JP2013213836A - Surface defect inspection device and surface defect inspection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface defect inspection device capable of easily inspecting color unevenness and irregularities on the surface of a sample.SOLUTION: A surface defect inspection device includes: an illumination unit capable of radiating a plurality of pieces of light having different polarization directions from each other for each area; an imaging unit for detecting reflected light of the light radiated to an inspection object by the illumination unit; and a rotatable analyzer provided on a reflected light incident side of the imaging unit. The surface defect inspection device inspects defects on the surface of the inspection object by rotating the analyzer to photograph images in different polarization directions by the imaging unit.

Description

  The present invention relates to a surface defect inspection apparatus and a surface defect inspection method.

  Cases and cases are often colored and painted with a transparent resin material to obtain an aesthetic appearance. When such coloring and coating with a resin material are performed, surface defects with irregularities such as color irregularities, scratches, and irregularities may occur, and irregularities such as color irregularities and surface defects generated on such surfaces may occur. It is necessary to detect.

  As a method of detecting such surface color unevenness and surface defect of the transparent resin film, as shown in FIG. 1, the surface to be inspected is irradiated with bright and dark pattern illumination, and the reflected light from the surface is irradiated. There is a method to perform by detecting. Specifically, the light and dark pattern illumination 310 is irradiated on a member on which a coating film 301 and a transparent resin film 302 are formed on a member to be inspected for surface defects. For convenience of explanation, it is assumed that the color unevenness 303 and the unevenness 304 of the transparent resin film 302 exist on the surface of the member to be inspected for surface defects. The light / dark pattern illumination 310 is a light / dark pattern illumination, and is a light source that does not emit light in the region 310B and emits light in the regions 310A and 310C. Thus, the reflected light of the light emitted by the light / dark pattern illumination 310 is imaged by the image sensor 320. FIG. 2 shows an image captured in this manner, and a light / dark pattern is formed on the surface of a member to be inspected for surface defects corresponding to the light / dark pattern illumination 310. In this method, when the unevenness 304 of the transparent resin film 302 exists in the regions 300A and 300C that are irradiated with light by the pattern illumination 310 and become bright portions, a bright pattern is reflected around the unevenness 304. In the unevenness 304, a dark pattern is projected. Thereby, the distortion of the pattern reflected on the surface of the transparent resin film 302 can be detected, and the unevenness 304 of the transparent resin film 302 can be detected as shown in FIG. However, as shown in FIG. 2, when the color unevenness 303 exists in the region 300 </ b> B that is a dark part where no light is irradiated, the color unevenness 303 cannot be detected. 3 is an enlarged view of a region A3 surrounded by a broken line in FIG. 2, that is, an enlarged view of a portion where the unevenness 304 of the transparent resin film 302 exists.

  Further, as another method for detecting surface color unevenness and surface defects of the resin material, as shown in FIG. 4, the surface to be inspected is irradiated with light from the hue pattern illumination 330 and reflected from the surface. There is a method for detecting light. The hue pattern illumination 330 used at this time has different hues of light emitted from the regions 330A and 330C and the region 330B. For example, the regions 330A and 330C are blue light, and the region 330B is yellow. It is a light source that emits light. When such a hue pattern illumination 330 is used, the surface regions 300A, 300B, and 300C of the surface to be inspected are irradiated with light of any hue. There is a possibility that the color unevenness 303 can also be detected. However, the color unevenness may not be detected depending on the relationship between the color of the coating film 301 of the member to be inspected for surface defects and the color of the light irradiated by the hue pattern illumination 330. For example, when a member to be inspected is coated with a blue-violet coating film 301, when light of yellow and other hues is irradiated, blue light and yellow light due to a complementary color relationship are blue. Purple becomes a dark part and uneven color cannot be detected.

  On the other hand, as a method for detecting color unevenness, as shown in FIG. 5, there is a method of irradiating the surface to be inspected with white uniform illumination 350 and measuring the reflected light from the surface. . In this method, there is no dark part caused by illumination, and the light does not irradiate light of a complementary color relationship by hue, and therefore, the color unevenness 303 can be detected as shown in FIG. However, as shown in FIG. 7, with respect to the unevenness 304 of the transparent resin film 302, the reflected light from the unevenness 304 of the transparent resin film 302 is incident on the image sensor 320 in the same manner as the reflected light of other flat portions. It cannot be detected. FIG. 7 is an enlarged view of a region A7 surrounded by a broken line in FIG. 6, and is an enlarged view of a portion where the unevenness 304 of the transparent resin film 302 exists.

JP-A-7-239222 Japanese Patent No. 3054227

  As described above, there is no method for easily inspecting the surface defect on the surface coated with the colored and transparent resin material, and the surface defect on the surface coated with the colored and transparent resin material is easily performed. A surface defect inspection apparatus and a surface defect inspection method that can be inspected easily are desired.

  According to one aspect of the present embodiment, an illumination unit capable of irradiating light of mutually different polarization directions for each region, and detecting reflected light irradiated to the inspection object from the illumination unit An imaging unit, and a rotatable analyzer provided on the reflected light incident side of the imaging unit, and by rotating the analyzer, the imaging unit captures images having different polarization directions. Thus, it is characterized in that a defect on the surface of the inspection object is inspected.

  Further, according to another aspect of the present embodiment, the illumination unit capable of irradiating light of different polarization directions for each region, and the reflected light irradiated to the inspection object from the illumination unit And an imaging unit for detection, wherein the imaging unit is a polarization imaging camera and inspects a defect on the surface of the inspection target.

  In addition, according to another aspect of the present embodiment, an illumination unit capable of irradiating light of a plurality of hues for each region, and reflected light emitted from the illumination unit to the inspection object are detected. In the surface defect inspection method using the surface defect inspection apparatus having a plurality of light emitting elements capable of emitting different wavelengths in each region, the illumination unit includes: A reference luminance distribution acquisition step of irradiating white light to acquire a reference luminance distribution, and in the irradiation unit, by causing a part of the plurality of light emitting elements to emit light, adjacent regions in the respective regions have different hues. A light emitting step for emitting light to the light source, a luminance adjusting step for adjusting the luminance of the regions having different hues, an imaging step for imaging the inspection object after adjusting the luminance, and a previous step based on the captured image. And characterized in that for inspecting a defect on the surface of the test object.

