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

Abstract

By performing full-circumference inspections and multi-surface inspections, which require multiple imaging means, with a single image processing unit, the inspection system can be made more compact and equipment costs reduced. [Solution] A multi-plane imaging system comprising an imaging section 1 having an illumination means 15 for illuminating an imaging object W and a plurality of imaging units 10 arranged at a distance around the imaging object, an imaging unit control section 22 for controlling the imaging units, an imaging control section 2 having an image synthesis section 21 for synthesizing a plurality of image signals from the imaging object acquired by the plurality of imaging units to create a single synthetic image, and communication means 3 for connecting the imaging section and the imaging control section. The imaging unit comprises imaging means, a plane mirror arranged on the optical axis of the imaging means and rotatable about the optical axis, and an imaging means holding section for holding the imaging means and the plane mirror.

Description

[Technical Field]

[0001] The present invention relates to a ring imaging system that multifacetically images the inner and outer peripheral surfaces of a three-dimensional object, and to an appearance inspection system and an appearance inspection method that use the same. [Background technology]

[0002] Three-dimensional objects with inner and outer peripheries, such as beverage containers with openings on the top surface, and annular components such as O-rings and screw washers, are subject to visual inspection because their appearance quality is important. Drinking containers have product names and product names printed on their exterior surfaces, and are also decorated to add value to their appearance design and functionality. Therefore, the state of decoration applied to the container, such as printing, coloring, and painting, is inspected by capturing images of the container's outer periphery. Images of the container's inner surface, including the opening and interior, must also be captured to inspect for scratches and foreign matter. Annular components also need to be inspected for scratches on their inner and outer peripheries. However, in order to inspect a three-dimensional object having inner and outer peripheral surfaces from multiple sides, it is necessary to install multiple imaging means and lighting means, which results in a larger inspection device, higher equipment costs, and a larger installation space.

[0003] Patent Document 1 discloses an inspection device for three-dimensional objects, which includes an optical system that acquires multiple optical images of a three-dimensional object to be inspected, a photoelectric conversion means that converts the incident optical images electrically, and an optical propagation means that supplies the optical images acquired by the multiple optical systems to the photoelectric conversion means as an optical image for one screen. It also discloses an inspection device that includes multiple imaging means, each of which is a set of an imaging device and a mirror that projects optical images of the three-dimensional object to be inspected from multiple directions onto the imaging device by changing the reflection angle, and an image processing means that integrates the imaging results of the multiple imaging means into one screen. Patent document 2 discloses an appearance inspection device that includes multiple imaging means consisting of cameras and mirrors that capture oblique images of an object to be inspected from different directions, and a display means that displays each of the oblique images captured by the multiple imaging means. Patent document 3 discloses an inspection device that includes a reflecting unit arranged at a distance from the side of a container, an imaging unit that images the decorative part of the container through the reflecting unit, and an inspection device that inspects the decorative part based on the image captured by the imaging unit. However, Patent Document 3 is an invention that avoids the horizontal expansion of the installation space of the entire device even if the optical path length from the container to the imaging unit is increased by passing through a reflecting unit, and does not disclose imaging the inner and outer surfaces of the container from multiple angles. [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] Patent Publication No. 2021-105554 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention aims to combine multiple images output from multiple imaging means into a single composite image that is substantially equivalent to a single image acquired from a single imaging means, thereby enabling full-circle inspections and multi-face inspections that require multiple imaging means to be performed with a single image processing unit, thereby making the inspection system more compact and reducing equipment costs. [Means for solving the problem]

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

[0007] (Mode 1) A multi-plane imaging system comprising an imaging section including an illumination means for illuminating an object to be imaged and a plurality of imaging units arranged at a distance around the object to be imaged, an imaging unit control section for controlling the imaging units, an imaging control section including an image synthesis section 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 section and the imaging control section, wherein the imaging unit comprises an imaging means, a plane mirror arranged on the optical axis of the imaging means and rotatable about the optical axis, and an imaging means holding section for holding the imaging means and the plane mirror. The image synthesis unit aggregates multiple images output from multiple imaging means into a single synthesized image using an FPGA (Field-Programmable Gate Array), making it substantially equivalent to a single image acquired from a single imaging means. This allows full-circumference inspections and multi-surface inspections that require multiple imaging means to be performed with a single image processing unit, making the imaging system more compact and reducing equipment costs. In addition, 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 select and image the inner or outer peripheral surfaces of the object to be imaged.

