Surface evaluation device and surface evaluation method

Abstract

To easily evaluate the planar optical anisotropy of the surface or coated surface of a component.SOLUTION: The present invention comprises: a wavelength filter unit 11 with an aperture for forming an aperture hole 11a at the image-side focus position of a large-diameter convex lens 10 that forms an object-side telecentric optical system, through which is passed a regular reflected light parallel to an optical axis C centering around the optical axis C, as well as being provided with a plurality of wavelength filters having different wavelength bands in correspondence to different circumferential angles and arranged in radial form toward the radially outer side from the outer circumference of the aperture hole 11a, with diffusion light passed through via the plurality of wavelength filters; an aperture mechanism 12 for switching between a restricted state in which the regular reflected light passing through the aperture hole 11a is passed through and a full-open state in which the whole including the diffusion light passed via each wavelength filter is passed through; and an imaging sensor 14 for acquiring a reference image having been imaged in the restricted state and an evaluation image having been imaged in the full-open state. The optical anisotropy of the surface of a component is evaluated in the evaluation image on the basis of a waveform component superimposed on the reference image.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a surface evaluation device and a surface evaluation method that can easily evaluate the surface optical anisotropy of the surface of a part or a painted surface. [Background technology]

[0002] Conventionally, the appearance of the surfaces of molded parts such as plastic parts and painted surfaces is impaired if they have optical anisotropy that differs from the design intent. This optical anisotropy is generally evaluated by using multiple or movable lasers or optical sensors to measure the diffusion direction of reflected light from the surfaces of molded parts and painted surfaces.

[0003] Patent Document 1 discloses an optical arrangement in which a beam from a white light source is passed through a pinhole and directed at a plane to be inspected, the reflected light is returned to the objective lens again and passes through a beam splitter near the focal plane, the optical arrangement has a number of concentric rings on the focal plane, and a different color filter is arranged for each band of the rings, and the light passing through the filters is colored according to the magnitude of the tilt angle of the object to be inspected, and the color distribution is displayed in color. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 63-26512 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the above-mentioned method of measuring optical anisotropy using laser light or an optical sensor measures only one point on the surface or painted surface of a molded part, so it is not possible to easily measure the distribution of the optical anisotropy of the entire surface or painted surface of the molded part. When multiple parts are assembled, if there is a difference in the optical anisotropy of the surfaces or painted surfaces of the assembled molded parts, even if the brightness and color of the surfaces or painted surfaces of the molded parts are the same, the overall appearance will be poor. From this point of view, it is also desired to be able to easily measure the areal optical anisotropy of the surfaces or painted surfaces of molded parts.

[0006] The present invention has been made to solve the above-mentioned problems, and aims to provide a surface evaluation device and a surface evaluation method that can easily evaluate the surface optical anisotropy of the surface of a part or a painted surface. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems and achieve the object, the present invention provides a surface evaluation device for evaluating the planar optical anisotropy of the surface of one or more components, the surface evaluation device comprising: a large-diameter convex lens forming an object-side telecentric optical system; and an aperture hole formed at an image-side focal position of the large-diameter convex lens perpendicular to an optical axis, the aperture hole being centered on the optical axis at a position through which the optical axis passes, and allowing regular reflected light parallel to the object-side optical axis to pass through. The aperture hole also has a plurality of wavelength filters arranged radially outward in the radial direction from the outer periphery of the aperture hole, the wavelength filters having different wavelength bands corresponding to different angles in the circumferential direction, and the light is diffused through the plurality of wavelength filters. The present invention is characterized in that it comprises a wavelength filter section with an aperture that passes diffuse light, an aperture mechanism that is arranged on the image side of the large-diameter convex lens and switches between an aperture state that passes specularly reflected light that passes through the aperture hole and a fully open state that passes all light including diffuse light that has passed through each wavelength filter, and an imaging section that acquires a reference image, which is an image of the surface of the part captured with the aperture mechanism in the aperture state, and an evaluation image, which is an image of the surface of the part captured with the aperture mechanism in the fully open state, and evaluates the optical anisotropy of the surface of the part based on the wavelength components superimposed on the reference image on the evaluation image.