  Further, according to another aspect of the present embodiment, the illumination unit capable of irradiating light of different polarization directions for each region, and the reflected light irradiated to the inspection object from the illumination unit In a surface defect inspection method using a surface defect inspection apparatus having an imaging unit for detection and a rotatable analyzer provided on the incident side of the reflected light of the imaging unit, the analyzer is connected to the mutual A first imaging step of imaging by the imaging unit in accordance with a position where light in one polarization direction among different polarization directions passes through the analyzer, and the other of the polarization directions different from each other in the analyzer. A second imaging step of imaging by the imaging unit in accordance with a position where light in the polarization direction passes through the analyzer, and light in both polarization directions different from each other in the analyzer are substantially uniform in the analyzer. According to the position where it passes through A third imaging step of imaging the serial imaging unit, and characterized by inspecting a defect on the surface of said object.

  Further, according to another aspect of the present embodiment, the illumination unit capable of irradiating light of different polarization directions for each region, and the reflected light irradiated to the inspection object from the illumination unit In a surface defect inspection method using a surface defect inspection apparatus having an imaging unit for detection and a rotatable analyzer provided on the incident side of the reflected light of the imaging unit, the analyzer is connected to the mutual A first imaging step of imaging by the imaging unit in accordance with a position where light in one polarization direction among different polarization directions passes through the analyzer, and the other of the polarization directions different from each other in the analyzer. The second imaging step of imaging by the imaging unit in accordance with the position where the light in the polarization direction passes through the analyzer, the image obtained in the first imaging step, and the second imaging step Superimposed It has an image processing step of obtaining an image superimposed by, characterized by inspecting a defect on the surface of said object.

  Further, according to another aspect of the present embodiment, the illumination unit capable of irradiating light of different polarization directions for each region, and the reflected light irradiated to the inspection object from the illumination unit In the surface defect inspection method using a surface defect inspection apparatus that is a polarization imaging camera, the imaging unit irradiates the inspection object with light from the illumination unit and detects the polarization imaging. An imaging process for imaging with a camera; a polarization image conversion process for converting the captured image into a polarized image; and a luminance image conversion process for converting the captured image into a luminance image; It is characterized by inspecting for defects on the surface.

  According to the disclosed surface defect inspection apparatus and surface defect inspection method, it is possible to easily inspect surface defects on a surface that is colored and coated with a transparent resin material.

Explanatory drawing of the conventional surface defect inspection method (1) Photograph obtained by the surface defect inspection method shown in FIG. Main part enlarged photograph in FIG. Explanatory drawing of the conventional surface defect inspection method (2) Explanatory drawing of the conventional surface defect inspection method (3) Photograph obtained by the surface defect inspection method shown in FIG. Main part enlarged photograph in FIG. Configuration diagram of a surface defect inspection apparatus in the first embodiment Main part enlarged view in FIG. Flowchart of surface defect inspection method in the first embodiment Explanatory drawing (1) of the surface defect inspection method in 1st Embodiment Explanatory drawing (2) of the surface defect inspection method in 1st Embodiment Explanatory drawing (3) of the surface defect inspection method in 1st Embodiment Flowchart of surface defect inspection method according to second embodiment The block diagram of the surface defect inspection apparatus in 3rd Embodiment Main part enlarged view in FIG. Flowchart of surface defect inspection method in the third embodiment The block diagram of the surface defect inspection apparatus in 4th Embodiment Main part enlarged view in FIG. Flowchart of surface defect inspection method in the fourth embodiment Explanatory drawing (1) of the surface defect inspection method in 4th Embodiment Explanatory drawing (2) of the surface defect inspection method in 4th Embodiment Explanatory drawing (3) of the surface defect inspection method in 4th Embodiment Flowchart of surface defect inspection method in the fifth embodiment The block diagram of the surface defect inspection apparatus in 5th Embodiment Flowchart of surface defect inspection method according to sixth embodiment

  The form for implementing is demonstrated below.

[First Embodiment]
A first embodiment will be described.

(Surface defect inspection equipment)
The surface defect inspection apparatus according to the present embodiment will be described with reference to FIGS. The surface defect inspection apparatus according to the present embodiment inspects surface defects of the surface of a member such as a casing on which a coating film 11 and a transparent resin film 12 are applied. In the description of the present embodiment, the color unevenness 13 and the unevenness 14 of the transparent resin film 12 are applied to those in which the coating film 11 and the transparent resin film 12 are applied on the surface of a member to be inspected. It shall have defects such as. The surface defect apparatus in the present embodiment includes an illumination unit 20, light emission adjustment units 41, 42 and 43, a control unit 50 and an imaging unit 60. FIG. 9 is an enlarged view of a main part in which a part of the illumination unit 20 of the surface defect inspection apparatus according to the present embodiment is enlarged.

  The illuminating unit 20 emits light of different hues for each predetermined region, and includes a light emitting region 21, a light emitting region 22, and a light emitting region 23 that emit different light emission colors. The light emitting region 21, the light emitting region 22, and the light emitting region 23 have a red light emitting diode 31, a green light emitting diode 32, and a blue light emitting diode 33, respectively. By changing the values of currents flowing through the red light emitting diode 31, the green light emitting diode 32, and the blue light emitting diode 33, the hues of the light emitting region 21, the light emitting region 22, and the light emitting region 23 can be adjusted. The illumination unit 20 is provided with a diffusion plate 24 on the side from which light is emitted.

  The light emission adjustment units 41, 42, and 43 are for controlling the light emission regions 21, 22, and 23 connected to the respective light emission adjustment units 41, 42, and 43. That is, the light emission adjusting units 41, 42, and 43 can control the values of currents that flow through the red light emitting diode 31, the green light emitting diode 32, and the blue light emitting diode 33 in the light emitting regions 21, 22, and 23. Thereby, in each light emission area | region 21, 22, and 23, the light of an independent hue can be emitted.

  The control unit 50 controls the light emission adjustment units 41, 42, and 43 and performs image processing and the like obtained in the imaging unit 60. A storage unit 51 is connected to the control unit 50 and can store necessary information and the like.

  The image pickup unit 60 picks up an image of what is irradiated with light from the illumination unit 20 to which the coating film 11 and the transparent resin film 12 to be inspected are applied. The imaging unit 60 can detect a two-dimensional image.

(Surface defect inspection method)
Next, the surface defect inspection method according to this embodiment will be described with reference to FIG. The surface defect inspection method in the present embodiment uses the above-described surface defect inspection apparatus.

  First, in step 102 (S102), the illumination unit 20 irradiates the inspection target with white light. Specifically, the light emission adjusting units 41, 42, and 43 control the current values that flow through the red light emitting diode 31, the green light emitting diode 32, and the blue light emitting diode 33 in the light emitting regions 21, 22, and 23, respectively. Is controlled to emit white light. As a result, white light is irradiated to the coating film 11 and the transparent resin film 12 to be inspected.

