Multi-plane imaging system, and visual inspection system and visual inspection method using the same.

Abstract

By enabling 360-degree and multi-plane inspections, which typically require multiple imaging methods, through a single image processing system, the inspection system can be made more compact, reducing equipment costs. [Solution] The multi-plane imaging system comprises an imaging unit 1 equipped with an illumination means 15 for illuminating an object to be imaged W and a plurality of imaging units 10 spaced apart around the object to be imaged; an imaging unit control unit 22 for controlling the imaging units; an imaging control unit 2 equipped with an image synthesis unit 21 that synthesizes multiple image signals from the object to be imaged acquired by the plurality of imaging units to create a single composite image; and a communication means 3 connecting the imaging unit and the imaging control unit. The imaging unit comprises an imaging means, a plane mirror arranged on the optical axis of the imaging means and rotatable with respect to the optical axis, and an imaging means holding unit that holds the imaging means and the plane mirror.

Description

Technical Field

[0001] The present invention relates to an annular imaging system for multi-faceted imaging of the inner and outer peripheral surfaces of a three-dimensional shaped article, and an appearance inspection system and an appearance inspection method using the same.

Background Art

[0002] Three-dimensional shaped objects having inner and outer peripheral surfaces, such as drinking containers having an opening on the upper surface, and annular members such as O-rings and screw washers, are subject to appearance inspection because their appearance quality is important. For drinking containers, variety displays such as contents and product names are printed on the outer surface of the container, and decorative treatments are performed to赋予 value such as appearance design and functions. Therefore, the decorative state such as printing, coloring, and painting applied to the container is inspected by capturing an image of the outer peripheral surface of the container. In addition, it is necessary to inspect the opening and the inside of the container for scratches, foreign objects, etc. by capturing an image of the inner surface. Annular members also need to be inspected for scratches on the inner and outer peripheral surfaces. However, in order to inspect a three-dimensional shaped object having inner and outer peripheral surfaces multi-faceted, it is necessary to install a plurality of imaging means and lighting means, which increases the size of the entire inspection apparatus, raises the equipment cost, and increases the installation space.

[0003] Patent Document 1 discloses an inspection apparatus for a three-dimensional shaped object including an optical system that acquires a plurality of optical images of the three-dimensional shaped object to be inspected, a photoelectric conversion means that electrically converts the incident optical image, and an optical propagation means that supplies the optical images acquired by the plurality of optical systems as an optical image for one screen to the photoelectric conversion means. Further disclosed is an inspection apparatus including a plurality of imaging means each including an imaging device and a mirror that projects an optical image of a three-dimensional shaped object viewed from multiple aspects by changing the reflection angle onto the imaging device, and an image processing means that integrates the imaging results of the plurality of imaging means onto one screen. Patent Document 2 discloses an appearance inspection apparatus including a plurality of imaging means each including a camera and a mirror that capture perspective images of an object to be inspected from different directions, and a display means that displays the respective perspective images captured by the plurality of imaging means. Patent Document 3 discloses a device comprising a reflective section positioned spaced apart to the side of a container, an imaging section that images the decorative section of the container via the reflective section, and an inspection device that inspects the decorative section based on the image captured by the imaging section. However, Patent Document 3 is an invention that avoids the horizontal expansion of the overall installation space of the device even when the optical path length from the container to the imaging unit is widened by using a reflective section, and does not disclose imaging of the inner and outer surfaces of the container in a multifaceted manner. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 6-160038 [Patent Document 3] Japanese Patent Application Publication No. 11-304721 [Patent Document 2] Japanese Patent Publication No. 2021-105554 [Overview of the project] [Problems that the invention aims to solve]

[0005] The present invention aims to achieve full-circumference inspection and multi-face inspection, which would otherwise require multiple imaging means, through a single image processing operation by integrating multiple images output from multiple imaging means into a single composite image, thereby making it substantially equivalent to a single image acquired from a single imaging means. This results in a more compact inspection system and reduced equipment costs. [Means for solving the problem]

