Appearance inspection system, appearance inspection device, control method for appearance inspection device, and program

Abstract

To provide a technique for supporting visual inspection of a portion where an abnormality has been detected without adding separate illumination means and imaging means in an appearance inspection system.SOLUTION: An appearance inspection system comprises: illumination means that irradiates an inspection object with illumination light under illumination conditions based on variable illumination parameters; imaging means that images the inspection object; inspection means that inspects the inspection object on the basis of feature quantities of a first image captured under a first imaging condition defined by at least predetermined illumination parameters using the illumination means and the imaging means; and display means that can display a second image captured under a second imaging condition having illumination parameters different from those of the first imaging condition, using the illumination means and the imaging means, for a region including at least an inspection portion where a defect has been detected by the inspection means.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to an appearance inspection system, an appearance inspection device, and a control method and program for an appearance inspection device. [Background technology]

[0002] Visual inspection devices have been known for some time that detect defects in products based on photographed images of the products (including determining the presence or absence of defects and the type of defects). These inspection devices generally detect defects by irradiating an object to be inspected (hereinafter also referred to as a workpiece or an object to be inspected) with illumination light, capturing the reflected light (and / or transmitted light) of the illumination light with a camera, and setting a threshold value for detecting anomalies based on the feature amount of pixel values ​​corresponding to defects that appear in the photographed image.

[0003] For products that are diagnosed as defective by inspection using such a visual inspection device, it is common for an inspector to visually inspect the image used for the inspection (hereinafter simply referred to as the inspection image) again to confirm whether a non-defective product has been detected as defective. For this reason, a visual inspection terminal is provided in addition to the visual inspection device on the product production line.

[0004] Conventional visual inspection terminals display images taken by visual inspection equipment to detect defects, and inspectors visually inspect the images. However, while humans can best distinguish between good and defective products using uniform, shadow-free images taken under white light, the images used for inspection by visual inspection equipment are images used to classify good and defective products based on features such as color brightness (images that make it easier for the inspection program to distinguish between good and defective products), and are therefore not suitable for visual inspection by the human eye.

[0005] In response to this, a technology has been proposed in which a visual inspection terminal used together with a substrate appearance inspection device is equipped with dedicated imaging and lighting means, and images suitable for assisting in checking defects through visual inspection are captured and displayed (for example, Patent Documents 1 and 2). Such a technology makes it possible to perform visual inspection based on images suitable for visual inspection by the human eye. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-58170 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-349540 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the techniques described in the above patent documents require an additional imaging system (camera, lighting) that is different from the appearance inspection device, which poses a problem of increasing the device size (inspection line space) and costs.

[0008] The present invention has been made in consideration of the above-described circumstances, and its purpose is to provide a technology that supports visual inspection of areas where abnormalities have been detected in an appearance inspection system without adding separate lighting and photographing means. [Means for solving the problem]

[0009] In order to solve the above problems, the visual inspection system according to the present invention employs the following configuration: an illumination means for irradiating the object to be inspected with illumination light under illumination conditions based on variable illumination parameters; an imaging means for imaging the inspection object; an inspection means for inspecting the inspection object based on a feature amount of a first image captured under first imaging conditions defined based on at least the predetermined illumination parameters using the illumination means and the imaging means; a display means capable of displaying a second image of an area including at least an inspection point where a defect has been detected by the inspection means, the second image being captured using the illumination means and the imaging means under second imaging conditions in which the illumination parameters are different from the first imaging conditions; and The visual inspection system has the following features.

[0010] The shooting conditions referred to here include, for example, lighting conditions defined by various lighting parameters such as the color (wavelength), intensity (brightness), and irradiation direction of the illumination light, and combinations of these, as well as shooting conditions defined by various imaging parameters such as the camera exposure time and gain, and combinations of these.

[0011] With this configuration, the first image (an image taken under imaging conditions optimized for visual inspection by the inspection means) and the second image (an image taken under imaging conditions optimized for visual inspection) can be obtained using the same lighting means and imaging means, thereby realizing a visual inspection system that can increase the efficiency and accuracy of visual inspection while suppressing increases in the installation space and costs of the device.

[0012] The illumination unit may be configured to change the illumination parameter related to the color of the illumination light, and the second photographing condition may be a color of the illumination light adjusted for visual inspection. The color of the illumination light adjusted for visual inspection may be, for example, white.

[0013] The illumination means may be configured to change the illumination parameter related to the irradiation direction of the illumination light, and the second photographing condition may be the irradiation direction adjusted for visual inspection. The irradiation direction may include either a circumferential direction on a horizontal plane centered on the inspection object or a circumferential direction on a vertical plane centered on the inspection object. The irradiation direction adjusted for visual inspection may be, for example, irradiation from two opposing directions on a circle on a horizontal plane centered on the inspection object.

[0014] The illumination means may also include coaxial incident illumination that irradiates the object to be inspected with illumination light along the same axis as the optical axis of the imaging means, and circumferential illumination that irradiates the object to be inspected with illumination light from concentric circumferential directions centered on the axis.

[0015] The photographing means may photograph the corresponding second image only for the first image including the inspection location for which the inspection result by the inspection means is unsatisfactory. In this case, images for visual inspection are acquired only for areas where defects are detected by visual inspection based on feature quantities, which can contribute to reducing the inspection takt time and the memory capacity required to hold image data.