  Next, in step 104 (S104), the reference luminance distribution imaged by the imaging unit 60 is stored. Specifically, the reflected light of the light applied to the object to which the coating film 11 and the transparent resin film 12 to be inspected are applied by the illumination unit 20 is captured by the imaging unit 60 and captured by the imaging unit 60. A reference luminance distribution is calculated based on the obtained image information and stored in the storage unit 51. In addition, as described later, the surfaces of the coating film 11 and the transparent resin film 12 to be inspected are irradiated with light of the light emitting regions 21, 22 and 23 in the illumination unit 20, respectively. Regions 10A, 10B, and 10C are formed. Therefore, the reference luminance distribution 71 shown in FIG. 11A can be obtained based on the reflected light in these regions 10A, 10B, and 10C. FIG. 11B shows the luminance state in the reference luminance distribution 71 with tones.

  Next, in step 106 (S106), the hue pattern of the light emission colors of the light emission regions 21, 22 and 23 in the illumination unit 20 is set. Specifically, the initial setting of the hue pattern is performed so that the emission colors of the light emitting areas 21, 22 and 23 have different hues. Based on the set hue pattern, the light emission adjusting units 41, 42, and 43 control the values of current flowing through the red light emitting diode 31, the green light emitting diode 32, and the blue light emitting diode 33 in the respective light emitting regions 21, 22, and 23. As a result, each of the light emitting regions 21, 22 and 23 emits light having a predetermined hue.

  Next, in step 108 (S108), it is determined whether or not the reference luminance distribution 71 obtained in step 104 can be adjusted based on the set hue pattern. Specifically, in the illuminating unit 20, when light of a predetermined color is emitted in each of the light emitting regions 21, 22, and 23, a region like a luminance distribution 72 shown in FIG. In 10A, 10B, and 10C, the image luminance values have different distributions. Note that FIG. 12B shows the luminance in the luminance distribution 72 as a tone. Whether or not such a luminance distribution 72 can be adjusted to a state close to the reference luminance distribution 71, that is, whether or not an adjustment approximate to the reference luminance distribution 71 shown in FIG. Is judged. If it is determined that it is possible to adjust to a state close to the reference luminance distribution 71, the process proceeds to step 110. On the other hand, if it is determined that it is not possible to adjust to a state close to the reference luminance distribution 71, the process proceeds to step 112.

  Next, in step 110 (S110), the brightness of the light emitting areas 21, 22 and 23 in the illumination unit 20 is adjusted. Specifically, the light emission adjusting units 41, 42, and 43 control the current values flowing in the red light emitting diode 31, the green light emitting diode 32, and the blue light emitting diode 33 in the respective light emitting regions 21, 22, and 23 to adjust the luminance. I do. At this time, the brightness adjustment is performed without changing the hue in each of the light emitting regions 21, 22, and 23.

  On the other hand, in step 112 (S112), the hue pattern in the light emitting areas 21, 22 and 23 is reset. That is, the current hue pattern in the light emitting areas 21, 22 and 23 cannot be adjusted to a state close to the reference luminance distribution, or the hue difference interval is narrow as will be described later. Therefore, the hue pattern in the light emitting areas 21, 22 and 23 is changed, and the hue pattern in the light emitting areas 21, 22 and 23 is reset. In the resetting of the hue pattern, the light emission adjusting units 41, 42, and 43 control the values of currents flowing through the red light emitting diode 31, the green light emitting diode 32, and the blue light emitting diode 33 in the respective light emitting regions 21, 22, and 23. By doing.

  Next, in step 114 (S114), it is determined whether or not the hue difference of the hue pattern in each of the light emitting regions 21, 22 and 23 is appropriate. Specifically, it is determined whether the hue difference is not too close, that is, whether the interval between the hues is too narrow in the hue circle shown in FIG. If the hue difference is too close, a surface defect cannot be made accurately, so such a determination is made. As shown in FIG. 13, it is preferable that the colors 81, 82, and 83 are separated from each other on the hue ring. When it is determined that the hue difference of the hue pattern in each of the light emitting areas 21, 22 and 23 is appropriate, the process proceeds to step 116. On the other hand, if it is determined that the hue difference of the hue pattern in each of the light emitting areas 21, 22 and 23 is not appropriate, the process proceeds to step 112.

  Next, in step 116 (S116), the hue and brightness in each of the light emitting areas 21, 22 and 23 are stored. Specifically, the hue and brightness in each of the light emitting areas 21, 22, and 23 are stored in the storage unit 51.

  Next, in step 118 (S118), the illumination unit 20 applies the coating film 11 and the transparent resin film 12 to be inspected for light adjusted in hue and brightness in each of the light emitting regions 21, 22 and 23. The image is picked up by the image pickup unit 60.

  Next, in step 120 (S120), the irregularity defect and the color unevenness are detected. Specifically, irregularities are detected based on the image data captured by the imaging unit 60 in step 118, and color unevenness is detected by converting the image data into a luminance image.

  Next, in step 122 (S122), it is determined whether the coating with the coating 11 and the transparent resin film 12 to be inspected is a good product or a defective product. Specifically, in step 120, if color unevenness or uneven defects are detected, it is determined as a defective product and is not shipped as a product. On the other hand, if no color unevenness or unevenness defect is detected in step 120, the product is determined to be non-defective and is shipped.

  Thus, the surface defect inspection method in the present embodiment is completed. In the surface defect inspection method in the present embodiment, it is possible to easily detect color unevenness and uneven defects in the transparent resin material.

[Second Embodiment]
Next, a second embodiment will be described. The present embodiment is a surface defect inspection method using the surface defect inspection apparatus in the first embodiment.

  Based on FIG. 14, the surface defect inspection method in the present embodiment will be described.

  First, in step 202 (S202), the illumination unit 20 irradiates the inspection target with white light. Specifically, the light emission adjusting units 41, 42, and 43 cause current to flow through the red light emitting diode 31, the green light emitting diode 32, and the blue light emitting diode 33 in each of the light emitting regions 21, 22, and 23, and the lighting unit 20 emits white light. Control to emit. As a result, white light is irradiated to the coating film 11 and the transparent resin film 12 to be inspected.

  Next, in step 204 (S204), the illumination unit 20 is applied with the coating film 11 and the transparent resin film 12 to be inspected with the white light adjusted in each of the light emitting areas 21, 22 and 23. Irradiated and imaged by the imaging unit 60.

  Next, in step 206 (S206), color unevenness is detected. Specifically, color unevenness is detected based on the image data imaged by the imaging unit 60 in step 204.

