Image inspection device, image inspection method, image inspection program, and image formation system

Abstract

To provide an image inspection device which can further shorten a time required for processing from reference image generation to image inspection compared to the prior art, an image inspection method, an image inspection program, and an image formation system.SOLUTION: An image inspection device 300 has a control part 310 which performs inspection of an image formed on each of a plurality of recording media on the basis of acquired image data. The control part 310 generates a reference image used for inspection of each image formed on each of the plurality of recording media.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to an image inspection device, an image inspection method, an image inspection program, and an image forming system. [Background technology]

[0002] Conventionally, the quality of a print is inspected by comparing a read image of a print to be inspected with a preregistered reference image. The reference image may be, for example, an image of a print that is read and has no quality abnormalities. The presence or absence of quality abnormalities is determined, for example, by an inspector visually checking the image and judging whether or not there are abnormalities. For example, the image forming apparatus described in Patent Document 1 below is known as an image forming apparatus having an image inspection unit that inspects the quality of a print.

[0003] However, it takes time and effort for an inspector to visually check all pages of a printed matter to obtain a reference image, as in the image forming device of Patent Document 1. In response to this, Patent Document 2 below discloses a print inspection device that inspects the quality of a printed matter by comparing a document image as a reference image with a scanned image. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-146514 A [Patent Document 2] JP 2015-53561 A Summary of the Invention [Problem to be solved by the invention]

[0005] The print inspection device of Patent Document 2 uses the document image as the reference image, thereby saving the time and effort required for visual confirmation when creating the reference image. However, there is a problem in that a large amount of memory storage space is consumed when the document image has a large number of pages.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide an image inspection device, an image inspection method, an image inspection program, and an image forming system that can prevent large amounts of memory storage space from being consumed even when the number of pages of a document image is large. [Means for solving the problem]

[0007] The above object of the present invention can be achieved by the following means.

[0008] (1) An image inspection device having a control unit that inspects images formed on multiple recording media based on acquired image data, and the control unit generates a reference image for each copy to be used in inspecting the images formed on each of the multiple recording media.

[0009] (2) The image inspection device according to (1) above, wherein the reference image is generated based on the acquired image data.

[0010] (3) An image inspection device as described in (1) or (2) above, wherein the control unit controls the generation of the reference image and the formation of the image on the recording medium to be performed in parallel for a first part of the multiple parts.

[0011] (4) An image inspection device as described in (1) or (2) above, wherein the control unit controls a reference image generation process for generating the reference image and an inspection process including forming the image on the recording medium and inspecting the read image generated by reading the recording medium on which the image is formed, in parallel for a first part of the multiple parts.

[0012] (5) The image inspection device according to (1) or (2) above, wherein the control unit controls the generation of a reference image for a second part of the multiple parts to be performed in parallel with the inspection of the first part of the recording medium.

[0013] (6) The image inspection device described in (1) or (2) above, wherein the control unit controls the generation of a reference image for the (n+1)th copy of the multiple copies to be performed in parallel with the inspection of the nth copy of the recording medium.

[0014] (7) An image inspection method for an image inspection device having a control unit that inspects images formed on each of a plurality of recording media based on acquired image data, the image inspection method including a step in which the control unit generates, for each copy, a reference image to be used for inspecting the images formed on each of the plurality of recording media.

[0015] (8) An image inspection program for an image inspection device having a control unit that inspects images formed on multiple recording media based on acquired image data, the image inspection program causing the control unit to execute a process including a procedure for generating, for each copy, a reference image to be used in inspecting the images formed on each of the multiple recording media.

[0016] (9) An image forming system having an image forming unit that forms an image on a recording medium based on acquired image data, and the image inspection device described in (1) or (2) above. Effect of the Invention

[0017] According to the present invention, a reference image used for inspecting images formed on each of a plurality of sets of paper is generated for each set. Therefore, the memory area in the page memory that stores the reference image after the inspection of the inspection image is completed can be released. As a result, even if the number of pages of the document image is large, it is possible to prevent a large amount of memory area in the page memory from being consumed. [Brief description of the drawings]

