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

Abstract

To efficiently inspect images.SOLUTION: An image inspection apparatus comprises: an acquisition unit 51 which acquires image data to be subjected to image formation; a reading unit which reads an image of image data formed on a recording medium and outputs read data; and an inspection unit 53 which is operable in a first mode in which first inspection data is generated on the basis of the image data and the read data output by the reading unit is compared with the first inspection data and in a second mode in which the read data output by the reading unit upon reading a first image is stored in a storage device as second inspection data, and the read data output by the reading unit upon reading a second image is compared with the second inspection data. The inspection unit 53 switches between the first mode and the second mode on the basis of a remaining storage capacity of the storage device.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an image inspection device, an image inspection method, and an image inspection program, and more particularly to an image inspection device that inspects an image formed on a recording medium, an image inspection method executed by the image inspection device, and an image inspection program that causes a computer to execute the image inspection method. [Background technology]

[0002] There is known an apparatus for inspecting an image formed on a recording medium such as paper by an image forming apparatus such as an MFP (Multifunction Peripheral). In the image forming apparatus, it is preferable that the image formed on the recording medium does not have defects. For this reason, there is known an inspection method in which a reference image is prepared in advance, and an image formed on the recording medium is compared with the reference image to detect an image with defects. For example, Japanese Patent Application Laid-Open No. 2015-53561 describes an inspection device that includes a reading unit that reads a printed material and generates an inspection image, an acquisition unit that acquires the original image from which the printed material is generated, a multi-value conversion unit that converts the original image into multi-values, a first smoothing unit that performs a first smoothing on the multi-value original image, a detection unit that performs edge detection on the original image that has been subjected to the first smoothing using an edge threshold based on the number of printing lines of the printed material, a second smoothing unit 219 that performs a second smoothing on non-edge areas of the multi-value original image that correspond to areas that have not been detected as edges in the edge detection, an image processing unit that performs image processing on the original image that has been subjected to the second smoothing to generate a master image, and an inspection unit that compares the inspection image with the master image to inspect the quality of the printed material.

[0003] In this inspection device, one master image is stored in the storage device each time a print job is executed. Therefore, when multiple print jobs are executed that use different image data for image formation, the same number of master images as the number of print jobs are stored in the storage device. Because the storage device has a finite storage capacity, if the remaining storage capacity becomes low, newly generated master images cannot be stored. In this case, the user must manually select and delete master images that are unlikely to be used in the future, which reduces work efficiency. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-53561 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made to solve the above-mentioned problems, and one of the objects of the present invention is to provide an image inspection apparatus capable of inspecting an image efficiently.

[0006] Another object of the present invention is to provide an image inspection method that can efficiently inspect an image.

[0007] A further object of the present invention is to provide an image inspection program that can efficiently inspect an image. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, according to one aspect of the present invention, an image inspection device includes an acquisition unit that acquires image data to be used for image formation, a reading unit that reads an image of the image data formed on a recording medium and outputs the read data, and an inspection unit that is operable in a first mode in which first inspection data is generated based on the image data and the read data output by the reading unit is compared with the first inspection data, and a second mode in which the read data output by the reading unit after reading the first image is stored in a storage device as second inspection data and the read data output by the reading unit after reading the second image is compared with the second inspection data, and the inspection unit switches between the first mode and the second mode based on the remaining memory capacity of the storage device.

[0009] According to another aspect of the present invention, an image inspection method is an image inspection method executed by an image inspection device, and includes: an acquisition step of acquiring image data to be used for image formation; a reading step of reading an image of the image data formed on a recording medium and outputting the read data; and an inspection step operable in a first mode of generating first inspection data based on the image data and comparing the read data output in the reading step with the first inspection data; and a second mode of reading the first image in the reading step and storing the output read data as second inspection data in a storage device and comparing the output read data of the second image in the reading step with the second inspection data, wherein the inspection step includes switching between the first mode and the second mode based on the remaining memory capacity of the storage device.

[0010] According to another aspect of the present invention, an image inspection program is an image inspection program executed by a computer that controls an image inspection device, and causes the computer to execute an acquisition step of acquiring image data to be used for image formation, a reading step of reading an image of the image data formed on a recording medium and outputting the read data, and an inspection step that can operate in a first mode of generating first inspection data based on the image data and comparing the read data output in the reading step with the first inspection data, and a second mode of reading the first image in the reading step and storing the output read data as second inspection data in a storage device, and comparing the output read data of the second image in the reading step with the second inspection data, wherein the inspection step includes switching between the first mode and the second mode based on the remaining memory capacity of the storage device. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a front view showing the appearance of an image forming system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view schematically illustrating the internal configuration of the MFP. [Figure 3] FIG. 1 is a block diagram illustrating an example of an outline of a hardware configuration of an image inspection device. [Figure 4] FIG. 2 is a block diagram showing an example of functions of a CPU included in the image inspection device. [Figure 5] FIG. 3 is a block diagram showing an example of detailed functions of a first inspection unit. [Figure 6] FIG. 4 is a block diagram showing an example of detailed functions of a second inspection unit. [Figure 7] 10 is a flowchart showing an example of the flow of an image inspection process. [Figure 8] 10 is a flowchart showing an example of the flow of a first inspection process. [Figure 9] 10 is a flowchart showing an example of the flow of a second inspection process. [Figure 10] FIG. 10 is a block diagram showing an example of functions of a CPU included in an image inspection device according to a modified example. [Figure 11] 10 is a flowchart showing an example of the flow of image inspection processing in a modified example. [Figure 12] 10 is a flowchart showing an example of the flow of an inspection mode determination process. [Figure 13] 10 is a flowchart showing an example of the flow of a third inspection process. DETAILED DESCRIPTION OF THE INVENTION

[0012] An image forming system according to an embodiment of the present invention will now be described with reference to the accompanying drawings. In the following description, identical components are designated by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

[0013] FIG. 1 is a front view showing the appearance of an image forming system according to an embodiment of the present invention. Referring to FIG. 1, the image forming system 1 includes a multifunction peripheral (MFP) 100, an image inspection device 200, and a post-processing device 300. The MFP 100 functions as an image forming device and forms an image on a recording medium based on image data. The MFP 100 can form images on any of a variety of recording media. Recording media include paper, overhead projector (OHP) sheets, fabric, and the like. In the following description, unless otherwise specified, the recording medium will be paper. The MFP 100 also includes an operation panel 160. The operation panel 160 includes a display unit that displays images and an input unit that accepts user operations. The display unit is, for example, a liquid crystal display (LCD) or an organic electroluminescence (EL) display. The input unit is, for example, a keyboard and a pointing device such as a touch panel.