[0008] In addition, the present invention is characterized in that, in the above-mentioned invention, it further comprises an evaluation processing unit that generates a difference image between the evaluation image and the reference image, and calculates and outputs the light diffusion direction and / or light diffusion amount of diffused light reflected from the surface of the part based on the wavelength components that appear in the difference image.

[0009] In the present invention, in the above-mentioned invention, the evaluation processing unit creates and displays a light diffusion directivity graph in which the calculation results are displayed in polar coordinates.

[0010] In the present invention, in the above-mentioned invention, the evaluation processing unit displays a reference circle as an evaluation reference value of the amount of light diffusion on the light diffusion directivity graph.

[0011] In the present invention, in the above-mentioned invention, the wavelength filters of the wavelength filter portion with aperture are arranged without any gaps in the circumferential direction.

[0012] In the present invention, in the above-mentioned invention, the wavelength filters of the wavelength filter portion with aperture are disposed discretely in the circumferential direction, and light is blocked between the wavelength filters.

[0013] In the present invention, in the above-mentioned invention, each wavelength filter is a wavelength band of visible light, and the imaging section receives visible light.

[0014] In the present invention, in the above-mentioned invention, the wavelength filter includes a wavelength band other than visible light, and the imaging section has a function of receiving the wavelength band other than visible light.

[0015] In the present invention, in the above-mentioned invention, the surface of the one or more components is a surface of a plurality of assembled components.

[0016] The present invention also provides a surface evaluation method for evaluating the planar optical anisotropy of the surface of one or more components, comprising a reference image capturing step of capturing a reference image, which is a surface image of the component obtained by capturing specularly reflected light parallel to the object-side optical axis that passes through an aperture hole positioned at an image-side focal position in an object-side telecentric optical system, and an evaluation image capturing step of capturing an evaluation image, which is a surface image of the component obtained by capturing diffused light passing through a plurality of wavelength filters that are arranged radially outward from the outer periphery of the aperture hole and have different wavelength bands corresponding to different circumferential angles, and specularly reflected light passing through the aperture hole, and is characterized in that the optical anisotropy of the surface of the component is evaluated based on the wavelength components superimposed on the reference image on the evaluation image.

[0017] In addition, the present invention is characterized in that, in the above invention, it includes an evaluation processing step of generating a difference image between the evaluation image and the reference image, and calculating and outputting the light diffusion direction and / or magnitude of the light diffusion direction of the diffused light reflected from the surface of the part based on the wavelength components appearing in the difference image. Effect of the Invention

[0018] According to the present invention, the surface optical anisotropy of the surface or painted surface of a part can be evaluated. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a surface evaluation device according to the present embodiment. [Diagram 2] FIG. 2 is a diagram showing the configuration of an imaging camera with an aperture mechanism in a stopped-down state and an example of specularly reflected light and diffused light in the stopped-down state. [Diagram 3] FIG. 3 is a diagram showing the configuration of an imaging camera with an aperture mechanism fully open and an example of specularly reflected light and diffused light in the fully open state. [Figure 4] FIG. 4 is a diagram showing the configuration of a wavelength filter unit with a diaphragm. [Diagram 5] FIG. 5 is an explanatory diagram illustrating the wavelength bands of each wavelength filter. [Figure 6] FIG. 6 is a diagram showing an example of the reference image and the evaluation image. [Figure 7] FIG. 7 is a diagram showing an example of a light diffusion directivity graph. [Figure 8] FIG. 8 is a flowchart showing a procedure of evaluation processing of optical anisotropy by the control unit. [Figure 9] FIG. 9 is a diagram showing the configuration of a wavelength filter unit with a stop according to the first modification. [Figure 10] FIG. 10 is a diagram showing the wavelength bands of the wavelength filters of the wavelength filter unit with a diaphragm shown in FIG. [Figure 11] FIG. 11 is a diagram showing the configuration of a wavelength filter unit with a stop according to the second modification. [Figure 12] FIG. 12 is a diagram showing the wavelength bands of the wavelength filters of the wavelength filter unit with a diaphragm shown in FIG. [Figure 13] FIG. 13 is a diagram showing the configuration of a wavelength filter unit with a stop according to the third modification. [Figure 14] FIG. 14 is a diagram showing a configuration of an imaging camera as an example of the fourth modification. [Figure 15] FIG. 15 is a diagram showing the configuration of an imaging camera as another example of the fourth modification. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A surface evaluation device and a surface evaluation method according to the present embodiment will be described below with reference to the accompanying drawings.