[0018] [Figure 1] 1 is a schematic block diagram of a printing system according to an embodiment of the present invention. [Diagram 2] 2 is a schematic block diagram illustrating a configuration of the image forming system shown in FIG. 1. [Diagram 3]3 is a block diagram for explaining an overview of the control operations of a control unit and a print controller unit shown in FIG. 2. FIG. [Figure 4] 2 is a flowchart illustrating a processing procedure of an image inspection method by the image forming system shown in FIG. 1. [Diagram 5] 5 is a subroutine flowchart illustrating details of inspection of an inspection image in the flowchart shown in FIG. 4. [Figure 6] 2 is a schematic diagram showing the time series of processes of obtaining an original image, generating a reference image, forming an inspection image, and inspecting the inspection image. FIG. [Figure 7] 1A to 1C are schematic diagrams showing the printing of a plurality of copies of an original image in time series. [Figure 8] 10 is a schematic diagram showing in chronological order the processes of acquiring an original image, generating a reference image, forming an inspection image, and inspecting the inspection image when recovery printing is performed. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the attached drawings. In the description of the drawings, the same elements are given the same reference numerals, and duplicated explanations will be omitted. In addition, the dimensional ratios of the drawings are exaggerated for the convenience of explanation, and may differ from the actual ratios.

[0020] <Printing system configuration> FIG. 1 is a schematic block diagram of a printing system according to a first embodiment of the present invention, and FIG. 2 is a schematic block diagram illustrating the configuration of the image forming system shown in FIG.

[0021] 1, the printing system 100 includes a client terminal 200 and an image forming system 300. The client terminal 200 and the image forming system 300 are connected to each other via a communication line 400 so as to be able to communicate with each other.

[0022] The client terminal 200 may be, for example, a personal computer, a tablet terminal, a smartphone, etc. A printer driver for converting manuscript data into a print job is installed in the client terminal 200. The printer driver generates a print job in a format compatible with a print controller unit 320 (see FIG. 2) of the image forming system 300, and transmits the print job to the image forming system 300 via a communication line 400. The client terminal 200 also includes a display and can display the inspection results of the printed matter (good / defective), images of defective printed matter, etc.

[0023] The print job includes, for example, print data in a PDL (Page Description Language) format and job information. The print data includes, for example, print data consisting of the first to m-th pages. The job information includes, for example, print settings such as the number of pages, the number of copies to be printed, the type of paper (recording medium), size, basis weight, single-sided printing / double-sided printing, and inspection settings (inspection on / off, inspection level). The user can issue an instruction to image forming system 300 to inspect an image by turning the inspection setting to inspection on.

[0024] The communication line 400 may include a LAN (Local Area Network) that connects computers or network devices together according to a specific standard, or a WAN (Wide Area Network) that connects LANs together with a dedicated line, etc. Examples of the specific standard include Ethernet (registered trademark), FDDI (Fiber Distributed Data Interface), and Wi-Fi (Wireless Fidelity).

[0025] The number of each of the above components connected to the communication line 400 is not limited to the example shown in FIG.

[0026] <Configuration of Image Forming System 300> 1 and 2, image forming system 300 has a control unit 310, a print controller unit 320, an image forming unit 330, an image reading unit 340, an image inspection unit 350, an operation display unit 360, a paper feed unit 370, a reference image generating unit 380, and a storage device 390. Image forming system 300 functions as an image inspection device.

[0027] <Configuration of control unit 310> The control unit 310 includes an image control CPU 311, a DRAM (Dynamic Random Access Memory) control IC 312, a memory 313, an image memory (DRAM) 314, a compression / decompression IC 315, a read processing unit 316, a write processing unit 317, a storage unit 318, and the like.

[0028] The image control CPU 311 loads various programs stored in the storage unit 318 into the memory 313, and performs overall control of the operation of the entire image forming system 300 in cooperation with the loaded programs.

[0029] The reading processing unit 316 performs various processes such as analog processing, A / D conversion processing, and shading processing on the analog image signal output from the scanner 341 of the image reading unit 340, and generates digital image (read image) data. The generated digital image data is output to the compression / expansion IC 315 by the DRAM control IC 312. The compression / expansion IC 315 performs compression processing on the digital image data and expansion processing on the compressed digital image data under the control of the DRAM control IC 312. The DRAM control IC 312 also controls input / output of the image memory (DRAM) 314 for the compressed and expanded digital image data.

[0030] The image memory 314 is made up of a DRAM and has an internal compression memory and page memory area, and temporarily stores compressed image data, decompressed image data, and the like.

[0031] The write processing unit 317 outputs the decompressed digital image data to an exposure unit 332 of the image forming unit 330 .

[0032] <Configuration of the Print Controller Unit 320> The print controller unit 320 analyzes the print job received from the client terminal 200 via the communication line 400, and executes processes such as color conversion, screening, and rasterization to generate an original image in a bitmap format. The generated original image is transmitted to the control unit 310. The print controller unit 320 functions as an original image acquisition unit.