[0014] The image inspection device 200 receives paper on which an image has been formed from the MFP 100 and detects noise from the image formed on the paper. The noise includes areas where dust or dirt has adhered, and areas caused by defects during image formation. The image inspection device 200 is equipped with a first scanner 206 and a second scanner 207, which are photoelectric conversion elements. The first scanner 206 and the second scanner 207 are arranged on either side of the transport path for the paper supplied from the MFP 100. Therefore, the image inspection device 200 can simultaneously read the images formed on the front and back of the paper supplied from the MFP 100.

[0015] The post-processing device 300 receives paper sheets from the image inspection device 200. The post-processing device 300 has multiple paper output trays and a sorting function that sorts multiple paper sheets and outputs them to one of the multiple paper output trays. Furthermore, the post-processing device 300 outputs paper sheets for which noise has been detected in the image formed on the paper sheets by the image inspection device 200 to a different paper output tray from paper sheets for which no noise has been detected. Specifically, when an error signal is input from the image inspection device 200, the post-processing device 300 outputs the paper sheets corresponding to the error signal to a predetermined paper output tray. The post-processing device 300 may also include a punching mechanism and a stapling mechanism. The punching mechanism is a mechanism that punches holes in a bundle of multiple paper sheets. The stapling mechanism is a mechanism that drives staples into a bundle of multiple paper sheets.

[0016] Fig. 2 is a cross-sectional view showing a schematic internal configuration of an MFP. Referring to Fig. 2, MFP 100 is an example of an image forming apparatus. MFP 100 includes a document reading unit 130 that reads a document, an automatic document feeder 120 that transports the document to document reading unit 130, an image forming unit 140 that forms an image on paper based on image data, and a paper feed unit 150 that supplies paper to image forming unit 140.

[0017] Original reading unit 130 exposes the image of an original placed on original glass 11 by automatic original feeder 120 with exposure lamp 13 attached to slider 12 that moves below it. Reflected light from the original is guided to lens 16 by mirror 14 and two reflecting mirrors 15 and 15A, and forms an image on CCD (Charge Coupled Devices) sensor 18.

[0018] The reflected light that forms an image on the CCD sensor 18 is converted into image data as an electrical signal within the CCD sensor 18. The image data is converted into printing data in cyan (C), magenta (M), yellow (Y), and black (K) and output to the image forming unit 140.

[0019] The image forming section 140 has developing units 20Y, 20M, 20C, and 20K and toner bottles 41Y, 41M, 41C, and 41K corresponding to yellow, magenta, cyan, and black, respectively, where "Y", "M", "C", and "K" represent yellow, magenta, cyan, and black, respectively.

[0020] The developing units 20Y, 20M, 20C, and 20K and the toner bottles 41Y, 41M, 41C, and 41K differ only in the color of the toner they handle, so here, the developing unit 20Y and the toner bottle 41Y for forming a yellow image will be described.

[0021] The toner bottle 41Y contains yellow toner. The toner bottle 41Y rotates using a toner bottle motor as a drive source and discharges toner to the outside. The toner discharged from the toner bottle 41Y is supplied to the developing unit 20Y. The toner bottle 41Y supplies developer to the developing unit 20Y when the remaining amount of toner contained in the developing unit 20Y falls below a predetermined lower limit.

[0022] The intermediate transfer belt 30 is suspended tightly by a drive roller 33 and a driven roller 34. When the drive roller 33 rotates counterclockwise in FIG. 2, the intermediate transfer belt 30 rotates counterclockwise in the drawing at a predetermined speed. As the intermediate transfer belt 30 rotates, the driven roller 34 rotates counterclockwise.

[0023] The developing unit 20Y contains developer. The developer contains non-magnetic toner and magnetic carrier. The developing unit 20Y receives toner from a toner bottle 41Y and agitates the toner and carrier. The developing unit 20Y forms a toner image using the toner contained in the developer and transfers the toner image to the intermediate transfer belt 30. The timing at which the developing unit 20Y transfers the toner image onto the intermediate transfer belt 30 is adjusted by detecting a reference mark on the intermediate transfer belt 30.

[0024] When forming a full-color image, the MFP 100 drives all of the developing units 20Y, 20M, 20C, and 20K. As a result, yellow, magenta, cyan, and black toner images are superimposed on the intermediate transfer belt 30. When forming a monochrome image, the MFP 100 drives any one of the developing units 20Y, 20M, 20C, and 20K. It is also possible to form an image using a combination of two or more of the developing units 20Y, 20M, 20C, and 20K.

[0025] Paper of different sizes is set in paper feed cassettes 35, 35A, and 35B, respectively. The paper stored in paper feed cassettes 35, 35A, and 35B is supplied to the transport path by take-out rollers 36, 36A, and 36B attached to paper feed cassettes 35, 35A, and 35B, respectively, and sent to timing roller 31 by paper feed roller 37.

[0026] Timing roller 31 transports the paper transported by paper feed roller 37 to the nip between intermediate transfer belt 30 and secondary transfer roller 26, which is a transfer member. Secondary transfer roller 26 generates an electric field in the nip. The toner image formed on intermediate transfer belt 30 is transferred to the paper transported by timing roller 31 by the action of the electric field force in this nip. The paper with the transferred toner image is transported to fixing roller 32, where it is heated and pressurized. This melts the toner and fixes it to the paper. The paper is then transported to image inspection device 200 by paper discharge roller 38.

[0027] The MFP 100 has a reversing unit 45. The reversing unit 45 has a reversing path 48 and a reversing roller 47. The paper sheet, on whose front surface the toner has been fixed by the fixing roller 32, is transported by the paper discharge roller 38. The paper discharge roller 38 transports the paper sheet partway and then reverses its rotation direction. As a result, the paper sheet enters the reversing path 48. The paper sheet that has entered the reversing path 48 is transported by the reversing roller 47. The reversing roller 47 transports the paper sheet partway and then reverses its rotation direction. As a result, the paper sheet, with its traveling direction reversed, travels along the reversing path 48 and is transported to the timing roller 31. The timing roller 31 transports the paper sheet supplied from the reversing unit 45 to the nip between the intermediate transfer belt 30 and the secondary transfer roller 26. The paper sheet, on whose back surface the toner image has been transferred at the nip, is transported to the fixing roller 32 and then transported to the image inspection device 200 by the paper discharge roller 38. In this way, the MFP 100 forms images on both sides of the paper sheet.

[0028] Here, an example will be described in which MFP 100 employs a tandem system equipped with developing units 20Y, 20M, 20C, and 20K that form four color toners on paper. However, MFP 100 may employ a four-cycle system in which four color toners are transferred sequentially onto paper using a single photosensitive drum.

[0029] In this way, MFP 100 forms an image on paper based on image data output by document reading unit 130 after reading a document, or based on image data received from an external source.