  Next, in step 208 (S208), the inspection object is irradiated with light of a predetermined hue pattern. Specifically, the light emission adjusting units 41, 42, and 43 control the current values flowing in the red light emitting diode 31, the green light emitting diode 32, and the blue light emitting diode 33 in the light emitting regions 21, 22, and 23 to emit light. For example, only the red light emitting diode 31 emits light in the light emitting region 41, only the green light emitting diode 32 emits light in the light emitting region 42, and only the blue light emitting diode 33 emits light in the light emitting region 43. Thereby, the light of the hue pattern which becomes a different luminescent color in each light emission area | region 21,22,23 of the illumination part 20 can be irradiated.

  Next, in step 210 (S210), the illumination unit 20 applies the coating film 11 and the transparent resin film 12 to be inspected with the light of the hue pattern adjusted in each of the light emitting regions 21, 22 and 23. The object is irradiated and imaged by the imaging unit 60.

  Next, in step 212 (S212), an uneven defect is detected. Specifically, the irregularity defect of the transparent resin film 12 is detected based on the image data imaged by the imaging unit 60 in step 210.

  Next, in step 214 (S214), a determination is made as to whether the coated film 11 and the transparent resin film 12 to be inspected are good or defective. Specifically, in step 212, if color unevenness or uneven defects are detected, it is determined as a defective product and is not shipped as a product. On the other hand, if no color unevenness or unevenness defect is detected in step 212, the product is determined to be non-defective and is shipped.

  In the present embodiment, the color unevenness and the unevenness of the transparent resin film can be easily achieved only by controlling the red light emitting diode 31, the green light emitting diode 32, and the blue light emitting diode 33 in each of the light emitting regions 21, 22, and 23 of the illumination unit 20. Defects can be detected.

[Third Embodiment]
Next, a third embodiment will be described. In this embodiment, when the object to be inspected is painted in a predetermined color or the like, it is possible to more easily detect uneven color and uneven defects in the transparent resin film.

(Surface defect inspection equipment)
The surface defect inspection apparatus according to the present embodiment will be described with reference to FIGS. The surface defect inspection apparatus according to the present embodiment inspects surface defects of the surface of a member such as a casing on which a coating film 11 and a transparent resin film 12 are applied. In the description of the present embodiment, the color unevenness 13 and the unevenness 14 of the transparent resin film 12 are applied to those in which the coating film 11 and the transparent resin film 12 are applied on the surface of a member to be inspected. It shall have defects such as. The surface defect apparatus in the present embodiment includes an illumination unit 120, light emission adjustment units 141, 142, and 143, a control unit 150, and an imaging unit 160. FIG. 16 is an enlarged view of a main part in which a part of the illumination unit 120 of the surface defect inspection apparatus in the present embodiment is enlarged.

  The illumination unit 120 emits light of different hues for each predetermined region, and includes a light emitting region 121, a light emitting region 122, and a light emitting region 123 that emit light of different colors. The light emitting area 121 has a red light emitting diode 131, the light emitting area 122 has a green light emitting diode 132, and the light emitting area 123 has a blue light emitting diode 133. The luminance in each of the light emitting region 121, the light emitting region 122, and the light emitting region 123 can be adjusted by changing the values of currents flowing through the red light emitting diode 131, the green light emitting diode 132, and the blue light emitting diode 133. The illumination unit 120 is provided with a diffusion plate 124 on the side from which light is emitted. In addition, the light emission color of the light emitting diode arrange | positioned in the light emission area | regions 121, 122, and 123 is not limited to the said light emission color.

  The light emission adjustment units 141, 142, and 143 are for controlling the light emission regions 121, 122, and 123 connected to the respective light emission adjustment units 141, 142, and 143. That is, the light emission adjusting units 141, 142, and 143 can control the values of current flowing through the red light emitting diode 131 in the light emitting region 121, the green light emitting diode 132 in the light emitting region 122, and the blue light emitting diode 133 in the light emitting region 123.

  The control unit 150 controls the light emission adjustment units 141, 142, and 143, and performs image processing and the like obtained in the imaging unit 160. A storage unit 151 is connected to the control unit 150 and can store necessary information and the like.

  The imaging unit 160 captures an image of the light applied to the coating with the coating film 11 and the transparent resin film 12 to be inspected by the illumination unit 120. The imaging unit 160 can detect a two-dimensional image.

(Surface defect inspection method)
Next, the surface defect inspection method in the present embodiment will be described with reference to FIG. In the surface defect inspection method in the present embodiment, the luminescent color, that is, the hue in the luminescent regions 121, 122, and 123 of the illumination unit 120 is determined in advance.

  First, in step 302 (S302), the brightness of the light emitting regions 121, 122, and 123 in the illumination unit 120 is adjusted. Specifically, the light emission adjustment units 141, 142, and 143 control the current values flowing in the red light emitting diode 131, the green light emitting diode 132, and the blue light emitting diode 133 in the respective light emitting regions 121, 122, and 123 to adjust the luminance. I do.

  Next, in step 304 (S304), the luminance in each of the light emitting areas 121, 122, and 123 is stored. Specifically, the luminance in each of the light emitting areas 121, 122, and 123 is stored in the storage unit 151.

  Next, in step 306 (S306), the illumination unit 120 applies the coating film 11 and the transparent resin film 12 to be inspected with light adjusted to hue and brightness in each of the light emitting regions 121, 122, and 123. The image is picked up by the image pickup unit 160. Specifically, in each of the regions 121, 122, and 123, the light of each hue is irradiated onto the coating of the coating film 11 and the transparent resin film 12 to be inspected, so that the regions 110C, 110B, and 110A is formed, and this image is captured by the imaging unit 160.

  Next, in step 308 (S308), the detection of uneven defects and color unevenness is performed. Specifically, the unevenness defect is detected based on the image data picked up by the image pickup unit 160, and color unevenness is detected by converting the image data into a luminance image.

  Next, in step 310 (S310), a determination is made as to whether the coating film 11 and the transparent resin film 12 to be inspected are non-defective or defective. Specifically, in step 308, when color unevenness or uneven defects are detected, it is determined as a defective product and is not shipped as a product. On the other hand, in step 308, if no color unevenness or unevenness defect is detected, the product is determined to be non-defective and is shipped.

  Thus, the surface defect inspection method in the present embodiment is completed. In the surface defect inspection method in the present embodiment, it is possible to easily detect color unevenness and uneven defects in the transparent resin material.

[Fourth Embodiment]
Next, a fourth embodiment will be described. The present embodiment relates to a surface defect inspection apparatus and a surface defect inspection method using polarized light.