[0033] The print controller unit 320 is configured to include a controller control unit 321, a reference image generation control unit 322, a DRAM control IC 323, an image memory (DRAM) 324, a communication control unit 325, a communication I / F 326, etc. The controller control unit 321 comprehensively controls the operation of each unit of the print controller unit 320. In addition, the controller control unit 321 receives a print job from the client terminal 200, etc. via the communication I / F 326. The communication control unit 325 controls the communication I / F 326.

[0034] The received print job includes print data (mainly in PDL format) that is the source of the document image, and job information that describes print settings such as the type of paper to be used. The print controller unit 320 performs rasterization (RIP) processing to convert the print data into bitmap data for each page based on the print settings. The RIP image after the rasterization processing is temporarily stored in the image memory 324. The RIP image in the image memory 324 is temporarily stored in the compressed memory area in the image memory 314 via the compression / decompression IC 315 under the control of the DRAM control IC 323 of the print controller unit 320 and the DRAM control IC 312 of the control unit 310. During normal printing, the RIP image stored in the compressed memory area is decompressed by the compression / decompression IC 315 and sent to the image forming unit 330 as a document image via the write processing unit 317, where it is printed.

[0035] The reference image generation control unit 322 outputs a reference image generation instruction to the reference image generation unit 380 (described later) to generate a reference image based on the document image at a predetermined generation timing. The predetermined generation timing may be, for example, when the inspection setting is on and the document image acquisition unit acquires the document image. The reference image generation unit 380 generates a reference image based on the reference image generation instruction.

[0036] Ideally, it is considered that the read image generated by reading the inspection image formed on paper matches the document image in terms of contents. However, when the inspection image formed on paper is read by a scanner, an error may occur in the read image with respect to the document image due to various factors such as variations in the paper transport path, deviations in the reading position by the scanner, color reproducibility, and differences in paper type. In addition, an error may occur in the document image depending on the reading resolution by the scanner. Therefore, a simple comparison between the read image and the document image is likely to cause an error, and it is not realistic to inspect the inspection image by simply comparing the read image and the document image. Therefore, in this embodiment, various processes are performed on the document image with respect to the position, resolution, color, etc., so that the image can be compared with the read image, and a reference image is generated, and the read image is compared with the reference image. As a result, the comparison with the read image is appropriately performed, and the inspection of the printed matter can be performed with high accuracy. Details of the generation process of the reference image will be described later. Although FIG. 2 illustrates an example in which the reference image generation control unit 322 is provided in the print controller unit 320, the reference image generation control unit 322 may be configured to be provided in the control unit 310.

[0037] <Configuration of Image Forming Unit 330> The image forming unit 330 forms (prints) an image on a sheet (recording medium) by an electrophotographic method including the steps of charging, exposing, developing, transferring, and fixing, according to an instruction from the control unit 310. In this embodiment, the image forming unit 330 forms an inspection image to be inspected by the image inspection unit 350 on a sheet under image forming conditions set based on the print settings. The image forming unit 330 has a printer control unit 331, an exposure unit 332, and the like. The printer control unit 331 is connected to the image control CPU 311 by serial communication, and receives control from the image control CPU 311. The printer control unit 331 drives a LD (Laser Diode) of the exposure unit 332 by a signal from the writing processing unit 317, and forms an electrostatic latent image corresponding to the document image on a photoconductor (not shown). The toner image formed on the photoconductor is developed through a developing process, and transferred onto a sheet supplied from the paper feed unit 370. The unfixed toner image on the sheet is then fixed by heating and pressing. The paper on which the toner image is fixed is transported to the image reading unit 340 .

[0038] The image forming unit 330 also includes a print sheet discharge device that distinguishes paper (waste paper) on which an inspection image detected as abnormal by the image inspection unit 350 has been formed from paper on which a normal inspection image has been formed, and discharges (purges) the paper.

[0039] <Configuration of image reading unit 340> The image reading unit 340 has a scanner 341 and a scanner control unit 342. The scanner 341 reads the paper (printed material) conveyed on the conveying path, for example, by a CCD (Charge Coupled Device) image sensor. The scanner control unit 342 controls the scanner to read the inspection image formed on the paper conveyed from the image forming unit 330 in accordance with a reading instruction from the control unit 310. The scanner control unit 342 outputs the read image obtained by reading the inspection image formed on the paper to the control unit 310.