[0006] The problems of the present invention can be solved by the following embodiments (1) to (7). Specifically,

[0007] (Aspect 1) A multi-plane imaging system comprising: an imaging unit having illumination means for illuminating an object to be imaged and a plurality of imaging units arranged spaced apart around the object to be imaged; an imaging unit control unit for controlling the imaging units; an imaging unit control unit having an image synthesis unit for synthesizing a plurality of image signals from the object to be imaged acquired by the plurality of imaging units to create a single composite image; and a communication means for connecting the imaging unit and the imaging unit control unit, wherein the imaging unit comprises imaging means, a plane mirror arranged on the optical axis of the imaging means and rotatable with respect to the optical axis, and an imaging means holding unit for holding the imaging means and the plane mirror. The image synthesis unit combines multiple images output from multiple imaging means into a single composite image using an FPGA (Field-Programmable Gate Array), making it substantially equivalent to a single image acquired from a single imaging means. This enables 360-degree inspection and multi-face inspection, which would otherwise require multiple imaging means, to be performed with a single image processing, allowing for a more compact imaging system and reduced equipment costs. Furthermore, by arranging multiple imaging units, each combining an imaging means and a plane mirror, at intervals around the object to be imaged, it is possible to arbitrarily select and image the inner and outer surfaces of the object.

[0008] (Aspect 2) The imaging unit is a multi-plane imaging system as described in Aspect 1, characterized in that it can be independently and individually moved up, down, left, and right by the imaging unit control unit. By independently moving the imaging unit up, down, left, and right, the inner and outer surfaces of the object to be imaged can be arbitrarily selected and imaged, and the system can easily accommodate different workpiece diameters.

[0009] (Aspect 3) The multi-plane imaging system according to either aspect 1 or 2, characterized in that the illumination means is either surface illumination or pseudo-coaxial incident illumination, either alone or in combination. By employing surface illumination as the illumination method, a uniform illumination light can be directed onto the object being inspected. Furthermore, by employing coaxial incident illumination, the illumination light can be directed onto the object being imaged from the same axis as the imaging direction of the imaging device.

[0010] (Aspect 4) A multi-faceted visual inspection system comprising: an inspection unit comprising illumination means for illuminating an object to be inspected, transport means for transporting the object to be inspected, and a plurality of imaging units arranged spaced apart around the object to be inspected; an imaging unit control unit for controlling the imaging units; an image synthesis unit for synthesizing a plurality of image signals from the object to be inspected acquired by the plurality of imaging units to create a single composite image; an inspection control unit comprising an image processing unit for image processing the composite image created by the image synthesis unit and a determination unit for determining the inspection image processed by the image processing unit; and a communication means for connecting the inspection unit and the inspection control unit, wherein the imaging unit comprises imaging means, a plane mirror arranged on the optical axis of the imaging means and rotatable with respect to the optical axis, and an imaging means holding unit for holding the imaging means and the plane mirror. The image synthesis unit combines multiple images output from multiple imaging means into a single composite image using an FPGA (Field-Programmable Gate Array), making it substantially equivalent to a single image acquired from a single imaging means. This allows image processing in the image processing unit and pass / fail judgment in the judgment unit to be performed by a single image processing unit. As a result, 360-degree inspections and multi-face inspections that would normally require multiple imaging means can be performed by a single image processing unit, making the visual inspection system more compact and reducing equipment costs. Furthermore, by arranging multiple imaging units, each combining an imaging means and a plane mirror, at intervals around the object to be inspected, the inner and outer surfaces of the object can be arbitrarily selected for visual inspection.

[0011] (Aspect 5) The imaging unit is a multi-faceted visual inspection system as described in Aspect 4, characterized in that it can be independently and individually moved up, down, left, and right by the imaging unit control unit. By independently moving the imaging unit up, down, left, and right, the inner and outer surfaces of the object being inspected can be arbitrarily selected and imaged, and the system can easily accommodate different workpiece diameters.