[0030] FIG. 3 is a block diagram showing an example of an outline of the hardware configuration of an image inspection device. Referring to FIG. 3, the image inspection device 200 includes a central processing unit (CPU) 201, a read-only memory (ROM) 202, a random access memory (RAM) 203, a solid-state drive (SSD) 204, a communication unit 205, a first scanner 206, a second scanner 207, and a serial interface 208. The CPU 201 controls the entire image inspection device 200. The ROM 202 stores programs to be executed by the CPU 201. The RAM 203 is a volatile storage device and is used as a work area for the CPU 201. The SSD 204 is a storage device that stores data in a non-volatile manner. The communication unit 205 communicably connects the CPU 201 to the MFP 100 and the post-processing device 300.

[0031] The serial interface 208 is an interface for serial communication with an external device. In this case, the serial communication is based on the USB (Universal Serial Bus) standard. An external device capable of communication based on the USB standard can be connected to the serial interface 208. The CPU 201 can access the external device via the serial interface 208. The external device includes a storage device such as a CD drive 211 or a USB memory. In this example, the external device is the CD drive 211. A CD-ROM 212 can be attached to the CD drive. The CPU 201 loads a program recorded on the CD-ROM 212 attached to the CD drive 211 into the RAM 203 and executes it.

[0032] Each of the first scanner 206 and the second scanner 207 is a photoelectric conversion element that converts received light into read data as an electrical signal and outputs the read data. In this embodiment, the first scanner 206 and the second scanner 207 are CCDs (Charge Coupled Devices). Note that the photoelectric conversion element is not limited to a CCD, and other elements such as a CMOS sensor may be used. The first scanner 206 optically reads a first image formed on the front side of a sheet of paper supplied from the MFP 100, and outputs the read data, which is electronic data, to the CPU 201. The second scanner 207 optically reads a second image formed on the back side of a sheet of paper supplied from the MFP 100, and outputs the read data, which is electronic data, to the CPU 201.

[0033] The medium for storing the program executed by CPU 201 is not limited to CD-ROM 212, but may be a semiconductor memory such as an optical disk, an optical card, a mask ROM, or an EPROM. Optical disks include CD-ROMs (Compact Disk ROMs), MOs (Magnetic Optical Discs), MDs (Mini Discs), and DVDs (Digital Versatile Discs). When a semiconductor memory is used as the medium for storing the program executed by CPU 201, the external device may be, for example, a USB memory. The USB memory includes a semiconductor memory such as an EPROM and a serial communication circuit. CPU 201 loads the program recorded on CD-ROM 212 into RAM 203 and executes it. The program here includes not only a program directly executable by CPU 201, but also a source program, a compressed program, an encrypted program, and the like.

[0034] Furthermore, the image inspection device 200 may be connected to the Internet via the communication unit 205 or the serial interface 208. In this case, the CPU 201 can download a program from a computer connected to the Internet and store it in the SSD 204. Furthermore, a program may be written to the SSD 204 by a computer connected to the Internet. The CPU 201 loads the program stored in the SSD 204 into the RAM 203 and executes it.

[0035] Fig. 4 is a block diagram showing an example of functions of a CPU included in the image inspection device. The functions shown in Fig. 4 are realized by CPU 201 included in image inspection device 200 as CPU 201 executes an image inspection program stored in ROM 202, SSD 204, or CD-ROM 212. Referring to Fig. 4, CPU 201 includes an acquisition unit 51, an inspection unit 53, a reading unit 55, a memory capacity acquisition unit 57, and an inspection information storage unit 59.

[0036] Acquisition unit 51 controls communication unit 205 to acquire a print job. The print job includes image data to be used for image formation and printing conditions. Acquisition unit 51 outputs the image data included in the print job to inspection unit 53. The print job is generated by MFP 100. When a user operates MFP 100, the user inputs printing conditions into MFP 100 and scans an original, causing MFP 100 to generate a print job. Acquisition unit 51 communicates with MFP 100 and acquires the print job from MFP 100 in response to MFP 100 generating the print job. The print job is also input to MFP 100 from an external device. When a user operates a personal computer (PC) to specify image data and set printing conditions, the PC generates the print job. The PC transmits the print job to MFP 100. Acquisition unit 51 communicates with MFP 100 and acquires the print job from MFP 100 in response to MFP 100 receiving the print job from the PC.

[0037] The reading unit 55 controls the communication unit 205 to detect that the MFP 100 has formed an image on a sheet of paper. The MFP 100 forms an image on a sheet of paper by executing a print job. The sheet of paper on which the image has been formed by the MFP 100 is transported to the image inspection device 200. The reading unit 55 controls the first scanner 206 and the second scanner 207 to cause the first scanner 206 to read the image formed on the front side of the sheet of paper and the second scanner 207 to read the image formed on the back side of the sheet of paper. The reading unit 55 acquires the read data output by the first scanner 206 and the read data output by the second scanner 207. The reading unit 55 outputs the read data to the inspection unit 53.

[0038] When MFP 100 executes a print job, MFP 100 forms images of image data included in the print job on multiple sheets of paper in sequence. The multiple sheets of paper on which the images have been formed are transported to image inspection device 200 in the order in which the images were formed. Therefore, reading unit 55 outputs multiple pieces of read data corresponding to the multiple sheets of paper to inspection unit 53 in the same order as the arrangement of the multiple sheets of paper.

[0039] The storage capacity acquiring unit 57 acquires the remaining storage capacity of the SSD 204. The remaining storage capacity is the amount of data that can be additionally stored in the SSD 204. The storage capacity acquiring unit 57 outputs the remaining storage capacity to the inspection unit 53.

[0040] The inspection unit 53 includes a first inspection unit 65, a second inspection unit 67, and a switching unit 69. The switching unit 69 receives the remaining memory capacity as an input from the memory capacity acquisition unit 57. The switching unit 69 switches the inspection mode between a first mode and a second mode based on the remaining memory capacity. The first mode is an inspection mode in which the first inspection unit 65 is operated but the second inspection unit 67 is not operated. The second mode is an inspection mode in which the first inspection unit 65 is not operated but the second inspection unit 67 is operated.

[0041] Switching unit 69 determines the inspection mode before a print job is executed by MFP 100. If the remaining storage capacity is equal to or less than first threshold value TH1, switching unit 69 determines the inspection mode to be the first mode, and if the remaining storage capacity is greater than first threshold value TH1, switching unit 69 determines the inspection mode to be the second mode. First threshold value TH1 is a predetermined value that is set by an administrator of image forming system 1 and stored in SSD 204. When switching unit 69 determines the inspection mode to be the first mode, it outputs an instruction to first inspection unit 65 to operate and an instruction to second inspection unit 67 to stop. When switching unit 69 determines the inspection mode to be the second mode, it outputs an instruction to first inspection unit 65 to stop and an instruction to second inspection unit 67 to operate.