[0040] <Configuration of image inspection unit 350> The image inspection unit 350 performs image inspection based on the reference image. More specifically, the image inspection unit 350 obtains the reference image and the read image, and compares the reference image and the read image for each page, thereby inspecting the inspection image formed on the paper.

[0041] The image inspection unit 350 has an image inspection control unit 351. The image inspection control unit 351 has an image control CPU 311, or a CPU, RAM, ROM, and auxiliary storage device (not shown). The function of inspecting the inspection image is realized by the CPU executing an image inspection program. The image inspection control unit 351, for example, calculates the difference (error) in pixel values ​​between the reference image and the read image for each page, and judges the quality of the inspection image according to the magnitude of the difference. The calculation of the difference can be performed for each page, each object, or each area. For example, when the difference is calculated for each page, if the total value of the pixel differences in a page is less than a specified value, a "good" inspection result is output, and if the total value of the differences is equal to or greater than the specified value, a "bad" inspection result is output. In addition, when the difference is calculated for each object or each area, the inspection result can be configured to be "good" or "bad" depending on the total value of the pixel differences in the selected object or area.

[0042] If the inspection result of the inspection image is "good", control unit 310 determines that the printed matter is a good product, and if the inspection result of the inspection image is "bad", control unit 310 determines that the printed matter is a defective product.

[0043] <Configuration of Operation Display Unit 360> The operation display unit 360 includes a touch panel display 361, an operation control unit 362, a numeric keypad as hard keys, a start button, a stop button, and the like. The touch panel display includes, for example, a touch sensor and an LCD (Liquid Crystal Display) arranged on the back of the touch sensor. The operation control unit 362 accepts input from the touch sensor and hard keys, and transmits the input data to the control unit 310. The operation control unit 362 also receives output data from the control unit 310 and displays it on the LCD. The operation display unit 360 is used for inputting various settings (e.g., inspection on / off and inspection level of the inspection setting) and instructions (e.g., an instruction to start printing) by the user. The operation display unit 360 is also used for outputting (displaying) the state of the image forming system 300, the inspection results of printed matter (good / bad), images of defective printed matter, and the like.

[0044] <Configuration of Paper Feeding Unit 370> The paper feed unit 370 includes at least one large-capacity paper tray, and supplies paper to the image forming unit 330 one sheet at a time.

[0045] <Configuration of the reference image generating unit 380> The reference image generating unit 380 generates a reference image based on the original image acquired by the original image acquiring unit, and outputs the generated reference image to the control unit 310. The reference image generating unit 380 can be realized by a CPU (not shown) other than the image control CPU 311 executing an image inspection program. This allows the generation of the reference image and the formation and inspection of an inspection image to be executed in parallel.

[0046] Conventionally, the same CPU is configured to generate the reference image and form and inspect the inspection image. Therefore, the CPU executes the formation and inspection of the inspection image after the generation of the reference image for each copy is completed, so the generation of the reference image and the formation and inspection of the inspection image cannot be executed in parallel. In this embodiment, the generation of the reference image and the formation and inspection of the inspection image may be executed by different CPUs. With this configuration, the generation of the reference image and the formation and inspection of the inspection image can be executed in parallel.

[0047] Furthermore, the CPU processing load (processing time) for generating the reference image may increase or decrease depending on the complexity of the document image, the presence or absence of variable printing, etc. For example, if the document image is complex, the CPU processing load for generating the reference image may increase significantly. By having a CPU other than image control CPU 311 take charge of generating the reference image, the processing load on image control CPU 311 can be reduced.

[0048] <Configuration of storage device 390> The storage device 390 stores the reference image generated by the reference image generating unit 380. When reprinting an original image, the control unit 310 does not need to generate the reference image again by using the reference image stored in the storage device 390. Therefore, it is possible to save the time required for generating the reference image.

[0049] <Overview of Control Operations of Control Unit 310 and Print Controller Unit 320> FIG. 3 is a block diagram for explaining an overview of the control operations of the control unit 310 and the print controller unit 320 shown in FIG.

[0050] First, the control unit 310 receives an original image and job information from an original image acquisition unit (print controller unit 320) ((1) Image input). The original image is a RIP image obtained by rasterizing print data.

[0051] When the reference image generating unit 380 receives an instruction to generate a reference image from the reference image generation control unit 322 ((2)-1 instruction to generate a reference image), the reference image generating unit 380 generates a reference image based on the document image acquired by the document image acquiring unit, and outputs the generated reference image to the control unit 310. The control unit 310 stores the reference image in the page memory 1.

