Dichroism inspection apparatus

Abstract

A dichroism inspection apparatus according to one embodiment of the present invention comprises: a lighting module for radiating light onto a surface of an object under inspection; a camera module for extracting image information from the surface of the object under inspection; and a dichroism determination module for inspecting the color of the object under inspection and determining dichroism through the image information extracted by the camera module. The camera module and the lighting module operate in conjunction with each other and can be present in the same number.

Description

Unique inspection device

[0001] The present invention relates to a device and method for effectively determining whether an anomaly occurs with respect to a reference color by analyzing the color of the surface of an object, and more specifically, to a device and method for determining an anomaly by utilizing the difference in camera response characteristics of a specific wavelength band using spectrum-controlled lighting on the surface to be inspected.

[0002] In general, a method for examining / judging the uniformity of the coating solvent applied to the surface of a workpiece can be a method for analyzing the coating state of the surface of the workpiece. To this end, an inspection for the uniformity of the coating can be performed by attaching a colorimeter to the surface of the workpiece.

[0003] However, since various vehicle parts, such as car bodies and bumpers, may be manufactured by different companies, technology may be required to manage color difference values ​​for each of the various vehicle parts.

[0004] However, conventional colorimeters are designed to be attached to the surface of a workpiece, making real-time colorimetry and color inspection difficult. Consequently, colorimetry and color inspection of all automotive components are also challenging, potentially leading to color differences between components during the final assembly process.

[0005]

[0006] Domestic Patent Publication No. 10-2003-0019735 (“High-resolution multi-functional spectrophotometer”) discloses a method for judging the color quality of a sample by bringing the sample into contact with reflected light and then performing an inspection.

[0007] However, this also does not take into account the problem that real-time color measurement and color inspection are difficult because the colorimeter comes into contact with the surface of the sample.

[0008]

[0009] The problem to be solved by the present invention is to provide a precision color and colorimetric inspection device optimized for a target sample based on camera characteristics that takes into account the spectral response characteristics of the camera channel and the spectrum control lighting for real-time color inspection and colorimetric identification in a non-contact manner.

[0010]

[0011] A two-color inspection device according to one embodiment of the present invention includes a lighting module that irradiates a surface of an inspection target with light of a plurality of different wavelengths, a camera module that extracts image information from the surface of the inspection target, and a two-color determination module that inspects the color of the inspection target and determines the two-color through the image information extracted from the camera module. It is preferable that the camera module and the lighting module operate in conjunction with each other and are arranged in the same number.

[0012] Furthermore, it is preferable that the above-mentioned two-color inspection device further includes a wavelength range setting module that sets the wavelength ranges of the lighting module and the camera module, and that the lighting module operates in conjunction with the camera module by the wavelength range setting module.

[0013] Furthermore, it is preferable that the above-mentioned two-color inspection device further include an inspection color band determination module that determines an inspection color band for setting the wavelength range of the wavelength range setting module.

[0014] Furthermore, it is preferable that the inspection color band determination module irradiates the surface of the inspection target with two or more light sources having different spectral distributions and determines the inspection color band based on the characteristics of the two or more light sources.

[0015] Furthermore, it is preferable that the two or more light sources are sequentially irradiated onto the surface of the inspection target.

[0016] Furthermore, it is preferable that the two or more light sources are simultaneously irradiated onto the surface of the inspection target.

[0017] Furthermore, it is preferable that the inspection color band discrimination module receives characteristics of the two or more light sources through the camera module, and that the two-color discrimination module and the inspection color band discrimination module receive information from the camera module through different channels.

[0018] Furthermore, it is preferable that the inspection color band determination module determines the inspection color band based on information measured by the camera module.

[0019] Furthermore, it is preferable that the inspection color band determination module determines the inspection color band based on an MES signal or a user input signal.

[0020] Furthermore, it is preferable that the inspection color band determination module includes an RGB camera and determines the inspection color band based on information measured from the RGB camera.

[0021] Furthermore, it is preferable that the inspection color band discrimination module discriminates the inspection color band by discriminating a band in which a heterochromatic phenomenon appears in a plurality of different color bands.

[0022] Furthermore, it is preferable that the lighting module includes spectrum control lighting capable of controlling spectral characteristics, and the inspection color band determination module determines the inspection color band based on a center wavelength band in a short wavelength region among the spectral characteristics of the spectrum control lighting.