[0042] The first inspection unit 65, the details of which will be described later, generates first inspection data and uses the first inspection data to inspect the read data input from the reading unit 55. The first inspection unit 65 generates inspection information indicating the inspection results and outputs it to the inspection information storage unit 59.

[0043] The second inspection unit 67, whose details will be described later, stores the second inspection data in SSD 204 and inspects the read data input from the reading unit 55 using the second inspection data. The second inspection unit 67 generates inspection information indicating the inspection results and outputs it to the inspection information storage unit 59.

[0044] The inspection information storage unit 59 stores the inspection information input from either the first inspection unit 65 or the second inspection unit 67 in the SSD 204. In response to the inspection information input from either the first inspection unit 65 or the second inspection unit 67, the inspection information storage unit 59 adds and stores the inspection information in the SSD 204. Since the inspection information is generated each time the read data is inspected, multiple pieces of inspection information are stored in the SSD 204 when the execution of the print job by the MFP 100 is completed. The inspection information storage unit 59 generates an inspection report after the execution of the print job by the MFP 100 is completed. The inspection report includes information that tally the multiple pieces of inspection information. When the inspection report is generated, the inspection information storage unit 59 deletes the multiple pieces of inspection information from the SSD 204.

[0045] FIG. 5 is a block diagram showing an example of detailed functions of the first inspection unit 65. Referring to FIG. 5, the first inspection unit 65 includes a first inspection data generation unit 71, a first comparison unit 73, and an erasure unit 75. The first inspection data generation unit 71 receives image data included in a print job from the acquisition unit 51. In response to the image data received from the acquisition unit 51, the first inspection data generation unit 71 generates first inspection data based on the image data. For example, the first inspection data generation unit 71 performs edge enhancement processing to enhance edges, smoothing processing to reduce changes in pixel values ​​of the image data, and the like, on the image data, and generates the data as the first inspection data. The first inspection data generation unit 71 stores the first inspection data in RAM 203.

[0046] The first comparison unit 73 receives read data from the reading unit 55. The read data is electronic data obtained by the first scanner 206 and the second scanner 207 scanning a sheet of paper on which an image of image data is formed. After receiving an instruction to operate from the switching unit 69, the first comparison unit 73 compares the read data with the first inspection data stored in the RAM 203. The first inspection data generation unit 71 generates inspection information indicating the comparison result and outputs the inspection information to the inspection information storage unit 59. The first comparison unit 73, for example, calculates the difference between the first inspection data and the read data. If the difference is equal to or less than a predetermined threshold, the first comparison unit 73 determines that the read data meets the inspection standard. However, if the difference is greater than the predetermined threshold, the first comparison unit 73 determines that the read data does not meet the inspection standard. The first comparison unit 73 controls the communication unit 205 to output the inspection results to the post-processing device 300 and the MFP 100. When the post-processing device 300 receives an inspection result that is determined not to satisfy the inspection criteria, it outputs the paper to a predetermined paper output tray for error output.When the MFP 100 receives an inspection result that is determined not to satisfy the inspection criteria, it either forms the target image again or stops execution of the print job.

[0047] When MFP100 forms images on multiple sheets of paper, multiple pieces of scanned data corresponding to the multiple sheets of paper are input from reading unit 55 to first comparing unit 73 in the same order as the arrangement of the multiple sheets of paper. First comparing unit 73 compares each of the multiple pieces of scanned data with the first inspection data in the order input from reading unit 55. First comparing unit 73 outputs multiple pieces of inspection information corresponding to the multiple sheets of paper to inspection information storage unit 59. The inspection information includes error information. For example, the error information includes information identifying the page on which the error occurred, the portion of the scanned data where the difference is equal to or greater than a predetermined threshold, the difference value, etc. Furthermore, when MFP100 is notified of the inspection information, it displays an error message on the display unit of operation panel 160. The error message may include the error information.

[0048] Erasing unit 75 deletes the first inspection data stored in RAM 203. The timing for deleting the first inspection data is after execution of the print job by MFP 100 is completed and after read data is no longer input to first comparing unit 73.

[0049] FIG. 6 is a block diagram showing an example of detailed functions of the second inspection unit. Referring to FIG. 6, second inspection unit 67 includes second inspection data storage unit 77 and second comparison unit 79. Read data is input to second inspection unit 67 from reading unit 55. Here, when MFP 100 executes a print job, the image formed on the first sheet of paper is referred to as the first image, and images formed on the second and subsequent sheets of paper are referred to as the second image. After an instruction to operate is input from switching unit 69, second inspection data storage unit 77 receives read data from reading unit 55, which reads and outputs the first image, and stores the read data in SSD 204 as second inspection data.

[0050] In response to input of the read data output by the reading unit 55 after reading the second image, the second comparison unit 79 compares the read data with the second inspection data stored in the SSD 204. The second comparison unit 79 generates inspection information indicating the comparison result and outputs the inspection information to the inspection information storage unit 59. The second comparison unit 79, for example, calculates the difference between the second inspection data and the read data. The second inspection unit 67 determines that the read data meets the inspection standard if the difference is equal to or less than a predetermined threshold, but determines that the read data does not meet the inspection standard if the difference is greater than the predetermined threshold. The second comparison unit 79 controls the communication unit 205 to output the inspection result to the post-processing device 300 and the MFP 100. If the post-processing device 300 receives an inspection result that indicates the print data does not meet the inspection standard, the post-processing device 300 ejects the paper to a paper output tray predetermined for error output. If the MFP 100 receives an inspection result that indicates the print data does not meet the inspection standard, the MFP 100 either re-forms the target image or stops execution of the print job.

[0051] When MFP 100 forms images on multiple sheets of paper, multiple pieces of read data corresponding to the multiple sheets of paper are input from reading unit 55 to second inspection data storage unit 77 or second comparison unit 79 in the same order as the arrangement of the multiple sheets of paper. Second inspection data storage unit 77 regards the read data output by reading unit 55 after reading a first image as second inspection data. Thereafter, second comparison unit 79 compares each of the multiple pieces of read data output by reading unit 55 after reading multiple second images with the second inspection data in the order input from reading unit 55. Second comparison unit 79 outputs multiple pieces of inspection information corresponding to the multiple sheets of paper on which the multiple second images are formed, to inspection information storage unit 59.

[0052] 7 is a flowchart showing an example of the flow of image inspection processing. The image inspection processing is performed by CPU 201 included in image inspection device 200 as CPU 201 executes an image inspection program stored in ROM 202, SSD 204, or CD-ROM 212.

[0053] 7, CPU 201 included in image inspection device 200 acquires image data (step S01) and proceeds to step S02. CPU 201 communicates with MFP 100, and acquires image data included in the print job from MFP 100 in response to MFP 100 generating or externally receiving a print job. The image data is data that MFP 100 uses to form an image.