[0052] As described above, the reference image generating unit 380 performs various processes on the document image with respect to the position, resolution, color, and the like to generate a reference image. For example, the reference image generating unit 380 can extract position information of the content portion from the document image and add or embed the position information in the reference image so that the content portions (contents) of the reference image and the read image can be compared. That is, the reference image generated by the reference image generating unit 380 has positioning information for aligning the reference image and the read image when performing image inspection based on the reference image. The positioning information includes contour information and edge information of the image. In addition, the reference image generated by the reference image generating unit 380 has area information on the inspection area and the inspection excluded area used when performing image inspection based on the reference image. Furthermore, the reference image generating unit 380 can adjust the resolution of the document image to match the resolution of the scanner of the image reading unit 340 to generate a reference image. Furthermore, the reference image generating unit 380 can generate a reference image by converting the color space of the original image so that the color space matches the color space (for example, RGB) used by the scanner of the image reading unit 340 .

[0053] Furthermore, when the control unit 310 receives an original image from the original image acquisition unit, it instructs the image forming unit 330 to form an image and outputs the original image stored in the page memory 1 to the image forming unit 330 ((2)-2 Image output). In this embodiment, the image forming unit 330 forms an inspection image on paper based on the original image. The generation of the reference image by the reference image generation unit 380 and the formation of the inspection image by the image forming unit 330 are performed in parallel.

[0054] When the reference image generation is completed, the reference image generation unit 380 notifies the reference image generation control unit 322 of the completion of reference image generation ((3)-1 Reference image generation completed). Furthermore, when the image formation unit 330 has completed image formation on the paper, it notifies the control unit 310 of the completion of output ((3)-2 Output completed). The storage device 390 saves the generated reference image ((4)-1 Save reference image).

[0055] Furthermore, upon receiving the notification that output is complete, the control unit 310 immediately outputs an image reading instruction to the image reading unit 340 ((4)-2 Image reading instruction). The image reading unit 340 reads the paper on which the inspection image is formed, and outputs the read image of the paper to the control unit 310. The control unit 310 stores the read image in the page memory 2. Upon completing reading of the paper, the image reading unit 340 notifies the completion of image reading ((5)-2 Image reading completion).

[0056] Upon receiving notification that image reading is complete, the control unit 310 outputs an image inspection instruction to the image inspection unit 350 ((6)-2 Image inspection instruction). The image inspection unit 350 obtains the reference image and the read image from the page memory 1 and the page memory 2, respectively, and inspects the inspection image by comparing the reference image with the read image. Then, the image inspection unit 350 outputs the inspection result of the inspection image to the control unit 310 ((7)-2 Image inspection result).

[0057] In response to an instruction from a user, the control unit 310 performs control so that the inspection result (good / bad) of the printed matter is displayed on the operation display unit 360 or the display of the client terminal 200 based on the inspection result of the inspection image.

[0058] <Image inspection method> Fig. 4 is a flowchart illustrating the processing procedure of an image inspection method by the image forming system 300 shown in Fig. 1. Fig. 5 is a subroutine flowchart illustrating the details of the inspection of the inspection image in the flowchart shown in Fig. 4. The processing shown in Figs. 4 and 5 is realized by the image control CPU 311 executing an image inspection program. Fig. 6 is a schematic diagram showing each process of obtaining an original image, generating a reference image, forming an inspection image, and inspecting the inspection image in chronological order. Fig. 7 is a schematic diagram showing the printing of multiple copies of an original image in chronological order.

[0059] As shown in FIG. 4, first, the control unit 310 acquires an original image (step S101). The original image may consist of one or more copies, and each copy may include one or more pages. When the original image consists of multiple copies, the control unit 310 receives the original image (RIP image) from the original image acquisition unit one page at a time, from the first page to the final mth page, for each copy, starting from the first copy to the final Nth copy. For example, FIG. 6 illustrates a case in which the original image consists of multiple copies and the first page to the eighth page of the nth copy are received in order. In addition, in FIG. 6 and FIG. 7, "1P" represents the first page (similarly for "2P" and the like). In addition, "print preparation" in the formation of the inspection image includes initial settings and preparations of each unit (for example, warming up of the fixing unit) according to the image formation conditions in the image forming unit 330.

[0060] Next, the control unit 310 stores the document images (step S102). When a print job is started, the control unit 310 stores the document images acquired from the document image acquisition unit in the page memory 1 page by page.