[0016] Further, the photographing means photographs the inspection object under photographing conditions based on variable photographing parameters, and the first photographing conditions are defined based on predetermined illumination parameters and predetermined photographing parameters, and the illumination parameters related to the illumination means and the photographing parameters are changed only for the first image including the inspection point where the inspection result by the inspection means is unsatisfactory. The second image may be captured using different imaging parameters related to the means. By adjusting the imaging parameters in addition to the illumination parameters, an image can be captured in which halation (bloated highlights) caused by foreign matter is suppressed.

[0017] Furthermore, the photographing means may be configured to wait for the inspection means to finish the inspection of each first image before photographing the next first image. This configuration allows for more efficient inspection than waiting for the completion of inspection of all inspection points and then aligning the illumination means and photographing means (relatively) with respect to a point where a defect has been detected. Furthermore, since it is not necessary to realign the photographing means with respect to the object to be inspected, it is possible to prevent adverse effects such as misalignment that may occur when doing so.

[0018] The appearance system may further include an image processing unit that performs predetermined image processing on the second image, and the display unit may display the second image after the image processing has been performed. The image processing may include, for example, changing the brightness or contrast of the second image, or highlighting a point of interest. This not only makes the lighting parameters and imaging parameters more suitable for visual inspection, but also makes the acquired image more suitable for visual inspection, thereby further reducing the burden on the inspector.

[0019] The display means may display the first image including the inspection location where the inspection means has determined that the inspection was defective, and the second image capturing the corresponding area, side by side. With this configuration, an inspector can perform a visual inspection of the second image optimized for visual inspection while checking the first image where the inspection means has actually determined that the inspection was defective.

[0020] The present invention can also be understood as an appearance inspection device as follows: an illumination means for irradiating the object to be inspected with light under illumination conditions based on variable illumination parameters; an imaging means for imaging the inspection object; an inspection means for inspecting the inspection object based on a feature amount of a first image captured under first imaging conditions defined based on at least the predetermined illumination parameters using the illumination means and the imaging means; an output means for outputting a second image of a region including at least an inspection point where a defect has been detected by the inspection means, the second image being captured under second imaging conditions in which the illumination parameters are different from the first imaging conditions using the illumination means and the imaging means; The visual inspection device has the following features.

[0021] The term "output" as used herein also includes transmitting image data to another device via a communication means.

[0022] The present invention can also be understood as a control method for an appearance inspection apparatus as follows: A control method for a visual inspection apparatus including an illumination unit that irradiates an inspection object with illumination light under illumination conditions based on variable illumination parameters, an imaging unit, and an inspection unit, comprising: a first photographing step of photographing the inspection object under first photographing conditions defined based on at least the predetermined illumination parameters by the illumination means and the photographing means; an inspection step of inspecting the inspection object based on a feature amount of a first image captured under the first photographing condition by the inspection means; a second photographing step of photographing an area including at least an inspection point where a defect has been detected in the inspection step, using the illumination means and the photographing means under second photographing conditions in which the illumination parameters are different from the first photographing conditions; an output step of outputting a second image captured under the second photographing condition; The present invention relates to a method for controlling an appearance inspection apparatus, comprising the steps of:

[0023] The present invention can also be understood as a program for causing a computer to execute the above-described method, or a computer-readable recording medium on which such a program is non-transitoryly recorded.

[0024] The above processes and means can be freely combined and implemented as long as no technical contradiction occurs. [Effects of the Invention]

[0025] According to the present invention, it is possible to provide a technology for supporting visual inspection of a location where an abnormality has been detected in a visual inspection system without adding a separate lighting means and photographing means. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a block diagram showing an outline of the functional configuration of a visual inspection system according to an application example. [Figure 2] FIG. 2 is a schematic diagram showing a schematic configuration of an inspection device main body according to an application example. [Figure 3] FIG. 3 is a schematic diagram showing an overview of the entire appearance inspection system according to the embodiment. [Figure 4] FIG. 4 is a block diagram showing an outline of the functional configuration of the visual inspection system according to the embodiment. [Figure 5] FIG. 5 is a schematic diagram showing the configuration of the imaging unit of the visual inspection apparatus according to the embodiment. [Figure 6] FIG. 6 is an explanatory diagram of the configuration of the illumination unit of the visual inspection apparatus according to the embodiment. [Figure 7] FIG. 7 is a flowchart showing an example of the flow of processing performed by the visual inspection apparatus according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings.

[0028] <Application example> The present invention can be applied, for example, as an appearance inspection system according to this application example. FIG. 1 is a block diagram showing an outline of the functional configuration of an appearance inspection system 9 according to this application example, and FIG. 2 is a diagram showing a schematic configuration of an inspection device main body 91 according to this application example. As shown in FIG. 1, the appearance inspection system 9 according to this application example photographs an object to be inspected (hereinafter also referred to as a workpiece) and performs an appearance inspection of the workpiece based on the acquired photographed image data. The appearance inspection system 9 includes an inspection device main body 91, a control unit 92, an output unit 93, an input unit 94, and a memory unit 95, which are communicatively connected. The inspection device main body 91 also includes an imaging unit 911, a first illumination unit 912, and a second illumination unit 913.