[0023] Furthermore, the two-color inspection device includes a light that irradiates light to a test sample and a camera that measures the light irradiated to the test sample, and further includes a response characteristic modeling module that models a spectral response characteristic of the camera by measuring an actual intensity in a specific wavelength range of light irradiated from the light, and it is preferable that the two-color determination module determines the color inspection and two-color of the test object by considering the spectral response characteristic of the camera modeled in the response characteristic modeling module.

[0024] Furthermore, it is preferable that the lighting is a monochrome or spectrum-controlled lighting having a short wavelength band, and the inspection sample is a white reflective patch.

[0025] Furthermore, it is preferable that the response characteristic modeling module further includes a light intensity meter for measuring the intensity of light irradiated from the light, and that the response characteristic modeling module compares the intensity of light measured by the light intensity meter with the intensity of light measured by the camera to determine the spectral response characteristic of the camera.

[0026] Furthermore, it is preferable that the inspection sample is a color patch composed of a plurality of colors, and the response characteristic modeling module further includes a database section in which spectral distribution data of the lighting and spectral characteristic data for the color patch are stored.

[0027] Furthermore, it is preferable that the above-mentioned color discrimination module determines the color of the inspection object and the color difference based on a plurality of spectral response characteristic values ​​of the camera identified for a plurality of different wavelength bands.

[0028] Furthermore, it is preferable that the above-mentioned anisotropy determination module calculates an estimated spectral response characteristic value of the camera based on a plurality of spectral response characteristic values ​​of the camera, and compares the estimated spectral response characteristic value with a reference value to determine anisotropy of the inspection target.

[0029] Furthermore, it is preferable that the above-mentioned two-color discrimination module calculates a Lab color coordinate estimation value based on the above-mentioned spectral response characteristic estimation value, and compares the Lab color coordinate estimation value with a reference Lab color coordinate value to determine the two-color of the inspection target.

[0030] Furthermore, it is preferable that the above-mentioned two-color determination module calculates an R / G / B estimation value for each wavelength based on the plurality of spectral response characteristic values, and compares the R / G / B estimation value for each wavelength with the R / G / B reference value for each wavelength to determine the two-color of the inspection target.

[0031] Furthermore, it is preferable that the above-mentioned two-color discrimination module measures the spectral response characteristic value of the camera at a basic light quantity and the spectral response characteristic value of the camera at a changed light quantity, and calculates a difference value between the spectral response characteristic value at the basic light quantity and the spectral response characteristic value at the changed light quantity to determine a plurality of spectral response characteristic values ​​of the camera for a plurality of different wavelength bands.

[0032] Furthermore, the above-described color inspection device further includes a display module that receives data from the color discrimination module and displays it to a user, and it is preferable that the color discrimination module generates data on an area where a color difference occurs in the inspection target and transmits the data on the area where a color difference occurs to the display unit.

[0033] According to the effect of the present invention, the quality of vehicle parts such as bumpers can be improved through real-time color and two-color inspection.

[0034] According to another effect of the present invention, product history management through real-time full inspection may be possible.

[0035] According to another effect of the present invention, it is possible to identify the cause of defects and seek improvement measures through a combination of defective product identification and history management.

[0036]

[0037] Figure 1 is a schematic diagram of a two-color inspection device according to one embodiment of the present invention.

[0038] Figure 2 is a schematic diagram of a two-color inspection device according to another embodiment of the present invention.

[0039] FIG. 3 is a drawing for explaining a response characteristic modeling module of a two-color inspection device according to one embodiment of the present invention.

[0040] FIGS. 4 and 5 are graphs for explaining the operation of the response characteristic modeling module of the two-color inspection device according to one embodiment of the present invention.

[0041] FIG. 6 is a drawing for explaining a response characteristic modeling module of a two-color inspection device according to another embodiment of the present invention.

[0042] FIG. 7 is a drawing for explaining the operation process of the two-color determination module of the two-color inspection device according to one embodiment of the present invention.

[0043] FIG. 8 and FIG. 9 are graphs for explaining the operation of the inspection color band determination module of the two-color inspection device according to one embodiment of the present invention.

[0044] FIG. 10 is a graph for explaining the operation of a two-color determination module of a two-color inspection device according to one embodiment of the present invention.

[0045]

[0046] The present invention's coating state analysis system and method will now be described in detail with reference to the accompanying drawings. The drawings presented below are provided as examples to ensure that those skilled in the art can fully grasp the spirit of the present invention. Therefore, the present invention is not limited to the drawings presented below and may be embodied in other forms. Furthermore, like reference numerals designate like elements throughout the specification.