(Surface defect inspection equipment)
A surface defect inspection apparatus according to the present embodiment will be described with reference to FIGS. The surface defect inspection apparatus according to the present embodiment inspects surface defects of the surface of a member such as a casing on which a coating film 11 and a transparent resin film 12 are applied. In the description of the present embodiment, the color unevenness 13 and the unevenness 14 of the transparent resin film 12 are applied to those in which the coating film 11 and the transparent resin film 12 are applied on the surface of a member to be inspected. It shall have defects such as. The surface defect apparatus in the present embodiment includes an illumination unit 220, a light emission adjustment unit 241, a control unit 250, an imaging unit 260, and an analyzer 270. FIG. 19 is an enlarged view of a main part in which a part of the illumination unit 220 of the surface defect inspection apparatus according to the present embodiment is enlarged.

  The illumination unit 220 emits white light, and a plurality of white light emitting diodes 221 are arranged. In the luminance adjustment, the luminance in the illumination unit 220 can be adjusted by changing the current value flowing through the white light emitting diode 221. The illumination unit 220 is provided with a diffusion plate 222 on the light emitting side, and the light transmitted through the diffusion plate 222 passes through the polarizing plate 230 and is irradiated onto the surface of a member to be inspected. . The polarizing plate 230 is formed by alternately arranging polarizing portions 230a and 230b having different polarization directions, and is formed such that the polarization direction in the polarizing portion 230a and the polarization direction in the polarizing portion 230b are substantially perpendicular to each other. . In this embodiment, the case where the white light emitting diode 221 is used is described. However, depending on the color of the surface of the member to be inspected, the red light emitting diode, the green light emitting diode, the blue light emitting diode, and these A combination of these may be used.

  The light emission adjustment unit 241 is for controlling the brightness of the white light emitting diode 221, and the light emission adjustment unit 241 controls the brightness of the illumination unit 220 by controlling the current value flowing through the white light emitting diode 221. Do.

  The control unit 250 controls the light emission adjustment unit 241 and performs image processing and the like obtained in the imaging unit 260. A storage unit 251 is connected to the control unit 250 and can store necessary information and the like.

  The image pickup unit 260 picks up an image of what is irradiated with light from the illumination unit 220 to which the coating film 11 and the transparent resin film 12 to be inspected are applied. The imaging unit 260 can detect a two-dimensional image.

  The analyzer 270 is provided in the previous stage of the imaging unit 260, and has a predetermined polarization direction among the reflected light of the light irradiated to the coating film 11 and the transparent resin film 12 to be inspected. It has a function of transmitting only the light. The analyzer 270 is installed in a rotatable state, and the rotation angle of the analyzer 270 can be controlled by the analyzer control unit 271. The analyzer control unit 271 is controlled by the control unit 250.

(Surface defect inspection method)
Next, the surface defect inspection method in the present embodiment will be described with reference to FIG.

  First, in Step 402 (S402), the illumination unit 220 causes the white light emitting diode 221 to emit light. Specifically, the light emission adjusting unit 241 controls the current value flowing through the white light emitting diode 221 to adjust the brightness, and the white light is applied to the coating film 11 and the transparent resin film 12 to be inspected. Irradiate.

  Next, in step 404 (S404), the analyzer 270 is rotated to adjust the polarization angle of the analyzer 270 to a predetermined angle φa. Specifically, the analyzer control unit 271 rotates the analyzer 270 so that the amount of light transmitted through the polarizing unit 230a in the polarizing plate 230 is substantially maximized, and the polarization angle of the analyzer 270 is a predetermined angle φa. Adjust to.

  Next, in step 406 (S406), the first imaging is performed in the state in step 404. That is, an image of the coating film 11 and the transparent resin film 12 to be inspected is applied by the imaging unit 260. Specifically, only the light transmitted through the polarizing portion 230 a in the polarizing plate 230 is reflected by the coating film 11 and the transparent resin film 12 to be inspected, and enters the imaging unit 260 through the analyzer 270. Therefore, in this state, an image obtained by reflecting the light irradiated on the region 210B and the region 210D in the coating film 11 and the transparent resin film 12 to be inspected is captured. As a result, as in the luminance distribution 273 shown in FIG. 21A, the images of the areas 210B and 210D become bright portions and the areas 210A and 210C become dark portions are captured. FIG. 21B shows the luminance in the luminance distribution 273 with a tone.

  Next, in step 408 (S408), the analyzer 270 is rotated by about 90 ° to adjust the polarization angle of the analyzer 270 to be the angle φb. Specifically, by rotating the analyzer 270 by about 90 °, the light amount of the light transmitted through the polarizing portion 230b in the polarizing plate 230 becomes a position where the light amount is substantially maximized. At this time, the polarization angle of the analyzer 270 is the angle φb.

  Next, in step 410 (S410), the second imaging is performed in the state in step 408. That is, an image of the coating film 11 and the transparent resin film 12 to be inspected is applied by the imaging unit 260. Specifically, only the light transmitted through the polarizing part 230 b in the polarizing plate 230 is reflected by the coating film 11 and the transparent resin film 12 to be inspected, and enters the imaging unit 260 through the analyzer 270. Therefore, in this state, an image obtained by reflecting the light irradiated on the area 210A and the area 210C in the coating film 11 and the transparent resin film 12 to be inspected is captured. As a result, as in the luminance distribution 274 shown in FIG. 22A, the images of the areas 210A and 210C become bright parts and the areas 210B and 210D become dark parts are captured. Note that FIG. 22B shows the luminance in the luminance distribution 274 as a tone.

  Next, in step 412 (S412), the analyzer 270 is rotated by about 45 ° to adjust the polarization angle of the analyzer 270 to be the angle φc. Specifically, by rotating the analyzer 270 by about 45 °, the amount of light transmitted through the polarizing portion 230a and the amount of light transmitted through the polarizing portion 230b in the polarizing plate 230 are made substantially the same. Can do. At this time, the polarization angle of the analyzer 270 becomes the angle φc.

  Next, in step 414 (S414), the third imaging is performed in the state in step 412. That is, an image of the coating film 11 and the transparent resin film 12 to be inspected is applied by the imaging unit 260. Specifically, the light transmitted through the polarizing part 230 b and the light transmitted through the polarizing part 230 b in the polarizing plate 230 are reflected by the coating film 11 and the transparent resin film 12 to be inspected, and are imaged through the analyzer 270. 260 is incident. Therefore, in this state, an image in which the light applied to the areas 210A, 210B, 210C, and 210D is incident on the coating film 11 and the transparent resin film 12 to be inspected is captured. As a result, an image with substantially uniform brightness can be obtained in the areas 210A, 210B, 210C, and 210D as in the luminance distribution 275 shown in FIG. Note that FIG. 23B shows the luminance in the luminance distribution 275 as a tone.