[0029] The control unit 92 is configured with a processor such as a CPU (Central Processing Unit), and includes, as functional modules, an imaging control unit 920, an image processing unit 921, an inspection unit 922, and an illumination control unit 923. The output unit 93 is used to output an interface screen, inspection results, acquired images, etc., and is typically configured with a display device. When a second image for visual inspection, which will be described later, is generated, the output unit 93 displays this image.

[0030] The input unit 94 is used to input conditions and parameters required for the inspection, and is configured with various input devices such as a keyboard, a mouse, a controller, a touch panel, etc. The storage unit 95 is configured with a main memory such as a RAM (Random Access Memory), for example. The visual inspection system 9 is configured with a storage device, an auxiliary storage device such as a hard disk, etc. The control unit 92, output unit 93, input unit 94, and storage unit 95 may be configured integrally with the inspection device main body 91, or may be configured as a separate general-purpose computer. When the control unit 92, output unit 93, input unit 94, and storage unit 95 are configured integrally with the inspection device main body, the visual inspection system 9 can also be considered as a visual inspection device.

[0031] The photography control unit 920 drives the photography unit (camera) 911, workpiece holder (not shown), etc. of the inspection device main body 91, and controls the operation of the device related to photography of the workpiece. Specifically, it drives and controls the camera and workpiece holder so that a first image can be acquired for all of the parts of the workpiece that are to be inspected, and when a defect is detected in the workpiece by the inspection unit 922 described below, it drives and controls the camera and workpiece holder so that a second image for visual inspection is taken in the same field of view as the image in which the defect was detected.

[0032] The image processing unit 921 processes the image data of the workpiece photographed by the photographing unit 911, and generates a first image for inspection by the inspection unit 922 and a second image for visual inspection by an inspector. Here, the first image is an image generated based on an image of the workpiece photographed under photographing conditions in which lighting parameters for inspection by the inspection unit 922 have been set, and the second image is an image generated under photographing conditions in which lighting parameters for visual inspection by an inspector have been set. The image data of the workpiece photographed by the photographing unit 911 is stored in the storage unit 95.

[0033] The inspection unit 922 judges whether the workpiece is good or bad based on the first image generated by the image processing unit 921. Specifically, based on a threshold value of the feature amount set in advance according to the type of defect, the inspection unit 922 judges whether there is a defect in the workpiece and determines the type of defect from the feature amount of each pixel that constitutes the image.

[0034] The lighting control unit 923 controls the first lighting unit 912 and the second lighting unit 913 (described later) to set the light irradiated onto the workpiece to a predetermined lighting condition. Here, the lighting condition is a condition defined by each lighting parameter, such as the color (wavelength), intensity (brightness), and irradiation direction of the lighting light, and a combination of these. The lighting control unit 923 first sets each lighting to the lighting condition for the first image, and if a defect in the workpiece is detected based on the captured first image, sets each lighting to the lighting condition for the second image for visual inspection. The lighting conditions for the first image and the second image are defined differently, and in this application example, the lighting condition for the second image is set so that white light is irradiated onto the workpiece.

[0035] As shown in FIG. 2, the photographing unit 911 of this application example is disposed above the workpiece W with its optical axis facing vertically. A beam splitter 914 such as a half mirror is disposed on the optical axis of this photographing unit 911, and a first illumination unit 912 for coaxial epi-illumination is disposed relative to the beam splitter 914 in a direction perpendicular to the optical axis of the photographing unit 911. This first illumination unit 912 is configured with a plurality of LED (Light Emitting Diode) light sources (912R, 912G, 912B) that respectively emit light of, for example, red, green, and blue. Each LED light source is disposed with its optical axis facing the beam splitter 914, and the light emitted from each LED light source is mixed and irradiated toward the workpiece W via the beam splitter 914.

[0036] A second illumination unit 913 for oblique incidence illumination is provided below the beam splitter 914. This second illumination unit 913 is configured with multiple LED light sources (913R, 913G, 913B) each with its optical axis oriented vertically and arranged in a ring shape. A diffuser 915 is disposed between the second illumination unit 913 and the workpiece W. As a result, the red, green, and blue light are mixed and irradiated toward the workpiece W via the diffuser 915.

[0037] Here, for the first lighting unit 912 and the second lighting unit 913, only the red, green, and blue light sources may be switchable on and off, or the light amount (illumination intensity) for each LED light source may be adjustable in stages, for example, in 256 stages.

[0038] According to the configuration of this application example as described above, if a defect is detected in a workpiece during inspection by the inspection unit 922, a second image is separately captured under lighting conditions for visual inspection for the same field of view as the first image in which the defect was detected, and this second image is displayed on the output unit 93. Here, the second image is an image captured under lighting conditions suitable for visual inspection for a field of view that includes the location determined to be defective by the inspection unit 922, which contributes to improving the accuracy and efficiency of visual inspection by the inspector and can also reduce the burden on the inspector. Furthermore, because the camera and lighting for capturing the second image are the same as those for capturing the first image for visual inspection by the inspection unit 922, problems such as an increase in installation space and cost for the device do not arise (or are limited).

