Image inspection device

Abstract

The present invention provides an image inspection device that can avoid over-detection of printing misalignment and other issues without relaxing inspection conditions. [Solution] The image inspection device 10 comprises an imaging device 12, a control device 13, and a display device 16. The control device 13 comprises an image acquisition unit 20, a reference image memory, a difference processing unit, and a detection processing unit. The reference image is a pre-image, and the reference image is updated at predetermined timings. The control device 13 uses a pre-image inspection function in which the detection processing unit determines whether or not an image is defective using the difference between the pre-image and the image captured by the imaging device. With this configuration, defects that change sequentially and do not actually need to be judged as defects, such as printing misalignment, will not be judged as defects. In other words, over-detection, which detects defects that do not actually need to be judged as defects, can be avoided, and inspection accuracy is improved.

Description

Technical Field

[0005] , ,

[0004] , , , , ,

[0001] The present invention relates to an image inspection apparatus. More specifically, the present invention relates to an image inspection apparatus capable of extracting defects in a captured image using a reference image.

Background Art

[0002] Patent Document 1 discloses an image inspection apparatus that performs an inspection for detecting a defective image included in a printed image. This image inspection apparatus includes an imaging unit that captures an image of the printed image, and a defective image detection unit that detects a defective image from the captured image based on predetermined inspection conditions. This defective image detection unit detects a defective image by comparing and collating the captured image captured by the imaging unit with an original image corresponding to the data of the printing source.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when an original image is used for detecting a defective image, in the case of defects that do not actually need to be determined as defects, such as misalignment of the paper due to meandering, stretching, speed fluctuations, or acceleration / deceleration during conveyance, or misregistration in the printed matter, there is a problem that it is likely to fall into a situation called over - detection where it is determined as a defect. In order to avoid this over - detection, in the method using the original image, it is necessary to relax the inspection conditions, but when the inspection conditions are relaxed, there is a problem that the accuracy of defect detection decreases.

[0005] <00000​​[Means for solving the problem]

[0006] The first invention's image inspection apparatus comprises an imaging device for imaging an object to be inspected, a control device for extracting defects in an image captured by the imaging device by performing image processing on the image captured by the imaging device, and a display device for displaying the image captured including the extracted defects. The control device comprises an image acquisition unit for acquiring an image captured from the imaging device, a reference image memory for holding a reference image of the image captured, a difference processing unit for performing difference processing using the image captured and the reference image, and a detection processing unit for determining whether the difference extracted by the difference processing corresponds to a defect. The reference image is a prior image acquired by the image acquisition unit before the image captured in which the detection processing unit determined whether the difference corresponds to a defect. In the case The reference image is updated at a predetermined timing, and the control device uses a pre-image inspection function to determine whether the detection processing unit is defective, using the difference between the pre-image and the image captured by the imaging device. Furthermore, if the reference image is the original image provided for printing the object to be inspected, or the original image prepared during the inspection preparation period, the control device has an original image inspection function that uses the difference between the original image and the captured image to determine whether the detection processing unit has a defect, and at least one of the pre-image inspection function and the original image inspection function is selectable, and the display device can alternately display a first result image showing the location of the defect detected by the pre-image inspection function and a second result image showing the location of the defect detected by the original image inspection function without changing the display position of the defect. It is characterized by the following. The 2 The image inspection apparatus of the invention is the first 1 In the invention, the image inspection apparatus has non-volatile storage, and the original image and the captured image are stored in the non-volatile storage. The 3 In the first invention, the image inspection apparatus of the present invention has the control device as follows: The reference image memory comprises a first reference image memory and a second reference image memory, and the difference processing unit comprises a first difference processing unit and a second difference processing unit, The detection processing unit comprises a first detection processing unit and a second detection processing unit. The first difference processing unit performs difference processing using the reference image held in the first reference image memory, the second difference processing unit performs difference processing using the reference image held in the second reference image memory, the first detection processing unit determines whether the difference extracted by the difference processing in the first difference processing unit corresponds to a defect, and the second detection processing unit determines whether the difference extracted by the difference processing in the second difference processing unit corresponds to a defect. The second detection processing unit determines whether at least one of the following is a defect: a periodically occurring defect, a densely occurring defect, a defect that can be identified as an insect, a defect that can be identified as hair, or a defect that can be identified as red. The first detection processing unit determines whether it is a defect using an index different from the index used by the second detection processing unit to determine it is a defect. The detection results from the first detection processing unit and the detection results from the second detection processing unit are displayed on the display device. The 4The image inspection apparatus of the invention is the first 3 In the present invention, if the second detection processing unit determines that a defect exists, the display of the corresponding type of defect in the display device is changed. The 5 In the first invention, the image inspection apparatus of the present invention is configured such that the control device includes a hardware processing device and a software processing device. Furthermore, the control device includes a first reference image memory and a second reference image memory as the reference image memory. The aforementioned difference processing unit as , the first differential processing unit and the second differential processing unit The detection processing unit comprises a first detection processing unit, a second detection processing unit, a third detection processing unit, and a fourth detection processing unit, wherein the first difference processing unit performs difference processing using a reference image held in the first reference image memory, the second difference processing unit performs difference processing using a reference image held in the second reference image memory, the first and second detection processing units determine whether the difference extracted by the difference processing in the first difference processing unit corresponds to a defect, and the third and fourth detection processing units determine whether the difference extracted by the difference processing in the second difference processing unit corresponds to a defect. The first difference processing unit is included in the hardware processing unit, and the second difference processing unit is included in the software processing unit. [Effects of the Invention]