[0054] In step S02, the remaining storage capacity is acquired, and the process proceeds to step S03. CPU 201 controls SSD 204 to acquire the remaining storage capacity. The remaining storage capacity is the amount of data that can be additionally stored in SSD 204. In step S03, the remaining storage capacity is compared with a first threshold value TH1. If the remaining storage capacity is equal to or greater than the first threshold value TH1, CPU 201 proceeds to step S04, and if the remaining storage capacity is less than the first threshold value TH1, the process proceeds to step S06.

[0055] In step S04, the inspection mode is set to the first mode, and the process proceeds to step S04. In step S04, a first inspection process is executed, and the process proceeds to step S08. The first inspection process, which will be described in detail later, is a process for inspecting an image formed on paper by MFP 100, and inspection information indicating the inspection result is stored in SSD 204.

[0056] In step S06, the inspection mode is set to the second mode, and the process proceeds to step S07. In step S07, a second inspection process is executed, and the process proceeds to step S08. The second inspection process, which will be described in detail later, is a process for inspecting an image formed on paper by MFP 100, and inspection information indicating the inspection result is stored in SSD 204.

[0057] In step S08, an inspection report is generated, and the process proceeds to step S09. In step S05, a first inspection process is executed, and inspection information is stored in SSD 204. In step S07, a second inspection process is executed, and inspection information is stored in SSD 204. In step S08, CPU 201 generates an inspection report by aggregating the inspection information. In the next step S09, the inspection information stored in SSD 204 is erased, and the process ends.

[0058] FIG. 8 is a flowchart showing an example of the flow of the first inspection process. The first inspection process is a process executed in step S05 of the image inspection process. With reference to FIG. 8, CPU 201 generates first inspection data (step S11) and proceeds to step S12. CPU 201 generates the first inspection data by performing image processing on image data acquired from MFP 100. The image processing is, for example, edge enhancement processing or smoothing processing. The image processing may also include color conversion processing for converting colors. CPU 201 stores the first inspection data in RAM 203.

[0059] In step S12, the image is read. When the MFP 100 executes a print job, a sheet of paper on which an image of the image data is formed is transported to the image inspection device 200. The CPU 201 controls the first scanner 206 and the second scanner 207 to read the image formed on the sheet of paper. The CPU 201 acquires the read data output by the first scanner 206 and the second scanner 207.

[0060] In step S13, the CPU 201 compares the read data with the first inspection data stored in the RAM 203, and proceeds to step S14. For example, the CPU 201 calculates the difference between the read data and the first inspection data and compares the difference with a threshold value. If the difference is equal to or greater than the threshold value, it is determined to be an error, and if the difference is less than the threshold value, it is determined to be normal.

[0061] In step S14, CPU 201 generates inspection information indicating the results of the comparison, stores it in SSD 204, and proceeds to step S15. In step S15, it is determined whether the next sheet of paper exists. CPU 201 communicates with MFP 100 and determines whether the next sheet of paper exists based on whether execution of the print job has ended. If execution of the print job by MFP 100 has not ended, the process returns to step S12, but if execution of the print job by MFP 100 has ended, the process proceeds to step S16. In step S16, the first inspection data stored in RAM 203 is erased, and the process returns to image inspection processing.

[0062] FIG. 9 is a flowchart showing an example of the flow of the second inspection process. The second inspection process is a process executed in step S07 of the image inspection process. Referring to FIG. 9, CPU 201 reads an image. When MFP 100 executes a print job, sheets of paper on which an image of image data is formed are continuously transported to image inspection device 200. CPU 201 controls first scanner 206 and second scanner 207 to read the first image formed on the first sheet of paper. CPU 201 acquires the read data output by first scanner 206 and second scanner 207.

[0063] In step S22, the CPU 201 stores the second inspection data in the SSD 204, and the process proceeds to step S23. The read data acquired in step S21 is stored in the SSD 204 as the second inspection data.

[0064] In step S23, the image is read, and the process proceeds to step S24. When the MFP 100 executes a print job, sheets of paper on which images of image data are formed are successively transported to the image inspection device 200. The CPU 201 controls the first scanner 206 and the second scanner 207 to read the second images formed on the second and subsequent sheets of paper. The CPU 201 acquires the read data output by the first scanner 206 and the second scanner 207.

[0065] In step S24, CPU 201 compares the read data with the second inspection data stored in SSD 204, and proceeds to step S25. For example, CPU 201 calculates the difference between the read data and the second inspection data and compares the difference with a threshold. CPU 201 determines an error if the difference is equal to or greater than the threshold, and determines a normal state if the difference is less than the threshold.

[0066] In step S25, CPU 201 generates inspection information indicating the results of the comparison, stores it in SSD 204, and proceeds to step S26. In step S26, it is determined whether the next sheet of paper exists. CPU 201 communicates with MFP 100 and determines whether the next sheet of paper exists based on whether execution of the print job has ended. If execution of the print job by MFP 100 has not ended, the process returns to step S23, but if execution of the print job by MFP 100 has ended, the process proceeds to step S26.

[0067] In step S26, CPU 201 determines whether the next sheet of paper exists. CPU 201 communicates with MFP 100 and determines whether the next sheet of paper exists based on whether execution of the print job has ended. If execution of the print job by MFP 100 has not ended, the process returns to step S23, but if execution of the print job by MFP 100 has ended, the process returns to image inspection processing.

[0068] <Modification> In the above-described embodiment, when the inspection mode is switched to the second mode, the second inspection data and inspection information are stored in SSD 204. The inspection information is erased after the inspection report is generated, but is stored in SSD 204 until the inspection report is generated. Therefore, when generating the inspection report and switching the inspection mode to the second mode, SSD 204 needs to have a remaining memory capacity for storing the second inspection data and inspection information. In a modified example, image inspection device 200 predicts the remaining memory capacity for storing the second inspection data and inspection information in SSD 204 and determines the inspection mode.

[0069] Fig. 10 is a block diagram showing an example of functions of a CPU included in an image inspection device according to a modified example. The functions shown in Fig. 10 are realized by CPU 201 included in image inspection device 200 when CPU 201 executes an image inspection program stored in ROM 202, SSD 204, or CD-ROM 212. Referring to Fig. 10, the functions differ from those shown in Fig. 4 in that a prediction unit 61 and a saving unit 63 are added, and that inspection information storage unit 59 is changed to inspection information storage unit 59A. The other functions are the same as those shown in Fig. 4. Therefore, description thereof will not be repeated here.