[0021] <Summary configuration> FIG. 1 is a schematic diagram showing the configuration of a surface evaluation device 1 according to the present embodiment. As shown in FIG. 1, the surface evaluation device 1 acquires an image of specularly reflected light from the surface S of a molded part 100 captured by an imaging camera 8 having an object-side telecentric optical system (reference image) and an image of specularly reflected light and diffused light from the surface S of the molded part 100 (evaluation image), and calculates the light diffusion direction and / or the magnitude of the light diffusion direction of the diffused light based on a difference image between the reference image and the evaluation image to evaluate the optical anisotropy. The surface evaluation device 1 may evaluate the optical anisotropy by visually comparing the reference image and the evaluation image without calculating the light diffusion direction and / or the magnitude of the light diffusion direction of the diffused light based on the difference image. The surface evaluation device 1 includes an input unit 2, a display unit 3, a storage unit 4, a control unit 5, a light source 6, a beam splitter 7, and an imaging camera 8. The molded part 100 is, for example, a resin injection molded part, but may also be a part having a painted surface or a part with a surface treatment.

[0022] The input unit 2 is an input interface such as a mouse or a keyboard. The display unit 3 is a display interface such as a liquid crystal display that displays various information. The storage unit 4 is a storage device such as a hard disk drive or a non-volatile memory. The light source 6 is a white light source that emits parallel light perpendicular to the surface S via a beam splitter 7, and the light reflected from the surface S is input to the imaging camera 8 via the beam splitter 7. At this time, the specularly reflected light from the surface S is made parallel to the optical axis of the imaging camera 8. The imaging camera 8 is an imaging device that constitutes an image-side telecentric system that captures the reflected light from the surface S.

[0023] Note that, without using the beam splitter 7, specularly reflected light from the surface S may be reflected and input to the imaging camera 8 in parallel with the optical axis of the imaging camera 8. In this case, collimated light from the light source 6 is made obliquely incident on the surface S, and the optical axis of the surface S or the imaging camera 8 is tilted.

[0024] The control unit 5 is a control unit that controls the entire surface evaluation device 1, and has an image acquisition processing unit 5a, an evaluation processing unit 5b, and a display processing unit 5c. The control unit 5 stores programs corresponding to these functional units in a storage device such as a non-volatile memory or a magnetic disk device, and loads these programs into the memory and executes them with the CPU, thereby executing the corresponding processes.

[0025] The image acquisition processing unit 5a operates the light source 6 and the imaging camera 8 to acquire a surface image of the surface S of the molded part 100. The image acquisition processing unit 5a controls an aperture mechanism (described later) in the imaging camera 8 to acquire a reference image of specularly reflected light passing through a wavelength filter unit with an aperture (described later) and an evaluation image including specularly reflected light and diffused light.

[0026] The evaluation processing unit 5b generates a difference image between the reference image and the evaluation image, and calculates the light diffusion direction and / or the magnitude of the light diffusion direction of the diffused light based on the generated difference image to evaluate the optical anisotropy of the surface S. Furthermore, the evaluation processing unit 5b creates a light diffusion directivity graph that displays the calculation results in polar coordinates.

[0027] The display processing unit 5c outputs and displays the reference image and the evaluation image on the display unit 3, and also outputs and displays the light diffusion directivity graph on the display unit 3.