[0007] According to the first invention, the reference image is a prior image acquired by the image acquisition unit before the captured image in which the detection processing unit determined whether the difference corresponds to a defect. In the case The control device uses a pre-image inspection function that determines whether a defect exists by using the difference between a pre-image and an image captured by the imaging device. This prevents defects that change sequentially and do not actually need to be considered defects, such as printing misalignment, from being mistakenly identified as defects. In other words, it avoids over-detection, which would otherwise detect defects that do not actually need to be considered defects, thus improving inspection accuracy. Furthermore, the control device has an original image inspection function that uses the difference between the original image and the captured image to determine whether the detection processing unit is defective. Since at least one of the pre-image inspection function and the original image inspection function can be selected, two types of functions can be selected for defect detection, allowing for stricter inspection conditions for each defect detection step, and further improving inspection accuracy. Furthermore, the display device can alternately display a first result image showing the location of defects detected by the pre-image inspection function and a second result image showing the location of defects detected by the original image inspection function, without changing the display position of the defects. This makes it easy to compare multiple images and to recognize the status of the defects, such as whether or not a defect has been detected and whether the severity of the defect has changed. The 2 According to the invention, the image inspection device has non-volatile storage, and since the original image and captured image are stored in the non-volatile storage, inspection results can be obtained while changing the inspection conditions on a personal computer, making it possible to perform inspections under many conditions. The 3According to the invention, the control device comprises a first detection processing unit and a second detection processing unit as detection processing units. The second detection processing unit determines whether at least one periodically occurring defect is a defect, and the first detection processing unit determines whether it is a defect using an index different from the index used by the second detection processing unit to determine if it is a defect. The detection results from the first detection processing unit and the detection results from the second detection processing unit are displayed on a display device, thereby enabling reliable identification of highly critical defects and improving inspection accuracy. The 4 According to the invention, when a defect is determined by the second detection processing unit, the display of the corresponding defect type is changed on the display device, allowing the user of the image inspection device to easily recognize the type of defect. The 5 According to the invention, the control device is configured to include a hardware processing unit and a software processing unit, and the differential processing unit is configured to include a first differential processing unit and a second differential processing unit, and since the first differential processing unit is included in the hardware processing unit and the second differential processing unit is included in the software processing unit, a part of the differential processing is included in the software processing unit, so that the processing for the differential can be flexibly changed. [Brief explanation of the drawing]

[0008] [Figure 1] This is a block diagram showing the functional configuration of the control device for an image inspection apparatus according to the first embodiment of the present invention. [Figure 2] This is an explanatory diagram of the overall configuration of an image inspection apparatus according to the first embodiment of the present invention. [Figure 3] Figure 1 is an explanatory diagram of the pre-image inspection function of the image inspection device. [Figure 4] Figure 1 is an explanatory diagram of the original image inspection function of the image inspection device. [Figure 5] Figure 1 shows the first screen of the display device of the image inspection apparatus. [Figure 6] This is a block diagram showing the functional configuration of the control device for an image inspection apparatus according to a second embodiment of the present invention. [Figure 7]It is a block diagram showing the functional configuration of a control device of an image inspection apparatus according to a third embodiment of the present invention. [Figure 8] It is the second screen of the display device of the image inspection apparatus of FIG. 1. [Figure 9] It is the third screen of the display device of the image inspection apparatus of FIG. 1. [Figure 10] It is the fourth screen of the display device of the image inspection apparatus of FIG. 1.

