Image inspection apparatus, image inspection method, image inspection program, and image forming system

Abstract

This invention provides an image inspection device, an image inspection method, an image inspection program, and an image forming system that can further shorten the processing time from the generation of a reference image to image inspection compared to conventional technologies. [Solution] The image inspection device 300 has a control unit 310 that inspects images formed on each of multiple recording media based on acquired image data. The control unit 310 generates a reference image for each of the multiple recording media used for inspecting the images formed on each of the multiple recording media.

Description

Technical Field

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

Background Art

[0002] Conventionally, inspection of the quality of printed matter has been performed by comparing a pre-registered reference image with a read image obtained by reading the printed matter to be inspected. The reference image can be, for example, an image without abnormality in quality among the images obtained by reading the printed matter. Whether there is an abnormality in quality is determined, for example, by an inspector visually checking and judging the presence or absence of an abnormality. As an image forming apparatus having an image inspection unit for inspecting the quality of printed matter, for example, an image forming apparatus described in Patent Document 1 below is known.

[0003] However, as in the image forming apparatus of Patent Document 1, it takes time and effort for an inspector to visually check all pages of the printed matter in order to obtain a reference image. On the other hand, Patent Document 2 below discloses a printed matter inspection apparatus that inspects the quality of printed matter by comparing a manuscript image as a reference image with a read image.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The printed matter inspection apparatus of Patent Document 2 can save the time and effort of visually checking in creating a reference image by using a manuscript image as the reference image. However, there is a problem that a large amount of memory storage area is consumed when the number of pages of the manuscript image is large.

[0006] The present invention has been made in view of the above circumstances, and aims to provide an image inspection device, an image inspection method, an image inspection program, and an image forming system that can suppress the consumption of a large amount of memory storage space even when the number of pages of the original image is large. [Means for solving the problem]

[0007] The above objectives of the present invention are achieved by the following means.

[0008] (1) 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, wherein the control unit generates a reference image for use in inspecting the images formed on each of the plurality of recording media, for each unit that inspects the images, and performs the inspection of the images.

[0009] (2) The control unit has an image processing unit that inspects the images formed on each of the multiple recording media based on the acquired image data. The control unit generates a reference image for each of the multiple recording media used for inspecting the images formed on each of the media. The control unit performs, for the first of the plurality of parts, a reference image generation step of generating the reference image, and the formation of the image on the recording medium and reading the recording medium on which the image has been formed. An image inspection device that controls the inspection process, which includes the inspection of the read image generated by taking it, to be performed in parallel.

[0010] (3) 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, wherein the control unit generates a reference image for each of the plurality of recording media used for inspecting the images formed on each of the plurality of recording media, and the control unit controls the generation of the reference image for the second of the plurality of recording media to be performed in parallel with the inspection of the first recording media.

[0011] (4) 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, wherein the control unit generates a reference image for each of the plurality of recording media used for inspecting the images formed on each of the plurality of recording media, and the control unit controls the generation of the reference image for the (n+1)th of the plurality of recording media to be performed in parallel with the inspection of the nth recording media.

[0012] (5) The reference image is generated based on the acquired image data, using the image inspection apparatus described in any one of (1) to (4) above.

[0013] (6) The image inspection apparatus according to any one of (1) to (4) above, wherein the control unit controls the first of the plurality of parts to perform the generation of the reference image and the formation of the image on the recording medium in parallel.

[0014] (7) An image inspection method for an image inspection apparatus having a control unit that inspects images formed on each of a plurality of recording media based on acquired image data, the control unit comprising the steps of generating a reference image for use in inspecting the images formed on each of the plurality of recording media for each of the parts that inspect the images, and inspecting the images.

[0015] (8) An image inspection method for an image inspection apparatus having a control unit that inspects images formed on each of a plurality of recording media based on acquired image data, wherein the control unit includes a step of generating a reference image for each of the plurality of recording media used for inspecting the images formed on each of the plurality of recording media, and the control unit controls the first of the plurality of media to perform in parallel a reference image generation step of generating the reference image and an inspection step including the formation of the image on the recording media and the inspection of a read image generated by reading the recording media on which the image has been formed.

[0016] (9) An image inspection method for an image inspection apparatus having a control unit that inspects images formed on each of a plurality of recording media based on acquired image data, wherein the control unit includes the step of generating a reference image for each of the plurality of recording media to be used for inspecting the images formed on each of the plurality of recording media, and the control unit controls the generation of the reference image for the second of the plurality of recording media to be performed in parallel with the inspection of the first recording media.

[0017] (10) An image inspection method for an image inspection apparatus having a control unit that inspects images formed on each of a plurality of recording media based on acquired image data, wherein the control unit includes the step of generating a reference image for each of the plurality of recording media to be used for inspecting the images formed on each of the plurality of recording media, and the control unit controls the generation of the reference image of the (n+1)th of the plurality of parts to be performed in parallel with the inspection of the nth recording media.