[0070] The prediction unit 61 receives a print job from the acquisition unit 51. The prediction unit 61 predicts the data volume of the test information based on the print job. The print job includes image data. The prediction unit 61 predicts the data volume of the scanned data from the image data. The print job also includes printing conditions. The printing conditions include the number of sheets of paper (number of pages) on which images are formed. The prediction unit 61 determines the number of pieces of test information from the number of sheets of paper. The prediction unit 61 predicts the data volume of the multiple pieces of test information to be stored in the SSD 204 based on the data volume of the test information per piece and the number of pieces of test information. The data volume of the test information may differ between when the test result is normal and when there is an error. The prediction unit 61 predicts the number of pieces of test information whose test result corresponds to normal and the number of pieces of test information whose test result corresponds to an error based on a predetermined error occurrence rate. The prediction unit 61 predicts the data volume of the multiple pieces of test information to be stored in the SSD 204 based on the number and data volume of the test information whose test result corresponds to normal and the number and data volume of the test information whose test result corresponds to an error. The prediction unit 61 outputs the predicted data amount of the examination information to the switching unit 69, the saving unit 63, and the examination information storage unit 59A.

[0071] The saving unit 63 calculates a predicted remaining storage capacity, which is the amount of data that can be further stored when inspection information is stored in the SSD 204. If the predicted remaining storage capacity is equal to or less than a second threshold value TH2, the saving unit 63 saves at least a portion of the data already stored in the SSD 204 from the SSD 204. The second threshold value TH2 is a predetermined value set by an administrator of the image forming system 1 and stored in the SSD 204. Specifically, the saving unit 63 erases at least a portion of the data stored in the SSD 204 from the SSD 204 or moves it to another storage device. The other storage device is a device external to the image inspection device 200, and may be, for example, a device that can communicate with the image inspection device 200. The other storage device is, for example, a storage device connected to the Internet. The SSD 204 may store multiple pieces of second inspection data. The SSD 204 erases or moves at least a portion of the multiple pieces of inspection data to another storage device.

[0072] The switching unit 69 receives the remaining storage capacity from the storage capacity acquisition unit 57 and the data amount of the inspection information from the prediction unit 61. When at least a portion of the second inspection data stored in the SSD 204 is erased or moved to another storage device by the saving unit 63, the remaining storage capacity acquired by the storage capacity acquisition unit 57 is output to the switching unit 69.

[0073] The switching unit 69 calculates a predicted remaining storage capacity, which is the amount of data that can be additionally stored when the inspection information is stored in the SSD 204. The switching unit 69 determines the inspection mode based on the predicted remaining storage capacity. If the predicted remaining storage capacity is equal to or smaller than a first threshold value TH1, the switching unit 69 determines the inspection mode to be the first mode, and if the predicted remaining storage capacity is greater than the first threshold value TH1, the switching unit 69 determines the inspection mode to be the second mode.

[0074] When the switching unit 69 determines the inspection mode to be the first mode, the inspection information storage unit 59A determines whether to generate an inspection report. When the predicted remaining memory capacity is equal to or less than a third threshold value TH3, the inspection information storage unit 59A determines not to generate an inspection report. The third threshold value TH3 is a predetermined value that is set by an administrator of the image forming system 1 and stored in SSD 204. In this case, the inspection information storage unit 59A does not store the inspection information input from the first inspection unit 65 or the second inspection unit 67 in SSD 204. When the predicted remaining memory capacity is greater than the third threshold value TH3, the inspection information storage unit 59A determines to generate an inspection report. In this case, the inspection information storage unit 59A stores the inspection information input from the first inspection unit 65 or the second inspection unit 67 in SSD 204, and determines whether to generate an inspection report after MFP 100 finishes executing the print job.

[0075] 11 is a flowchart showing an example of the flow of image inspection processing in the modified example. The image inspection processing in the modified example is processing performed by CPU 201 provided in image inspection device 200 as CPU 201 executes an image inspection program in the modified example stored in ROM 202, SSD 204, or CD-ROM 212.

[0076] 11, CPU 201 included in image inspection device 200 acquires image data (step S31) and proceeds to step S02. CPU 201 communicates with MFP 100, and acquires image data included in the print job from MFP 100 in response to MFP 100 generating or externally receiving a print job. The image data is data that MFP 100 uses to form an image.

[0077] In step S32, the remaining storage capacity is acquired, and the process proceeds to step S23. The CPU 201 controls the SSD 204 to acquire the remaining storage capacity. The remaining storage capacity is the amount of data that can be additionally stored in the SSD 204. In step S23, an inspection mode determination process is executed, and the process proceeds to step S34. The inspection mode determination process will be described in detail later, but it is a process of setting an inspection mode and a report flag. The report flag is set to ON if an inspection report is to be generated, and is set to OFF if an inspection report is not to be generated.

[0078] In step S34, the process branches depending on the inspection mode determined by the inspection mode determination process. If the inspection mode is the first mode, the process proceeds to step S35. In step S35, a third inspection process is executed, and the process proceeds to step S36. Details of the third inspection process will be described later. In step S34, if the inspection mode is the second mode, the process proceeds to step S37. In step S37, a second inspection process is executed, and the process proceeds to step S38.

[0079] In step S36, it is determined whether the report flag is ON. If the report flag is set to ON, the process proceeds to step S38; if not, the image inspection process ends. If the process proceeds to step S38, the third inspection process is executed, and the inspection information is stored in SSD 204.

[0080] In step S38, an inspection report is generated, and the process proceeds to step S39. CPU 201 generates the inspection report by aggregating the inspection information stored in SSD 204. In the next step S39, the inspection information stored in SSD 204 is erased, and the process ends.

[0081] 12 is a flowchart showing an example of the flow of the inspection mode determination process. The inspection mode determination process is a process executed in step S33 of the image inspection process in the modified example. Referring to FIG. 12, CPU 201 predicts the amount of inspection information (step S41) and proceeds to step S42. Based on the print job acquired from MFP 100, CPU 201 predicts the data amount of inspection information that will be generated by image inspection device 200 while the print job is being executed in MFP 100.

[0082] In step S42, it is determined whether the predicted remaining storage capacity is equal to or less than a second threshold value TH2. The predicted remaining storage capacity is a value obtained by subtracting the amount of test information from the remaining storage capacity, which is the amount of data that can be added and stored in SSD 204. If the predicted remaining storage capacity is equal to or less than the second threshold value TH2, the process proceeds to step S43; otherwise, the process proceeds to step S45.

[0083] In step S43, the CPU 201 erases or saves to another storage device at least a portion of the data already stored in the SSD 204, and proceeds to step S44. In step S44, the remaining storage capacity is acquired, and the process proceeds to step S45.

[0084] In step S45, the remaining memory capacity is compared with a first threshold value TH1. If the remaining memory capacity is equal to or less than the first threshold value TH1, the process proceeds to step S46; otherwise, the process proceeds to step S50. In step S50, the report flag is set to ON, and the process proceeds to step S51. In step S51, the inspection mode is set to the second mode, and the process returns to the image inspection process.