[0047] At this time, if there is no other definition in the technical and scientific terms used, they have the meaning commonly understood by a person of ordinary skill in the technical field to which this invention belongs, and the description of known functions and configurations that may unnecessarily obscure the gist of the present invention in the following description and attached drawings are omitted.

[0048] In addition, a system refers to a set of components including devices, mechanisms, and means that are organized and interact regularly to perform necessary functions.

[0049] Typically, automobile bodies and bumpers can be manufactured and painted through different processes. Consequently, color differences between various vehicle parts can exceed a certain range, making them visible to the naked eye. This discoloration can also occur during vehicle repairs due to differences between the original surface color and the newly painted surface color.

[0050] Accordingly, the heterochromatic phenomenon can be determined by setting a reference color and comparing the reference color with the surface color of the object to be inspected.

[0051] For example, data on areas where an anisotropic phenomenon occurs can be managed in the Lab color space, a three-dimensional coordinate system. The Lab color space is a three-dimensional coordinate system that represents brightness (L+, L-), the degree of red and green (a+, a-), and the degree of yellow and blue (b+, b-).

[0052] And, the color difference value caused by the anisotropic phenomenon can be measured through the difference in each coordinate value in the Lab color space. For example, when the differences in the coordinate values ​​in L, a, and b are expressed as △L, △a, and △b, respectively, the color difference value △E can be calculated using the following formula.

[0053]

[0054] A color inspection device according to one embodiment of the present invention can determine whether a color phenomenon has occurred on the surface of an inspection object to be inspected by analyzing the surface color of the inspection object to be inspected in consideration of the spectral response characteristics of the camera and comparing it with a reference color.

[0055] Hereinafter, a two-color inspection device according to various embodiments of the present invention will be described in detail with reference to FIGS. 1 to 10.

[0056] Figure 1 is a schematic diagram of a two-color inspection device according to one embodiment of the present invention.

[0057] A two-color inspection device according to one embodiment of the present invention includes a lighting module (100) that irradiates a surface of an inspection target with light of a plurality of different wavelengths, a camera module (200) that extracts image information from the surface of the inspection target, and a two-color determination module (400) that inspects the color of the inspection target and determines the two-color through the image information extracted from the camera module (200). It is preferable that the camera module (200) and the lighting module (100) operate in conjunction with each other and are arranged in the same number.

[0058] Here, the color discrimination module (400) can be implemented in the form of a program executable by a computer or processor or hardware that operates by executing the same.

[0059] Meanwhile, the camera modules (200) and lighting modules (100) may be arranged in the same number, i.e., as a pair. At this time, the number of camera modules (200) and lighting modules (100) may be arranged as many as the number of inspection areas.

[0060] The lighting module (100) may include spectrum-controlled lighting capable of controlling the spectral band. Accordingly, the lighting module (100) may be configured to irradiate light of multiple wavelengths onto the surface of the inspection target by controlling the spectral band. Here, the spectral band is generated and evaluated based on the wavelength band of visible light, from 380 nm to 780 nm, and thus may be set in consideration of human visual characteristics.

[0061] Since the maximum wavelength of the wavelength band may vary depending on the cut-off wavelength of the filter when the camera module (200) has an IR filter, the maximum wavelength band can be adjusted by taking the filter band into consideration when analyzing the wavelength in conjunction with the lighting module (100).

[0062] The color inspection device further includes a wavelength range setting module (300) that sets the wavelength range of the lighting module (100) and the camera module (200), and it is preferable that the lighting module (100) operates in conjunction with the camera module (200) by the wavelength range setting module (300).

[0063] Here, the wavelength region setting module (300) can be implemented in the form of a program executable by a computer or processor or in the form of hardware that operates by executing the same.

[0064] The color discrimination module (400) uses the spectral response characteristics of the camera to inspect the color of the inspection object and determine the presence of a color difference. Accordingly, the color discrimination module (400) can measure the actual intensity of illumination by taking into account the spectral response characteristics of the camera, even if the maximum wavelength of the wavelength band changes due to the cut-off wavelength generated by the camera's filter.

[0065] A camera's spectral response characteristic is its ability to respond within a specific wavelength band. Monochrome cameras exhibit different response characteristics across the entire band depending on wavelength. Furthermore, RGB cameras have a characteristic where only specific sub-wavelength bands are passed through filters corresponding to the R / G / B bands on the same sensor. These characteristics are influenced not only by the sensor itself but also by filters and optical elements.