[0012] (Aspect 6) The illumination means is a multi-faceted visual inspection system according to either aspect 4 or aspect 5, characterized in that the illumination means is either surface illumination or pseudo-coaxial incident illumination, either alone or in combination. By employing surface illumination as the illumination method, a uniform illumination light can be directed onto the object being inspected. Furthermore, by employing coaxial incident illumination, the illumination light can be directed onto the object being inspected from the same axis as the imaging direction of the imaging device.

[0013] (Aspect 7) An appearance inspection method using a multi-face appearance inspection system as described in any of Aspects 4 to 6, comprising: an imaging condition setting step in which, based on the appearance of the object to be inspected, the arrangement of the lighting means and the imaging unit control unit set the vertical position of each of the multiple imaging units, the angle and position of the plane mirror, and the optical path length between the imaging means and the plane mirror; an inspection image synthesis step in which an inspection image is created by receiving reflected light from the object to be inspected and synthesizing multiple image signals acquired by the multiple imaging units; a plane image extraction step in which a plane image is created from the inspection image synthesized in the inspection image synthesis step; a pre-processing step in which the plane image is corrected; a feature extraction step in which features are extracted from the corrected plane image; a post-processing step in which the feature extracted inspection image is corrected; a blob analysis step in which the corrected inspection image is subjected to blob analysis; and an inspection image determination step in which the pass or fail of the inspection image is determined based on the inspection image subjected to blob analysis. [Effects of the Invention]

[0014] According to the present invention, by integrating multiple images output from multiple imaging means into a single composite image, it is possible to make it substantially equivalent to a single image acquired from a single imaging means. This enables full-circumference inspection and multi-face inspection, which would otherwise require multiple imaging means, to be realized with a single image processing, thereby making the inspection system more compact and reducing equipment costs. Furthermore, by arranging multiple imaging units, each combining an imaging means and a plane mirror, in a circular arrangement around the object to be imaged, it is possible to arbitrarily select and image the inner and outer surfaces of the object. [Brief explanation of the drawing]

[0015] [Figure 1] It is a configuration diagram illustrating the configuration of the multi-faceted imaging system of the present invention. [Figure 2] It is a side view showing one embodiment of the imaging unit constituting the multi-faceted imaging system of the present invention. [Figure 3] It is a cross-sectional view (A-A´) illustrating an embodiment of imaging by the multi-faceted imaging system of the present invention. [Figure 4] It is a photograph showing an imaging image of an annular member by the multi-faceted imaging system of the present invention. [Figure 5] It is a photograph showing an imaging image of a container by the multi-faceted imaging system of the present invention. [Figure 6] It is a configuration diagram illustrating the configuration of the multi-faceted appearance inspection system of the present invention. [Figure 7] It is a flow chart explaining the inspection flow of the multi-faceted appearance inspection system of the present invention. [Figure 8] It is a cross-sectional view (A-A´) illustrating an inspection mode of the multi-faceted appearance inspection system of the present invention.

Embodiments for Carrying Out the Invention

[0016] Embodiments for carrying out the present invention will be described based on FIGS. 1 to 8. However, FIGS. 1 to 8 are merely examples of embodiments and are not limited thereto. For example, the arrangement of the imaging units is not limited to being arranged at an equal distance (annular shape) from the imaging object, and also includes those not arranged at an equal distance from the imaging object.

[0017] A. Multi-faceted imaging system 1. Configuration of the multi-faceted imaging system FIG. 1 is a configuration diagram illustrating one embodiment of the multi-faceted imaging system 100 of the present invention. The multi-faceted imaging system 100 of the present invention is composed of an imaging unit 1 in which a plurality of imaging units 10 are spaced apart around an imaging object W, an imaging control unit 2, and communication means 3 connecting the imaging unit 1 and the imaging control unit 2. The imaging unit 1 consists of an illumination means 15 for illuminating the object to be imaged W, and a plurality of imaging units 10 that are spaced apart from the center line of the object to be imaged W and surround the object to be imaged W. The imaging control unit 2 includes an image synthesis unit 21 that synthesizes multiple image signals acquired by each of the multiple imaging units (10a to 11f) into a single composite image, an imaging unit control unit 22 that controls the imaging unit 10, and an information storage unit 23. The following will describe the object to be imaged W, the imaging unit 1, the imaging control unit 2, and the communication means 3 in that order.

