JP6422191B2 - Oblique illumination imaging device - Google Patents

Description

  The present invention relates to an oblique illumination imaging apparatus and method for inspecting the color and texture of an image for evaluating the coloring of a product.

  Regarding the adjustment of color and texture, the inventions of Patent Documents 1 and 2 have been proposed. In the present invention, a camera having three spectral sensitivities (S1 (λ), S2 (λ), S3 (λ)) linearly converted equivalent to the CIE XYZ color matching function, and three spectral sensitivities acquired by the camera are obtained. An arithmetic processing unit that obtains and calculates coloring data obtained by converting the image having tristimulus values X, Y, and Z in the CIE XYZ color system, and an illumination unit that irradiates the measurement object. Among the coloring data obtained by imaging the measurement object, the specified inspection area is set, and the inspection object and the reference object are measured from the X, Y, and Z values of each pixel in the inspection area. By calculating the normalized x and y values for the inspection region, dividing the inspection region of the xy coordinates of the xy chromaticity diagram by a grid, and adding the number of pixels of the inspection object and the reference object belonging to each lattice, xy Create a chromaticity coordinate histogram distribution, or Generates an XYZ chromaticity coordinate histogram distribution by accumulating the number of pixels of the XYZ chromaticity coordinate histogram acquired in the three-dimensional XYZ coordinates, and generates two xy chromaticity coordinate histogram distributions or XYZ colors of the inspection object and the reference object The color and its texture are inspected by calculating the Lab average value and the spread degree difference calculation indicating the overlapping ratio of the degree coordinate histogram distribution.

  There is also provided a handy type two-dimensional colorimeter by dome illumination using the two-dimensional colorimeter applied to the inventions of Patent Documents 1 and 2 above. The imaging device 601 includes a camera 602, an arithmetic processing device 603, a display device 607, an LED illumination unit 606, a dome-shaped cover 608, and a switch (not shown). A camera 602 is arranged at the upper center part of the dome-shaped cover 608 so that a lower measurement object can be imaged while holding the camera 602 by hand, and an illumination part 606 is formed in a circular arc on the upper inner wall surface in the peripheral part. A plurality of light sources are arranged so as to irradiate light to provide indirect illumination. The illumination unit 606 employs LED illumination having a color rendering property of 92 or more, and is an indirect illumination type high color rendering white light source. The camera 602 is equipped with a measuring head that can accurately measure color and texture without being affected by external light. The camera 602 uses a color visual reproduction camera method (measurement measurement), and is not affected by movement. Have sex.

Japanese Unexamined Patent Publication No. 2015-155892 WO2015 / 107889 Publication

  However, for example, with the spread of eco-cars in recent years, different materials have been adopted regardless of the interior and exterior in order to reduce the weight by combining light and durable materials, and color matching of different materials is required. ing. Also, metallic colors and pearl colors are commonly used as body colors in order to enhance the texture of the car.

  The above-mentioned handy two-dimensional colorimeters with dome illumination described in Patent Documents 1 and 2 are integrating sphere illuminations in which uniform illumination conditions are set everywhere and uniform images without shadows are obtained, and there is an advantage that color differences can be easily understood.

  However, since the illumination light strikes the camera from all angles, it works in a direction that cancels the metallic feeling and is counterproductive to obtaining an image that evaluates the metallic feeling, and is difficult to realize. For example, in various situations, such as the door and fender, bonnet and fender base materials are different, and the arrangement of glitter materials (aluminum flakes, etc.), there is a flip-flop phenomenon that changes shade and brightness depending on the viewing angle. This is a problem, and it is very difficult to analyze and evaluate the metallic feeling, and there is an inconvenience that accurate analysis and evaluation of the color distribution accompanying the flip-flop phenomenon cannot be obtained.

  Therefore, an object of the present invention is to provide an oblique illumination imaging apparatus and method capable of imaging an object by a two-dimensional colorimeter that contributes to accurate and precise evaluation accompanying the flip-flop phenomenon.