Embodiments for Carrying Out the Invention

[0009] Next, embodiments of the present invention will be described based on the drawings. However, the embodiments shown below are examples of an image inspection apparatus for embodying the technical idea of the present invention, and the present invention is not limited to the following image inspection apparatus.

[0010] (First Embodiment) <Overall Configuration> FIG. 2 shows a schematic explanatory view of the overall configuration of an image inspection apparatus 10 according to a first embodiment of the present invention. As shown in FIG. 2, the image inspection apparatus 10 includes an imaging device 12 that images an inspection target, a control device 13 that extracts defects in the captured image by performing image processing on the captured image captured by the imaging device 12, a display device 16 that displays the captured image including the extracted defects, and an input device 17 to the control device 13.

[0011] In this embodiment, the inspection target is a sheet-like printing paper 11. The material of this printing paper 11 is not particularly limited. Further, the inspection target is not limited to the printing paper 11. For example, it may be three-dimensional such as a box like a rectangular parallelepiped. Also, the inspection target may be in a roll shape. Further, the inspection target may be a linear material such as a wire, a harness, a tube, or a fiber. Furthermore, there is no problem even if it is a pattern formed on a secondary battery, a capacitor, a semiconductor, an electronic substrate, and sheets, films, materials, etc. used for them.

[0012] In this embodiment, the imaging device 12 that images the object under inspection is a line sensor camera. However, it is not limited to this. For example, an area sensor camera is also acceptable. Furthermore, the imaging device 12 can be color or monochrome.

[0013] In this embodiment, the control device 13 is configured to include a hardware processing unit 14 and a software processing unit 15. However, the configuration of the control device 13 is not limited to this. For example, it may consist of only the hardware processing unit 14, or only the software processing unit 15.

[0014] In this embodiment, the hardware processing device 14 specifically includes a substrate on which electronic components are mounted. It has functions such as acquiring images captured by the imaging device 12, performing image processing such as performing difference processing using the captured image and a reference image, and detecting defects.

[0015] In this embodiment, the software processing unit 15 has functions for inputting and outputting data with the hardware processing unit 14. The software processing unit 15 also has a function for outputting an output signal for display to the display device 16 and a function for receiving an input signal from the input device 17.

[0016] In this embodiment, the display device 16 is a liquid crystal monitor. This display device 16 is capable of displaying defect inspection conditions or defect inspection results.

[0017] In this embodiment, the input device 17 is a keyboard and a mouse. Although the display device 16 and the input device 17 are shown separately in Figure 2, the representation is not limited to this. For example, the liquid crystal monitor, which is the display device 16, may also have an input function. For example, a user of the image inspection apparatus 10 according to this embodiment can select between the pre-image inspection function and the original image inspection function, which will be described later, using the input device 17 while viewing the display device 16.

[0018] <Functional configuration of control device 13> Figure 1 shows a block diagram representing the functional configuration of the control device 13 that constitutes the image inspection apparatus 10 according to the first embodiment of the present invention. As described in the overall configuration, in this embodiment, the control device 13 is configured to include a hardware processing device 14 and a software processing device 15.

[0019] In this embodiment, the hardware processing unit 14 of the control device 13 has an image acquisition unit 20 that acquires images captured from the imaging device 12. The image acquisition unit 20 has the function of acquiring images captured from the imaging device 12. It is acceptable whether the acquired images are analog or digital signals.

[0020] In this embodiment, the hardware processing unit 14 of the control device 13 is equipped with two reference image memories: a first reference image memory 21a and a second reference image memory 21b. Each reference image memory holds a reference image, and the first reference image memory 21a and the second reference image memory 21b can each hold different reference images. In this embodiment, the control device 13 is configured to have two reference image memories, but it is not limited to this configuration. For example, there may be a configuration with one reference image memory, or three or more.