[0039] <Embodiment> Next, an example of an embodiment of the present invention will be described in more detail. However, unless otherwise specified, the dimensions, materials, shapes, relative positions, and the like of the components described in this embodiment are not intended to limit the scope of the present invention to those.

[0040] (Overall system configuration) FIG. 3 is a schematic diagram showing the schematic configuration of an appearance inspection system 1 according to this embodiment. The appearance inspection system 1 according to this embodiment is installed in a manufacturing line for products (for example, component-mounted boards), and is configured to photograph a product (hereinafter, workpiece) W to be inspected, and perform an appearance inspection of the workpiece based on the photographed image data obtained. As shown in FIG. 3, the appearance inspection system 1 is generally configured to include an appearance inspection device 10, a teaching terminal 20, a NAS (Network Attached Storage) 30, and a visual inspection terminal 40, and these elements are connected via a LAN (Local Area Network) or a WAN (Wide Area Network). They are connected by communication networks such as the Network.

[0041] The appearance inspection device 10 is equipped with an imaging optical system as described below, and judges whether the workpiece W is good or bad based on image data acquired by photographing the workpiece W. Details of the appearance inspection device 10 will be described later.

[0042] The teaching terminal 20 is a terminal for creating an inspection program for image inspection by the appearance inspection device 10 and for changing the settings of the appearance inspection device 10. Specifically, it is possible to set inspection standards for inspection and photographing conditions such as lighting conditions (lighting parameters) and photographing conditions (photography parameters) when photographing the workpiece W, and transmit these to the appearance inspection device 10 and the NAS 30. The teaching terminal can be configured, for example, by a general-purpose computer, but a dedicated device can also be used.

[0043] The NAS 30 is a large-capacity storage means for storing various information such as an inspection program created by the teaching terminal 20, photographing conditions, design information related to the workpiece W, and data of images photographed by the appearance inspection device 10. Note that a configuration in which a data server is employed instead of the NAS 30 may also be used.

[0044] The visual inspection terminal 40 is configured by a computer equipped with a display means, and is a terminal that allows an inspector to visually confirm whether or not a workpiece W that has been determined to be defective by the visual inspection device 10 is actually a defective product. An image including the area determined to be defective by the visual inspection device 10 is displayed on the display means of the visual inspection terminal 40, and the inspector visually checks the image, determines whether or not the determination result of the visual inspection device 10 is correct, and inputs the determination result.

[0045] (visual inspection equipment) Fig. 4 is a block diagram showing an outline of the functional configuration of the appearance inspection device 10 according to this embodiment. Fig. 5 is a schematic diagram showing the configuration of the photographing unit 11 of the appearance inspection device 10 according to this embodiment. As shown in Fig. 4, the appearance inspection device 10 according to this embodiment includes, as its functional configuration, the photographing unit 11, a control unit 12, an output unit 13, an input unit 14, a storage unit 15, and a communication unit 16.

[0046] The photographing unit 11 has, as a hardware configuration, an imaging optical system of a camera 111, lighting means (112, 113, 114, 115), and means for holding a workpiece W, and is responsible for functions related to photographing the workpiece W. The specific hardware configuration of the photographing unit 11 will be described later.

[0047] The control unit 12 is a processing unit, and includes, as functional modules, an imaging control unit 120, an image processing unit 121, an inspection unit 122, and an illumination control unit 123. These functional modules will be described later.

[0048] The output unit 13 can be configured with a hardware such as a liquid crystal display device, and outputs various interface screens, test results, images captured by the imaging unit 11, and the like.

[0049] The input unit 14 may employ, as its hardware configuration, for example, a keyboard, a mouse, a controller, a touch panel, etc., and is used to input various information relating to the visual inspection of the workpiece W.

[0050] The memory unit 15 includes, for example, a main memory device such as RAM and an auxiliary memory device such as a hard disk, and can store various data such as programs for realizing each functional module of the control unit 12, image data acquired by the camera 111, and inspection programs.

[0051] The communication unit 16 can adopt an appropriate communication interface as a hardware configuration depending on the communication network to which it is connected, such as a wired communication port or a wireless communication antenna, and performs bidirectional information communication with the teaching terminal 20, NAS 30, and visual inspection terminal 40.

[0052] (Configuration of the shooting unit) Next, the optical system of the imaging unit 11 will be described in detail with reference to Fig. 5 and Fig. 6. Fig. 5 is a deformed cross-sectional view of the imaging unit 11 when viewed from a direction perpendicular to the optical axis direction of the camera 111, and Fig. 6 is an explanatory diagram showing the second illumination unit 113, third illumination unit 114, and fourth illumination unit 115 of the imaging unit 11 in a plan view.

[0053] 5, the photographing unit 11 has a dome-shaped portion that covers the inspection position, and includes a camera 111 as an observation optical system, and a half mirror 116 disposed between the camera 111 and the inspection position. The photographing unit 11 also includes a first illumination unit 112, a second illumination unit 113, a third illumination unit 114, and a fourth illumination unit 115 as an illumination optical system.