[0008] (Aspect 2) In the multi-plane imaging system according to aspect 1, the imaging units can be moved independently and individually up, down, left, and right by the imaging unit control unit. By independently moving the imaging units up, down, left, and right, the inner and outer surfaces of the object to be imaged can be selected and imaged at will, making it easy to accommodate the workpiece diameter.

[0009] (Aspect 3) In the multi-plane imaging system according to aspect 1 or 2, the illumination means is either surface illumination or pseudo-coaxial epi-illumination, either alone or in combination. By using surface illumination as the illumination means, it is possible to irradiate the inspection object with uniform illumination light, and by using coaxial epi-illumination, it is possible to irradiate the object with illumination light from the same axis as the imaging direction of the imaging means.

[0010] (Embodiment 4) An illumination means for illuminating an object to be inspected, a conveyance means for conveying the object to be inspected, and a plurality of imaging units arranged at intervals around the object to be inspected. of a multi-face appearance inspection system comprising an inspection unit including an imaging unit control unit that controls the imaging units; an image synthesis unit that synthesizes multiple image signals from the inspection object acquired by the multiple imaging units to create a single synthetic image; an inspection control unit that includes an image processing unit that performs image processing on the synthetic image created by the image synthesis unit and a judgment unit that judges the inspection image image processed by the image processing unit; and communication means that connects the inspection unit and the inspection control unit, wherein the imaging unit includes an imaging means, a plane mirror that is arranged on the optical axis of the imaging means and is rotatable about the optical axis, and an imaging means holding unit that holds the imaging means and the plane mirror. The image synthesis unit aggregates multiple images output from multiple imaging means into a single synthesized 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. This allows full-circumference inspections and multi-face inspections that require multiple imaging means to 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, it is possible to arbitrarily select the inner or outer surface of the object to be inspected for visual inspection.

[0011] (Aspect 5) The multi-face visual inspection system according to aspect 4 is characterized in that the imaging units can be moved up, down, left, and right independently and individually by the imaging unit control unit. By independently moving the imaging units up, down, left, and right, the inner and outer surfaces of the object to be inspected can be selected and imaged, easily adapting to the workpiece diameter.

[0012] (Aspect 6) A multi-face appearance inspection system according to either aspect 4 or aspect 5, characterized in that the illumination means is either surface illumination or pseudo-coaxial epi-illumination, either alone or in combination. This is because the use of surface illumination as the illumination means allows the object to be illuminated with uniform illumination light, and the use of coaxial epi-illumination allows the object to be illuminated with illumination light from the same axis as the imaging direction of the imaging means.

[0013] (Aspect 7) An appearance inspection method using a multi-faceted appearance inspection system described in any one of aspects 4 to 6, comprising an imaging condition setting step in which 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 based on the aspect of the object to be inspected; an inspection image synthesis step in which reflected light from the object to be inspected is received and an inspection image is created by synthesizing multiple image signals acquired by the multiple imaging units; a plain image extraction step in which a plain image is created from the inspection image synthesized in the inspection image synthesis step; a pre-processing step in which the plain image is corrected; a feature extraction step in which features are extracted from the corrected plain 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 judgment step in which the pass / fail of the inspection image is judged based on the blob-analyzed inspection image. [Effects of the Invention]