[0066] The spectral response characteristics of a camera can be determined by comparing the light intensity measured by the camera with the actual light intensity. For example, when the surface of an inspection target is illuminated with light for a specific wavelength range, if the camera characteristic has a value of 1 in wavelength band a but a value of 0.5 in wavelength band b, the value of 200 under the illumination of wavelength band a can be regarded as the actual intensity of 200, and if a value of 150 is measured under illumination of the same intensity in wavelength band b, the response characteristic in the actual wavelength band b can be determined as the measured value of 150 actually having an intensity of 300 in the corresponding band, considering the characteristic that the camera response characteristic in wavelength band b is 0.5. In this way, in order to measure the response characteristics in a corresponding band with a camera through illumination, the response characteristics of the camera in that band must be known in order to measure the actual illumination intensity.

[0067] That is, the two-color inspection device can improve the precision of the two-color inspection by identifying the exact wavelength characteristics by determining the two-color based on the response characteristics for the entire spectrum or the response characteristics of a specific spectrum based on the response characteristics for each wavelength band for the inspection target.

[0068] The lighting module (100) and the camera module (200) can operate in conjunction with each other by being set to a specific wavelength range in consideration of the camera response characteristics.

[0069] For example, if the wavelength response characteristics in the characteristic region of lighting are analyzed using the R / G / B channels, the response characteristics of the corresponding band can be identified through the cumulative sum of the overlapping portions of the R / G / B camera sensor responses. To this end, by considering the camera response values ​​linked to lighting, various wavelength bands can be identified in a short time. In addition, the characteristics of the entire wavelength region can be identified by combining the combination of the response characteristics of the R / G / B channels by combining the corresponding wavelength regions analyzed based on the set wavelength region.

[0070] According to one embodiment of the present invention, the color inspection device can clearly determine a characteristic to be measured in a specific wavelength range by setting the wavelength range to the lighting module (100) and the camera module (200) using the wavelength range setting module (300).

[0071] Specifically, in order to know the characteristics of the entire wavelength from 380 nm to 780 nm, the characteristics of a specific wavelength region can be analyzed in advance. At this time, by dividing the short wavelengths divided into some areas of the corresponding wavelength region into small areas and irradiating only the light of the corresponding wavelength region, the characteristics of the corresponding wavelength region can be clearly known.

[0072] Figure 2 is a schematic diagram of a two-color inspection device according to another embodiment of the present invention.

[0073] Referring to FIG. 2, it is preferable that a two-color inspection device according to another embodiment of the present invention further includes an inspection color band determination module (500) that determines an inspection color band for setting a wavelength range of a wavelength range setting module (300).

[0074] Here, the inspection color band determination module (500) can be implemented in the form of a program executable by a computer or processor or hardware that operates by executing the same.

[0075] The color inspection device may include a determination module (500) that determines an optimal inspection wavelength range, i.e., an optimal inspection color band, to minimize characteristics that vary depending on the inspection target to be inspected. At this time, the inspection color band may be determined based on R / G / B values ​​measured by a camera or estimated based on color values ​​(S) converted from R / G / B values ​​into a color space such as HSV.

[0076] It is preferable that the inspection color band determination module (500) irradiates the surface of the inspection target with two or more light sources having different spectral distributions and determines the inspection color band based on the characteristics of the two or more light sources.

[0077] At this time, two or more light sources may be sequentially irradiated onto the surface of the inspection target. Alternatively, two or more light sources may be simultaneously irradiated onto the surface of the inspection target.

[0078] When performing colorimetric inspections on actual conveyor lines, it can be crucial to quickly understand characteristics across various lighting bands. Therefore, to improve inspection speed, a method can be used to simultaneously examine the spectral response characteristics of R / G / B sensors across two or more non-overlapping spectral regions. This allows for the processing of signals in the corresponding wavelength bands by each sensor, even when receiving input from different sensors. Consequently, response characteristics across two or more wavelength bands can be simultaneously understood, significantly improving measurement speed.

[0079] The camera used for determining the inspection color band of the inspection color band determination module (500) can use a camera included in the camera module (100).