[0018] (11) The reference image is generated based on the acquired image data using the image inspection method described in any one of (7) to (10) above.

[0019] (12) The image inspection method according to any one of (7) to (10) above, wherein the control unit controls the first of the plurality of parts to perform the generation of the reference image and the formation of the image on the recording medium in parallel.

[0020] (13) An image inspection program for an image inspection apparatus having a control unit that inspects images formed on each of a plurality of recording media based on acquired image data, the image inspection program causing the control unit to execute a process that includes generating a reference image for each of the units that inspect the images, and performing the inspection of the images.

[0021] An image inspection program for an image inspection apparatus having a control unit that inspects images formed on each of a plurality of recording media based on acquired image data, the program including a procedure for generating a reference image for use in inspecting the images formed on each of the plurality of recording media, wherein the control unit controls so as to perform in parallel, for a first one of the plurality of parts, a reference image generation step of generating the reference image and an inspection step including forming the image on the recording media and inspecting a read image generated by reading the recording media on which the image is formed.

[0022] (15) An image inspection program for an image inspection apparatus having a control unit that inspects images formed on each of a plurality of recording media based on acquired image data, the program including a procedure for generating a reference image for use in inspecting the images formed on each of the plurality of recording media. The image inspection program in which the control unit controls so as to perform the generation of the reference image for a second one of the plurality of parts in parallel with the inspection of the recording media for the first one of the plurality of parts.

[0023] (16) An image inspection program for an image inspection apparatus having a control unit that inspects images formed on each of a plurality of recording media based on acquired image data, the program including a procedure for generating a reference image for use in inspecting the images formed on each of the plurality of recording media. The image inspection program in which the control unit controls so as to perform the generation of the reference image for an (n + 1)-th one of the plurality of parts in parallel with the inspection of the recording media for an n-th one of the plurality of parts.

[0024] (17) The reference image is generated based on the acquired image data, and the image inspection program according to any one of (13) to (16) above.

[0025] (18) The image inspection program according to any one of (13) to (16) above, in which the control unit controls so as to perform the generation of the reference image and the formation of the image on the recording media in parallel for a first one of the plurality of parts.

[0026] (19) An image forming system comprising an image forming unit that forms an image on a recording medium based on acquired image data, and an image inspection device according to any one of (1) to (4) above. [Effects of the Invention]

[0027] According to the present invention, a reference image used for inspecting images formed on each of 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 has been completed can be freed up. As a result, even when the number of pages of the original image is large, the consumption of a large amount of memory area in the page memory can be suppressed. [Brief explanation of the drawing]

[0028] [Figure 1] This is a schematic block diagram of a printing system according to one embodiment of the present invention. [Figure 2] Figure 1 is a schematic block diagram illustrating the configuration of the image forming system shown. [Figure 3] Figure 2 is a block diagram illustrating the general control operation of the control unit and print controller unit shown in Figure 2. [Figure 4] Figure 1 is a flowchart illustrating the processing steps of an image inspection method using the image forming system shown. [Figure 5] Figure 4 shows a subroutine flowchart illustrating the details of the inspection of inspection images. [Figure 6] This schematic diagram shows the time-series process of acquiring the original image, generating the reference image, forming the inspection image, and inspecting the inspection image. [Figure 7] This is a schematic diagram showing the printing of multiple copies of an original document image in chronological order. [Figure 8] This schematic diagram shows the time-series process of acquiring the original image, generating a reference image, forming an inspection image, and inspecting the inspection image when a recovery print is performed. [Modes for carrying out the invention]

[0029] Embodiments of the present invention will be described below with reference to the attached drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant explanations are omitted. Also, the dimensional ratios in the drawings are exaggerated for illustrative purposes and may differ from the actual ratios.

[0030] <Printing System Configuration> Figure 1 is a schematic block diagram of a printing system according to the first embodiment of the present invention, and Figure 2 is a schematic block diagram illustrating the configuration of the image forming system shown in Figure 1.

[0031] As shown in Figure 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 that they can communicate with one another.

[0032] The client terminal 200 can be, for example, a personal computer, a tablet, or a smartphone. The client terminal 200 has a printer driver installed for converting document data into a print job. The printer driver generates a print job in a format compatible with the print controller unit 320 (see Figure 2) of the image forming system 300 and transmits the print job to the image forming system 300 via the communication line 400. The client terminal 200 also has a display that can show the inspection results of the printed materials (good / defective), images of defective printed materials, etc.

[0033] A print job includes, for example, print data in PDL (Page Description Language) format and job information. The print data includes, for example, print data consisting of pages 1 to m. The job information includes, for example, print settings such as the number of pages, number of copies, type of paper (recording medium), size, basis weight, single-sided / double-sided printing, and inspection settings (inspection on / off, inspection level). The user can instruct the image forming system 300 to perform image inspection by turning the inspection setting on.