[0028] <Acquisition of reference images and evaluation images> Fig. 2 is a diagram showing the configuration of the imaging camera 8 when the aperture mechanism 12 is in the apertured state, and an example of the specular reflected light L and diffused light L1, L2 in the apertured state. Fig. 3 is a diagram showing the configuration of the imaging camera 8 when the aperture mechanism 12 is in the fully open state, and an example of the specular reflected light L and diffused light L1, L2 in the fully open state. Note that the diffused light L1 is an example of diffused light diffused in the -X direction from position P1, and the diffused light L2 is an example of diffused light diffused in the +X direction from position P1.

[0029] 2 and 3, the imaging camera 8 is provided on the surface S side with a large-diameter convex lens 10 that has a large-diameter input area capable of inputting all specularly reflected light L from the surface S parallel to the optical axis C and forms an object-side telecentric optical system. The large-diameter convex lens 10 has a large diameter and a large thickness in the direction of the optical axis C, so it is preferable to use a Fresnel lens.

[0030] The wavelength filter section with iris 11 is disposed at a focal point FC on the image side of the large-diameter convex lens 10. As shown in FIG. 4, the wavelength filter section with iris 11 is disposed at the position of the focal point FC perpendicular to the optical axis C. The wavelength filter section with iris 11 is formed with an aperture hole 11a at a position where the optical axis C passes through, which passes the specularly reflected light L parallel to the optical axis C on the surface S side with the optical axis C as the center. The wavelength filter section with iris 11 is provided with a plurality of wavelength filters F1 to F4 (F) which are disposed radially from the outer periphery of the aperture hole 11a toward the outside in the radial direction and have different wavelength bands LF1 to LF4 corresponding to different angles in the circumferential direction, and passes the diffused light L1, L2 via the plurality of wavelength filters F1 to F4.

[0031] Specifically, as shown in Fig. 4 and Fig. 5, a wavelength filter F1 having a wavelength band LF1 that transmits violet wavelengths is arranged in the +Y direction from the aperture hole 11a, a wavelength filter F2 having a wavelength band LF2 that transmits blue-green wavelengths is arranged in the -X direction from the aperture hole 11a, a wavelength filter F3 having a wavelength band LF3 that transmits yellow wavelengths is arranged in the -Y direction from the aperture hole 11a, and a wavelength filter F4 having a wavelength band LF4 that transmits red wavelengths is arranged in the +X direction from the aperture hole 11a. Each wavelength filter F1 to F4 is arranged at an equal angle (90°) without gaps in the circumferential direction. Note that each wavelength band LF1 to LF4 is arranged so as to be discrete and at equal intervals in the visible light region, but it does not have to be discrete or at an equal angle as long as the passage of each wavelength band LF1 to LF4 can be distinguished.

[0032] The diaphragm mechanism 12 is disposed on the image side of the large-diameter convex lens 10, specifically, disposed close to the image side of the wavelength filter unit 11 with diaphragm. The diaphragm mechanism 12 switches between a small-diameter diaphragm state that passes only the specular reflected light L passing through the diaphragm hole 11a and a large-diameter diaphragm full-open state that passes all of the specular reflected light L passing through the diaphragm hole 11a and the diffused light L1, L2 passing through each of the wavelength filters F1 to F4 under the control of the control unit 5. The diaphragm mechanism 12 can use diaphragm blades that switch between the diaphragm state and the full-open state. Note that the diaphragm mechanism 12 may be configured to prepare two diaphragms in advance, a diaphragm in the diaphragm state and a diaphragm in the full-open state, and switch between the diaphragms by sliding them in the X direction.

[0033] In a state where the large-diameter convex lens 10, the diaphragm-equipped wavelength filter section 11, and the diaphragm mechanism 12 are arranged, as shown in Fig. 2, when the diaphragm mechanism 12 is in a diaphragm state, the diffused light L1 shown by the dashed line diffuses from the position P1 in the -X direction and passes through each of the wavelength filters F1 to F4 of the diaphragm-equipped wavelength filter section 11, specifically the wavelength filter F2, but is blocked by the diaphragm mechanism 12. Also, the diffused light L2 shown by the dashed line diffuses from the position P1 in the +X direction and passes through each of the wavelength filters F1 to F4 of the diaphragm-equipped wavelength filter section 11, specifically the wavelength filter F4, but is blocked by the diaphragm mechanism 12. On the other hand, as shown in Fig. 3, when the diaphragm mechanism 12 is in a fully open state, the diffused light L1 and L2 shown by the dashed lines pass through the diaphragm mechanism 12 and reach the position P2 of the image sensor 14 via the diaphragm convex lens 13 to form an image.