[0080] For example, the inspection color band discrimination module (500) can receive characteristics of two or more light sources through the camera module (200). At this time, it is preferable that the two-color discrimination module (400) and the inspection color band discrimination module (500) receive information from the camera module (200) through different channels. Accordingly, the inspection color band discrimination module (500) can determine the inspection color band based on the information measured by the camera module (200).

[0081] Additionally, the camera used for the inspection color band determination module (500) can be used by installing a separate camera from the camera module (100).

[0082] For example, the inspection color band determination module (500) includes an RGB camera and can determine the inspection color band based on information measured from the RGB camera.

[0083] Meanwhile, the inspection color band determination module (500) can directly receive the inspection color band based on the MES signal or user input signal.

[0084] FIG. 3 is a drawing for explaining a response characteristic modeling module of a two-color inspection device according to one embodiment of the present invention.

[0085] According to FIG. 3, the two-color inspection device according to the present invention includes a light source (620A, 620B) that irradiates light to an inspection sample (SA, SB) and a camera (610A, 610B) that measures the light irradiated to the inspection sample, and further includes a response characteristic modeling module (600) that models the spectral response characteristic of the camera (610A, 610B) by measuring the actual intensity in a specific wavelength range of the light irradiated from the light source (620A, 620B), and the two-color determination module (400) preferably determines the color of the inspection target and the two-color by considering the spectral response characteristic of the camera modeled in the response characteristic modeling module (600).

[0086] Here, the response characteristic modeling module (600) can be implemented in the form of a program executable by a computer or processor or in the form of hardware that operates by executing the same.

[0087] The response characteristic modeling module (600) is configured to adjust the response characteristics of the camera by accurately modeling the camera response characteristics.

[0088] For example, the light (620A) may be a monochrometer or a spectrum-controlled light source with a short wavelength band, and the test sample (SA) may be a white reflective patch. In this case, the motochromator or a short wavelength light source can be used to project a narrow wavelength band onto a white target with high reflectivity, thereby determining the response characteristics in the narrow band, and based on this, the response characteristics of the camera in the entire wavelength band can be determined.

[0089] Meanwhile, the response characteristic modeling module (600) further includes a light intensity meter (630A) for measuring the intensity of light irradiated from the light (620A), and the response characteristic modeling module (600) can compare the intensity of light measured by the light intensity meter (630A) with the intensity of light measured by the camera (610A) to determine the spectral response characteristics of the camera (610A).

[0090] FIGS. 4 and 5 are graphs for explaining the operation of the response characteristic modeling module of the two-color inspection device according to one embodiment of the present invention.

[0091] Fig. 4 is an example graph of camera response characteristics measured using a monochrometer of R / G / B channels, and Fig. 5 is an example graph of camera response characteristics normalized by considering the intensity of the light source. In this case, in Figs. 4 and 5, the X-axis represents wavelength (nm), and the Y-axis represents response characteristics (sensitivity).

[0092] In this way, since the response characteristic modeling module (600) may have differences in response characteristics not only due to differences in camera characteristics but also due to differences in the intensity of the light quantity of the wavelength being investigated if the amount of light in the investigated wavelength band is different, a process may be required to measure the light intensity in the relevant wavelength band and offset the differences in response characteristics that may occur due to the difference in light intensity.

[0093] Accordingly, in the response characteristic modeling module (600), a process of adjusting the response characteristics of the camera using the response characteristics of the light source can be performed.

[0094] FIG. 6 is a drawing for explaining a response characteristic modeling module of a two-color inspection device according to another embodiment of the present invention.

[0095] Meanwhile, the test sample (SB) is a color patch composed of multiple colors, and the response characteristic modeling module (600) may further include a database section in which spectral distribution data of the lighting (620B) and spectral characteristic data for the color patch are stored.

[0096] For example, the camera measurements used in the response characteristic modeling module (600) can utilize the spectral response characteristics of a specific wavelength for the inspection sample. For example, the response characteristics of the camera across the entire wavelength can be obtained based on the camera measurements for multiple color patches.

[0097] Meanwhile, the method of using multiple color patches in this way is effective in that it can obtain effective wavelength response characteristics even with relatively small measurement data by taking advantage of the characteristic that the response characteristics of an actual camera sensor do not change abruptly at surrounding wavelengths.

[0098] In addition, the response characteristic modeling module (600) can optimize the camera response characteristic by utilizing the characteristic that the camera spectral response has continuous values ​​for each wavelength band of each R / G / B sensor in a certain wavelength range.

[0099] FIG. 7 is a drawing for explaining the operation process of the two-color determination module of the two-color inspection device according to one embodiment of the present invention.