[0014] According to the present invention, by combining multiple images output from multiple imaging means into a single composite image that is substantially equivalent to a single image acquired from a single imaging means, it is possible to perform all-around inspections and multi-face inspections that require multiple imaging means with a single image processing, thereby making the inspection system more compact and reducing equipment costs. Furthermore, by arranging a plurality of imaging units, each of which combines an imaging means and a plane mirror, spaced apart in a circular ring around the object to be imaged, it is possible to select and image the inner and outer surfaces of the object to be imaged as desired. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a configuration diagram illustrating an example of the configuration of a multi-plane imaging system according to the present invention; [Figure 2] 1 is a side view showing one embodiment of an imaging unit that constitutes the multi-plane imaging system of the present invention. [Figure 3] 1 is a cross-sectional view (AA') illustrating an embodiment of imaging by the multi-plane imaging system of the present invention. [Figure 4] 10 is a photograph showing an image of an annular member captured by the multi-plane imaging system of the present invention. [Figure 5] 10 is a photograph showing an image of a container captured by the multi-plane imaging system of the present invention. [Figure 6] 1 is a configuration diagram illustrating a configuration of a multi-face visual inspection system according to the present invention; [Figure 7] FIG. 2 is a flow chart illustrating an inspection flow of the multi-face visual inspection system of the present invention. [Figure 8] 2 is a cross-sectional view (AA') illustrating an example of an inspection mode of the multi-face visual inspection system of the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] An embodiment of the present invention will be described with reference to Figs. 1 to 8. However, Figs. 1 to 8 are merely examples of the embodiment, and the present invention is not limited to these. For example, the arrangement of the imaging units is not limited to those arranged at equal distances (annular) from the object to be imaged, and arrangements where the imaging units are not arranged at equal distances from the object to be imaged are also included.

[0017] A. Multi-plane imaging system 1. Configuration of multi-plane imaging system FIG. 1 is a block diagram illustrating one embodiment of a multi-plane imaging system 100 of the present invention. The multi-plane imaging system 100 of the present invention is composed of an imaging section 1 in which multiple imaging units 10 are arranged at a distance around an object W to be imaged, an imaging control section 2, and a communication means 3 that connects the imaging section 1 and the imaging control section 2. The imaging section 1 is composed of an illumination means 15 that illuminates the object W to be imaged, and a plurality of imaging units 10 that are spaced apart and arranged to surround the object W at a predetermined distance from the center line of the object W. The imaging control unit 2 includes an image synthesis unit 21 that synthesizes multiple image signals acquired by 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 image capture object W, the image capture unit 1, the image capture control unit 2, and the communication means 3 will be described below in that order.

[0018] 2. Image capture target The imaging target object W to be imaged by the multi-plane imaging system 100 of the present invention is not particularly limited as long as it is a three-dimensional object with inner and outer circumferential surfaces. Specific examples include cylindrical objects with an opening on the top surface (e.g., beverage containers such as cans and bottles) whose outer circumferential surfaces are decorated by printing, coloring, painting, or texture, and annular members with inner and outer circumferential surfaces (e.g., O-rings and screw washers). It may be necessary to image both the inner and outer circumferential surfaces of cylindrical objects and annular members with an opening on the top surface, and simultaneous imaging of the inner and outer circumferential surfaces can shorten imaging time and simplify imaging equipment.

[0019] 3. Imaging unit The imaging section 1 constituting the multi-plane imaging system 100 of the present invention includes 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 selected appropriately depending on the form of the imaging target W to be imaged. Specifically, planar illumination, bar illumination, ring illumination, dome illumination, spot illumination, and coaxial epi-illumination consisting of a housing that houses a light source and a half mirror can be used. When coaxial epi-illumination is used, illumination light is irradiated onto the imaging target W from the same axis as 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 W to be imaged, and in the case of planar illumination, it can be placed directly above, on the side, or below the object W to be imaged as appropriate.

[0021] (3-2) Imaging unit 2 is a side view showing one embodiment of an imaging unit 10 constituting the multi-plane imaging system 100 of the present invention. The imaging unit 10 is composed of an imaging means 11, a plane mirror 13 that projects reflected images of the imaging target W seen from multiple directions onto the imaging means 11 by changing the reflection angle, an imaging unit holder 12 that holds the imaging means 11 and the plane mirror 13, and an imaging unit driver 14 that is disposed below the imaging unit holder 12 and drives the imaging unit holder 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 holder 12 by the imaging unit driver 14 are controlled by an imaging unit controller 22 of the imaging controller 2. Fig. 3 is a cross-sectional view (AA') illustrating an embodiment of imaging by the multi-plane imaging system 100 of the present invention. Fig. 3(a) shows an embodiment in which the outer peripheral surface of the imaging object W is imaged, Fig. 3(b) shows an embodiment in which the outer peripheral surface and inner peripheral surface of the imaging object W are imaged, and Fig. 3(c) shows an embodiment in which the peripheral surfaces of the bottom and opening of the imaging object W are imaged.