[0085] In step S46, the predicted remaining memory capacity is compared with a third threshold value TH3. When step S43 is executed, the predicted remaining memory capacity is a value obtained by subtracting the amount of examination information predicted in step S41 from the remaining memory capacity acquired in step S44. If the predicted remaining memory capacity is equal to or less than the third threshold value TH3, the process proceeds to step S47; otherwise, the process proceeds to step S48. In step S47, the report flag is set to OFF, and the process proceeds to step S49. In step S48, the report flag is set to ON, and the process proceeds to step S49. In step S49, the examination mode is set to the first mode, and the process returns to the image examination process.

[0086] Fig. 13 is a flowchart showing an example of the flow of the third inspection process. The third inspection process is a process executed in step S35 of the image inspection process in the modified example. Referring to Fig. 13, what differs from the first inspection process shown in Fig. 8 is that step S13A is added between step S13 and step S14. The other processes are the same as the processes shown in Fig. 8, and therefore description thereof will not be repeated here.

[0087] In step S13A, it is determined whether the report flag is set to ON. If the report flag is set to ON, the process proceeds to step S14; otherwise, the process skips step S14 and proceeds to step S15. If the report flag is set to ON, the examination information is stored in the SSD 204; if the report flag is set to OFF, the examination information is not stored in the SSD 204.

[0088] <Second Modification> The image forming system 1 may be instructed to execute multiple print jobs. In this case, the image forming system 1 determines the order in which to execute each of the multiple print jobs, and executes the multiple print jobs in the determined order. For example, the order in which the image forming system 1 is instructed to execute the print jobs determines the execution order.

[0089] When the first print job in the execution order is executed by the MFP 100, the image inspection device 200 may determine that the remaining storage space of the SSD 204 will be insufficient if the inspection mode is set to the first mode or the second mode. In this case, the image inspection device 200 identifies print jobs that are second or later in the order and that will not cause the remaining storage space of the SSD 204 to be insufficient if the inspection mode is set to the first mode or the second mode. The image inspection device 200 determines to execute the identified print job before the first print job. The image inspection device 200 outputs an instruction to the MFP 100 to execute the identified print job. This increases the number of print jobs for which inspection reports are generated.

[0090] As described above, the image inspection device 200 in this embodiment switches the inspection mode between the first mode and the second mode based on the remaining storage capacity of the SSD 204, which is a non-volatile storage device. When the image inspection device 200 operates in the second mode, the second inspection data is stored in the SSD 204. Therefore, if the storage capacity of the SSD 204 is low, the image inspection device 200 may not be able to operate in the second mode. When the storage capacity of the SSD 204 is high, the image inspection device 200 operates in the second mode. When the storage capacity of the SSD 204 is low, the image inspection device 200 operates in the first mode. When the image inspection device 200 operates in the first mode, the first inspection data is not stored in the SSD 204. Therefore, even if the storage capacity of the SSD 204 is low, the image inspection device 200 can operate in the first mode. This makes it possible to provide an image inspection device that can efficiently inspect images.

[0091] Furthermore, image inspection device 200 erases the first inspection data from RAM 203 after completing operation in the first inspection mode, and does not erase the second inspection data from SSD 204 after completing operation in the second inspection mode. When image inspection device 200 operates in the second inspection mode, the second inspection data remains stored in SSD 204, making it possible to reuse the second inspection data the next time the same image data is inspected.

[0092] Furthermore, image inspection device 200 predicts the data volume of inspection information before an image is formed by MFP 100, and switches the inspection mode to either the first mode or the second mode based on the predicted data volume of the inspection information. This allows inspection information to be saved reliably.

[0093] Furthermore, even if the image inspection device 200 operates in the first inspection mode, if the remaining storage capacity of the SSD 204 is insufficient, the image inspection device 200 does not store the inspection information in the SSD 204. Therefore, an image can be formed without stopping the inspection of the image.

[0094] Furthermore, when the image inspection device 200 operates in the first or second inspection mode, if the remaining storage capacity of the SSD 204 becomes insufficient, at least a portion of the existing data stored in the SSD 204 is deleted or moved to another storage device, so that an image can be formed without interrupting the inspection of the image.

[0095] Furthermore, if the earliest print job is executed and the remaining storage capacity of the SSD 204 is insufficient when the image inspection device 200 operates in the first or second inspection mode, the image inspection device 200 executes the second or subsequent print jobs. This allows the number of print jobs for which inspection reports are generated to be increased.

[0096] <Summary of implementation form> (Item 1) An acquisition unit that acquires image data that is the subject of image formation; a reading unit that reads an image of the image data formed on a recording medium and outputs the read data; an inspection unit operable in a first mode in which first inspection data is generated based on the image data and the read data output by the reading unit is compared with the first inspection data, and a second mode in which the read data output by the reading unit after reading a first image is stored in a storage device as second inspection data and the read data output by the reading unit after reading a second image is compared with the second inspection data; The inspection unit switches between the first mode and the second mode based on the remaining memory capacity of the storage device.

[0097] According to this aspect, the operation of the inspection unit is switched between a first mode and a second mode based on the remaining memory capacity of the storage device. When the inspection unit operates in the first mode, first inspection data is generated based on image data, and the read data output by the reading unit is compared with the first inspection data. When the inspection unit operates in the second mode, the read data output by the reading unit after reading the first image is stored in the storage device as second inspection data, and the read data output by the reading unit after reading the second image is compared with the second inspection data. When the inspection unit operates in the second mode, the second inspection data is stored in the storage device. Therefore, if the storage capacity of the storage device is low, the inspection unit may not be able to operate in the second mode. On the other hand, when the inspection unit operates in the first mode, the first inspection data is not stored in the storage device. Therefore, even if the storage capacity of the storage device is low, the inspection unit can operate in the first mode. This makes it possible to provide an image inspection device that can efficiently inspect images.

[0098] (Item 2) The image inspection device described in Item 1, wherein the inspection unit discards the first inspection data after completing operation in the first mode, and does not erase the second inspection data from the storage device after completing operation in the second mode.

[0099] According to this aspect, when the inspection unit operates in the second mode, the second inspection data is stored in the storage device, so that it can be reused the next time the same image data is inspected.

[0100] (Item 3) An inspection information storage unit that generates inspection information indicating a comparison result by the inspection unit and stores the inspection information in the storage device; a prediction unit that predicts a data amount of the inspection information before the inspection unit starts an operation, Item 2. The image inspection device according to item 1, wherein the inspection unit further switches between the first mode and the second mode based on the predicted data amount of the inspection information.

[0101] According to this aspect, the data amount of the test information is predicted before the operation of the test unit is started, and the mode is switched to either the first mode or the second mode based on the predicted data amount of the test information, thereby making it possible to reliably store the test information.