[0018] 2. Object to be imaged The object W to be imaged by the multi-face imaging system 100 of the present invention is not particularly limited as long as it is a three-dimensional object having inner and outer surfaces. Specifically, this includes cylindrical bodies with an opening on the top surface (e.g., beverage containers such as cans and bottles) and containers with decorations such as printing, coloring, painting, or unevenness on the outer surface, and annular members having inner and outer surfaces (e.g., O-rings, screw washers, etc.). Cylinders and annular members with an opening on the top surface may require imaging of both the inner and outer surfaces, and imaging both the inner and outer surfaces simultaneously can shorten the imaging time and simplify the imaging equipment.

[0019] 3. Imaging Unit The imaging unit 1 constituting the multi-plane imaging system 100 of the present invention comprises an illumination means 15 and an imaging unit 10.

[0020] (3-1) Lighting means The form of the illumination means 15 of the multi-plane imaging system 100 of the present invention can be appropriately selected depending on the characteristics of the object W to be imaged. Specifically, planar illumination, bar illumination, annular illumination, dome illumination, spot illumination, and coaxial reflected illumination consisting of a housing that houses a light source and a half mirror can be employed. When coaxial reflected illumination is employed, illumination light is irradiated onto the object W to be imaged from a direction coaxial with the imaging direction of the imaging means 11 via the half mirror. In the case of annular illumination, the illumination means 15 is preferably placed directly above the object to be imaged W, and in the case of planar illumination, it can be appropriately placed directly above, to the side of, or below the object to be imaged W.

[0021] (3-2) Imaging Unit Figure 2 is a side view showing one embodiment of the imaging unit 10 that constitutes the multi-face imaging system 100 of the present invention. The imaging unit 10 consists of an imaging means 11, a plane mirror 13 that projects reflected images of the object to be imaged W viewed from multiple sides onto the imaging means 11 by changing the reflection angle, an imaging unit holding part 12 that holds the imaging means 11 and the plane mirror 13, and an imaging unit drive part 14 which is located below the imaging unit holding part 12 and drives the imaging unit holding part 12 up, down, left, and right. The rotation angle (θ) of the plane mirror 13 and the up, down, left, and right movement of the imaging unit holding part 12 by the imaging unit drive part 14 are controlled by the imaging unit control part 22 of the imaging control unit 2. Figure 3 is a cross-sectional view (AA') illustrating an embodiment of imaging by the multi-plane imaging system 100 of the present invention. Figure 3(a) shows an embodiment in which the outer surface of the object to be imaged W is imaged, Figure 3(b) shows an embodiment in which the outer and inner surfaces of the object to be imaged W are imaged, and Figure 3(c) shows an embodiment in which the bottom and opening surfaces of the object to be imaged W are imaged.

[0022] (3-2-1) Imaging means The imaging means 11 constituting the imaging unit 10 of the present invention uses an integrated circuit (IC) that converts reflected light into an image signal, specifically an image sensor made of a large number of photodiodes arranged on a planar silicon substrate, and an integrated circuit such as a charge-coupled device (CCD) or complementary metal oxide semiconductor (CMOS) is used for data transfer. It also consists of an optical system that forms an image of the workpiece on the imaging surface of the solid-state image sensor, and a signal processing circuit that processes the output of the solid-state image sensor to obtain a brightness value for each pixel. Depending on the nature of the object to be inspected W, an area camera or a line scan camera can be appropriately selected. When the object to be imaged W is stationary, an area camera can be suitably used. When the object to be imaged W is continuously moving, a line camera can be suitably used.