[0061] Next, reference image generation control unit 322 controls the generation of a reference image used for inspecting the inspection image. Reference image generation unit 380 generates a reference image according to an instruction from reference image generation control unit 322 (step S103). For example, when the first page of a document image is acquired and stored in page memory 1, reference image generation control unit 322 controls reference image generation unit 380 to generate a reference image based on the first page of the document image. Reference image generation unit 380 generates a reference image based on the first page of the document image. A reference image is generated similarly for the second page of the document image.

[0062] Next, the storage device 390 stores the reference image generated by the reference image generating unit 380 (step S104). For example, the storage device 390 stores the first and second pages of the document image. Also, as shown in FIG. 6, in parallel with the processes of steps S103 and S104, the control unit 310 controls the image forming unit 330 to form an inspection image on a sheet based on the document image and job information received from the document image acquiring unit. For example, the control unit 310 performs printing preparation and controls the image forming unit 330 to form an inspection image on a sheet for the document image of the first page. The image forming unit 330 forms an inspection image on a sheet for the first page of the document image according to the instruction of the control unit 310 (step S105). After the inspection image of the document image of the first page is formed, an inspection image of the document image of the second page is also formed on a sheet in the same manner.

[0063] Next, the image inspection unit 350 determines whether a reference image has been generated for each page of the acquired document image (step S106). If a reference image has been generated (step S106: YES), the image inspection unit 350 inspects the inspection image formed by the image forming unit 330 (step S107). On the other hand, if a reference image has not been generated (step S106: NO), the image inspection unit 350 waits until a reference image is generated. For example, if a reference image of the same document image (first page) as the document image (first page) that is the basis of the inspection image inspected in step S107 has not been generated, the image inspection unit 350 waits until a reference image of this document image (first page) is generated.

[0064] 6, the generation of a reference image by reference image generating section 380 and the formation and inspection of an inspection image by image forming section 330 are performed in parallel. This enables image forming system 300 to further reduce the time required for processing from the generation of a reference image to image inspection, as compared to the conventional technology.

[0065] [Parallel generation of a reference image and formation of a test image on paper] For example, in the example shown in the figure, the generation of the reference images of the first page (1P) and the second page (2P) and the preparation for printing are performed in parallel, and the generation of the reference image of the third page (3P) and the formation of the inspection image of the first page (1P) (first half) are performed in parallel. Then, the generation of the reference image of the fourth page (4P) and the formation of the inspection image of the first page (1P) (second half) are performed simultaneously. Note that in the figure, the generation of the reference image of the third page (3P) and the formation of the inspection image of the first page (1P) are shown to start simultaneously, but this is not limited to this. The formation of the inspection image of the first page (1P) can be started at an appropriate timing after the completion of the preparation for printing, and the generation of the reference image of the third page (3P) can be started at an appropriate timing after the generation of the reference image of the second page (2P). The start timing of the generation of the reference image and the generation of the inspection image is the same for the subsequent pages.

[0066] [Parallel generation of a reference image, formation of a test image on paper, and inspection of the test image] After that, generation of a reference image of the fifth page (5P), formation of an inspection image of the second page (2P), and inspection of the inspection image of the first page are simultaneously performed.

[0067] As shown in FIG. 5, in the process of inspecting the inspection image, the inspection image formed on paper is read by the image reading unit 340 (step S201), and the inspection image is inspected by the image inspection unit 350 by comparing the read image with a reference image (step S202).

[0068] The control unit 310 repeats the processes of steps S101 to S107 until the inspection of the inspection images for all pages (from the first page to the final m-th page) is completed (step S108).

[0069] Furthermore, the control unit 310 repeats printing until the number of copies set in the job information is reached (step S109). As shown in Fig. 7, in this embodiment, when the set number of copies is, for example, N, the reference image generating unit 380 generates a reference image N times until printing is completed. That is, the reference image generating unit 380 performs a process of generating a reference image for each page for each copy, thereby generating a reference image for each copy to be used for inspecting the inspection image formed on each of the multiple copies of paper by the image forming unit 330.

[0070] As described above, in this embodiment, the control unit 310 can control the generation of a reference image and the formation of an inspection image to be performed in parallel. When the number of copies to be printed is multiple, the control unit 310 can control the generation of a reference image and the formation of an image on paper to be performed in parallel for each copy. For example, the control unit 310 controls the generation of a reference image and the formation of an inspection image to be performed in parallel for the first copy of the multiple copies.