  In view of the above problems, the present invention provides an imaging unit including a two-dimensional colorimeter having three spectral sensitivities (S1 (λ), S2 (λ), and S3 (λ)) linearly converted equivalently to the CIE XYZ color matching functions. A housing having a predetermined shape and having an opening, rotatably supporting the imaging unit and providing a trajectory to rotate, and providing a window at the center, and through which the light is transmitted A covering material that is passed through and covered by the opening of the housing, the housing covers a pair of light-shielding side plates facing each other at an interval, and an end surface of a space between the side plates, and light An elastic sheet-like light shielding material having an arc-shaped cross section, and an intermediate portion of the light shielding material, the two-dimensional colorimeter is fixed, and is 180 ° or less along the end face of the space A rotation member that rotates in a predetermined rotation direction within an angular range of the angle, and a position that is disposed in the space and that avoids the optical axis of the two-dimensional colorimeter. An illumination unit that obliquely illuminates the window with a plurality of illuminations arranged symmetrically with respect to the two-dimensional colorimeter, and an optical axis of the two-dimensional colorimeter and light of the illumination unit An oblique illumination imaging apparatus characterized in that an axis is arranged toward the window and images an imaging target under the oblique illumination.

  It is preferable that the rotating member is U-shaped, and the pair of base portions are pivotally attached to the center of rotation and move along an arcuate track.

  It is preferable that the light shielding material is a light-shielding bellows or a stretchable sheet member that can move along an arcuate path, and has a structure that prevents disturbance light.

  It is preferable that the illuminating unit is a bar-shaped LED illuminating unit, which is arranged symmetrically at a plurality of locations in the space, and the LED illuminating unit performs oblique illumination on the window.

  The covering material is preferably made of a porous sponge.

  The oblique illumination is an illumination system that captures an image by applying light obliquely to an imaging target.

  According to the present invention, it is possible to measure a metallic feeling and a flip-flop, which could not be sufficiently evaluated in the past, by measuring an imaging target at different angles. In addition, a handy imaging device can be provided.

It is a perspective view which shows the structure of the oblique illumination imaging device of embodiment of this invention. It is a side view which shows arrangement | positioning of the illumination part of the oblique illumination imaging device of this invention embodiment. It is a block diagram of the two-dimensional colorimeter 2 of the imaging part 2 of the oblique illumination imaging device of this invention embodiment. It is a specific example of the system which acquires image information according to three spectral sensitivities in Embodiment 1 of this invention. (A) is explanatory drawing in the case of using a dichroic mirror. (B) is explanatory drawing in the case of using a filter turret. (C) is explanatory drawing at the time of attaching an optical filter to the image pick-up element 53 microscopically. It is a function which shows the spectral sensitivity of the two-dimensional colorimeter 2 which is an XYZ color system camera in Embodiment 1 of this invention.

  An oblique illumination imaging apparatus 1 according to a preferred embodiment 1 of the present invention will be described with reference to FIGS.

  The oblique illumination imaging device 1 has three spectral sensitivities (S1 (λ), S2 (λ), and S3 (λ)) that are linearly converted equivalently to the CIE XYZ color matching functions, as shown in FIGS. It has an imaging unit 2 and a housing 4 having a predetermined shape that supports the imaging unit 2 in a rotatable manner and has an opening 3. A window 5 is provided at the center, and light passes through the window 5. And a covering material 6 that covers the opening 3 of the housing 4. The casing 4 covers a pair of light-shielding side plates 7 facing each other at an interval and the end face of the space S between the side plates 7 and shields light, and is a stretchable sheet-like light shielding material having an arc-shaped cross section. 8 and an intermediate portion of the light shielding member 8, the imaging unit 2 is fixed, and a rotating member 9 that rotates in an angular range of 170 ° along the end surface of the space S is disposed in the space S. , Illumination units 10a to 10d for obliquely illuminating light on the window 5, and a machine frame 11 to which the covering material 6, the side plate 7, the light shielding material 8 and the rotating member 9 are attached, and the optical axis L of the imaging unit 2 is It arrange | positions so that it may pass through the window 5, and images an imaging target under oblique illumination, It is characterized by the above-mentioned. Here, each part will be described with reference to the x-axis (vertical direction), the y-axis (horizontal direction), and the z-axis (vertical direction) (lowercase letters are different from the XYZ color system).

  The imaging unit 2 includes a two-dimensional color meter 2a of a part number RC-500 of Paparabo Co., Ltd. and a mechanism unit (not shown) for attachment. As shown in FIG. 6, the two-dimensional colorimeter 2a has three spectral sensitivities (S1 (λ), S2 (λ), S3 (λ)) that are linearly converted equivalently to the CIE XYZ color matching functions. An arithmetic processing unit 24 that converts three spectral sensitivities of the obtained image into tristimulus values XYZ in the CIE XYZ color system and an image display unit 25 that displays the image are provided. A moving image is also possible instead of a still image. The mechanism portion (not shown) is a mechanism for detaching from the rotating member 9.