  Next, in step 416 (S416), detection of uneven defects and color unevenness is performed. Specifically, the irregular defect is detected based on the image captured by the imaging unit 260 in steps 406 and 410, and the color unevenness is detected based on the image captured by the imaging unit 260 in step 414. A specific method for detecting irregularities and color unevenness is the same as that in the first embodiment.

  Next, in step 418 (S418), it is determined whether the coating film 11 and the transparent resin film 12 to be inspected are non-defective or defective. Specifically, in step 416, when color unevenness or uneven defects are detected, it is determined as a defective product and is not shipped as a product. On the other hand, if no color unevenness or unevenness defect is detected in step 416, the product is determined to be non-defective and shipped.

  Thus, the surface defect inspection method in the present embodiment is completed. In the surface defect inspection method in the present embodiment, by using polarized light, it is possible to easily detect uneven color and uneven defects in the transparent resin material without depending on the hue of the light source.

[Fifth Embodiment]
Next, a fifth embodiment will be described. This embodiment is a surface defect inspection method performed using the surface defect inspection apparatus according to the fourth embodiment. The surface defect inspection method in the present embodiment will be described based on FIG.

  First, in step 502 (S502), the illumination unit 220 causes the white light emitting diode 221 to emit light. Specifically, the light emission adjusting unit 241 controls the current value flowing through the white light emitting diode 221 to adjust the brightness, and the white light is applied to the coating film 11 and the transparent resin film 12 to be inspected. Irradiate.

  Next, in step 504 (S504), the analyzer 270 is rotated to adjust the polarization angle of the analyzer 270 to a predetermined angle φa. Specifically, the analyzer control unit 271 rotates the analyzer 270 so that the amount of light transmitted through the polarizing unit 230a in the polarizing plate 230 is substantially maximized, and the polarization angle of the analyzer 270 is a predetermined angle φa. Adjust to.

  Next, in step 506 (S506), the first imaging is performed in the state in step 504. That is, an image of the coating film 11 and the transparent resin film 12 to be inspected is applied by the imaging unit 260. Specifically, only the light transmitted through the polarizing portion 230 a in the polarizing plate 230 is reflected by the coating film 11 and the transparent resin film 12 to be inspected, and enters the imaging unit 260 through the analyzer 270. Therefore, in this state, an image obtained by reflecting the light irradiated on the region 210B and the region 210D in the coating film 11 and the transparent resin film 12 to be inspected is captured. As a result, as in the fourth embodiment, as in the luminance distribution 273 shown in FIG. 21A, an image is captured in which the areas 210B and 210D are bright portions and the areas 210A and 210C are dark portions.

  Next, in step 508 (S508), the analyzer 270 is rotated by about 90 ° to adjust the polarization angle of the analyzer 270 to be the angle φb. Specifically, by rotating the analyzer 270 by about 90 °, the light amount of the light transmitted through the polarizing portion 230b in the polarizing plate 230 becomes a position where the light amount is substantially maximized. At this time, the polarization angle of the analyzer 270 is an angle φb.

  Next, in step 510 (S510), the second imaging is performed in the state in step 508. That is, an image of the coating film 11 and the transparent resin film 12 to be inspected is applied by the imaging unit 260. Specifically, only the light transmitted through the polarizing part 230 b in the polarizing plate 230 is reflected by the coating film 11 and the transparent resin film 12 to be inspected, and enters the imaging unit 260 through the analyzer 270. Therefore, in this state, an image obtained by reflecting the light irradiated on the area 210A and the area 210C in the coating film 11 and the transparent resin film 12 to be inspected is captured. As a result, as in the fourth embodiment, as in the luminance distribution 274 shown in FIG. 22A, the images of the areas 210A and 210C become bright portions and the areas 210B and 210D become dark portions are imaged.

  Next, in step 512 (S512), image processing is performed. Specifically, by superimposing the image captured in step 506 and the image captured in step 510, a luminance distribution similar to the luminance distribution 275 shown in FIG. 23B in the fourth embodiment can be obtained. it can. That is, it is possible to obtain images with substantially uniform brightness in the areas 210A, 210B, 210C, and 210D.

  Next, in step 514 (S414), irregular defects and color unevenness are detected. Specifically, irregular defects are detected based on the images captured by the imaging unit 260 in steps 506 and 510, and color unevenness is detected based on the images captured by the imaging unit 260 in step 512. A specific method for detecting irregularities and color unevenness is the same as that in the first embodiment.

  Next, in step 516 (S516), a determination is made as to whether the coating film 11 and the transparent resin film 12 to be inspected are non-defective or defective. Specifically, in step 514, when color unevenness or uneven defects are detected, it is determined as a defective product and is not shipped as a product. On the other hand, if no color unevenness or unevenness defect is detected in step 514, the product is determined to be non-defective and is shipped.

  Thus, the surface defect inspection method in the present embodiment is completed. In the surface defect inspection method in the present embodiment, by using polarized light, it is possible to easily detect uneven color and uneven defects in the transparent resin material without depending on the hue of the light source.

[Sixth Embodiment]
Next, a sixth embodiment will be described. The surface defect inspection apparatus in the present embodiment uses a polarization imaging camera. Specifically, as shown in FIG. 25, a configuration in which a polarization imaging camera 280 is provided instead of the imaging unit 260 in the surface defect inspection apparatus in the fourth embodiment is the same as that in the fourth embodiment. Unlike the above, the analyzer 270 and the analyzer control unit 271 are unnecessary.

  The polarization imaging camera 280 has a polarization filter unit 281 in which a plurality of polarization filters are arranged for each pixel, and the polarization directions of the plurality of polarization filters are formed to be different polarization directions, for example, orthogonal directions. Has been. The polarization imaging camera 280 can detect light passing through a plurality of polarization filters for each pixel, and can capture images of a plurality of polarization directions with a single imaging.

  Next, the surface defect inspection method in the present embodiment will be described with reference to FIG.

  First, in Step 602 (S602), the illumination unit 220 causes the white light emitting diode 221 to emit light. Specifically, the light emission adjusting unit 241 controls the current value flowing through the white light emitting diode 221 to adjust the brightness, and the white light is applied to the coating film 11 and the transparent resin film 12 to be inspected. Irradiate.

  Next, in step 604 (S604), imaging is performed by the polarization imaging camera 280.

  Next, in step 606 (S606), polarization image conversion is performed on the image captured in step 604. Specifically, an image similar to the image captured in step 406 and step 410 of the fourth embodiment can be obtained by one imaging.

  Next, in step 608 (S608), luminance image conversion is performed on the image captured in step 604. Specifically, an image similar to the image captured in step 414 of the fourth embodiment can be obtained.