[0054] The camera 111 has an imaging element in which n x m light receiving elements are arranged in a matrix, and is capable of capturing color images. The light receiving elements that detect light output a signal to the control unit 12, which then acquires image data. Each light receiving element of the imaging element corresponds to each pixel of the captured image. The camera 111 is positioned so that its optical axis faces vertically above the workpiece W, and the inspection position where the workpiece W is placed is included in the imaging area, and the workpiece W at the inspection position is imaged through the half mirror 116. The workpiece W may be an item with or without uneven gloss.

[0055] Each of the first illumination unit 112, second illumination unit 113, third illumination unit 114, and fourth illumination unit 115 irradiates illumination light onto the workpiece W placed at the inspection position. As will be described later, each illumination unit is controlled by an illumination control unit 123 to adjust the color, light intensity, and direction of the illumination light irradiated onto the inspection object.

[0056] The first illumination unit 112 is provided at approximately the same height as the half mirror 116. The height direction here corresponds to the optical axis direction of the camera 111. The first illumination unit 112 has one or more light-emitting element groups, each group consisting of a red LED 112R that emits red light, a green LED 112G that emits green light, and a blue LED 112B that emits blue light. The red LED 112R, the green LED 112G, and the blue LED 112B are arranged with their light-emitting surfaces facing the half mirror 116. Light emitted by activating at least one of the red LED 112R, the green LED 112G, and the blue LED 112B is the illumination light of the first illumination unit 112. The illumination light of the first illumination unit 112 is irradiated onto the workpiece W by the half mirror 116 from a direction aligned with the optical axis of the camera 111. That is, the illumination light from the first illumination unit 112 is a coaxial epi-illumination that irradiates the object in a direction in which specularly reflected light reflected from the object to be inspected is received by each light receiving element of the camera 111.

[0057] The light emission intensities (including ON / OFF of light emission, the same applies below) of the red LED 112R, green LED 112G, and blue LED 112B are set under the control of the illumination control unit 123. The light emission intensity can be adjusted in 256 steps.

[0058] As shown in Figures 5 and 6, the second lighting unit 113, the third lighting unit 114, and the fourth lighting unit 115 are ring-shaped spaces in a planar view centered on the optical axis of the camera 111, and are arranged in this order from the inner side to the outer side of a circle centered on the optical axis of the camera 111.

[0059] As shown in FIG. 6, the second illumination unit 113, the third illumination unit 114, and the fourth illumination unit 115 are each divided into four equal parts in the circumferential direction: a first illumination area 110a, a second illumination area 110b, a third illumination area 110c, and a fourth illumination area 110d. The light intensity of each area can be adjusted. By dividing each illumination unit into four areas in this way, it is possible to irradiate the workpiece W with illumination light from eight directions by combining the areas to be illuminated (specifically, four directions when only one of the four areas is lit, and four directions when two adjacent areas are lit). The total number of combinations of illuminated areas is 13, including when all areas are lit.

[0060] The second illumination unit 113 has a plurality of light-emitting element groups, each group consisting of a red LED 113R that emits red light, a green LED 113G that emits green light, and a blue LED 113B that emits blue light. The second illumination unit 113 has a plurality of light-emitting element groups arranged in a ring shape, and the red LED 113R, green LED 113G, and blue LED 113B are attached with their light-emitting surfaces facing downward (toward the inspection position).

[0061] Further, a diffusion plate is attached to the lower end side of the second illumination section 113, which irradiates the illumination light from the second illumination section 113 at an angle so as to irradiate the inspection position.

[0062] The light emitted by emitting light from at least one of the red LED 113R, green LED 113G, and blue LED 113B is the illumination light of the second illumination unit 113. The light emission intensity (including ON / OFF of light emission) of the red LED 112R, green LED 112G, and blue LED 112B is set in 256 stages under the control of the illumination control unit 123.

[0063] It should be noted that the third illumination section 114 and the fourth illumination section 115 have the same configuration as the second illumination section 113, and therefore detailed description thereof will be omitted.

[0064] The second illumination section 113, the third illumination section 114, and the fourth illumination section 115 are each separated by a light blocking plate, which prevents the illumination light from an adjacent illumination section from being incident on each other's illumination section.

[0065] Light emitted by at least one color from each color LED of the second illumination unit 113, the third illumination unit 114, and the fourth illumination unit 115 is irradiated onto the workpiece W through a diffuser plate. Here, when LEDs of two or more colors are emitted, the light is mixed on the LED side of the diffuser plate and then irradiated onto the workpiece W through the diffuser plate. Note that the inclination angles of the diffuser plates of each illumination unit with respect to the optical axis of the camera 111 are different, and therefore the irradiation angles of the illumination light irradiated onto the workpiece W by the second illumination unit 113, the third illumination unit 114, and the fourth illumination unit 115 are different.

[0066] For example, illumination light produced by emitting light from at least one of the red LED 113R, green LED 113G, and blue LED 113B of the second illumination unit 113 is irradiated onto the workpiece W from a direction that forms an angle of approximately 20° with the optical axis of the camera 111. Furthermore, illumination light produced by emitting light from at least one of the red LED 114R, green LED 114G, and blue LED 114B of the third illumination unit 114 is irradiated onto the workpiece W from a direction that forms an angle of approximately 37° with the optical axis of the camera 111. Furthermore, illumination light produced by emitting light from at least one of the red LED 115R, green LED 115G, and blue LED 115B of the fourth illumination unit 115 is irradiated onto the workpiece W from a direction that forms an angle of approximately 60° with the optical axis of the camera 111. In FIG. 5, the solid arrow indicates the irradiation direction of the illumination light.