[0034] Communication line 400 may include a LAN (Local Area Network) connecting computers and network devices according to a predetermined standard, or a WAN (Wide Area Network) connecting LANs with dedicated lines. The predetermined standard is, for example, Ethernet (registered trademark), FDDI (Fiber Distributed Data Interface), Wi-Fi (Wireless Fidelity), etc.

[0035] Note that the number of each of the above-mentioned components connected to the communication line 400 is not limited to the example shown in Figure 1.

[0036] <Configuration of the image forming system 300> As shown in Figures 1 and 2, the image forming system 300 includes 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 feeding unit 370, a reference image generation unit 380, and a storage device 390. The image forming system 300 functions as an image inspection device.

[0037] <Configuration of the 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.

[0038] The image control CPU 311 loads various programs stored in the memory unit 318 into the memory 313 and, in cooperation with the loaded programs, comprehensively controls the operation of the entire image forming system 300.

[0039] 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 to generate digital image (read image) data. The generated digital image data is then output to the compression / decompression IC 315 by the DRAM control IC 312. The compression / decompression IC 315 performs compression processing on the digital image data and decompression processing on the digital image data after compression processing based on the control of the DRAM control IC 312. The DRAM control IC 312 also controls the input / output of the image memory (DRAM) 314 for the compressed / decompressed digital image data.

[0040] The image memory 314 is composed of DRAM and includes compressed memory and page memory areas internally, for temporarily storing compressed image data, decompressed image data, etc.

[0041] The writing processing unit 317 outputs the decompressed digital image data to the exposure unit 332 of the image forming unit 330.

[0042] <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, performs processing such as color conversion, screening, and rasterization, and generates a bitmap-formatted original image. The generated original image is transmitted to the control unit 310. The print controller unit 320 functions as an original image acquisition unit.

[0043] The print controller unit 320 comprises 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 interface 326, and the like. The controller control unit 321 comprehensively controls the operation of each part of the print controller unit 320. The controller control unit 321 also receives print jobs from client terminals 200, etc., via the communication interface 326. The communication control unit 325 controls the communication interface 326.

[0044] A received print job includes print data (mainly in PDL format) that forms the basis of the original 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 page-level bitmap data based on the print settings. The RIP image after rasterization is temporarily stored in the image memory 324. The RIP image in the image memory 324 is temporarily stored in the compressed memory area of ​​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 the original image via the writing processing unit 317 for printing to be performed.

[0045] 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 original image at a predetermined generation timing. The predetermined generation timing may be, for example, when the inspection setting is set to inspection ON and the original image acquisition unit acquires the original image. The reference image generation unit 380 generates a reference image based on the reference image generation instruction.

[0046] Ideally, the scanned image generated by reading the inspection image formed on the paper should match the original image in terms of content. However, when scanning the inspection image formed on the paper, errors may occur in the scanned image compared to the original image due to various factors such as variations in the paper transport path, deviations in the scanning position, color reproduction, and differences in paper type. Errors may also occur depending on the resolution of the scanner. Therefore, simply comparing the scanned image with the original image is likely to result in errors, and it is not practical to inspect the inspection image by simply comparing the scanned image with the original image. In this embodiment, various processes are applied to the original image regarding position, resolution, color, etc., to generate a reference image that can be compared with the scanned image, and the system is configured to compare the reference image with the scanned image. This ensures that the comparison with the scanned image is performed appropriately, allowing for accurate inspection of printed materials. Details of the reference image generation process will be described later. In Figure 2, an example is shown where the reference image generation control unit 322 is located in the print controller unit 320, but the reference image generation control unit 322 may also be configured to be located in the control unit 310.

[0047] <Configuration of the image forming unit 330> The image forming unit 330 forms (prints) an image on paper (recording medium) using an electrophotographic method that includes the steps of charging, exposure, development, transfer, and fixing, in accordance with the instructions of the control unit 310. In this embodiment, the image forming unit 330 forms an inspection image on the paper according to the image forming conditions set based on the print settings, which is inspected by the image inspection unit 350. The image forming unit 330 includes a printer control unit 331 and an exposure unit 332, etc. The printer control unit 331 is connected to the image control CPU 311 by serial communication and accepts control from the image control CPU 311. The printer control unit 331 drives the LD (Laser Diode) of the exposure unit 332 by a signal from the writing processing unit 317 to form an electrostatic latent image corresponding to the original image on the photoreceptor (not shown). The toner image formed on the photoreceptor is developed through the development process and transferred onto the paper supplied from the paper feeding unit 370. The unfixed toner image on the paper is then fixed by heating and pressurizing. The paper on which the toner image has been fixed is transported to the image reading unit 340.

[0048] Furthermore, the image forming unit 330 is equipped with a print sheet output device that separates and outputs (purges) sheets on which an abnormal inspection image has been detected by the image inspection unit 350 (waste paper) from sheets on which a normal inspection image has been formed.