The system shown in FIG. 4A is a system using a dichroic mirror. This is because light of a specific wavelength is reflected by the dichroic mirror 22c ′, and the remaining light that has been transmitted is further reflected by another dichroic mirror 22a ′ to be spectrally separated, and the image pickup devices 23a, 23b. , 23c are read in parallel. Here, the dichroic mirror 22a ′ corresponds to the optical filters 22a and 22b, and the dichroic mirror 22c ′ corresponds to the optical filter 22c. Light incident from the photographic lens 21 is reflected by the dichroic mirror 22c ′ according to the spectral sensitivity S3, and the remaining light is transmitted. The light reflected by the dichroic mirror 22c ′ is reflected by the reflecting mirror 26, and the spectral sensitivity S3 is obtained by the imaging device 23c. On the other hand, the light transmitted through the dichroic mirror 22c ′ is reflected by the dichroic mirror 22a ′, and the light according to the spectral sensitivity S1 is transmitted, and the remaining light according to the spectral sensitivity S2 is transmitted . The light transmitted through the dichroic mirror 22a ′ is imaged by the image sensor 23b to obtain the spectral sensitivity S2. The light reflected by the dichroic mirror 22a ′ is reflected by the reflecting mirror 29, and the spectral sensitivity S1 is obtained by the imaging device 23a . Instead of the dichroic mirror, a dichroic prism having the same characteristics may be used to split the light into three, and the image sensors 23a, 23b, and 23c may be bonded to the positions where each light is transmitted.

  The system shown in FIG. 4B uses a filter turret 27. Optical filters 22a, 22b, and 22c are provided on a filter turret 27 having the same direction as the incident light from the photographing lens 21 as a rotation axis, and these are mechanically rotated. S1, S2, and S3 are obtained.

  FIG. 4C shows a system in which the optical filters 22 a, 22 b, and 22 c are microscopically attached to the image sensor 23. The optical filters 22a, 22b, and 22c on the image sensor 23 are provided in a Bayer array type. This arrangement is such that the optical filter 22b is provided in half of the area on the image sensor 23 divided into a grid, and the optical filter 22a and the optical filter 22c are equally arranged in the remaining half of the area. That is, the arrangement amount is optical filter 22a: optical filter 22b: optical filter 22c = 1: 2: 1. It is not particularly disturbed in the present embodiment that the arrangement of the optical filters 22a, 22b, and 22c is other than the Bayer arrangement. Each of the optical filters 22a, 22b, and 22c is very fine and is attached to the image sensor 23 by printing. However, in the present invention, this arrangement is not meaningful, but a filter having characteristics of spectral sensitivity (S1 (λ), S2 (λ), S3 (λ)) is attached to the image sensor.

The spectral sensitivity of the two-dimensional colorimeter 2a satisfies the router condition, and the spectral sensitivities (S1 (λ), S2 (λ), S3 (λ)) are obtained from XYZ color matching functions as shown in FIG. This is a mountain shape having no negative value and having a single peak, and is equivalently converted from the condition that the peak values of the respective spectral sensitivity curves are equal and the overlapping of spectral sensitivity curves is minimized. Specifically, the spectral sensitivities (S1 (λ), S2 (λ), S3 (λ)) have the following characteristics.
Peak wavelength Half width 1/10 width S1 582nm 523-629nm 491-663nm
S2 543nm 506-589nm 464-632nm
S3 446 nm 423-478 nm 409-508 nm

  The peak wavelength of the spectral characteristic S1 can be handled as 580 ± 4 nm, the peak wavelength of the spectral characteristic S2 is 543 ± 3 nm, and the peak wavelength of the spectral characteristic S3 can be handled as 446 ± 7 nm.

  The spectral sensitivities (S1 (λ), S2 (λ), S3 (λ)) of the two-dimensional colorimeter 2a are mountain shapes having a single peak having no negative value from the CIE XYZ spectral characteristics. The curve is equivalently converted from the condition that the peak values of the curves are equal and the overlapping of the spectral sensitivity curves is minimized. The curve of the spectral characteristic S1 has a peak wavelength of 582 nm and a half-value width of 523 to 629 nm. The 1/10 width is 491 to 663 nm. The curve of the spectral characteristic S2 has a peak wavelength of 543 nm, a full width at half maximum of 506 to 589 nm, and a 1/10 width of 464 to 632 nm. The curve of the spectral characteristic S3 has a peak wavelength of 446 nm, a full width at half maximum of 423 to 478 nm, and a 1/10 width of 409 to 508 nm.

The three spectral sensitivities (S1 (λ), S2 (λ), S3 (λ)) are obtained using Equation 1. For details about the spectral characteristics themselves, refer to JP-A-2005-257827.