[0021] In this embodiment, the hardware processing unit 14 of the control device 13 includes two difference processing units: a first difference processing unit 22a and a second difference processing unit 22b. The difference processing unit performs difference processing using the image captured from the imaging device 12 and the reference image held in the reference image memory. In this embodiment, the control device 13 has a configuration with two difference processing units, but it is not limited to this configuration. For example, there may be a configuration with one difference processing unit or three or more units.

[0022] In addition, in this embodiment, the first difference processing unit 22a performs difference processing using the reference image held in the first reference image memory 21a, and the second difference processing unit 22b performs difference processing using the reference image held in the second reference image memory 21b. However, the configuration is not limited to this. For example, it is also acceptable to have one reference image memory and two difference processing units. In this case, the two difference processing units use the reference image held in one reference image memory. It is also acceptable to have one reference image memory and one difference processing unit. In this case, the one difference processing unit uses the reference image held in one reference image memory.

[0023] In this embodiment, the hardware processing unit 14 of the control device 13 includes two detection processing units: a first detection processing unit 23a and a second detection processing unit 23b. The detection processing unit determines whether the difference extracted by the difference processing in the difference processing unit constitutes a defect. In this embodiment, the first detection processing unit 23a determines whether the difference extracted by the difference processing in the first difference processing unit 22a constitutes a defect, and the second detection processing unit 23b determines whether the difference extracted by the difference processing in the second difference processing unit 22b constitutes a defect. Note that the configuration of the detection processing unit is not limited to this. For example, there may be a configuration with one detection processing unit or three or more.

[0024] In this embodiment, the software processing unit 15 of the control device 13 includes a first detection condition setting unit 30 and a second detection condition setting unit 31. The first detection condition setting unit 30 and the second detection condition setting unit 31 are electrically connected to the input device 17. The user of the image inspection device 10 uses the input device 17 to set the inspection conditions of the first detection processing unit 23a from the first detection condition setting unit 30. The user of the image inspection device 10 also uses the input device 17 to set the inspection conditions of the second detection processing unit 23b from the second detection condition setting unit 31. The inspection conditions are, for example, the density of a portion of an image, the dispersion of the density of that portion, the width of that portion, the length of that portion, the area of ​​that portion, the circularity of that portion, the occupancy rate of that portion, the hue of that portion, the saturation of that portion, and the brightness of that portion, when the control device 13 determines that a portion of the captured image is defective.

[0025] In this embodiment, the software processing unit 15 of the control device 13 includes a detection result display unit 32. The detection result display unit 32 is electrically connected to the display device 16. When the user of the image inspection device 10 sets inspection conditions from the first detection condition setting unit 30 or the second detection condition setting unit 31, the user sets the inspection conditions using the display on the display device 16 based on the signal from the detection result display unit 32. The detection result display unit 32 also receives detection results from the first detection processing unit 23a and displays those detection results on the display device 16, and also receives detection results from the second detection processing unit 23b and displays those detection results on the display device 16.

[0026] <Original Image Inspection Function> The original image inspection function performed by the image inspection device 10 according to this embodiment will be explained with reference to Figure 4. Figure 4 is an explanatory diagram of the original image inspection function of the image inspection device 10 according to this embodiment. In Figure 4, the letter "F" is drawn in all of images from Image 1 to Image 4. The difference between Image 1 and Image 2 is the presence or absence of a vertical line below the horizontal bar at the bottom of the letter "F". Image 1 is the original image provided for printing the object to be inspected. The difference between Image 1 and Image 2 is the presence or absence of a vertical line. Note that this vertical line is sufficiently thin and can be judged not to be a printing defect. The difference between Image 2 and Image 3 is the length of this vertical line. The difference between Image 3 and Image 4 is also the length of this vertical line.

[0027] In the original image inspection function, the control device 13 holds the original image provided for printing the object to be inspected in the first reference image memory 21a. This is image 1. This original image is then held in the first reference image memory 21a until the series of inspections are completed. In the first inspection of the object to be inspected, image 2 is acquired by the image acquisition unit 20, and the first difference processing unit 22a performs difference processing using the original image 1 and image 2. The first detection processing unit 23a then determines whether the difference extracted by this difference processing corresponds to a defect. The original image may be digital data such as a PDF or image data. Furthermore, the original image may be an image captured before the start of the entire inspection, i.e., during the inspection preparation period, or an image captured by another device. It is also acceptable if the original image has undergone some kind of image processing.