[0100] The color discrimination module (400) can determine the color of an inspection target and determine the color of an object based on multiple spectral response characteristic values ​​of cameras (610A, 610B) identified for multiple different wavelength bands.

[0101] The process of determining a color based on R / G / B measurement values ​​according to multiple wavelength band illumination by the color determination module (400) is performed through the following steps.

[0102] First, a step (S110) of calculating a spectral response characteristic estimate based on R / G / B measurement values ​​according to multiple wavelength band illumination is performed, and a step (S120) of comparing the spectral response characteristic estimate and the spectral response characteristic reference value is performed.

[0103] Next, a step (S210) of calculating a Lab color coordinate estimate based on a spectral response characteristic estimate is performed, and a step (S220) of comparing the Lab color coordinate estimate with a reference Lab color coordinate value is performed.

[0104] Next, a step (S310) of calculating an R / G / B estimation value for each wavelength based on the R / G / B measurement values ​​according to multiple wavelength band illumination is performed, and a step (S320) of comparing the R / G / B estimation value for each wavelength with the R / G / B reference value for each wavelength is performed.

[0105] Finally, a step (S400) can be performed to determine the color difference of the inspection target by considering all comparison values ​​produced through each comparison step (S120, S220, S320).

[0106] In this way, the color discrimination module (400) can calculate an estimated spectral response characteristic value of the camera (610A, 610B) based on multiple spectral response characteristic values ​​of the camera (610A, 610B), and compare the estimated spectral response characteristic value with a reference value to determine the color of the inspection target.

[0107] In addition, the color discrimination module (400) can calculate a Lab color coordinate estimation value based on the spectral response characteristic estimation value and compare the Lab color coordinate estimation value with a reference Lab color coordinate value to determine the color of the inspection target.

[0108] In addition, the color difference determination module (400) can calculate an R / G / B estimation value for each wavelength based on a plurality of spectral response characteristic values, and compare the R / G / B estimation value for each wavelength with the R / G / B reference value for each wavelength to determine the color difference of the inspection target.

[0109] In this way, the method of determining anthracite based on camera measurements of various wavelength bands of light can use a method of directly comparing spectra based on spectrum estimation, a method of estimating Lab color coordinate values ​​based on spectrum estimation and comparing them, and a method of determining by comparing R / G / B values ​​by wavelength band for preset lighting.

[0110] Accordingly, in the two-color inspection device according to one embodiment of the present invention, since the inspection is performed based on the camera response according to the wavelength band with spectrum illumination, the accuracy of the measurement value can be improved compared to the conventional two-color determination method in that the Lab value is converted and used based on the spectrum estimation rather than directly estimating the Lab value from the R / G / B measurement value in the method using the Lab color coordinate value.

[0111] In addition, even when directly comparing R / G / B values, the precision of the measured value can be improved compared to the conventional two-color determination method because the R / G / B values ​​determined for each wavelength band are used.

[0112] FIG. 8 and FIG. 9 are graphs for explaining the operation of the inspection color band determination module of the two-color inspection device according to one embodiment of the present invention.

[0113] The inspection color band determination module (500) can determine the inspection color band by determining the band in which a different color phenomenon appears in a plurality of different color bands.

[0114] For example, the lighting module (100) includes a spectrum control light capable of controlling spectral characteristics, and the inspection color band determination module (500) can determine the inspection color band based on the center wavelength band of the short wavelength region among the spectral characteristics of the spectrum control light.

[0115]

[0116] Fig. 8 is a graph showing the spectral characteristics of a test sample whose test color is white, and Fig. 9 is a graph showing the spectral characteristics of a standard, a+ sample, and a- sample in a white sample. In this case, in Figs. 8 and 9, the X-axis represents the wavelength (nm), and the Y-axis represents the intensity of the wavelength.

[0117] Referring to Figure 8, for the standard sample (STD), anisotropy may occur in the form of brightness differences (L+ / L-), red-green color differences (a+ / a-), and yellow-blue color differences (b+ / b-). Depending on the color being measured, differences in the wavelength band where anisotropy primarily occurs may occur, and even for the same color, differences may occur depending on the type of anisotropy. In other words, it can be seen that the wavelength band where differences occur may vary depending on each sample.