  Next, in step 610 (S610), detection of irregularities and color unevenness is performed. Specifically, an uneven defect is detected based on the image obtained by converting the polarization image obtained in step 606, and color unevenness is detected based on the image obtained by converting the luminance image obtained in step 608. A specific method for detecting irregularities and color unevenness is the same as that in the first embodiment.

  Next, in step 612 (S612), it is determined whether the coating film 11 and the transparent resin film 12 to be inspected are non-defective or defective. Specifically, in step 610, if color unevenness or uneven defects are detected, it is determined as a defective product and is not shipped as a product. On the other hand, in step 610, if no color unevenness or unevenness defect is detected, the product is determined to be non-defective and is shipped.

  Thus, the surface defect inspection method in the present embodiment is completed. In the surface defect inspection method in the present embodiment, by using polarized light, it is possible to easily detect uneven color and uneven defects in the transparent resin material without depending on the hue of the light source. In the present embodiment, both color unevenness and defects due to unevenness can be simultaneously inspected by one imaging.

  Although the embodiment has been described in detail above, it is not limited to the specific embodiment, and various modifications and changes can be made within the scope described in the claims.

In addition to the above description, the following additional notes are disclosed.
(Appendix 1)
An illumination unit capable of emitting light of a plurality of hues for each region;
An imaging unit for detecting reflected light applied to the inspection object from the illumination unit;
Each of the regions has a plurality of light emitting elements capable of emitting different wavelengths.
The illumination unit may emit the plurality of light emitting elements to emit white light in each of the regions, and each of the illumination units emits light having different colors in adjacent regions. A part of the plurality of light emitting elements can emit light in the region of
A surface defect inspection apparatus for inspecting defects on a surface of the inspection object.
(Appendix 2)
The surface defect inspection apparatus according to appendix 1, wherein the plurality of light emitting elements are a red light emitting element, a green light emitting element, and a blue light emitting element.
(Appendix 3)
The surface defect inspection apparatus according to appendix 1 or 2, wherein the defects are unevenness and color unevenness on the surface of the inspection object.
(Appendix 4)
An illumination unit capable of irradiating light of different polarization directions for each region;
An imaging unit for detecting reflected light applied to the inspection object from the illumination unit;
A rotatable analyzer provided on the reflected light incident side of the imaging unit,
A surface defect inspection apparatus for inspecting a defect on the surface of the inspection object by picking up images of different polarization directions in an image pickup unit by rotating the analyzer.
(Appendix 5)
An illumination unit capable of irradiating light of different polarization directions for each region;
An imaging unit for detecting reflected light applied to the inspection object from the illumination unit;
2. The surface defect inspection apparatus according to claim 1, wherein the imaging unit is a polarization imaging camera and inspects a defect on the surface of the inspection object.
(Appendix 6)
The polarization filter provided in the polarization imaging camera has a plurality of regions in one pixel, and the polarization directions of the adjacent regions are orthogonal to each other. Surface defect inspection device.
(Appendix 7)
7. The surface defect inspection apparatus according to any one of appendices 4 to 6, wherein the illumination unit emits white light.
(Appendix 8)
8. The surface defect inspection apparatus according to any one of appendices 4 to 7, wherein the illumination unit is provided with a polarization filter for irradiating light in polarization directions orthogonal to each other in each adjacent region. .
(Appendix 9)
An illumination unit capable of irradiating light of a plurality of hues for each region; and an imaging unit for detecting reflected light irradiated to the inspection object from the illumination unit, and each region In the surface defect inspection method using the surface defect inspection apparatus having a plurality of light emitting elements capable of emitting different wavelengths,
A reference luminance distribution acquisition step of acquiring a reference luminance distribution by irradiating white light from the illumination unit;
A light emitting step of emitting light so that adjacent regions in each of the regions have different hues by causing a part of the plurality of light emitting elements to emit light in the irradiation unit;
A luminance adjustment step of adjusting the luminance of the regions having different hues;
After adjusting the luminance, an imaging step of imaging the inspection object;
A surface defect inspection method characterized by inspecting a defect on a surface of the inspection object based on the captured image.
(Appendix 10)
In the luminance adjustment step, when the luminance of the regions having different hues cannot be adjusted substantially uniformly, light of different hues is emitted by adjusting the emission intensity in the plurality of light emitting elements. 10. The surface defect inspection method according to appendix 9, wherein the luminance adjustment step is performed.
(Appendix 11)
An illumination unit capable of irradiating light of a plurality of hues for each region; and an imaging unit for detecting reflected light irradiated to the inspection object from the illumination unit, and each region In the surface defect inspection method using the surface defect inspection apparatus having a plurality of light emitting elements capable of emitting different wavelengths,
A white light image capturing step of irradiating the inspection object with white light from the illumination unit and capturing an image;
A first inspection step for inspecting the surface of the inspection object based on the white light image capturing step;
In the irradiation unit, a hue pattern light irradiation step of irradiating the inspection object with light having a different hue in each of the regions by causing a part of the plurality of light emitting elements to emit light, and imaging
A second inspection step for inspecting the surface of the inspection object based on the hue pattern light irradiation step;
And a method for inspecting a defect on a surface of the inspection object.
(Appendix 12)
The surface defect inspection method according to any one of appendices 9 to 11, wherein the plurality of light emitting elements are a red light emitting element, a green light emitting element, and a blue light emitting element.
(Appendix 13)
An illumination unit capable of irradiating light of a plurality of hues for each region; and an imaging unit for detecting reflected light irradiated to the inspection object from the illumination unit, and each region In the surface defect inspection method using the surface defect inspection apparatus having a light emitting element for emitting light having a different hue in adjacent regions in
A luminance adjustment step of adjusting the luminance of the regions having different hues;
After adjusting the luminance, an imaging step of imaging the inspection object;
A surface defect inspection method characterized by inspecting a defect on a surface of the inspection object based on the captured image.
(Appendix 14)
The light emitting element is any one of a red light emitting element, a green light emitting element, and a blue light emitting element, and the red light emitting element, the green light emitting element, and the blue light emitting element are sequentially arranged so that the hues in the adjacent regions are different from each other. The surface defect inspection method according to appendix 13, wherein the surface defect inspection method is arranged.
(Appendix 15)
15. The surface defect inspection method according to any one of appendices 9 to 14, wherein the defect is unevenness and color unevenness on the surface of the inspection object.
(Appendix 16)
An illuminating unit capable of irradiating light of mutually different polarization directions for each region, an imaging unit for detecting reflected light irradiated on the inspection object from the illuminating unit, and the reflection of the imaging unit In the surface defect inspection method using the surface defect inspection apparatus having a rotatable analyzer provided on the light incident side,
A first imaging step of imaging the analyzer by the imaging unit in accordance with a position where light in one polarization direction out of the mutually different polarization directions passes through the analyzer;
A second imaging step of imaging the analyzer by the imaging unit in accordance with a position where the light of the other polarization direction out of the mutually different polarization directions passes through the analyzer;
A third imaging step of imaging the analyzer by the imaging unit in accordance with a position where both lights having different polarization directions transmit the analyzer substantially uniformly;
And inspecting the surface of the inspection target for defects.
(Appendix 17)
An illuminating unit capable of irradiating light of mutually different polarization directions for each region, an imaging unit for detecting reflected light irradiated on the inspection object from the illuminating unit, and the reflection of the imaging unit In the surface defect inspection method using the surface defect inspection apparatus having a rotatable analyzer provided on the light incident side,
A first imaging step of imaging the analyzer by the imaging unit in accordance with a position where light in one polarization direction out of the mutually different polarization directions passes through the analyzer;
A second imaging step of imaging the analyzer by the imaging unit in accordance with a position where the light of the other polarization direction out of the mutually different polarization directions passes through the analyzer;
An image processing step of obtaining a superimposed image by superimposing the image obtained in the first imaging step and the image obtained in the second imaging step;
And inspecting the surface of the inspection target for defects.
(Appendix 18)
The surface defect inspection according to appendix 16 or 17, wherein an inspection for color unevenness of the inspection object is performed based on the image captured by the third imaging step or the superimposed image obtained by the image processing step. Method.
(Appendix 19)
19. The surface defect inspection method according to any one of appendices 16 to 18, wherein an inspection of color unevenness of the inspection target is performed based on the images captured in the first imaging step and the second imaging step.
(Appendix 20)
An illuminating unit capable of irradiating light of different polarization directions for each region; and an imaging unit for detecting reflected light irradiated on the inspection object from the illuminating unit; In the surface defect inspection method using the surface defect inspection apparatus that is a polarization imaging camera,
An imaging step of irradiating the inspection object with light from the illumination unit and imaging with the polarization imaging camera;
A polarized image conversion step of converting the captured image into a polarized image;
A luminance image conversion step of converting the captured image into a luminance image;
And inspecting the surface of the inspection target for defects.