[0022] (3-2-1) Imaging means The imaging means 11 constituting the imaging unit 10 of the present invention comprises an imaging element using an integrated circuit (IC) that photoelectrically converts reflected light into a video signal, specifically an array of many photodiodes on a planar silicon substrate, and an integrated circuit such as a charge-coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) is used for transfer, an optical system that focuses an image of the inspection workpiece on the imaging surface of the solid-state imaging element, and a signal processing circuit that processes the output of the solid-state imaging element to obtain a brightness value for each pixel. An area camera or a line scan camera can be appropriately selected depending on the type of the inspection object W. When the image capturing object W is stationary, an area camera can be suitably used. When the image capturing object 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 disposed directly below the optical axis of the imaging means 11, and serves to irradiate the imaging means 11 with light reflected from the imaging object W. The plane mirror 13 can irradiate the imaging means 11 with light reflected from any of the inner and outer peripheral surfaces of the imaging object W by controlling the rotation angle (θ) to change the reflection angle of the light reflected from the imaging object W.

[0024] (3-2-3) Imaging unit holder The imaging unit holding section 12 constituting the imaging unit 10 of the present invention serves to hold the imaging means 11 and the plane mirror 13, and to change the distance (L) between the imaging means 11 and the plane mirror 13. In addition, the imaging unit driving section 14 drives the imaging unit holding section 12 itself up, down, left, and right.

[0025] (3-2-4) Imaging unit drive unit The imaging unit driving section 14 constituting the imaging unit 10 of the present invention also drives the imaging unit holding section 12 itself up and down and left and right.

[0026] 4. Imaging control unit The imaging control unit 2 that constitutes the multi-plane imaging system 100 of the present invention includes an image synthesis unit 21, an imaging unit control unit 22, and an information storage unit 23, and may also include a display device 24 and an input device 25, which are various interfaces for input and output.

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

[0028] (4-2) Imaging unit control section The imaging unit control unit 21 that 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 / right driving of the imaging unit holding unit 12 by the imaging unit driving unit 14.

[0029] (4-3) Information storage section The information storage unit 21 constituting the imaging control unit 2 of the present invention includes a ROM (Read Only Memory) and a 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 required for executing these programs. The various programs and information stored in the ROM are loaded into the RAM and executed.

[0030] 5. Means of communication The communication means 3 of the present invention serves to transmit a plurality of image signals acquired by each of the plurality of imaging units (10a to 11f) to the image synthesis unit 21. It also has a function to control operations such as the timing of imaging of the imaging means 11 via a general-purpose communication interface such as Camera Link, USB (Universal Serial Bus), CXP (CoaXPress (registered trademark)), Gigabit Ethernet (GigE), etc.

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

[0032] B. Visual inspection system using a multi-surface imaging system 1.Configuration of visual inspection system using multi-surface imaging system FIG. 6 is a configuration diagram illustrating an example of the configuration of a visual inspection system (hereinafter referred to as a "multi-plane visual inspection system") that employs the multi-plane imaging system of the present invention. The multi-faceted visual inspection system 200 of the present invention is composed of an inspection section 4 in which multiple imaging units 10 are arranged at a distance around the object to be inspected W, an inspection control section 5, and a communication means 3 that connects the inspection section 4 and the inspection control section 5. The multi-surface visual inspection system 200 uses the imaging unit 1 of the multi-surface imaging system 100 described above as the inspection unit 4, and has the same configuration as the imaging unit 1 of the multi-surface imaging system 100 described above, except that it is provided with a transport means 6 for transporting the inspection object (image object) W. By using the imaging unit 1 of the multi-surface imaging system 100 as the inspection unit 4, the multi-surface visual inspection system 200 is characterized in that it can simultaneously inspect the inspection object W from multiple viewpoints. The inspection section 4 includes an illumination means 15 for illuminating the inspection object W, a plurality of imaging units 10 arranged at a predetermined distance from the center line of the inspection object W so as to surround the imaging object W, and a transport means 6 for transporting the inspection object 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 a composite image based on multiple inspection image signals acquired by each of the multiple imaging units (10a to 10f), an image processing unit 26 that performs image processing on the composite image synthesized by the image synthesis unit 21, a judgment unit 27 that judges whether the appearance of the inspection object 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 inspection object W, the inspection unit 10, and the communication means 3 are the same as those of the image capture object W and the image capture unit 1 described above, and therefore a description thereof will be omitted. The inspection control unit 5 will be described below.