[0067] (Controller function module) The photography control unit 120 drives the camera 111, the workpiece holding unit (not shown), etc., and controls the operation of the device related to photographing the workpiece. Specifically, for the camera 111, it determines the timing of imaging and adjusts imaging parameters such as exposure time and gain. Also, by changing the relative positional relationship on the horizontal plane between the camera 111 and the workpiece W, a first image is acquired for all of the inspection target locations of the workpiece W. Note that, if a defect is detected in the workpiece by the inspection unit 122 described below, it drives and controls the camera 111 and the workpiece holding unit so as to photograph a second image for visual inspection in the same field of view as the image in which the defect was detected.

[0068] Regarding the exposure time and gain of the camera 111, different parameters may be set for the first image for inspection by the inspection unit 122 and the second image for visual inspection, or different parameters may be set depending on the content of the workpiece W. Specifically, for example, in the case where there are many metal parts on a component mounting board, the exposure time may be lengthened and the gain may be reduced in order to suppress halation.

[0069] The image processing unit 121 processes the image data of the workpiece W captured by the camera 111, and generates a first image for inspection by the inspection unit 122 and a second image for visual inspection by an inspector. Examples of the image processing performed here include contrast correction, brightness correction, edge enhancement processing, etc.

[0070] The first image is an image generated based on an image of the workpiece photographed under photography conditions in which photography parameters for inspection by the inspection unit 122 have been set, and the second image is an image generated under photography conditions in which photography parameters for visual inspection by an inspector have been set. The second image generated by the image processing unit 121 is transmitted to the visual inspection terminal 40 via the communication unit 16 and displayed on the visual inspection terminal 40.

[0071] The inspection unit 122 performs a visual inspection of the first image generated by the image processing unit 121 in accordance with the inspection program. Specifically, the inspection unit 122 performs a visual inspection of the first image generated by the image processing unit 121 in accordance with the inspection program. Based on the threshold value, etc., the presence or absence of defects in the workpiece W and the type of defect are determined from the feature amounts of each pixel that makes up the image.

[0072] The lighting control unit 123 controls the light emission intensity of the LEDs in each lighting unit, the first lighting unit 112, the second lighting unit 113, the third lighting unit 114, and the fourth lighting unit 115, and sets the light irradiated onto the workpiece to meet specified lighting conditions.

[0073] The lighting control unit 123 first sets each lighting to achieve the lighting conditions for the first image, and if a defect in the workpiece is detected based on the captured first image, adjusts the light emission intensity of each LED to achieve the lighting conditions for the second image for visual inspection. Note that the lighting conditions for the first image and the lighting conditions for the second image are defined differently.

[0074] In addition, the photographing conditions, including the lighting conditions and imaging conditions, are set in advance for each work W (for example, using the teaching terminal 20) and stored in the memory unit 15 or NAS 30, and the photographing control unit 120 and the lighting control unit 123 read out the photographing conditions corresponding to the work W from the memory unit 15 or NAS 30 and adjust the imaging parameters and lighting parameters.

[0075] (Processing flow) Next, an example of the flow of processing executed by the visual inspection device 10 will be described with reference to Fig. 7. Fig. 7 is a flowchart showing an outline of the flow of processing when the visual inspection device 10 inspects a workpiece W. As shown in Fig. 7, when the workpiece W is transported to the inspection position, the lighting control unit 123 of the visual inspection device 10 reads out the shooting conditions for the first image corresponding to the workpiece W, and based on this, the lighting control unit 123 adjusts the lighting parameters of each of the lighting units, the first lighting unit 112, the second lighting unit 113, the third lighting unit 114, and the fourth lighting unit 115, for the first image (S101).

[0076] Next, the photography control unit 120 controls the driving of the camera 111 and the workpiece holding unit so that the inspection target portion of the workpiece W falls within the field of view of the camera 111, adjusts the exposure time and gain of the camera 111 based on the photography conditions for the first image, and then photographs the inspection target portion (S102). Subsequently, the image processing unit 121 processes the image acquired by the camera 111 to generate a first image (S103). Then, the inspection unit 122 inspects the inspection target portion based on the inspection program (for example, by comparing feature amounts obtained from the first image with inspection standards) (S104).

[0077] Here, if the inspection by the inspection unit 122 results in a pass (i.e., if no defects are detected; No in S105), the series of processes for one inspection target area is completed. If there are no other inspection target areas on the workpiece W (if all inspection target areas can be covered by images from only one field of view), the workpiece W is transported to the next process, and the inspection of that workpiece W is also completed. Note that if there are other inspection target areas on the workpiece W, the processes from step S101 are executed again for those inspection target areas.

[0078] On the other hand, if a defect is detected (determined as defective) in the inspection by the inspection unit 122 (Yes in step S105), the illumination control unit 123 reads out the photographing conditions for the second image, and based on the readout, adjusts the illumination parameters of the first illumination unit 112, the second illumination unit 113, the third illumination unit 114, and the fourth illumination unit 115 for the second image (S106). Subsequently, the photographing control unit 120 controls the driving of the camera 111 and the workpiece holding unit so that the location where the defect was detected in the inspection (or at least an area including the location) falls within the field of view of the camera 111, and adjusts the exposure time and gain of the camera 111 based on the photographing conditions for the second image, and then photographs the location where the defect was detected in the inspection (S107).