[0028] In the second inspection of the object under inspection, image 3 is acquired by the image acquisition unit 20, and the first difference processing unit 22a performs difference processing using the original image 1 and image 3. Then, the first detection processing unit 23a determines whether the difference extracted by this difference processing corresponds to a defect.

[0029] In the third inspection of the object under inspection, image 4 is acquired by the image acquisition unit 20, and the first difference processing unit 22a performs difference processing using the original image, image 1, and image 4. Then, the first detection processing unit 23a determines whether the difference extracted by this difference processing corresponds to a defect.

[0030] In this original image inspection function, for example, if there is a large difference in the length of the vertical lines between the original image (Image 1) and Image 4, even if it is judged not to be a printing defect, this part is more likely to be judged as a defect.

[0031] <Pre-image examination function> The pre-image inspection function performed in the image inspection apparatus 10 according to this embodiment will be explained with reference to Figure 3. Figure 3 is an explanatory diagram of the pre-image inspection function of the image inspection apparatus 10 according to this embodiment. The figure "F" depicted in Figures 1 to 4 is the same as that in Figure 4.

[0032] In the pre-image inspection function, the control device 13 stores the original image provided for printing of the object to be inspected in the second reference image memory 21b. This is image 1. In the first inspection of the object to be inspected, image 2 is acquired by the image acquisition unit 20, and the second difference processing unit 22b performs difference processing using the original image 1 and image 2. The second detection processing unit 23b then determines whether the difference extracted by this difference processing corresponds to a defect.

[0033] In the second inspection of the object under inspection, the second reference image memory 21b stores image 2, a preliminary image acquired by the image acquisition unit 20 during the first inspection, i.e., one inspection prior to this second inspection. Then, image 3 is acquired by the image acquisition unit 20, and the second difference processing unit 22b performs difference processing using the preliminary image 2 and image 3. Next, the second detection processing unit 23b determines whether the difference extracted by this difference processing corresponds to a defect.

[0034] In the third inspection of the object under inspection, the second reference image memory 21b stores image 3, a preliminary image acquired by the image acquisition unit 20 during the second inspection, i.e., one inspection prior to this third inspection. Then, image 4 is acquired by the image acquisition unit 20, and the second difference processing unit 22b performs difference processing using the preliminary image 3 and image 4. Next, the second detection processing unit 23b determines whether the difference extracted by this difference processing corresponds to a defect.

[0035] In this pre-image inspection function, for example, if the difference in the length of the vertical lines between image 3 and image 4 is not large, there is a higher probability that something that could not be judged as a printing defect will be correctly identified as not being a defect. In other words, it is possible to avoid false positives.

[0036] In this embodiment, the reference image is described as the previous captured image, but this is not limited to this. The reference image may be updated at predetermined intervals. For example, it is possible to use an image captured two or more years ago as the reference image. To explain this in more detail, it is also possible to set conditions for an captured image to become a reference image. For example, this could involve acquiring captured images at regular intervals, acquiring captured images in response to external instructions, or adopting only captured images without defects as the reference image. Furthermore, the reference image may be an image that has undergone image processing. Possible reference images include images with corrected print position misalignment, average images of multiple captured images, images with noise removed using a median filter, or images with only the defective parts cropped.

[0037] In this embodiment, at least one of the above-described pre-image inspection function and original image inspection function can be selected. That is, the user of the image inspection device 10 can use the display device 16 and the input device 17 to select which detection processing unit will operate these functions. Although two inspection functions have been described above, it is also possible to use either one of the inspection functions with two different inspection criteria.

[0038] <Effects of the image inspection device 10 according to this embodiment> The reference image is a pre-image acquired by the image acquisition unit 20 before the captured image, which has been judged by the detection processing unit as having a difference that constitutes a defect. The control device 13 uses a pre-image inspection function that uses the difference between the pre-image and the image captured by the imaging device 12 to determine whether the detection processing unit has a defect. As a result, defects that change sequentially and do not actually need to be judged as defects, such as printing misalignment, will not be judged as defects. In other words, over-detection, which would detect defects that do not actually need to be judged as defects, can be avoided, and inspection accuracy is improved.