[0023] (3-2-2) Plane mirror The plane mirror 13 constituting the imaging unit 10 of the present invention is positioned directly below the optical axis of the imaging means 11 and plays the role of irradiating the imaging means 11 with reflected light from the object to be imaged W. By controlling the rotation angle (θ) of the plane mirror 13, the reflection angle of the reflected light from the object to be imaged W can be changed, thereby irradiating the imaging means 11 with reflected light from any inner or outer surface of the object to be imaged W.

[0024] (3-2-3) Imaging unit holding section The imaging unit holder 12, which constitutes the imaging unit 10 of the present invention, is responsible for holding the imaging means 11 and the plane mirror 13, and for changing the distance (L) between the imaging means 11 and the plane mirror 13. In addition, the imaging unit drive unit 14 drives the imaging unit holder 12 itself up, down, left, and right.

[0025] (3-2-4) Imaging Unit Drive Unit The imaging unit drive unit 14, which constitutes the imaging unit 10 of the present invention, also plays a role in driving the imaging unit holding unit 12 itself up, down, left, and right. It is controlled by the imaging unit control unit 22 of the imaging control unit 2.

[0026] 4. Imaging Control Unit The imaging control unit 2 constituting the multi-surface imaging system 100 of the present invention comprises an image synthesis unit 21, an imaging unit control unit 22, and an information storage unit 23, and may also include various input / output interfaces such as a display device 24 and an input device 25.

[0027] (4-1) Image synthesis unit The image synthesis unit 21, which constitutes the imaging control unit 2 of the present invention, is composed of a board equipped with an FPGA (Field-Programmable Gate Array) that has the function of a CPU (Central Processing Unit) and the function of memory such as ROM (Read Only Memory) and RAM (Random Access Memory). It is responsible for synthesizing the image signals acquired from each imaging means (11a to 11f) to create a single composite image. The created composite image is output to the display device 24.

[0028] (4-2) Imaging Unit Control Unit The imaging unit control unit 21, which constitutes the imaging control unit 2 of the present invention, is responsible for controlling the rotation angle (θ) of the plane mirror 13, the distance (L) between the imaging means 11 and the plane mirror 13, and the up, down, left, and right movement of the imaging unit holding unit 12 by the imaging unit drive unit 14.

[0029] (4-3) Information storage section The information storage unit 21 constituting the imaging control unit 2 of the present invention includes ROM (Read Only Memory) and RAM (Random Access Memory). It stores various programs executed by the image synthesis unit 21 and the imaging unit control unit 22, as well as information necessary for the execution of these programs. The various programs and information stored in ROM are loaded into RAM and executed.

[0030] 5. Means of communication The communication means 3 of the present invention is responsible for transmitting multiple image signals acquired by each of the multiple imaging units (10a to 11f) to the image synthesis unit 21. It also has the function of controlling the operation of the imaging means 11, such as the timing of imaging, via a general-purpose communication interface such as Camera Link, USB (Universal Serial Bus), CXP (CoaXPress®), or Gigabit Ethernet (GigE).

[0031] 6. Composite image Figures 4(a) to 4(c) are photographs showing a composite image (annular member) captured by the multi-view imaging system 100 of the present invention and combined by the image synthesis unit 21. In each case, images of the inner and outer surfaces of the annular member captured by the six imaging means from multiple directions are combined into a single image. Figures 5(a) to 5(c) are photographs showing a composite image (top-opening container) captured by the multi-view imaging system 100 of the present invention and combined by the image synthesis unit 21. In each case, images of the inner and outer surfaces of the top-opening container, captured by the six imaging means from multiple directions, are combined into a single image.