[0118] Referring to Fig. 9, when performing two-color discrimination in the white wavelength region, it can be seen that there are points where the standard sample, the a+ color sample, and the a- color sample differ from the standard sample. Accordingly, since the difference in wavelength response between samples is small in the A wavelength band and the G wavelength band, they are not selected as inspection wavelength regions, and since the response characteristics in B, C, and D and the response characteristics in E and F show similar tendencies, and B, C, D and E, F show different tendencies, it is preferable to set at least one inspection wavelength region in B, C, and D, and to select at least one wavelength region among E and F to set the inspection region, and perform inspection by wavelength region.

[0119] Additionally, among B, C, and D, the C and F regions with distinct short-wavelength spectra can be selected. If the spectra of the C and F regions have little overlap in the camera response region, the C and F wavelength regions can be investigated simultaneously to perform measurement analysis.

[0120] FIG. 10 is a graph for explaining the operation of a two-color determination module of a two-color inspection device according to one embodiment of the present invention.

[0121] The color discrimination module (400) measures the spectral response characteristic value of the camera (610A, 610B) at the basic light quantity and the spectral response characteristic value of the camera (610A, 610B) at the changed light quantity, and calculates the difference value between the spectral response characteristic value at the basic light quantity and the spectral response characteristic value at the changed light quantity, thereby being able to determine multiple spectral response characteristic values ​​of the camera (610A, 610B) for multiple different wavelength bands.

[0122] Fig. 10 is a graph for explaining a spectral anisotropy inspection method based on variation. The X-axis of each graph of Fig. 10 (Fig. 10(a) to Fig. 10(i)) represents the wavelength of the measured light, and the Y-axis represents the intensity of the measured light.

[0123] The actual bumper and vehicle color inspection environments are subject to external lighting influences, including the presence of wavelength-spectrum illumination. In these environments, the influence of external lighting can be significant, in addition to wavelength-spectrum illumination. Therefore, if external light illuminates the inspection surface, this light can cause fluctuations in the measured camera values. To ensure robust color inspection despite these fluctuations, a method that considers spectral characteristics robust to external light fluctuations may be required.

[0124] Accordingly, the two-color inspection device according to one embodiment of the present invention can effectively minimize the influence of external ambient light, etc. by using a reference light and additional variable light with different intensity when examining wavelength band illumination.

[0125] For example, in Fig. 10, when the wavelength band illumination J to be measured is irradiated against ambient light having spectrum I, a spectrum that is the sum of I and J, such as the K wavelength spectrum, is produced. At this time, in a situation where the same ambient light is irradiated (I=I'), if the wavelength band illumination is additionally changed and the same wavelength band illumination having the size of J' is irradiated, it becomes the sum of I' and J', such as the K' wavelength spectrum. At this time, the difference between K-K' becomes the same as the difference between J-J', so that when there is an amount of ambient light, the change in the response characteristics in a specific wavelength band can be identified.

[0126] At this time, if the ambient light changes over time, it is possible to respond to the change by limiting the time interval to a minimum.

[0127] Meanwhile, the color detection device further includes a display module that receives data from the color detection module (400) and displays it to the user, and the color detection module (400) can generate data on an area where color variation occurs in the inspection target and transmit the data on the area where color variation occurs to the display module.

[0128] For example, a color detection device may mark a test subject to indicate to the user that the test subject has been determined to be a color defect, or may display the area where the color defect has occurred on a display module. Thus, the color detection device can easily convey information about the occurrence of color defects in the test subject to the user.

[0129] As described above, although the present invention has been described through limited embodiments and drawings, these are provided only to help with the overall understanding of the present invention, and the present invention is not limited to the above embodiments, and various modifications and variations are possible from the technical idea of ​​the present invention by a person having ordinary knowledge in the technical field to which the present invention belongs.

[0130] Therefore, the idea of ​​the present invention is not limited to the described embodiments, and all things that have equivalent or equivalent modifications to the claims described below are considered to fall within the scope of the idea of ​​the present invention.

Claims

1. A lighting module that irradiates multiple wavelengths of light onto the surface of an inspection target; A camera module for extracting image information from the surface of the inspection target; A color determination module that determines the color of the inspection target and the color difference through image information extracted from the camera module; A wavelength range setting module for setting the wavelength range of the lighting module and the camera module; and Includes an inspection color band determination module that determines an inspection color band for setting the wavelength range of the above wavelength range setting module, The above lighting module operates in conjunction with the camera module by the wavelength range setting module, The above inspection color band determination module irradiates the surface of the inspection target with two or more light sources having different spectral distributions, determines the inspection color band based on the characteristics of the two or more light sources, and receives the characteristics of the two or more light sources through the camera module. A two-color inspection device, wherein the two-color discrimination module and the inspection color band discrimination module receive information from the camera module through different channels.