[0034] The aperture convex lens 13 forms an image of the light that has passed through the aperture mechanism 12 on the image sensor 14. The image sensor 14 may be an array of normal RGB pixels that can receive at least the visible light range. The image sensor 14 may be arranged with pixels that are sensitive to each of the wavelength bands LF1 to LF4. The image sensor 14 may also have a multispectral function that disperses light into each of the wavelength bands LF1 to LF4.

[0035] <An example of evaluation of optical anisotropy> Here, the light diffused in the +Y direction passes through wavelength filter F1 and is filtered into purple light. The light diffused in the -X direction passes through wavelength filter F2 and is filtered into blue-green light. The light diffused in the -Y direction passes through wavelength filter F3 and is filtered into yellow light. The light diffused in the +X direction passes through wavelength filter F4 and is filtered into red light.

[0036] As a result, if the evaluation image has an image area that is purplish compared to the reference image, the diffuse light in this image area is diffused in the +Y direction. If the evaluation image has an image area that is blue-green compared to the reference image, the diffuse light in this image area is diffused in the -X direction. If the evaluation image has an image area that is yellowish compared to the reference image, the diffuse light in this image area is diffused in the +Y direction. If the evaluation image has an image area that is reddish compared to the reference image, the diffuse light in this image area is diffused in the +Y direction.

[0037] Furthermore, if the evaluation image has a higher density in the areas tinted with the transmitted wavelength colors of the wavelength filters F1 to F4 than the reference image, the amount of light diffusion in the direction corresponding to the transmitted wavelength color is large.

[0038] FIG. 6 is a diagram showing an example of a reference image D1 and an evaluation image D2. FIG. 6(a) is a reference image D1 obtained by capturing an image of the surface of a rear fender 101 and a rear door 102 of a vehicle in a combined state. FIG. 6(b) is an evaluation image D2 corresponding to the reference image D1. In the evaluation image D2, the surface of the rear fender 101 appears as a yellowish image, and the surface of the rear door 102 appears as a reddish image. From the arrangement relationship of the wavelength filters F1 to F4 shown in FIG. 4, it is visually evaluated that the reflected light from the surface of the rear fender 101 has optical anisotropy diffused in the -Y direction as indicated by the arrow A1, and the reflected light from the surface of the rear door 102 has optical anisotropy diffused in the +X direction as indicated by the arrow A2.

[0039] In order to quantitatively evaluate the optical anisotropy, the evaluation processing unit 5b generates a difference image by subtracting the reference image D1 from the evaluation image D2, and calculates the light diffusion direction and light diffusion amount of the reflected light based on the wavelength components that appear in the difference image. The light diffusion direction can be obtained based on the arrangement relationship of the wavelength filters F1 to F4. Moreover, the light diffusion amount can be obtained based on the transmission value (pixel value) of the diffused light that has passed through the wavelength filters F1 to F4 (wavelength bands LF1 to LF4).

[0040] The evaluation processing unit 5b uses the obtained light diffusion direction and light diffusion amount to create the light diffusion directivity graph shown in FIG. 7 and display it on the display unit 3. The light diffusion directivity graph is a polar coordinate display with the optical axis C of the XY plane centered on the optical axis C as the origin, and the radial size centered on the origin indicates the light diffusion amount. The light diffusion direction is displayed as a value that increases in angle clockwise from the +Y direction, with the +Y direction being 0° (360°), the -X direction being 90°, the -Y direction being 180°, and the X direction being 270°. In addition, in the light diffusion directivity graph, a reference circle B centered on the origin is drawn. The reference circle B is an evaluation reference value when evaluating the magnitude of the light diffusion amount. If there is a light diffusion amount exceeding this reference circle B, it can be determined that there is optical anisotropy that deteriorates the appearance. For example, in the light diffusion directivity graph shown in FIG. 7, it is quantitatively determined that there is optical anisotropy that deteriorates the appearance in the 180° direction. In addition, FIG. 7 shows that a large amount of light diffusion is also observed in the 270° direction, and it can also be seen that the light diffusion direction has optical anisotropy separated into two directions.