[0032] B. Visual inspection system using a multi-angle imaging system 1. Configuration of a visual inspection system using a multi-plane imaging system Figure 6 is a diagram illustrating the configuration of an appearance inspection system employing the multi-view imaging system of the present invention (hereinafter referred to as the "multi-view appearance inspection system"). The multi-faceted visual inspection system 200 of the present invention consists of an inspection unit 4 in which a plurality of imaging units 10 are arranged spaced apart around the object to be inspected W, an inspection control unit 5, and a communication means 3 that connects the inspection unit 4 and the inspection control unit 5. The multi-view inspection system 200 utilizes the imaging unit 1 of the multi-view imaging system 100 described above as the inspection unit 4, and its configuration is identical to the imaging unit 1 of the multi-view imaging system 100 described above, except that it includes a transport means 6 for transporting the object to be inspected (object to be imaged) W. The multi-view inspection system 200 is characterized by the fact that by using the imaging unit 1 of the multi-view imaging system 100 as the inspection unit 4, it can inspect the object to be inspected W simultaneously from multiple viewpoints. The inspection unit 4 includes an illumination means 15 for illuminating the object to be inspected W, a plurality of imaging units 10 arranged at a predetermined distance from the center line of the object to be inspected W and spaced apart to surround the object to be imaged W, and a transport means 6 for transporting the object to be inspected W. The inspection control unit 5 includes an imaging unit control unit 22 that controls the imaging unit 10, an image synthesis unit 21 that synthesizes and displays multiple inspection image signals acquired by each of the multiple imaging units (10a to 10f) as a composite image, an image processing unit 26 that processes the composite image synthesized by the image synthesis unit 21, a determination unit 27 that determines whether the appearance of the object to be inspected W is good or bad based on the inspection image created by the image processing unit 26, an information storage unit 23, an image storage unit 28, and a transport control unit 29. The configurations of the object to be inspected W, the inspection unit 10, and the communication means 3 are the same as those of the object to be imaged W and the imaging unit 1 described above, so their explanation will be omitted, and the inspection control unit 5 will be described below.

[0033] 2. Inspection and Control Unit The inspection control unit 5 constituting the multi-face appearance inspection system 200 of the present invention comprises an imaging unit control unit 22 that controls the imaging unit 10, an image synthesis unit 21 that synthesizes and displays multiple inspection image signals acquired by each of the multiple imaging units (10a to 10f) as a composite image, an image processing unit 26 that processes the composite image synthesized by the image synthesis unit 21, a determination unit 27 that determines whether the appearance of the object to be inspected W is good or bad based on the inspection image created by the image processing unit 26, an information storage unit 23, an image storage unit 28, and a transport control unit 29, and may also be equipped with various input / output interfaces such as a display device 24 and an input device 25.

[0034] (2-1) Image synthesis unit The image synthesis unit 21, which constitutes the inspection control unit 5 of the present invention, is composed of a board equipped with an FPGA (Field-Programmable Gate Array) that has the function of a CPU (Central Processing Unit) and the function of memory such as ROM (Read Only Memory) and RAM (Random Access Memory). It is responsible for synthesizing the image signals acquired from each imaging means (11a to 11f) to create a single composite image. The created composite image is output to the display device 24.

[0035] (2-2) Imaging Unit Control Unit The imaging unit control unit 21, which constitutes the inspection control unit 5 of the present invention, is responsible for controlling the rotation angle (θ) of the plane mirror 13, the distance (L) between the imaging means 11 and the plane mirror 13, and the up, down, left, and right movement of the imaging unit holding unit 12 by the imaging unit drive unit 14.

[0036] (2-3) Information storage section The information storage unit 23, which constitutes the inspection control unit 2 of the present invention, includes ROM (Read Only Memory) and RAM (Random Access Memory). It stores various programs executed by the image synthesis unit 21, the imaging unit control unit 22, and the transport control unit 29, as well as information necessary for the execution of these programs. The various programs and information stored in ROM are loaded into RAM and executed.

[0037] (2-2) Image Processing Unit The image processing unit 26, which constitutes the inspection control unit 5 of the present invention, is responsible for performing various image processing operations on the image information from the image synthesis unit 21 to create an inspection image.