  This color fidelity technology is based on information about the colors obtained by devices such as cameras, displays, printers, etc. from the outside. Compared with the color method, reproducibility can be obtained.

  The specifications of the 2D color meter 2a are, for example, an effective frequency value of about 5 million pixels, an effective area of 9.93 mm x 8.7 mm, an image size of 3.45 μm x 3.45 μm, a video output of 12 Bit, a camera interface GigE, and the number of frames (when adjusting focus) 3 to 7 frames / sec, shutter speed 1 / 15,600sec to 1 / 15sec, integration time up to 3 seconds, S / N ratio 60dB or more, lens mount F mount, operating temperature 0 ° C to 40 ° C, operating humidity 20% to 80% %.

  For an image, color information obtained primarily is a three-band visual sensitivity image S1i based on three normalized sensitivities (S1 (λ), S2 (λ), S3 (λ)) based on functions equivalent to XYZ color matching functions. , S2i, S3i (i = 1 to m, where m is the number of pixels), it is faithful to the sensitivity of the human eye and is highly accurate compared to the case of acquiring by RGB. Since the overlap of the standardized sensitivity (S1 (λ), S2 (λ), S3 (λ)) is small, the S / N ratio is sufficient, and the curve of the standardized sensitivity curve also changes naturally. Errors are kept to a minimum.

  As shown in FIG. 4, the two-dimensional colorimeter 2a includes a photographing lens 21, three optical filters 22a, 22b, and 22c arranged behind the photographing lens 21, and a rear of the optical filters 22a, 22b, and 22c. And an image pickup device 23 (CCD, CMOS, etc.) arranged. The three spectral sensitivities (S1 (λ), S2 (λ), and S3 (λ)) of the two-dimensional colorimeter 2a are obtained by multiplying the spectral transmittance of the optical filters 22a, 22b, and 22c and the spectral sensitivity of the image sensor 23. Is given. The arrangement relationship between the optical filters 22a, 22b, and 22c and the image sensor 23 in FIG. 4 is merely shown schematically. Specific examples of the method of acquiring image information according to the three spectral sensitivities (S1 (λ), S2 (λ), and S3 (λ)) will be given below. In the present embodiment, any of these can be adopted. Also, other methods can be adopted.

  The two-dimensional colorimeter 2a includes an arithmetic processing unit 24, and three-band visual sensitivity images S1i, S2i, S3i (T = 6500K) are obtained by spectral sensitivity (S1 (λ), S2 (λ), S3 (λ)). The acquired, recorded, and visualized image is displayed on the image display unit 25, and is transmitted to the control computer or the IOT server via a communication line such as the Internet. Transmission is not limited to a communication line, but may be performed by transport of a storage medium, wired connection, or other means.

  As shown in FIGS. 1 and 2, the opening 3 forms a rectangular opening, and the opening area is larger than that of the window 5.

  The casing 4 has a kamaboko shape as shown in FIGS. 1 and 2. The outer peripheral surface is made of a light-shielding member.

  The window 5 is rectangular as shown in FIGS. The optical axis L passes through the center of the window 5 when the two-dimensional colorimeter 2a is at the top position.

  The covering material 6 is a porous sponge sheet so that ambient light does not enter the space S. Although the covering material 6 is light-shielding, it can transmit part of light. There are closed cell rubber sponge, semi-open cell rubber sponge, closed cell polyethylene foam, open cell polyethylene foam and the like. The closed cell rubber sponge is a synthetic rubber sponge in a closed cell state in which individual bubbles are covered with a rubber film. Used for shading. Materials include natural rubber, chloroprene rubber, nitrile rubber, ethylene propylene rubber, silicon rubber, fluoro rubber, and the like. Semi-open cell rubber sponge is a foam made of synthetic rubber as a base material and made into a semi-open cell state. Materials include ethylene propylene rubber, nitrile rubber, polyvinyl chloride, and acrylic rubber. The closed-cell polyethylene foam is a closed-cell body based on a polyethylene resin. The material is a chemically cross-linked polyethylene foam. Open-cell polyethylene foam is obtained by modifying a polyethylene resin into a complex network polymer structure by chemical crosslinking. The material is a chemically cross-linked polyethylene foam. With this sponge sheet, for example, when pressed against a gently curved surface (border between parts such as a bumper and a fender) of an automobile or the like, disturbance light is prevented and a correct measurement result is obtained.