[0049] <Configuration of the image reading unit 340> The image reading unit 340 includes a scanner 341 and a scanner control unit 342. The scanner 341 reads the paper (printed material) being transported along the transport path, for example, using a CCD (Charge Coupled Device) image sensor. The scanner control unit 342 controls the scanner to read the inspection image formed on the paper transported from the image forming unit 330, according to the reading instructions from the control unit 310. The scanner control unit 342 outputs the read image, which is the inspection image formed on the paper, to the control unit 310.

[0050] <Configuration of the Image Inspection Unit 350> The image inspection unit 350 performs image inspection based on a reference image. More specifically, the image inspection unit 350 acquires a reference image and a read image, and inspects the inspection image formed on the paper by comparing the reference image and the read image page by page.

[0051] The image inspection unit 350 includes an image inspection control unit 351. The image inspection control unit 351 includes an image control CPU 311, or a CPU (not shown), RAM, ROM, and auxiliary storage device. The function of inspecting the inspection image is realized by the CPU executing an image inspection program. The image inspection control unit 351 calculates, for example, the difference (error) of pixel values ​​between a reference image and a read image for each page, and determines whether the inspection image is good or bad according to the size of the difference. The difference calculation can be performed for each page, each object, or each region. For example, when the difference is calculated for each page, if the total difference of pixels within a page is less than a specified value, an inspection result of "good" is output, and if the total difference is equal to or greater than the specified value, an inspection result of "bad" is output. Also, when the difference is calculated for each object or region, the system can be configured to output an inspection result of "good" or "bad" according to the total difference of pixel values ​​within the selected object or region.

[0052] The control unit 310 determines that the printed material is a good product if the inspection result of the inspection image is "good," and determines that the printed material is a defective product if the inspection result of the inspection image is "poor."

[0053] <Configuration of the operation display unit 360> The operation display unit 360 includes a touch panel display 361, an operation control unit 362, and hard keys such as a numeric keypad, start button, stop button, etc. The touch panel display includes, for example, a touch sensor and an LCD (Liquid Crystal Display) located behind the touch sensor. The operation control unit 362 receives 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 by the user (e.g., inspection on / off, inspection level in inspection settings) and instructions (e.g., instruction to start printing). The operation display unit 360 is also used for outputting (displaying) the status of the image forming system 300, the inspection results of printed materials (good / defective), images of defective printed materials, etc.

[0054] <Configuration of the paper feeding unit 370> The paper feeding unit 370 is equipped with at least one large-capacity paper tray and supplies paper to the image forming unit 330 one sheet at a time.

[0055] <Configuration of the reference image generation unit 380> The reference image generation unit 380 generates a reference image based on the original image acquired by the original image acquisition unit and outputs it to the control unit 310. The reference image generation unit 380 can be realized by a separate CPU (not shown) from the image control CPU 311 executing an image inspection program. This configuration allows for the parallel execution of reference image generation, inspection image formation, and inspection.

[0056] Conventionally, the generation of reference images and the formation and inspection of inspection images were performed by the same CPU. Therefore, the CPU performed the formation and inspection of inspection images only after the generation of reference images for each section was completed, making it impossible to perform the generation of reference images and the formation and inspection of inspection images in parallel. In this embodiment, the generation of reference images and the formation and inspection of inspection images may be performed by separate CPUs. With this configuration, the generation of reference images and the formation and inspection of inspection images can be performed in parallel.

[0057] Furthermore, the CPU processing load (processing time) for generating the reference image may increase or decrease depending on the complexity of the original image, whether or not variable data printing is performed, etc. For example, if the original image is complex, the CPU processing load for generating the reference image may increase significantly. By having a CPU other than the image control CPU 311 handle the generation of the reference image, the processing load on the image control CPU 311 can be reduced.

[0058] <Configuration of storage device 390> The storage device 390 stores the reference image generated by the reference image generation unit 380. When the control unit 310 reprints the original image, it uses the reference image stored in the storage device 390, eliminating the need to generate the reference image again. Therefore, the time required to generate the reference image can be saved.

[0059] <Overview of the control operation of the control unit 310 and the print controller unit 320> Figure 3 is a block diagram illustrating the general control operation of the control unit 310 and print controller unit 320 shown in Figure 2.

[0060] First, the control unit 310 receives the original image and job information from the original image acquisition unit (print controller unit 320) ((1) Image Input). The original image is a RIP image obtained by rasterizing the print data.

[0061] When the reference image generation unit 380 receives a reference image generation instruction from the reference image generation control unit 322 ((2)-1 Reference Image Generation Instruction), it generates a reference image based on the original image acquired by the original image acquisition unit and outputs it to the control unit 310. The control unit 310 stores the reference image in the page memory 1.