[0038] (2-3) Image storage unit The image storage unit 28 constituting the inspection control unit 5 of the present invention includes ROM (Read Only Memory) and RAM (Random Access Memory). The ROM stores various programs, such as inspection method programs executed by the CPU, and information necessary for the execution of these programs. The various programs and information stored in the ROM are loaded into the RAM and executed.

[0039] (2-4) Judgment section The determination unit 27, which constitutes the inspection control unit 5 of the present invention, is responsible for determining whether the appearance of the inner and outer surfaces of the object to be inspected W is good or bad. Specifically, it determines whether the inspection image is good or bad by comparing it with a reference image stored in the image storage unit 28.

[0040] (2-5) Transport Control Unit The transport control unit 29, which constitutes the inspection control unit 5 of the present invention, controls the transport means 6 that transports the objects to be inspected W at equal intervals. The objects to be inspected W are inspected on the transport means 6 in the inspection unit 4. After the inspection is complete, the objects to be inspected W are transported by the transport means 6.

[0041] C. Multi-faceted visual inspection method Figure 7 is a flowchart illustrating the inspection flow of the multi-faceted visual inspection system 200 of the present invention. Figure 8 is a cross-sectional view (AA') illustrating an inspection mode of the multi-faceted visual inspection system 200 of the present invention. The annular appearance inspection system 200 of the present invention performs an appearance inspection of the object to be inspected W in the following procedure.

[0042] 1. Setting the test conditions Based on the characteristics of the object W to be inspected (e.g., container, annular member, height, width), the arrangement of the illumination means 15 and the imaging unit 10, as well as the height of the imaging means 11 and the rotation angle (θ) of the plane mirror 13 are set (S11). Specifically, the arrangement of the illumination means 15 is selected to ensure that the illumination light irradiating the object W under inspection is appropriate, and the height of the imaging means 11 and the rotation angle (θ) of the plane mirror 13 are adjusted by the imaging unit drive unit 14 so that the imaging means 11 can appropriately receive reflected light from the inspection position of the object W under inspection.

[0043] 2. Image synthesis of examination images The image synthesis unit 21 synthesizes the image signals acquired from each imaging means (11a to 11f) to create a single inspection image (S12).

[0044] 3. Image Processing The image processing unit 26 performs image processing to enable the image synthesis unit 21 to determine a single inspection image. The image processing is performed in the following order: plane image extraction (S13), preprocessing (S14), feature extraction (S15), postprocessing (S16), and blob analysis (S17).

[0045] (3-1) Plain image extraction The plane image extraction process (S13) is a process that extracts one of the tonal components (composed of red, green, blue, hue, saturation, lightness (L), and lightness (V)) from the inspection image. For example, there is a process to extract the red (R) plane from an RGB image. The mode of the plain image extraction process (S13) can be appropriately selected depending on the characteristics of the inspection image.

[0046] (3-2) Pretreatment Preprocessing (S14) is performed to improve the accuracy of the feature extraction process (S15). Specifically, position correction, image calculation, LUT correction, brightness correction, blurring, etc., are appropriately selected and performed according to the characteristics of the plane-extracted image.

[0047] (3-3) Feature Extraction The feature extraction process (S15) extracts characteristic lines and density boundary regions from a plain image. Specifically, it involves selecting and performing region of interest (ROI), masking, reference difference, binarization, and optical character recognition (OCR) analysis as appropriate.

[0048] (3-4) Post-processing Post-processing (S16) is performed to improve the accuracy of the blob analysis process (S17). Specifically, hole filling, feature concatenation, feature calculation, and noise reduction are performed by appropriately selecting these processes according to the characteristics of the feature-extracted image.

[0049] (3-5) Blob analysis Blob analysis (S16) is an analysis process performed to provide the post-processed (S16) inspection image for inspection image judgment (S17). Specifically, shape feature analysis, string analysis, and distance analysis are appropriately selected and performed according to the characteristics of the post-processed image.