[0071] Further, a step of generating a reference image is defined as a reference image generating step, and a step including forming an inspection image on a sheet of paper and inspecting a read image generated by reading the sheet of paper on which the inspection image is formed is defined as an inspection step. The control unit 310 can control the reference image generating step and the inspection step to be performed in parallel for the n-th copy of the multiple copies. For example, the control unit 310 controls the reference image generating step and the inspection step to be performed in parallel for the first copy of the multiple copies.

[0072] Furthermore, the control unit 310 can control the generation of a reference image for the (n+1)th copy of the multiple copies to be performed in parallel with the inspection of the nth copy of paper. For example, the control unit 310 controls the generation of a reference image for the second copy of the multiple copies to be performed in parallel with the inspection of the first copy of paper.

[0073] Thus, in this embodiment, a reference image is generated based on the reception of the original image (starting from the reception of the original image), and an inspection image is formed on paper when preparations for printing are complete, and the inspection image is inspected. In this embodiment, the generation of the reference image and the formation and inspection of the inspection image are performed in parallel, so the time required for the process from the generation of the reference image to the image inspection can be shortened. As a result, the productivity of the series of steps up to the production of a printout without defects is improved. Also, by performing the process of generating a reference image for each page for multiple copies, the generation of a reference image is performed for each copy.

[0074] <Freeing page memory 1> In the inspection of the inspection image, the reference image that has been compared with the read image is no longer necessary. For example, at the timing when the control unit 310 receives the inspection result of the inspection image, the control unit 310 can release (make overwritable) the memory area of ​​the page memory 1 in which the reference image that has been compared with the read image is stored. A new reference image can be stored in the released memory area. This prevents the memory area of ​​the page memory 1 from being consumed in large quantities even when an original image with a large number of pages is expected.

[0075] <Print job> As described above, when the image forming system 300 receives a print job and the inspection setting in the job information is inspection on, it generates a reference image and forms an inspection image in parallel. The control unit 310 and the print controller unit 320 control the generation of a reference image by the reference image generating unit 380 and the formation of an inspection image by the image forming unit 330 to be performed in parallel by one (same) print job.

[0076] On the other hand, the image forming system 300 may realize the generation of the reference image and the formation and inspection of the inspection image by separate print jobs. The control unit 310 and the print controller unit 320 control the reference image generating process (reference image generating job) and the inspection process (inspection job) to be executed in parallel. Here, the reference image generating process includes the generation of the reference image by the reference image generating unit 380. The inspection process includes the formation of the inspection image on a sheet by the image forming unit 330, and the image inspection by the image inspection unit 350 of the read image generated by reading the sheet on which the inspection image is formed. For example, the reference image generating process can be executed by a CPU other than the image control CPU 311, and the inspection process can be executed by the image control CPU 311.

[0077] <Recovery Print> FIG. 8 is a schematic diagram showing, in chronological order, each process of obtaining an original image, generating a reference image, forming an inspection image, and inspecting the inspection image when recovery printing is performed.

[0078] The control unit 310 and the image forming unit 330 function as a recovery printing unit. When an abnormality is detected in the inspection image, the recovery printing unit executes reprinting (recovery printing) from the page of the document image corresponding to the page of the inspection image where the abnormality was detected. In this embodiment, the control unit 310 determines that an abnormality has been detected in the inspection image when the inspection image is defective as a result of inspection of the inspection image by the image inspection unit 350. The control unit 310 purges the paper on which the inspection image where the abnormality was detected has been formed to the outside of the image forming system 300 as waste paper.

[0079] Generally, the more complex the document image, the longer it takes for the reference image generating unit 380 to generate the reference image. For example, FIG. 7 illustrates an example in which the second page of the document image is complex and therefore the generation of the second page of the reference image takes time. The recovery printing unit executes recovery printing when the generation of the reference image is not completed before the inspection of the corresponding inspection image. For example, in the example shown in FIG. 7, the recovery printing unit waits for the completion of the generation of the reference image before performing recovery printing of the second page of the document image (the formation of the second page of the inspection image), since the generation of the second page of the reference image is not completed even after the formation of the second page of the inspection image. The control unit 310 purges the paper of the second page of the inspection image that has already been printed. This prevents the paper on which the uninspected inspection image is formed from being mixed with the paper on which the normal inspection image is formed.