[0041] The light diffusion directivity graph is an example of a graph showing the light diffusion direction and light diffusion amount of reflected light, and may be, for example, a graph in which the light diffusion direction is on the horizontal axis and the light diffusion amount is on the vertical axis.

[0042] <Evaluation of optical anisotropy> Fig. 8 is a flowchart showing the procedure of the evaluation process of optical anisotropy by the control unit 5. As shown in Fig. 8, first, the control unit 5 irradiates the surface S of the molded part 100 with light via the light source 6 (step S110). Then, the diaphragm mechanism 12 is set to the diaphragm state (step S120). Then, a reference image, which is an image of the light specularly reflected from the surface S, is obtained (step S130). Then, the diaphragm mechanism 12 is set to the fully open state (step S140). Then, an evaluation image, which is an image of the light specularly reflected from the surface S and the diffused light, is obtained (step S150).

[0043] Thereafter, the control unit 5 generates a difference image of the evaluation image with respect to the reference image (step S160).Furthermore, based on the wavelength components appearing in this difference image, a light diffusion directivity graph is generated in which the light diffusion direction and the light diffusion amount of the surface S are displayed in polar coordinates, and the light diffusion directivity graph is displayed on the display unit 3 together with the reference image and the evaluation image (step S170), and this process ends.

[0044] <Variation 1> Fig. 9 is a diagram showing the configuration of a wavelength filter section with an aperture 21 according to Modification 1. Fig. 10 is a diagram showing the wavelength bands of the wavelength filters F21 to F23 of the wavelength filter section with aperture 21 shown in Fig. 9. In the wavelength filter section with aperture 21 of Modification 1, three wavelength filters F21 to F23 are used instead of the four wavelength filters F1 to F4 in the wavelength filter section with aperture 11, as shown in Fig. 9. Each of the wavelength filters F21 to F23 has transmission characteristics of wavelength bands LF21 to LF23 of the three primary colors of blue, green, and red, as shown in Fig. 10. In Modification 1, the imaging sensor 14 corresponds to an image sensor using RGB pixels, making image processing easier.

[0045] <Variation 2> FIG. 11 is a diagram showing the configuration of the diaphragm-equipped wavelength filter section 31 according to the second modification. FIG. 11 is also a diagram showing the wavelength bands of the wavelength filters F31 to F34 of the diaphragm-equipped wavelength filter section 31 shown in FIG. 11. In the diaphragm-equipped wavelength filter section 31 according to the second modification, wavelength filters F31, F32, and F33 having the transmission characteristics of the wavelength filters F21, F22, and F23 of the three primary colors are arranged at the arrangement positions of the wavelength filters F1, F3, and F4 among the four wavelength filters F1 to F4 in the diaphragm-equipped wavelength filter section 11, and a wavelength filter F34 having the transmission characteristics of the infrared wavelength band LF34 is arranged at the arrangement position of the wavelength filter F2. The wavelength bands LF31 to LF33 shown in FIG. 12(b) have the same transmission characteristics as the wavelength bands LF21 to LF23. The image sensor 14 needs to be able to receive infrared light, here far-infrared light, but a normal image sensor has sensitivity to receive far-infrared light.

[0046] In this modified example 2, infrared light cannot be seen, but the image sensor 14 detects infrared light, so that, for example, a light diffusion directivity graph can be generated, and optical anisotropy can be evaluated. In addition, in this modified example 2, the wavelength intervals of the wavelength bands LF31 to LF34 can be widened compared to the embodiment, so that the directional separation accuracy of the diffusion direction of the diffused light can be improved. Note that the wavelength filter F34 is not limited to infrared light, and may have an ultraviolet light wavelength band.