[0039] The control device 13 has an original image inspection function that uses the difference between the original image and the captured image to determine whether the detection processing unit is defective. Since at least one of the pre-image inspection function and the original image inspection function can be selected, two types of functions can be selected when detecting defects, so the inspection conditions for defects can be made stricter in each defect detection process, and inspection accuracy is further improved.

[0040] <Inspection Result Display Screen> Figure 5 shows the first screen of the inspection result display screen shown on the display device 16 of the image inspection apparatus 10 according to this embodiment. The detection result display unit 32 is divided into multiple sections. The defect image display unit 40, located in the upper left of the first screen, shows an enlarged view of the area around each defect. In Figure 5, a 2x5 section is provided in the defect image display unit 40, and 10 defects are shown in enlargement.

[0041] In the lower left of the first screen, there is a selected defect details display unit 41 that shows the type and size of the defect selected by the user of the image inspection device 10 according to this embodiment before inspection.

[0042] The defect map display 43, located in the center of the first screen, shows the location of defects in the object being inspected. For example, in Figure 5, white squares, hatched squares, and black squares are displayed, with the shape or color changing depending on the type of defect to indicate its location. One of the black squares is surrounded by a dotted line. Those surrounded by this dotted line indicate defects with a high degree of criticality.

[0043] Here, the "criticality" of a defect refers to the indicator that is considered important in the industry in which the inspected item is used. For example, if the color red is not permitted, the criticality of a defect containing red will be high.

[0044] For example, the second detection processing unit 23b may detect defects that are highly critical and should definitely be judged as defects. In this case, the second detection processing unit 23b determines whether at least one of the following is a defect: defects that occur periodically, defects that occur in clusters, defects that can be judged as insects, defects that can be judged as hairs, or defects that can be judged as red. In this case, the first detection processing unit 23a determines whether it is a defect using an indicator different from any of the above five indicators that the second detection processing unit 23b uses to determine whether it is a defect. If it is determined to be one of the above five highly critical defects, the detection result by the first detection processing unit 23a and the detection result by the second detection processing unit 23b are shown on the defect map display 43 of the display device 16, for example, by surrounding a black square with a dotted line.

[0045] Furthermore, if the second detection processing unit 23b determines that there is a defect, the display of the corresponding defect type is changed on the display device 16. Specifically, on the defect image display unit 40, the color of the frame surrounding the area determined to be highly critical changes according to the type of defect.

[0046] The defect graph located on the right side of the first screen shows the number of detected defects and the extent of their types.

[0047] The control device 13 includes a first detection processing unit 23a and a second detection processing unit 23b as detection processing units. The second detection processing unit 23b determines whether at least one periodically occurring defect is a defect, and the first detection processing unit 23a determines whether it is a defect using an index different from the index used by the second detection processing unit 23b to determine a defect. The detection results from the first detection processing unit 23a and the detection results from the second detection processing unit 23b are displayed on the display device 16 in a comparable manner, thereby enabling reliable identification of highly critical defects and improving inspection accuracy.

[0048] If the second detection processing unit 23b determines that a defect exists, the display of the corresponding defect type is changed on the display device 16, allowing the user of the image inspection device 10 to easily recognize the type of defect.

[0049] (Second Embodiment) <Functional configuration of control device 13> Figure 6 shows a block diagram representing the functional configuration of the control device 13 of the image inspection apparatus 10 according to the second embodiment of the present invention. The main difference from the first embodiment is that the second reference image memory 21b, etc., are provided within the software processing device 15. The overall configuration is the same as in the first embodiment, so the explanation is omitted. In addition, the first detection condition setting unit 30, the second detection condition setting unit 31, and the detection result display unit 32, which were provided within the software processing device 15 in the first embodiment, are not described here.

[0050] In this embodiment, the software processing unit 15 includes an image retention memory 33. The image retention memory 33 acquires image data from the image acquisition unit 20.

[0051] In this embodiment, the software processing unit 15 includes a second reference image memory 21b and a second differential processing unit 22b in addition to the video retention memory 33. The second reference image memory 21b holds a reference image, similar to the reference image memory in the first embodiment. The first reference image memory 21a is provided in the hardware processing unit 14, and the second reference image memory 21b is provided in the software processing unit 15, but their functions are the same as in the first embodiment.