[0080] Furthermore, during recovery printing, the image inspection unit 350 can perform image inspection using the reference image stored in the storage device 390. This eliminates the need for the reference image generation unit 380 to generate the reference image again, thereby saving the time required for generating the reference image.

[0081] Furthermore, when recovery printing is performed, the document image stored in the page memory 1 in step S102 of FIG. 4 can be configured to be stored in the storage device 390. By using the document image stored in the storage device 390, the processes of steps S101 and S102, as well as the processes of generating and storing a reference image (steps S103 and S104), become unnecessary. Therefore, the control unit 310 and the print controller unit 320 control the print job so that only the processes of forming and inspecting an inspection image are executed. This can shorten the time it takes from the start of a print job to the completion of inspection of the printed matter. As a result, the productivity of printed matter is improved.

[0082] The image inspection device, image inspection method, and image inspection program of the present embodiment described above can achieve the following effects.

[0083] A reference image used for inspecting the images formed on each of the multiple copies of paper is generated for each copy. Therefore, the memory area in the page memory that stores the reference image after the inspection of the inspection image is completed can be released. As a result, even if the number of pages of the document image is large, it is possible to prevent a large amount of memory area in the page memory from being consumed.

[0084] As described above, the image inspection device, the image inspection method, and the image inspection program have been described in the embodiments. However, it goes without saying that those skilled in the art can appropriately add, modify, and omit the present invention within the scope of the technical concept thereof.

[0085] The image inspection program may be provided by a computer-readable recording medium such as a USB memory, a flexible disk, or a CD-ROM, or may be provided online via a network such as the Internet. In this case, the program recorded in the computer-readable recording medium is usually transferred and stored in a memory or storage. In addition, the inspection program may be provided as a standalone application software, or may be incorporated into the software of each device as a function of the server.

[0086] Furthermore, in the embodiment, a part or all of the processing executed by the inspection program may be replaced with hardware such as a circuit. [Explanation of symbols]

[0087] 100 printing systems, 200 client terminals, 300 Image forming system, 310 control section, 311 Image control CPU, 312 DRAM control IC, 313 Memory, 314 Image memory (DRAM), 315 Compression / Expansion IC, 316 reading processing section, 317 write processing section, 318 Memory section, 320 Print controller section, 321 Controller control section, 322 Reference image generation control unit, 323 DRAM control IC, 324 image memory (DRAM), 325 Communication control section, 326 communication I / F, 330 Image forming unit, 331 Printer control unit, 332 Exposure section, 333 Image reading device, 340 Image reading unit, 341 Scanner, 342 Scanner control unit, 350 Imaging Inspection Department, 351 Image inspection control unit, 360 operation display section, 361 LCD / touch sensor, 362 Operation control section, 370 Paper feed section, 380 Reference image generating unit, 390 storage device, 400 communication lines.

Claims

1. a control unit that inspects images formed on each of a plurality of recording media based on the acquired image data; The control unit generates a reference image for each copy used to inspect the images formed on each of the multiple copies of recording media.

2. The image inspection device according to claim 1 , wherein the reference image is generated based on the acquired image data.

3. The image inspection device according to claim 1 , wherein the control unit controls the generation of the reference image and the formation of the image on the recording medium to be performed in parallel for a first copy of the plurality of copies.

4. The image inspection device described in claim 1 or 2, wherein the control unit controls a reference image generation process for generating the reference image and an inspection process including forming the image on the recording medium and inspecting the read image generated by reading the recording medium on which the image is formed, in parallel for a first part of the multiple parts.

5. 3. The image inspection device according to claim 1, wherein the control unit controls generation of a reference image for a second copy of the plurality of copies to be performed in parallel with inspection of a first copy of the recording medium.

6. 3 . The image inspection device according to claim 1 , wherein the control unit controls generation of a reference image for an (n+1)th copy of the plurality of copies in parallel with inspection of an nth copy of the recording medium.

7. An image inspection method for an image inspection device having a control unit that inspects images formed on a plurality of recording media based on acquired image data, comprising: An image inspection method including a step in which the control unit generates, for each copy, a reference image used for inspecting the images formed on each of the multiple copies of recording media.

8. An image inspection program for an image inspection device having a control unit that inspects images formed on a plurality of recording media based on acquired image data, An image inspection program for causing the control unit to execute a process including a procedure for generating, for each copy, a reference image used for inspecting the images formed on each of the multiple copies of recording media.

9. an image forming unit that forms an image on a recording medium based on the acquired image data; The image inspection device according to claim 1 or 2, An image forming system comprising:

Images