[0047] <Modification 3> FIG. 13 is a diagram showing the configuration of the diaphragm-equipped wavelength filter unit 41 according to the modified example 3. In the above-mentioned embodiment and modified examples 1 and 2, the wavelength filters are arranged with no gaps in the circumferential direction, but in this modified example, as shown in FIG. 13, the wavelength filters F41 to F44 are arranged discretely in the circumferential direction. Specifically, the wavelength filters F41 to F44 are formed in a belt shape extending in the radial direction at intervals of 90°. The wavelength bands of the wavelength filters F41 to F44 are the same as the wavelength bands of the wavelength filters F1 to F4. Note that between the wavelength filters F41 to F44, shielding regions E1 to E4 that block the transmission of light are formed. According to the modified example 3, the optical anisotropy can be evaluated in the same way as in the embodiment and modified examples 1 and 2.

[0048] <Variation 4> Fig. 14 is a diagram showing the configuration of an imaging camera 81, which is an example of Modification 4. Fig. 15 is a diagram showing the configuration of an imaging camera 82, which is another example of Modification 4. In the above embodiment, the diaphragm mechanism 12 of the imaging camera 8 is disposed adjacent to the image side of the diaphragm-equipped wavelength filter section 11, but in the imaging camera 81 of Modification 4, as shown in Fig. 14, it is disposed adjacent to the object side of the diaphragm-equipped wavelength filter section 11, that is, the large-diameter convex lens 10 side. This also allows the diaphragm mechanism 12 to fulfill its function.

[0049] 15, in the imaging camera 82, the aperture mechanism 12 is disposed between the aperture convex lens 13 and the imaging sensor 14. In the imaging camera 82 shown in Fig. 15, a commercially available camera configuration consisting of the aperture convex lens 13, the aperture mechanism, and the imaging sensor 14 can be used.

[0050] In this embodiment and its modified examples, a reference image is captured and obtained, which is a surface image of a molded part obtained by capturing specularly reflected light parallel to the object-side optical axis that passes through an aperture hole located at the image-side focal position in an object-side telecentric optical system, and an evaluation image is captured and obtained, which is a surface image of the molded part obtained by capturing diffuse light that has passed through a plurality of wavelength filters that are arranged radially outward from the outer periphery of the aperture hole and have different wavelength bands corresponding to different circumferential angles, and specularly reflected light that has passed through the aperture hole.Therefore, the optical anisotropy of the surface of one or more molded parts can be easily evaluated based on the wavelength components superimposed on the reference image on the evaluation image.

[0051] In addition, a difference image between the evaluation image and the reference image is generated, and the light diffusion direction and / or magnitude of the light diffusion direction of the diffused light reflected from the surface of the molded part is calculated and output based on the wavelength components that appear in the difference image, thereby enabling a quantitative evaluation of optical anisotropy.

[0052] Note that the configurations illustrated in the above embodiments and modifications are merely functional schematics, and are not necessarily physically configured as illustrated. In other words, the form of distribution and integration of each device is not limited to that illustrated, and all or part of the devices can be functionally or physically distributed and integrated in any unit according to various loads, usage conditions, etc. [Industrial Applicability]

[0053] The surface evaluation device and surface evaluation method of the present invention are useful for easily evaluating the planar optical anisotropy of the surface of a part or a painted surface. [Explanation of symbols]

[0054] 1. Surface evaluation equipment 2 Input section 3 Display section 4 Storage section 5. Control section 5a Image acquisition processing section 5b Evaluation processing section 5c Display processing section 6 light source 7 Beam splitter 8,81,82 Imaging camera 10 Large diameter convex lens 11a Aperture 11, 21, 31, 41 Wavelength filter with aperture 12 Aperture mechanism 13 Aperture convex lens 14 Image sensor 100 Molded parts 101 Rear fender 102 Rear door A1, A2 arrows B Reference circle C optical axis D1 Reference Image D2 Evaluation Image E1~E4 Shielding area F1~F4, F21~F23, F31~F34, F41~F44 Wavelength filters FC focus L specular reflection light L1, L2 Diffused light LF1~LF4, LF21~LF23, LF31~LF34 wavelength bands P1,P2 position S surface