2. In paragraph 1, A two-color inspection device in which the two or more light sources are sequentially irradiated onto the surface of the inspection target.

3. In paragraph 1, A two-color inspection device in which the two or more light sources are simultaneously irradiated onto the surface of the inspection target.

4. In paragraph 1, The above-mentioned inspection color band determination module is a two-color inspection device that determines the inspection color band based on information measured by the above-mentioned camera module.

5. In paragraph 1, The above inspection color band determination module is a two-color inspection device that determines the inspection color band based on an MES signal or a user input signal.

6. In paragraph 1, The above inspection color band determination module includes an RGB camera, A two-color inspection device that determines the inspection color band based on information measured from the RGB camera.

7. In paragraph 1, The above-mentioned inspection color band discrimination module is a dichroic inspection device that discriminates the above-mentioned inspection color band by discriminating the band in which a dichroic phenomenon appears in a plurality of different color bands.

8. In paragraph 7, The above lighting module includes a spectrum control light capable of controlling spectral characteristics, The above-mentioned inspection color band determination module is a two-color inspection device that determines the inspection color band based on the center wavelength band of the short-wavelength region among the spectral characteristics of the spectrum control lighting.

9. In paragraph 1, A device comprising a light irradiating light onto a test sample and a camera measuring the light irradiated onto the test sample, and further comprising a response characteristic modeling module that models the spectral response characteristic of the camera by measuring the actual intensity in a specific wavelength range of the light irradiated from the light, A two-color inspection device in which the above-mentioned two-color discrimination module examines the color of the inspection target and determines the two-color by considering the spectral response characteristics of the camera modeled in the response characteristic modeling module.

10. In paragraph 9, The above lighting is a monochrome or spectrum-controlled lighting having a short wavelength band, The above test sample is a two-color test device, which is a white reflective patch.

11. In paragraph 10, The above response characteristic modeling module further includes a light intensity meter for measuring the intensity of light irradiated from the light, The above response characteristic modeling module is a two-color inspection device that compares the light intensity measured by the light intensity meter with the light intensity measured by the camera to determine the spectral response characteristics of the camera.

12. In paragraph 9, The above test sample is a color patch consisting of multiple colors, A two-color inspection device, wherein the response characteristic modeling module further includes a database section in which spectral distribution data of the lighting and spectral characteristic data for the color patch are stored.

13. In paragraph 9, The above-mentioned color discrimination module is a color discrimination inspection device that determines the color of the inspection target and the color difference based on the plurality of spectral response characteristic values ​​of the camera identified for a plurality of different wavelength bands.

14. In paragraph 13, A heterochromatic inspection device in which the above-mentioned heterochromatic identification module calculates an estimated spectral response characteristic value of the camera based on a plurality of spectral response characteristic values ​​of the camera, and compares the estimated spectral response characteristic value with a reference value to determine the heterochromaticity of the inspection target.

15. In paragraph 14, A two-color inspection device in which the above-mentioned two-color discrimination module calculates a Lab color coordinate estimation value based on the spectral response characteristic estimation value, and compares the Lab color coordinate estimation value with a reference Lab color coordinate value to determine the two-color of the inspection target.

16. In paragraph 13, A dichroic inspection device in which the above-mentioned dichroic discrimination module calculates an R / G / B estimation value for each wavelength based on the plurality of spectral response characteristic values, and compares the R / G / B estimation value for each wavelength with the R / G / B reference value for each wavelength to determine the dichroism of the inspection target.

17. In paragraph 13, A two-color inspection device in which the above-mentioned two-color determination module measures the spectral response characteristic value of the camera at a basic light quantity and the spectral response characteristic value of the camera at a changed light quantity, calculates the difference value between the spectral response characteristic value at the basic light quantity and the spectral response characteristic value at the changed light quantity, and determines multiple spectral response characteristic values ​​of the camera for multiple different wavelength bands.

18. In paragraph 1, Further comprising a display module that receives data from the above-mentioned color discrimination module and displays it to the user, A color detection device in which the above-mentioned color discrimination module generates data on an area in which a color difference has occurred in the inspection target and transmits the data on the area in which a color difference has occurred to the display module.

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