[0050] (4) Interpretation of examination images The determination unit 27 compares the inspection image with a reference image to determine whether the appearance of the object W to be inspected is good or bad (S18). The determination result is output to the display device 25. [Industrial applicability]

[0051] The present invention makes it possible to provide circumferential inspection and multi-face inspection that require multiple imaging means. [Explanation of Symbols]

[0052] 100 Multi-plane imaging system 200 Multi-faceted Visual Inspection System W: Object to be imaged, object to be inspected 1. Imaging Unit 2. Imaging control unit 3. Means of communication 4. Inspection Department 5. Inspection Control Unit 6. Conveying means 7 Half-mirror 10 Imaging Unit 11. Imaging means 12 Imaging unit holding section 13 plane mirror 14. Imaging unit drive unit 15 Lighting means 16. Object holding unit for imaging 17. Object Lifting and Lowering Section 21 Image Synthesis Unit 22 Imaging Unit Control Unit 23 Information storage section 24 Display device 25 Input devices 26 Image Processing Unit 27 Judgment section 28 Image storage unit 29. Transport Control Unit

Claims

1. An imaging unit comprising an illumination means for illuminating the object to be imaged and a plurality of imaging units arranged spaced apart around the object to be imaged, The imaging control unit includes an imaging unit control unit that controls the imaging unit, and an image synthesis unit that synthesizes multiple image signals from the object to be imaged acquired by the multiple imaging units to create a single composite image, A communication means connecting the imaging unit and the imaging control unit, A multi-plane imaging system comprising, The imaging unit comprises an imaging means, a plane mirror positioned on the optical axis of the imaging means and rotatable with respect to the optical axis, and an imaging means holding unit that holds the imaging means and the plane mirror. A multi-plane imaging system characterized by the following features.

2. The multi-plane imaging system according to claim 1, characterized in that the imaging unit can be independently and individually moved up, down, left, and right by the imaging unit control unit.

3. The multi-plane imaging system according to either claim 1 or 2, characterized in that the illumination means is either surface illumination or pseudo-coaxial incident illumination, either alone or in combination.

4. An inspection unit comprising an illumination means for illuminating the object to be inspected, a transport means for transporting the object to be inspected, and a plurality of imaging units arranged spaced apart around the object to be inspected, An inspection control unit comprising: an imaging unit control unit that controls the imaging unit; an image synthesis unit that synthesizes multiple image signals from the object to be inspected acquired by the multiple imaging units to create a single composite image; an image processing unit that processes the composite image created by the image synthesis unit; and a determination unit that determines the inspection image processed by the image processing unit, A communication means connecting the inspection unit and the inspection control unit, A multi-faceted visual inspection system comprising: The imaging unit comprises an imaging means, a plane mirror positioned on the optical axis of the imaging means and rotatable with respect to the optical axis, and an imaging means holding unit that holds the imaging means and the plane mirror. A multi-faceted visual inspection system characterized by the following features.

5. The multi-faceted visual inspection system according to claim 4, characterized in that the imaging unit can be independently and individually moved up, down, left, and right by the imaging unit control unit.

6. The multi-faceted visual inspection system according to either 4 or 5, characterized in that the illumination means is either surface illumination or pseudo-coaxial incident illumination, either alone or in combination.

7. A visual inspection method using a multi-face visual inspection system as described in any one of claims 4 to 6, Based on the characteristics of the object to be inspected, the imaging condition setting step involves setting the arrangement of the illumination means and the vertical position of each of the multiple imaging units, the angle and position of the plane mirror, and the optical path length between the imaging means and the plane mirror using the imaging unit control unit. An inspection image synthesis step involves receiving reflected light from the object to be inspected and creating an inspection image by combining multiple image signals acquired by multiple imaging units, and A plain image extraction step that creates a plain image from the inspection images synthesized in the inspection image synthesis step, A preprocessing step for correcting the plain image, A feature extraction step that extracts features from a corrected plain image, A post-processing step that corrects the feature-extracted inspection image, A blob analysis step is performed to analyze the corrected examination images, A test image determination step that determines whether a test image is pass or fail based on the test image analyzed by blob analysis, A visual inspection method consisting of the following.

Images