[0033] 2. Inspection control unit The inspection control unit 5 constituting the multi-sided appearance inspection system 200 of the present invention includes an imaging unit control unit 22 that controls the imaging unit 10, an image synthesis unit 21 that synthesizes and displays a composite image of multiple inspection image signals acquired by each of the multiple imaging units (10a to 10f), an image processing unit 26 that performs image processing on the composite image synthesized by the image synthesis unit 21, a judgment unit 27 that judges whether the appearance of the inspection object W is good or bad based on the inspection image created by the image processing unit 26, an information memory unit 23, an image memory unit 28, and a transport control unit 29, and may also include a display device 24 and an input device 25, which are various interfaces for input and output.

[0034] (2-1) Image synthesis unit The image synthesis unit 21 constituting the inspection control unit 5 of the present invention is configured by a board equipped with an FPGA (Field-Programmable Gate Array) that functions as a CPU (Central Processing Unit) and memory such as a ROM (Read Only Memory) and RAM (Random Access Memory). It plays a role in 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 a display device 24.

[0035] (2-2) Imaging unit control section 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 / right driving of the imaging unit holding unit 12 by the imaging unit driving unit 14.

[0036] (2-3) Information storage section The information storage unit 23 constituting the inspection control unit 2 of the present invention includes a ROM (Read Only Memory) and a 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 required when these programs are executed. The various programs and information stored in the ROM are loaded into the RAM and executed.

[0037] (2-2) Image processing unit The image processing unit 26 constituting the inspection control unit 5 of the present invention performs various image processing 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 a ROM (Read Only Memory) and a RAM (Random Access Memory). The ROM stores various programs, such as an inspection method program, executed by the CPU, as well as information required for executing these programs. The various programs and information stored in the ROM are loaded into the RAM and executed.

[0039] (2-4) Judgment section The judgment unit 27 constituting the inspection control unit 5 of the present invention plays a role in judging the quality of the appearance of the inner and outer peripheral surfaces of the inspection object W. Specifically, the quality is judged by comparing the inspection image with a reference image stored in the image storage unit 28.

[0040] (2-5) Transport control unit The transport control unit 29 constituting the inspection control unit 5 of the present invention controls the transport means 6 that transports the inspection objects W arranged at equal intervals. The inspection objects W are inspected on the transport means 6 in the inspection unit 4. After the inspection, the inspection objects W are transported by the transport means 6.

[0041] C. Multi-faceted visual inspection method Fig. 7 is a flow diagram illustrating the inspection flow of the multi-plane visual inspection system 200 of the present invention. Fig. 8 is a cross-sectional view (AA') illustrating an inspection mode of the multi-plane visual inspection system 200 of the present invention. The ring visual inspection system 200 of the present invention performs visual inspection of the inspection target W in the following procedure.

[0042] 1. Inspection condition setting Based on the configuration of the inspection object W (e.g., container, annular member, height, width), the arrangement of the illumination means 15 and the imaging unit 10, the height of the imaging means 11, and the rotation angle (θ) of the plane mirror 13 are set (S11). Specifically, the position of the lighting means 15 is selected to make the illumination light irradiated onto the inspection object W 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 driving unit 14 so that the imaging means 11 can appropriately receive reflected light from the inspection position of the inspection object W.

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

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

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

[0046] (3-2) Pretreatment The pre-processing (S14) is a process for improving the accuracy of the feature extraction process (S15). Specifically, position correction, image calculation, LUT correction, brightness correction, blurring, etc. are selected and performed as appropriate according to the state of the plane extraction image.