[0079] Then, the image processing unit 121 processes the image taken in step S107 to generate a second image (S108), and transmits the second image to the visual inspection terminal 40 via the communication unit 109 (S109), thereby completing the series of processes for one inspection target location. If there are no other inspection target locations on the workpiece W, the workpiece W is transported to the next process and the inspection is completed. If there are other inspection target locations on the workpiece W, the processes from step S101 are executed again for the inspection target locations.

[0080] According to the visual inspection system 1 of this embodiment as described above, the second image for visual inspection is acquired only at locations where defects are detected by inspection by the inspection unit 122, which contributes to shortening the inspection takt time and reducing the memory capacity for holding image data. Furthermore, since inspection is performed by the inspection unit 122 for each field of view, and if a defect is determined, photography is immediately performed by applying the photography conditions for the second image, so there is no need to realign the camera 111 and the workpiece holder, and it is possible to prevent adverse effects such as misalignment that may occur when doing so.

[0081] <Other> The above-described embodiments are merely illustrative of the present invention, and the present invention is not limited to the specific embodiments described above. Various modifications of the present invention are possible within the scope of its technical concept. For example, in the above-described embodiments, image processing of images for visual inspection is performed by the image processing unit 121 of the appearance inspection device 10, but such image processing may be performed by the visual inspection terminal 40. Furthermore, image processing of images used for visual inspection is not essential, and image processing may not be performed.

[0082] Furthermore, in the above embodiment, the flow was such that the inspection unit 122 judged each field of view as pass / fail, and then photographed the next field of view. However, if there are multiple inspection areas on the workpiece W (when multiple first image data need to be photographed), it is also possible to photograph all of the inspection areas first, without waiting for the inspection of each field of view to be completed.

[0083] In the above embodiment, an example has been shown in which only the second image is transmitted to the visual inspection terminal 40, but when the second image is transmitted, the corresponding first image (i.e., an image showing the location where the defect was detected) may also be transmitted together. The display means of the visual inspection terminal 40 may be configured to display the corresponding first and second images in a list (side by side).

[0084] <Appendix 1> Illumination means (112, 113, 114, 115, 912, 913) for irradiating an object to be inspected with illumination light under illumination conditions based on variable illumination parameters; An imaging means (111, 911) for imaging the object to be inspected; an inspection means (122, 922) for inspecting the inspection object based on a feature amount of a first image captured under first imaging conditions defined based on at least the predetermined illumination parameters using the illumination means and the imaging means; a display means (13, 20, 93) capable of displaying a second image captured by using the illumination means and the imaging means under second imaging conditions in which the illumination parameters are different from the first imaging conditions, for at least an area including an inspection point where a defect has been detected by the inspection means; A visual inspection system (1, 9) having the above.

[0085] <Appendix 2> the lighting means is configured to change the lighting parameter related to the color of the illumination light, The second photographing condition is one in which the color of the illumination light is adjusted for visual inspection. 2. The visual inspection system according to claim 1,

[0086] <Appendix 3> the illumination means is configured to be able to change the illumination parameters relating to the irradiation direction of the illumination light, The second photographing condition is one in which the irradiation direction is adjusted for visual inspection. 3. The visual inspection system according to claim 1 or 2,

[0087] <Appendix 4> capturing the corresponding second image only for the first image including the inspection location for which the inspection result by the inspection means is unsatisfactory; 4. A visual inspection system according to any one of claims 1 to 3.

[0088] <Appendix 5> the imaging means images the inspection object under imaging conditions based on variable imaging parameters; the first photographing condition is defined based on predetermined illumination parameters and predetermined imaging parameters, capturing the second image having different lighting parameters of the lighting means and different imaging parameters of the imaging means only for the first image including the inspection location for which the inspection result by the inspection means is unsatisfactory; 5. The visual inspection system according to claim 4,

[0089] <Appendix 6> Each time the photographing means photographs one of the first images, the photographing means waits until the inspection by the inspection means for the first image is completed before photographing the next of the first images. 6. A visual inspection system according to any one of appendices 1 to 5,

[0090] <Appendix 7> further comprising image processing means (121, 921) for performing predetermined image processing on the second image, the display means displays the second image after the image processing has been performed. 7. A visual inspection system according to any one of appendices 1 to 6,

[0091] <Appendix 8> the display means displays the first image including the inspection location where the inspection result by the inspection means was unsuccessful and the second image in which the area corresponding to the first image was photographed side by side. 8. A visual inspection system according to any one of appendices 1 to 7.

[0092] <Appendix 9> Illumination means (112, 113, 114, 115, 912, 913) for irradiating the object to be inspected with light under illumination conditions based on variable illumination parameters; An imaging means (111, 911) for imaging the object to be inspected; an inspection means (122, 922) for inspecting the inspection object based on a feature amount of a first image captured under first imaging conditions defined based on at least the predetermined illumination parameters using the illumination means and the imaging means; an output means (13, 93) for outputting a second image captured by using the illumination means and the imaging means under second imaging conditions in which the illumination parameters are different from the first imaging conditions, for at least a region including an inspection point where a defect has been detected by the inspection means; An appearance inspection device (9, 10) having the above.