[0062] As described above, the reference image generation unit 380 generates a reference image by performing various processes on the original image regarding its position, resolution, color, etc. For example, the reference image generation unit 380 can extract positional information of the content portion from the original image and add or embed this positional information into the reference image so that the content portions of the reference image and the scanned image can be compared. In other words, the reference image generated by the reference image generation unit 380 has alignment information for aligning the reference image and the scanned image when performing image inspection based on the reference image. This alignment information includes image contour information and edge information. Furthermore, the reference image generated by the reference image generation unit 380 has area information regarding inspection areas and inspection exclusion areas used when performing image inspection based on the reference image. In addition, the reference image generation unit 380 can generate a reference image by adjusting the resolution of the original image to match the resolution of the scanner of the image reading unit 340. Furthermore, the reference image generation unit 380 can generate a reference image by converting the color space of the original image to match the color space (for example, RGB) used by the scanner of the image reading unit 340.

[0063] Furthermore, when the control unit 310 receives a document image from the document image acquisition unit, it instructs the image forming unit 330 to form an image and outputs the document image stored in 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 the paper based on the document 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.

[0064] When the reference image generation unit 380 has finished generating the reference image, it notifies the reference image generation control unit 322 that the reference image generation is complete ((3)-1 Reference image generation complete). Also, when the image forming unit 330 has finished forming the image on the paper, it notifies the control unit 310 that the output is complete ((3)-2 Output complete). The storage device 390 saves the generated reference image ((4)-1 Reference image save).

[0065] Furthermore, as soon as the control unit 310 receives notification of output completion, it 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 has been formed and outputs the read image of the paper to the control unit 310. The control unit 310 saves the read image in the page memory 2. When the image reading unit 340 has finished reading the paper, it notifies that the image reading is complete ((5)-2 Image Reading Complete).

[0066] 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 acquires a reference image and a read image from page memory 1 and page memory 2, respectively, and inspects the inspection image by comparing the reference image and the read image. The image inspection unit 350 then outputs the inspection result of the inspection image to the control unit 310 ((7)-2 Image Inspection Result).

[0067] The control unit 310, in response to user instructions, controls the display of the inspection results (good / defective) of the printed material based on the inspection results of the inspection image, on the display of the operation display unit 360 or the client terminal 200.

[0068] <Image examination method> Figure 4 is a flowchart illustrating the processing steps of the image inspection method using the image forming system 300 shown in Figure 1. Figure 5 is a subroutine flowchart illustrating the details of the inspection of the inspection image in the flowchart shown in Figure 4. The processes shown in Figures 4 and 5 are realized by the image control CPU 311 executing the image inspection program. Figure 6 is a schematic diagram showing the processes of acquiring the original image, generating the reference image, forming the inspection image, and inspecting the inspection image in chronological order. Figure 7 is a schematic diagram showing the printing of multiple copies of the original image in chronological order.

[0069] As shown in Figure 4, first, the control unit 310 acquires the original image (step S101). The original image consists of one or more parts, and each part may contain one or more pages. If the original image consists of multiple parts, the control unit 310 receives each part sequentially, from the original image acquisition unit, one page at a time, from the first page to the final m-th page, for each part, starting from the first part to the final N-th part. For example, Figure 6 illustrates a case where the original image consists of multiple parts and pages 1 to 8 of the n-th part are received sequentially. In Figure 6 and Figure 7, "1P" represents the first page (and so on for "2P," etc.). Furthermore, "print preparation" in the formation of the inspection image includes initial settings and preparations of each part in the image forming unit 330 according to the image forming conditions (for example, warming up the fixing unit).

[0070] Next, the control unit 310 saves the original image (step S102). When a print job is started, the control unit 310 saves the original image acquired from the original image acquisition unit to the page memory 1 one page at a time.

[0071] Next, the reference image generation control unit 322 controls the generation of reference images used for inspecting the inspection images. The reference image generation unit 380 generates reference images according to the instructions of the reference image generation control unit 322 (step S103). For example, if the first page of the original image has been acquired and stored in page memory 1, the reference image generation control unit 322 controls the reference image generation unit 380 to generate a reference image based on the first page of the original image. The reference image generation unit 380 generates a reference image based on the first page of the original image. A reference image is similarly generated for the second page of the original image.

[0072] Next, the storage device 390 stores the reference image generated by the reference image generation unit 380 (step S104). For example, the storage device 390 stores the first and second pages of the original image. Also, as shown in Figure 6, in parallel with the processing in steps S103 and S104, the control unit 310 controls the image forming unit 330 to form an inspection image on the paper based on the original image and job information received from the original image acquisition unit. For example, the control unit 310 prepares for printing and controls the image forming unit 330 to form an inspection image on the paper for the first page of the original image. The image forming unit 330 forms an inspection image on the paper for the first page of the original image according to the instructions of the control unit 310 (step S105). After the inspection image for the first page of the original image is formed, an inspection image is similarly formed on the paper for the second page of the original image.