[0047] (3-3) Feature extraction The feature extraction process (S15) is a process for extracting characteristic lines and density boundary regions from a plain image. Specifically, it is performed by appropriately selecting from the following: Region of Interest (ROI), masking, reference difference, binarization, and optical character recognition (OCR) analysis.

[0048] (3-4) Post-processing Post-processing (S16) is a process for improving the accuracy of the blob analysis process (S17). Specifically, hole filling, feature linking, feature calculation, and noise removal are selected and performed as appropriate according to the state of the feature extraction image.

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

[0050] (4) Inspection image judgment The judgment unit 27 compares the inspection image with the reference image to judge whether the appearance of the inspection object W is good or bad (S18). [Industrial Applicability]

[0051] The present invention makes it possible to provide full-circumference 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 Imaged object, inspected object 1. Imaging unit 2. Imaging control section 3. Means of communication 4. Inspection Department 5 Inspection control section 6. Means of transport 7 Half Mirror 10. Imaging unit 11 Imaging means 12 Imaging unit holding section 13 plane mirror 14 Imaging unit drive section 15 Lighting means 16. Image capture object holder 17. Image capture object lifting unit 21 Image synthesis unit 22 Imaging unit control section 23 Information storage section 24 Display device 25 Input Devices 26 Image processing section 27 Judgment section 28 Image storage unit 29 Conveyor control unit

Claims

1. an imaging section including an illumination means for illuminating an object to be imaged and a plurality of imaging units arranged at intervals around the object to be imaged; an imaging control unit including an imaging unit control unit for controlling the imaging units; and an imaging control unit including an image synthesis unit for synthesizing a plurality of image signals from the imaging object acquired by the plurality of imaging units to create a single synthesized image; a communication means for connecting the imaging unit and the imaging control unit; A multi-plane imaging system comprising: the imaging unit includes an imaging means, a plane mirror disposed on an optical axis of the imaging means and rotatable about the optical axis, and an imaging means holder that holds the imaging means and the plane mirror; A multi-plane imaging system.

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

3. 3. The multi-plane imaging system according to claim 1, wherein said illumination means is either a surface illumination or a pseudo-coaxial epi-illumination, either alone or in combination.

4. an inspection unit including an illumination means for illuminating an inspection object, a transport means for transporting the inspection object, and a plurality of imaging units arranged at intervals around the inspection object; an inspection control unit including an imaging unit control unit that controls the imaging units; an image synthesis unit that synthesizes a plurality of image signals from the inspection object acquired by the plurality of imaging units to create a single synthetic image; an image processing unit that processes the synthetic image created by the image synthesis unit; and a determination unit that determines the inspection image image processed by the image processing unit; a communication means for connecting the inspection unit and the inspection control unit; A multi-surface visual inspection system comprising: the imaging unit includes an imaging means, a plane mirror disposed on an optical axis of the imaging means and rotatable about the optical axis, and an imaging means holder that holds the imaging means and the plane mirror; A multi-faceted visual inspection system.

5. 5. The multi-face appearance inspection system according to claim 4, wherein the imaging units can be moved up, down, left, and right independently and individually by the imaging unit control unit.

6. 6. A multi-face appearance inspection system according to claim 4, wherein said illumination means is either a surface illumination or a pseudo-coaxial epi-illumination, either alone or in combination.

7. A visual inspection method using the multi-face visual inspection system according to claim 4 or 5, comprising: an imaging condition setting step in which the arrangement of the illumination means and the vertical positions of each of the plurality of imaging units, the angle and position of the plane mirror, and the optical path length between the imaging means and the plane mirror are set by the imaging unit control unit based on the state of the inspection object; an inspection image synthesis step of receiving reflected light from the inspection object and synthesizing a plurality of image signals acquired by the plurality of imaging units to create an inspection image; a plain image extraction step of creating a plain image from the inspection image synthesized in the inspection image synthesis step; a pre-processing step of correcting the plain image; a feature extraction step of extracting features from the corrected plain image; a post-processing step of correcting the feature-extracted inspection image; a blob analysis step of performing blob analysis on the corrected inspection image; an inspection image determination step of determining whether the inspection image passes or fails based on the inspection image subjected to blob analysis; A visual inspection method comprising:

Images