[0052] In this embodiment, the software processing unit 15 includes a second difference processing unit 22b. The second difference processing unit 22b performs difference processing using the captured image from the video holding memory 33 and the reference image held in the second reference image memory 21b.

[0053] In this embodiment, the software processing unit 15 includes two detection processing units: a third detection processing unit 23c and a fourth detection processing unit 23d.

[0054] Furthermore, in this embodiment, the hardware processing unit 14 includes two detection processing units: a first detection processing unit 23a and a second detection processing unit 23b.

[0055] In this embodiment, the software processing unit 15 of the control device 13 includes a detection result display unit 32. The function of the detection result display unit 32 is the same as in the first embodiment. In this embodiment, the detection result display unit 32 receives detection results from the first detection processing unit 23a, the second detection processing unit 23b, the third detection processing unit 23c, and the fourth detection processing unit 23d, and displays the detection results on a display device 16 (not shown).

[0056] The control device 13 includes a hardware processing unit 14 and a software processing unit 15. The differential processing unit includes a first differential processing unit 22a and a second differential processing unit 22b. Since the first differential processing unit 22a is included in the hardware processing unit 14 and the second differential processing unit 22b is included in the software processing unit 15, a portion of the differential processing is included in the software processing unit 15, allowing for flexible modification of the processing for differences.

[0057] (Third embodiment) <Functional configuration of control device 13> Figure 7 shows a block diagram illustrating the functional configuration of the control device 13 of the image inspection apparatus 10 according to the third embodiment of the present invention. The main difference from the second embodiment is the addition of a non-volatile storage 37. The overall configuration and other details are the same as in the second embodiment, so a detailed explanation is omitted.

[0058] In this embodiment, a non-volatile storage 37 is provided in the image inspection device 10 in place of the second reference image memory 21b. This non-volatile storage 37 is, for example, an HDD (hard disk drive) or an SSD (solid state drive). The image inspection device 10 has a non-volatile storage 37, and since the original image and captured image are stored in the non-volatile storage 37, it is possible to perform simulations on a personal computer to obtain inspection results while changing the inspection conditions, making it possible to perform inspections under many conditions.

[0059] <Other examples of test result display screens> Figure 8 shows the second screen of the defect map display 43 displayed on the display device 16 of the image inspection apparatus 10 according to the first embodiment, and Figure 9 shows the third screen.

[0060] In Figure 8, defects in the first inspection result identified as defects by the second detection processing unit 23b are represented by squares, and defects in the second inspection result identified as defects by the first detection processing unit 23a are represented by circles. The severity of defects in each detection processing unit is divided into "minor," "major," and "critical," with the color becoming darker as the severity increases from "minor" to "critical." The defect map display 43 shows the location of defects in the uninspected object. However, if the defects are displayed as is, the defects in the first inspection result and the defects in the second inspection result will overlap. Therefore, in Figure 8, the second inspection target is displayed shifted to the right relative to the first inspection result. In this explanation, defects are detected by the original image inspection function in the first detection processing unit 23a, and by the pre-image inspection function in the second detection processing unit 23b. Furthermore, there can be two or more classifications of defect severity. It is also possible to change the display based on information about the location, shape, and color of the defect.

[0061] Figure 9 shows a first result image 43a displaying only the first inspection result, and a second result image 43b displaying only the second inspection result. These two images are displayed alternately according to instructions from the user of the image inspection device 10, without changing the position of the defects.

[0062] The display device 16 can alternately display a first result image 43a, which shows the location of a defect detected by the pre-image inspection function, and a second result image 43b, which shows the location of a defect detected by the original image inspection function, without changing the display position of the defect. This makes it easy to compare multiple images and to recognize the status of the defect, such as whether a defect has been detected or whether the severity of the defect has changed. The switching can be done by the user of the image inspection device 10 through their own operation, or the control device 13 may switch at predetermined intervals.

[0063] Figure 10 shows the fourth screen of the display screen shown by the display device 16 of the image inspection apparatus 10 according to the first embodiment. The left side of the fourth screen is the same as the first screen, and is provided with a defect image display unit 40 and a selected defect detailed information display unit 41.