[0073] Next, the image inspection unit 350 determines whether a reference image has been generated for each page of the acquired original 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 has not been generated for the original image (page 1) that will be the basis for the inspection image inspected in step S107, the unit waits until a reference image for this original image (page 1) is generated.

[0074] As shown in Figure 6, the generation of a reference image by the reference image generation unit 380 and the formation of an inspection image by the image forming unit 330, as well as the inspection of the inspection image, are performed in parallel. As a result, the image forming system 300 can further reduce the time required for processing from the generation of a reference image to image inspection compared to conventional technology.

[0075] [Generating reference images and forming inspection images on paper in parallel] For example, in the example shown in the figure, the generation of reference images for page 1 (1P) and page 2 (2P) and the preparation for printing are performed in parallel, and the generation of the reference image for page 3 (3P) and the formation of the first half of the inspection image for page 1 (1P) are performed in parallel. Then, the generation of the reference image for page 4 (4P) and the formation of the second half of the inspection image for page 1 (1P) are performed simultaneously. Note that although the figure shows the generation of the reference image for page 3 (3P) and the formation of the inspection image for page 1 (1P) starting simultaneously, this is not the only option. The formation of the inspection image for page 1 (1P) can start at an appropriate time after the preparation for printing is complete, and the generation of the reference image for page 3 (3P) can start at an appropriate time after the generation of the reference image for page 2 (2P). The timing for starting the generation of reference images and inspection images is the same for subsequent pages.

[0076] [Generating reference images, forming inspection images on paper, and inspecting the inspection images in parallel] Subsequently, the generation of the reference image on page 5 (5P), the formation of the examination image on page 2 (2P), and the examination of the examination image on page 1 are performed simultaneously.

[0077] As shown in Figure 5, in the process of inspecting the inspection image, the inspection image formed on the paper is read by the image reading unit 340 (step S201), and the inspection image is inspected by comparing the reference image with the read image by the image inspection unit 350 (step S202).

[0078] The control unit 310 repeats the process in steps S101 to S107 for all pages (from the first page to the final m-th page) until the inspection of the inspection images is completed (step S108).

[0079] Furthermore, the control unit 310 repeats printing until the number of copies set in the job information is reached (step S109). As shown in Figure 7, in this embodiment, the reference image generation unit 380 generates a reference image N times until printing is complete, for example, if the set number of copies is N. That is, the reference image generation unit 380 generates a reference image for each copy by performing a process to generate a reference image for each page, thereby generating a reference image for each copy used to inspect the inspection images formed on each of the multiple copies of paper by the image forming unit 330.

[0080] As described above, in this embodiment, the control unit 310 can be controlled to generate a reference image and form an inspection image in parallel. When there are multiple copies to print, the control unit 310 can be controlled to generate a reference image and form an image on paper in parallel for each copy. For example, the control unit 310 can be controlled to generate a reference image and form an inspection image in parallel for the first of the multiple copies.

[0081] Furthermore, the process of generating a reference image is called the reference image generation process, and the process including the formation of an inspection image on paper and the inspection of the generated read image by reading the paper on which the inspection image has been formed is called the inspection process. The control unit 310 can control the nth of the multiple parts to perform the reference image generation process and the inspection process in parallel. For example, the control unit 310 controls the first of the multiple parts to perform the reference image generation process and the inspection process in parallel.

[0082] Furthermore, the control unit 310 can control the generation of the (n+1)th reference image among the multiple parts to be performed in parallel with the inspection of the nth part of the paper. For example, the control unit 310 can control the generation of the second reference image among the multiple parts to be performed in parallel with the inspection of the first part of the paper.

[0083] In this embodiment, based on the reception of the original image (starting from the reception of the original image), a reference image is generated, and when the paper is ready for printing, an inspection image is formed and the inspection image is inspected. In this embodiment, since the generation of the reference image and the formation and inspection of the inspection image are performed in parallel, the time required for processing from the generation of the reference image to image inspection can be shortened. As a result, productivity in the series of processes until a flawless printed material is produced is improved. Furthermore, by performing the process of generating a reference image for each page for multiple copies, the generation of the reference image is performed for each copy.

[0084] <Release of page memory 1> In the inspection of inspection images, the reference image is no longer needed once the comparison with the scanned image has been completed. The control unit 310 can, for example, release (overwrite) the memory area of ​​page memory 1 where the reference image that has been compared with the scanned image is stored when it receives the inspection result of the inspection image. A new reference image can be stored in the released memory area. This suppresses the consumption of a large amount of memory area in page memory 1, even when a document image with a large number of pages is expected.

[0085] <Print Job> As described above, the image forming system 300 receives a print job, and if the inspection setting in the job information is set to inspection ON, it performs the generation of a reference image and the formation of an inspection image in parallel. The control unit 310 and the print controller unit 320 control the system so that the generation of a reference image by the reference image generation unit 380 and the formation of an inspection image by the image forming unit 330 are performed in parallel for one (identical) print job.