[0093] <Appendix 10> A control method for a visual inspection apparatus including an illumination unit that irradiates an inspection object with illumination light under illumination conditions based on variable illumination parameters, an imaging unit, and an inspection unit, comprising: a first photographing step (S102) of photographing under first photographing conditions defined based on at least the predetermined lighting parameters by the lighting means and the photographing means; an inspection step (104) of inspecting the inspection object based on a feature amount of a first image captured under the first photographing conditions by the inspection means; a second photographing step (S107) of photographing an area including at least an inspection point where a defect has been detected in the inspection step, using the illumination means and the photographing means under second photographing conditions in which the illumination parameters are different from the first photographing conditions; an output step (S109) of outputting a second image captured under the second photographing condition; A control method for an appearance inspection apparatus, comprising:

[0094] <Appendix 11> A program for causing an appearance inspection device to execute each step described in the method for controlling an appearance inspection device described in Appendix 10. [Explanation of symbols]

[0095] 1, 9... Visual inspection system 10. Visual inspection equipment 11. Photography Department 111···Camera 12, 92 Control section 13, 93... Output section 14, 94... Input section 15, 95...Storage section 16. Communications Department 112R, 113R, 114R, 115R...Red LED 112G, 113G, 114G, 115G...Green LED 112B, 113B, 114B, 115B...Blue LED 116···Half mirror 20 Teaching terminal 30···NAS 40 Visual inspection terminal 91 Inspection device main body 915···Diffuser W...Work

Claims

1. an illumination means for irradiating the object to be inspected with illumination light under illumination conditions based on variable illumination parameters; an imaging means for imaging the inspection object; an inspection means for inspecting the inspection object based on a feature amount of a first image captured under first imaging conditions defined based on at least the predetermined illumination parameters using the illumination means and the imaging means; a display means capable of displaying a second image of an area including at least an inspection point where a defect has been detected by the inspection means, the second image being captured using the illumination means and the imaging means under second imaging conditions in which the illumination parameters are different from the first imaging conditions; and An appearance inspection system comprising:

2. the lighting means is configured to change the lighting parameter related to the color of the illumination light, the second photographing condition is one in which the color of the illumination light is adjusted for visual inspection; 2. The visual inspection system according to claim 1, wherein:

3. the illumination means is configured to be able to change the illumination parameters relating to the irradiation direction of the illumination light, The second photographing condition is one in which the irradiation direction is adjusted for visual inspection.

2. The visual inspection system according to claim 1, wherein:

4. capturing the corresponding second image only for the first image including the inspection location for which the inspection result by the inspection means is unsatisfactory; 2. The visual inspection system according to claim 1, wherein:

5. the imaging means images the inspection object under imaging conditions based on variable imaging parameters; the first photographing condition is defined based on predetermined lighting parameters and predetermined imaging parameters, capturing the second image having different lighting parameters of the lighting means and different imaging parameters of the imaging means only for the first image including the inspection location for which the inspection result by the inspection means is unsatisfactory; 5. The visual inspection system according to claim 4.

6. the photographing means waits for the inspection by the inspection means to finish for each of the first images photographed, and then photographs the next first image.

2. The visual inspection system according to claim 1, wherein:

7. further comprising image processing means for performing predetermined image processing on the second image, the display means displays the second image after the image processing has been performed.

2. The visual inspection system according to claim 1, wherein:

8. the display means displays the first image including the inspection location where the inspection result by the inspection means is unsatisfactory and the second image in which the area corresponding to the first image is photographed side by side.

2. The visual inspection system according to claim 1, wherein:

9. an illumination means for irradiating the object to be inspected with light under illumination conditions based on variable illumination parameters; an imaging means for imaging the inspection object; Using the lighting means and the photographing means, based on at least the predetermined lighting parameters, an inspection means for inspecting the inspection object based on a feature amount of a first image captured under a first photographing condition defined by an output means for outputting a second image of a region including at least an inspection point where a defect has been detected by the inspection means, the second image being captured under second imaging conditions in which the illumination parameters are different from the first imaging conditions using the illumination means and the imaging means; An appearance inspection device having the above features.

10. A control method for a visual inspection apparatus including an illumination unit that irradiates an inspection object with illumination light under illumination conditions based on variable illumination parameters, an imaging unit, and an inspection unit, comprising: a first photographing step of photographing the inspection object under first photographing conditions defined based on at least the predetermined illumination parameters by the illumination means and the photographing means; an inspection step of inspecting the inspection object based on a feature amount of a first image captured under the first imaging condition by the inspection means; a second photographing step of photographing an area including at least an inspection point where a defect has been detected in the inspection step, using the illumination means and the photographing means under second photographing conditions in which the illumination parameters are different from the first photographing conditions; an output step of outputting a second image captured under the second photographing condition; A control method for an appearance inspection apparatus, comprising:

11. A program for causing a visual inspection apparatus to execute each step of the visual inspection apparatus control method according to claim 10.

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