[0102] (Item 4) The image inspection device described in Item 3, wherein the inspection information storage unit does not store the inspection information in the storage device if the remaining memory capacity of the storage device is insufficient even when the inspection unit operates in the first mode.

[0103] According to this aspect, the inspection information is not stored, so the inspection unit can operate in the first mode or the second mode. Therefore, the inspection of the image is not stopped, so the image can be inspected efficiently.

[0104] (Item 5) An image inspection device as described in Item 3 or 4, further comprising a backup unit that deletes or moves to a storage device other than the storage device at least a portion of the existing data stored in the storage device if the remaining storage capacity of the storage device is insufficient when the inspection unit operates in the first mode or the second mode.

[0105] According to this aspect, when the inspection unit operates in the first mode or the second mode, if the remaining storage capacity of the storage device is insufficient, at least a portion of the existing data stored in the storage device is deleted or moved to a storage device other than the storage device. As a result, the inspection of the image is not stopped, and the image can be inspected efficiently.

[0106] (Item 6) An image inspection device as described in any one of Items 1 to 5, further comprising a target change unit that processes second image data that is later in order than the first image data if the storage device has insufficient remaining storage space when operating in the first mode or the second mode on the first image data that is earliest in order when the acquisition unit acquires multiple pieces of image data.

[0107] According to this aspect, if the remaining storage capacity of the storage device is insufficient when the inspection unit operates in the first mode or the second mode for the first image data, which is the earliest image data, the second image data, which is later in order than the first image data, is processed. Therefore, the inspection of the image is not stopped, and the image can be inspected efficiently.

[0108] (Item 7) An image inspection method performed by an image inspection device, an acquisition step of acquiring image data to be used for image formation; a reading step of reading an image of the image data formed on a recording medium and outputting the read data; an inspection step operable in a first mode in which first inspection data is generated based on the image data and the read data output in the reading step is compared with the first inspection data, and a second mode in which the read data output from the first image read in the reading step is stored in a storage device as second inspection data and the read data output from the second image read in the reading step is compared with the second inspection data, An image inspection method, wherein the inspecting step includes switching to either the first mode or the second mode based on the remaining memory capacity of a storage device.

[0109] According to this aspect, it is possible to provide an image inspection method that can efficiently inspect an image.

[0110] (Item 8) An image inspection program executed by a computer that controls an image inspection device, an acquisition step of acquiring image data to be used for image formation; a reading step of reading an image of the image data formed on a recording medium and outputting the read data; an inspection step operable in a first mode in which first inspection data is generated based on the image data and the read data output in the reading step is compared with the first inspection data, and a second mode in which the read data output from the first image is read in the reading step is stored in a storage device as second inspection data and the read data output from the second image is read in the reading step is compared with the second inspection data; The image inspection program, wherein the inspection step includes switching between the first mode and the second mode based on the remaining memory capacity of a storage device.

[0111] According to this aspect, it is possible to provide an image inspection program that can efficiently inspect an image.

[0112] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0113] 1 Image forming system, 100 MFP, 200 Image inspection device, 300 Post-processing device, 120 Automatic document feeder, 130 Document reading unit, 140 Image forming unit, 150 Paper feeding unit, 160 Operation panel, 201 CPU, 202 ROM, 203 RAM, 205 Communication unit, 206 First scanner, 207 Second scanner, 208 Serial interface, 211 CD drive, 212 CD-ROM, 51 Acquisition unit, 53 Inspection unit, 55 Reading unit, 57 Memory capacity acquisition unit, 59, 59A Inspection information storage unit, 61 Prediction unit, 63 Evacuation unit, 65 First inspection unit, 67 Second inspection unit, 69 Switching unit, 71 First inspection data generation unit, 73 First comparison unit, 75 Erasing unit, 77 Second inspection data storage unit, 79 Second comparison unit.

Claims

1. an acquisition unit that acquires image data that is the target of image formation; a reading unit that reads an image of the image data formed on a recording medium and outputs the read data; an inspection unit operable in a first mode in which first inspection data is generated based on the image data and the read data output by the reading unit is compared with the first inspection data, and a second mode in which the read data output by the reading unit after reading a first image is stored in a storage device as second inspection data and the read data output by the reading unit after reading a second image is compared with the second inspection data; The inspection unit switches between the first mode and the second mode based on the remaining memory capacity of the storage device.

2. 2. The image inspection device according to claim 1, wherein the inspection unit discards the first inspection data after completing operation in the first mode, and does not erase the second inspection data from the storage device after completing operation in the second mode.

3. an inspection information storage unit that generates inspection information indicating a comparison result by the inspection unit and stores the inspection information in the storage device; a prediction unit that predicts a data amount of the inspection information before the inspection unit starts an operation, The image inspection device according to claim 1 , wherein the inspection unit further switches between the first mode and the second mode based on the predicted data amount of the inspection information.

4. The image inspection device according to claim 3 , wherein the inspection information storage unit does not store the inspection information in the storage device if the remaining storage capacity of the storage device is insufficient even when the inspection unit operates in the first mode.

5. The image inspection device described in claim 3, further comprising a backup unit that deletes or moves at least a portion of the existing data stored in the storage device to a storage device other than the storage device if the remaining memory capacity of the storage device is insufficient when the inspection unit operates in the first mode or the second mode.

6. The image inspection device of claim 1, further comprising a target change unit that processes second image data that is later in order than the first image data if the remaining memory capacity of the storage device is insufficient when operating in the first mode or the second mode on the first image data that is earliest in order when multiple pieces of image data are acquired by the acquisition unit.

7. An image inspection method performed by an image inspection device, comprising: an acquisition step of acquiring image data to be used for image formation; a reading step of reading an image of the image data formed on a recording medium and outputting the read data; an inspection step operable in a first mode in which first inspection data is generated based on the image data and the read data output in the reading step is compared with the first inspection data, and a second mode in which the read data output from the first image read in the reading step is stored in a storage device as second inspection data and the read data output from the second image read in the reading step is compared with the second inspection data, The image inspection method, wherein the inspecting step includes switching between the first mode and the second mode based on the remaining memory capacity of a storage device.

8. An image inspection program executed by a computer that controls an image inspection device, an acquisition step of acquiring image data to be used for image formation; a reading step of reading an image of the image data formed on a recording medium and outputting the read data; an inspection step operable in a first mode in which first inspection data is generated based on the image data and the read data output in the reading step is compared with the first inspection data, and a second mode in which a first image is read in the reading step, and the read data output in the reading step is stored in a storage device as second inspection data, and the read data output in the reading step is compared with the second inspection data; The image inspection program, wherein the inspection step includes switching between the first mode and the second mode based on the remaining memory capacity of a storage device.

Images