10A, 10B, 10C Region 11 Coating 12 Transparent resin film 13 Color unevenness 14 Concavity and convexity 20 Illumination part 21, 22, 23 Light emitting region 24 Diffusion plate 31 Red light emitting diode 32 Green light emitting diode 33 Blue light emitting diode 41, 42, 43 Light emission adjustment Unit 50 control unit 51 storage unit 60 imaging unit

Claims (9)

An illumination unit capable of irradiating light of different polarization directions for each region;
An imaging unit for detecting reflected light applied to the inspection object from the illumination unit;
A rotatable analyzer provided on the reflected light incident side of the imaging unit,
A surface defect inspection apparatus for inspecting a defect on the surface of the inspection object by picking up images of different polarization directions in an image pickup unit by rotating the analyzer. An illumination unit capable of irradiating light of different polarization directions for each region;
An imaging unit for detecting reflected light applied to the inspection object from the illumination unit;
2. The surface defect inspection apparatus according to claim 1, wherein the imaging unit is a polarization imaging camera and inspects a defect on the surface of the inspection object.   The polarizing filter provided in the polarization imaging camera has a plurality of regions in one pixel, and the polarization directions of the adjacent regions are orthogonal to each other. Surface defect inspection equipment. An illumination unit capable of irradiating light of a plurality of hues for each region; and an imaging unit for detecting reflected light irradiated to the inspection object from the illumination unit, and each region In the surface defect inspection method using the surface defect inspection apparatus having a plurality of light emitting elements capable of emitting different wavelengths,
A reference luminance distribution acquisition step of acquiring a reference luminance distribution by irradiating white light from the illumination unit;
A light emitting step of emitting light so that adjacent regions in each of the regions have different hues by causing a part of the plurality of light emitting elements to emit light in the irradiation unit;
A luminance adjustment step of adjusting the luminance of the regions having different hues;
After adjusting the luminance, an imaging step of imaging the inspection object;
A surface defect inspection method characterized by inspecting a defect on a surface of the inspection object based on the captured image. An illuminating unit capable of irradiating light of mutually different polarization directions for each region, an imaging unit for detecting reflected light irradiated on the inspection object from the illuminating unit, and the reflection of the imaging unit In the surface defect inspection method using the surface defect inspection apparatus having a rotatable analyzer provided on the light incident side,
A first imaging step of imaging the analyzer by the imaging unit in accordance with a position where light in one polarization direction out of the mutually different polarization directions passes through the analyzer;
A second imaging step of imaging the analyzer by the imaging unit in accordance with a position where the light of the other polarization direction out of the mutually different polarization directions passes through the analyzer;
A third imaging step of imaging the analyzer by the imaging unit in accordance with a position where both lights having different polarization directions transmit the analyzer substantially uniformly;
And inspecting the surface of the inspection target for defects. An illuminating unit capable of irradiating light of mutually different polarization directions for each region, an imaging unit for detecting reflected light irradiated on the inspection object from the illuminating unit, and the reflection of the imaging unit In the surface defect inspection method using the surface defect inspection apparatus having a rotatable analyzer provided on the light incident side,
A first imaging step of imaging the analyzer by the imaging unit in accordance with a position where light in one polarization direction out of the mutually different polarization directions passes through the analyzer;
A second imaging step of imaging the analyzer by the imaging unit in accordance with a position where the light of the other polarization direction out of the mutually different polarization directions passes through the analyzer;
An image processing step of obtaining a superimposed image by superimposing the image obtained in the first imaging step and the image obtained in the second imaging step;
And inspecting the surface of the inspection target for defects.   7. The surface defect according to claim 5, wherein color unevenness inspection of the inspection target is performed based on the image captured by the third imaging step or the superimposed image obtained by the image processing step. Inspection method.   8. The surface defect inspection method according to claim 5, wherein the color unevenness of the inspection object is inspected based on the images captured in the first imaging step and the second imaging step. . An illuminating unit capable of irradiating light of different polarization directions for each region; and an imaging unit for detecting reflected light irradiated on the inspection object from the illuminating unit; In the surface defect inspection method using the surface defect inspection apparatus that is a polarization imaging camera,
An imaging step of irradiating the inspection object with light from the illumination unit and imaging with the polarization imaging camera;
A polarized image conversion step of converting the captured image into a polarized image;
A luminance image conversion step of converting the captured image into a luminance image;
And inspecting the surface of the inspection target for defects.