[0086] On the other hand, the image forming system 300 may perform the generation of a reference image, the formation of an inspection image, and the inspection as separate print jobs. The control unit 310 and the print controller unit 320 control the reference image generation process (reference image generation job) and the inspection process (inspection job) to be executed in parallel. Here, the reference image generation process includes the generation of a reference image by the reference image generation unit 380. The inspection process includes the formation of an inspection image on paper by the image forming unit 330 and the image inspection by the image inspection unit 350 of the read image generated by reading the paper on which the inspection image has been formed. For example, the reference image generation process may be executed by a CPU other than the image control CPU 311, and the inspection process may be executed by the image control CPU 311.

[0087] <Recovery Printing> Figure 8 is a schematic diagram illustrating the time-series process of acquiring the original image, generating a reference image, forming an inspection image, and inspecting the inspection image when recovery printing is performed.

[0088] 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 performs reprinting (recovery printing) from the page of the original 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 if the inspection image is found to be defective as a result of inspection by the image inspection unit 350. The control unit 310 purges the paper on which the inspection image with the detected abnormality was formed as waste paper to the outside of the image forming system 300.

[0089] Furthermore, generally speaking, the more complex the original image, the longer it takes for the reference image generation unit 380 to generate the reference image. For example, Figure 7 illustrates that the second page of the original image is complex, and therefore it takes time to generate the second page of the reference image. The recovery printing unit performs recovery printing if the generation of the reference image is not completed by the time of inspection of the corresponding inspection image. For example, in the example shown in Figure 7, the recovery printing unit waits for the generation of the reference image to be completed before performing recovery printing of the second page of the original image (formation of the second page of the inspection image) because the generation of the second page of the reference image has not been 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 with the uninspected inspection image from being mixed with the paper with the normal inspection image.

[0090] Furthermore, the image inspection unit 350 can perform image inspection using the reference image stored in the storage device 390 during recovery printing. This eliminates the need for the reference image generation unit 380 to generate the reference image again, thus saving time required for generating the reference image.

[0091] Furthermore, when performing a recovery print, the system can be configured to save the original image stored in page memory 1 in step S102 of Figure 4 to storage device 390. By using the original image stored in storage device 390, the processes of steps S101 and S102 become unnecessary, in addition to the processes of generating and saving the reference image (steps S103 and S104). Therefore, the control unit 310 and the print controller unit 320 control the print job to execute only the processes of forming and inspecting the inspection image. This reduces the time required from the start of the print job to the completion of inspection of the printed material. As a result, the productivity of printed materials is improved.

[0092] The image inspection apparatus, image inspection method, and image inspection program of this embodiment described above can achieve the following effects.

[0093] A reference image is generated for each of the multiple copies of the paper used to inspect the images formed on each copy. Therefore, the memory area in the page memory that stores the reference image after the inspection of the inspected images has been completed can be freed up. As a result, even when the number of pages in the original image is large, the consumption of a large amount of memory area in the page memory can be suppressed.

[0094] As described above, the image inspection apparatus, image inspection method, and image inspection program have been explained in the embodiments. However, it goes without saying that the present invention can be appropriately added to, modified, and omitted by those skilled in the art within the scope of its technical concept.

[0095] The image inspection program may be provided on a computer-readable recording medium such as a USB memory stick, flexible disk, or CD-ROM, or it may be provided online via a network such as the Internet. In this case, the program recorded on the computer-readable recording medium is usually transferred to memory or storage and stored therein. Furthermore, this inspection program may be provided, for example, as a standalone application software, or it may be incorporated into the software of each device as a function of a server.

[0096] Furthermore, in the embodiment, some or all of the processing performed by the inspection program may be replaced and executed by hardware such as circuits. [Explanation of symbols]

[0097] 100 printing systems, 200 client terminals, 300 image forming systems, 310 Control unit, 311 Image control CPU, 312 DRAM control IC, 313 memory, 314 Image memory (DRAM), 315 Compression / Decompression IC, 316 Reading processing unit, 317 Writing processing unit, 318 Memory section, 320 Print Controller Section, 321 Controller control unit, 322 Reference image generation control unit, 323 DRAM control IC, 324 Image memory (DRAM), 325 Communication control unit, 326 Communication I / F, 330 Image forming unit, 331 Printer control unit, 332 Exposure section, 333 Image reading device, 340 Image reading unit, 341 Scanners, 342 Scanner control unit, 350 Image Inspection Department, 351 Image inspection control unit, 360 operation display section, 361 LCD / touch sensor, 362 Operation control unit, 370 Paper feed section, 380 Reference image generation unit, 390 storage device, 400 communication lines.

Claims

1. It has a control unit that inspects the images formed on each of multiple recording media based on the acquired image data, The control unit generates a reference image for each unit that performs the image inspection, and performs the image inspection, wherein the control unit generates a reference image for use in inspecting images formed on each of the plurality of recording media, and the image inspection is performed.