[0064] A detection condition setting unit 45 is provided on the right side of the fourth screen. The user of the image inspection device 10 can change the values ​​of the detection condition setting unit 45 using the input device 17 while viewing the screen of the detection condition setting unit 45. When the user changes the values ​​of the detection condition setting unit 45, the criteria for determining whether or not an image is defective in the detection processing unit change, and therefore the display of the defective image display unit 40 and the selected defect detailed information display unit 41 changes. [Explanation of Symbols]

[0065] 10. Image inspection device 12 Imaging device 13 Control device 14 Hardware Processing Units 15 Software Processing Units 20 Image acquisition unit 21a First reference image memory (reference image memory) 21b Second reference image memory (reference image memory) 22a First Differential Processing Unit (Differential Processing Unit) 22b Second Differential Processing Unit (Differential Processing Unit) 23a First detection processing unit (detection processing unit) 23b Second detection processing unit (detection processing unit) 37 Non-volatile storage

Claims

1. An imaging device for imaging the subject to be examined, A control device that extracts defects in an image captured by the imaging device by performing image processing on the image captured, A display device that displays the captured image including the extracted defects, The control device is An image acquisition unit that acquires images captured from the aforementioned imaging device, A reference image memory that holds a reference image of the captured image, A difference processing unit that performs difference processing using the captured image and the reference image, The system includes a detection processing unit that determines whether the difference extracted by the aforementioned difference processing constitutes a defect, If the reference image is a prior image acquired by the image acquisition unit before the captured image in which the detection processing unit determined whether the difference corresponds to a defect, The aforementioned reference image is updated at predetermined intervals. The control device uses a pre-image inspection function that determines whether the detection processing unit is defective by using the difference between the pre-image and the image captured by the imaging device. The reference image is the original image provided for printing the object to be inspected, or the original image prepared during the inspection preparation period. The control device has an original image inspection function that uses the difference between the original image and the captured image to determine whether the detection processing unit is defective. At least one of the aforementioned pre-image inspection function and the aforementioned original image inspection function can be selected. The display device is capable of alternately displaying a first result image showing the location of a defect detected by the pre-image inspection function and a second result image showing the location of a defect detected by the original image inspection function, without changing the display position of the defect. An image inspection device characterized by the following features.

2. The aforementioned image inspection device has non-volatile storage, The original image and the captured image are stored in the non-volatile storage. The image inspection apparatus according to feature 1.

3. The control device is The aforementioned reference image memory comprises a first reference image memory and a second reference image memory, The difference processing unit comprises a first difference processing unit and a second difference processing unit, The aforementioned detection processing unit comprises a first detection processing unit and a second detection processing unit, The first difference processing unit performs difference processing using the reference image held in the first reference image memory. The second difference processing unit performs difference processing using the reference image held in the second reference image memory. The first detection processing unit determines whether the difference extracted by the difference processing in the first difference processing unit corresponds to a defect. The second detection processing unit determines whether the difference extracted by the difference processing in the second difference processing unit corresponds to a defect. The second detection processing unit determines whether at least one of the following is a defect: a periodically occurring defect, a densely occurring defect, a defect that can be identified as an insect, a defect that can be identified as hair, or a defect that can be identified as red. The first detection processing unit determines whether a defect exists using an index different from the index used by the second detection processing unit to determine a defect, The detection result from the first detection processing unit and the detection result from the second detection processing unit are displayed on the display device. The image inspection apparatus according to feature 1.

4. If the second detection processing unit determines that a defect exists, the display of the corresponding defect type is changed on the display device. The image inspection apparatus according to feature 3.

5. The control device is configured to include a hardware processing unit and a software processing unit. Furthermore, the control device, The aforementioned reference image memory comprises a first reference image memory and a second reference image memory, The difference processing unit comprises a first difference processing unit and a second difference processing unit, The aforementioned detection processing unit comprises a first detection processing unit, a second detection processing unit, a third detection processing unit, and a fourth detection processing unit. The first difference processing unit performs difference processing using the reference image held in the first reference image memory. The second difference processing unit performs difference processing using the reference image held in the second reference image memory. The first detection processing unit and the second detection processing unit determine whether the difference extracted by the difference processing in the first difference processing unit corresponds to a defect. The third detection processing unit and the fourth detection processing unit determine whether the difference extracted by the difference processing in the second difference processing unit corresponds to a defect. The first difference processing unit is included in the hardware processing unit, The second difference processing unit is included in the software processing unit. The image inspection apparatus according to feature 1.

Images