including the inspection method, so that it continues to store the information even after the inspection is performed, regardless of whether the inspection method is the first method or the second method.

4. a creation means for creating an inspection report showing the results of the inspection; The inspection report includes an image in which the volume of the reference image data used in the inspection is reduced, or an image in which the volume of the read data obtained by reading the printout in which the defect was detected is reduced, The storage means stores the inspection report in association with information indicating the inspection conditions.

4. The inspection device according to claim 3.

5. 3. The inspection apparatus according to claim 2, wherein said storage means determines whether or not to continue to store said reference image data after said inspection is performed based on an instruction from a user.

6. 6. The inspection device according to claim 5, further comprising a display means for displaying a UI screen for receiving instructions from a user.

7. The inspection device according to claim 6, characterized in that the UI screen displays possible storage periods when selecting to continue storing the reference image data used in the second method even after the inspection is performed.

8. The inspection device described in claim 6, characterized in that when a user selects via the UI screen to continue saving the reference image data used in the second method even after the inspection is performed, the storage means stores the reference image data used in the second method so that it continues to be stored for a certain period of time even after the inspection is performed.

9. 2. The inspection device according to claim 1, wherein the storage device used for storage by said storage means is a non-volatile storage device.

10. 2. The inspection device according to claim 1, wherein the storage means stores the set reference image data so that it continues to be stored even after the inspection is performed in accordance with the inspection method when a print job that instructs printing of the printed matter is stored so that it continues to be stored even after the inspection is performed.

11. A control method for an inspection device that inspects printed matter, comprising: a setting step of setting reference image data generated based on the printing data of the printed matter for the inspection; a storing step of storing the set reference image data so that the set reference image data continues to be stored even after the execution of the inspection in order to use the same for another inspection according to the inspection method; A control method comprising:

12. A program for causing a computer to execute the control method according to claim 11.

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