2. It has a control unit that inspects the images formed on each of multiple recording media based on the acquired image data, The control unit generates a reference image for each of the multiple recording media used for inspecting the images formed on each of the media. The control unit controls the first of the plurality of parts to perform in parallel a reference image generation step of generating the reference image and an inspection step including forming the image on the recording medium and inspecting the read image generated by reading the recording medium on which the image has been formed.

3. It has a control unit that inspects the images formed on each of multiple recording media based on the acquired image data, The control unit generates a reference image for each of the multiple recording media used for inspecting the images formed on each of the media. The control unit controls the generation of the second reference image among the plurality of parts to be performed in parallel with the inspection of the first recording medium, in an image inspection device.

4. It has a control unit that inspects the images formed on each of multiple recording media based on the acquired image data, The control unit generates a reference image for each of the multiple recording media used for inspecting the images formed on each of the media. The control unit controls the generation of the (n+1)th reference image among the plurality of parts in parallel with the inspection of the nth part recording medium, in an image inspection device.

5. The image inspection apparatus according to any one of claims 1 to 4, wherein the reference image is generated based on the acquired image data.

6. The image inspection apparatus according to any one of claims 1 to 4, wherein the control unit controls the first of the plurality of parts to perform the generation of the reference image and the formation of the image on the recording medium in parallel.

7. An image inspection method for an image inspection apparatus having a control unit that inspects images formed on each of multiple recording media based on acquired image data, An image inspection method comprising the steps of: the control unit generating a reference image for use in inspecting images formed on each of the plurality of recording media, for each unit that performs the image inspection; and performing the image inspection.

8. An image inspection method for an image inspection apparatus having a control unit that inspects images formed on each of multiple recording media based on acquired image data, The control unit includes the step of generating a reference image for each of the plurality of recording media used for inspecting the images formed on each of the media, Image inspection method, wherein the control unit controls the first of the plurality of parts to perform in parallel a reference image generation step of generating the reference image and an inspection step including forming the image on the recording medium and inspecting the read image generated by reading the recording medium on which the image has been formed.

9. An image inspection method for an image inspection apparatus having a control unit that inspects images formed on each of multiple recording media based on acquired image data, The control unit includes the step of generating a reference image for each of the plurality of recording media used for inspecting the images formed on each of the media, An image inspection method comprising the control unit controlling the generation of the second reference image among the plurality of parts in parallel with the inspection of the first recording medium.

10. An image inspection method for an image inspection apparatus having a control unit that inspects images formed on each of multiple recording media based on acquired image data, The control unit includes the step of generating a reference image for each of the plurality of recording media used for inspecting the images formed on each of the media, An image inspection method comprising: the control unit controlling the generation of the (n+1)th reference image among the plurality of parts in parallel with the inspection of the nth part recording medium.

11. The image inspection method according to any one of claims 7 to 10, wherein the reference image is generated based on the acquired image data.

12. The image inspection method according to any one of claims 7 to 10, wherein the control unit controls the first of the plurality of parts to perform the generation of the reference image and the formation of the image on the recording medium in parallel.

13. An image inspection program for an image inspection device having a control unit that inspects images formed on each of multiple recording media based on acquired image data, An image inspection program that causes the control unit to execute a process including the procedure for performing the image inspection, which involves generating a reference image for use in inspecting images formed on each of the multiple recording media, for each unit that performs the image inspection.

14. An image inspection program for an image inspection device having a control unit that inspects images formed on each of multiple recording media based on acquired image data, The procedure includes generating a reference image for each of the multiple recording media used for inspecting the images formed on each of the aforementioned media, The control unit controls the first of the plurality of units to perform in parallel a reference image generation step of generating the reference image and an inspection step including forming the image on the recording medium and inspecting the read image generated by reading the recording medium on which the image has been formed.

15. An image inspection program for an image inspection device having a control unit that inspects images formed on each of multiple recording media based on acquired image data, The procedure includes generating a reference image for each of the multiple recording media used for inspecting the images formed on each of the aforementioned media, The control unit is an image inspection program that controls the generation of the second reference image among the plurality of parts to be performed in parallel with the inspection of the first recording medium.

16. An image inspection program for an image inspection device having a control unit that inspects images formed on each of multiple recording media based on acquired image data, The procedure includes generating a reference image for each of the multiple recording media used for inspecting the images formed on each of the aforementioned media, The control unit is an image inspection program that controls the generation of the (n+1)th reference image among the plurality of parts in parallel with the inspection of the nth part recording medium.

17. The image inspection program according to any one of claims 13 to 16 generates the reference image based on the acquired image data.

18. The image inspection program according to any one of claims 13 to 16, wherein the control unit controls the first of the plurality of parts to perform the generation of the reference image and the formation of the image on the recording medium in parallel.

19. An image forming unit that forms an image on a recording medium based on acquired image data, An image inspection apparatus according to any one of claims 1 to 4, An image forming system having the following features.

Images