Claims

1. 1. A surface evaluation device for evaluating areal optical anisotropy of a surface of one or more components, comprising: a large-diameter convex lens forming an object-side telecentric optical system; a wavelength filter section with an aperture, which is disposed perpendicular to the optical axis at the image-side focal position of the large-diameter convex lens, and which has an aperture hole formed at the position through which the optical axis passes, and which passes specularly reflected light parallel to the object-side optical axis with the optical axis as its center, and which is disposed radially outward from the outer periphery of the aperture hole in the radial direction, and which has a plurality of wavelength filters having different wavelength bands corresponding to different angles in the circumferential direction, and which passes diffused light through the plurality of wavelength filters; an aperture mechanism that is disposed on the image side of the large-diameter convex lens and that switches between an aperture state that passes specularly reflected light that passes through the aperture hole and a fully open state that passes all light including diffused light that has passed through each wavelength filter; an imaging unit that acquires a reference image, which is a surface image of the component captured with the diaphragm mechanism in the diaphragm state, and an evaluation image, which is a surface image of the component captured with the diaphragm mechanism in the fully open state; and evaluating optical anisotropy of the surface of the part based on wavelength components superimposed on the reference image on the evaluation image.

2. The surface evaluation device according to claim 1, further comprising an evaluation processing unit that generates a difference image between the evaluation image and the reference image, and calculates and outputs the light diffusion direction and / or light diffusion amount of diffused light reflected from the surface of the part based on the wavelength components that appear in the difference image.

3. 3. The surface evaluation device according to claim 2, wherein the evaluation processing unit creates and displays a light diffusion directivity graph in which the calculation results are displayed in polar coordinates.

4. 4. The surface evaluation device according to claim 3, wherein the evaluation processing unit displays a reference circle as an evaluation reference value of the amount of light diffusion for the light diffusion directivity graph.

5. 5. The surface evaluation device according to claim 1, wherein the wavelength filters of the wavelength filter unit with aperture are arranged without gaps in the circumferential direction.

6. 5. The surface evaluation device according to claim 1, wherein the wavelength filters of the wavelength filter section with aperture are arranged discretely in the circumferential direction, and light is blocked between the wavelength filters.

7. Each wavelength filter is a wavelength band of visible light, 7. The surface evaluation device according to claim 1, wherein the imaging unit receives visible light.

8. the wavelength filter includes a wavelength band other than visible light; 7. The surface evaluation device according to claim 1, wherein the imaging unit has a function of receiving light in a wavelength band other than visible light.

9. 9. The surface evaluation device according to claim 1, wherein the surface of the one or more components is a surface of a plurality of assembled components.

10. 1. A surface evaluation method for evaluating areal optical anisotropy of one or more surfaces of components, comprising the steps of: a reference image capturing step of capturing a reference image, which is a surface image of the component, obtained by capturing specularly reflected light parallel to an object-side optical axis passing through a diaphragm hole disposed at an image-side focal position in an object-side telecentric optical system; an evaluation image capturing step of capturing an evaluation image, which is a surface image of the component, obtained by capturing diffuse light through a plurality of wavelength filters arranged radially outward from the outer periphery of the aperture hole and having different wavelength bands corresponding to different angles in the circumferential direction, and regular reflected light through the aperture hole; Including, A surface evaluation method comprising: evaluating optical anisotropy of the surface of the part based on wavelength components superimposed on the reference image on the evaluation image.

11. The surface evaluation method according to claim 10, further comprising an evaluation processing step of generating a difference image between the evaluation image and the reference image, and calculating and outputting the light diffusion direction and / or magnitude of the light diffusion direction of diffused light reflected from the surface of the part based on the wavelength components appearing in the difference image.

Images