  As shown in FIGS. 1 and 2, the side plate 7 is a semicircular light-shielding plate member, and has a structure in which a plurality of holes 7 a are formed so as to form a semicircular circumference to prevent ambient light. Arc-shaped rails 7 b that guide both ends of the light shielding material 8 are provided inside the side plates 7. The rail 7b is U-shaped in cross section or U-shaped, and guides the side end of the light shielding material 8 in the x-axis direction. A light-absorbing sheet of the same material as that of the covering material 6 is attached to prevent ambient light.

  As shown in FIGS. 1 and 2, the light shielding member 8 is a belt-like thin member, and is an arc-shaped bellows of a light-shielding flat sheet that can move along the arc orbit of the rail 7b, and prevents disturbance light. Structure. A rotating member 9 is provided between the pair of light shielding members 8. For example, a roll type bellows (manufactured by Hasegawa bellows Co., Ltd.) can be mentioned. This is a bellows cover of a shape memory resin that expands and contracts mainly in a plane, and covers the upper surface of the space S. With respect to the light shielding property, either a light-absorbing sheet made of the same material as that of the covering material 6 or a shape memory resin sheet itself may be light-shielding property, thereby preventing ambient light. The sheet itself is wound up and has a structure in which both ends bend when stretched in order to store the shape of the sheet. A pair of rigid rod-shaped members arranged in parallel are fixed at both upper and lower ends of the shape memory resin sheet so as to extend in the y-axis direction, and the rod-shaped material at one end thereof is the y-axis of the rotating member 9. It is connected to a directional member (the upper horizontal member in the figure), and the rod member at the other end is fixed to the machine casing 11 in the y-axis direction. It is easy to install and can be installed using only screw holes. It is light and has the advantage of being able to handle fast movements because the film has a shape memory.

  The rotating member 9 is U-shaped, and includes a pair of vertical members extending in the z-axis direction and a horizontal member extending in the y-axis direction connecting both ends of the vertical member. The pair of base portions 9a are pivotally attached to the rotation center C, and move along the circular arc track in the X-axis direction. A notch 9 a urged outward by a spring is provided on the outer arm of the rotating member 9 by a spring. A notch operating portion 9b is provided on the end surface of the rotating member 9, and the notch 9a is elastically retracted by the notch operating portion 9b. The imaging unit 2 is fixed to the end face member in the y-axis direction of the rotating member 9 so as to be detachable with one touch.

  Illumination units 10a to 10d are arranged at positions avoiding the optical axis L of the two-dimensional colorimeter 2a, arranged in the x-axis direction, and in the y-axis direction at a plurality of locations in the space S with reference to the two-dimensional colorimeter 2a. It is the rod-shaped LED illumination part arranged in left and right symmetrically. The center of the optical axis surface N extending in a plane shape in the x-axis direction is disposed so as to pass through the window 5. The illumination units 10a to 10d perform oblique illumination on the two-dimensional colorimeter 2a, light passes through the window 5, and reflected light returns from the window 5 to the space S and enters the finder 2b. Rod-shaped transparent plastic fixing members 10e to 10h for attaching the illumination units 10a to 10d in a circular arc shape in the y-axis direction are provided in the y-axis direction, and their base ends are fixed to the side plate 7. Has been.

  The illumination units 10a to 10d perform oblique illumination at positions avoiding the optical axis L of the two-dimensional colorimeter 2a, and are set at predetermined intervals or appropriately so as to form two-degree angles of 45 ° and 75 ° from the vertical. They are arranged in an upwardly convex arc shape at intervals. It is good also as three steps of 45 degrees, 60 degrees, and 75 degrees. The directions of the illumination units 10a to 10d are set parallel to each other. By switching ON / OFF of the illumination units 10a to 10d, it is possible to switch the irradiation angle in two steps or more than three steps.

  Next, the operation of the oblique illumination imaging device 1 will be described. In FIGS. 1 and 2, the finder 2b of the two-dimensional colorimeter 2a and the vertical central axis of the window 5 are coaxial on the z axis. When the power is turned on, first, the opening 3 is applied to the surface of the imaging target, the angle of the imaging unit 2 is selected, the notch operation unit 9b is pushed down to correspond to this angle, and as shown by the dotted line in FIG. The rotation member 9 is rotated in the x-axis direction about the rotation center C in the clockwise direction R or the counterclockwise direction L. At this time, since the light shielding material expands and contracts, the light shielding in the space S is maintained. When the desired hole 7a is placed at the position of the notch 9a and the notch operation portion 9b is released, the notch 9a is fitted into the hole 7a, and the position of the imaging unit 2 is fixed. The optical axis L can be changed by selecting the position of the hole 7a. The angle of the optical axis L is a few steps, but the number of steps can be set as appropriate. Next, the angles of the illumination units 10a to 10d are selected from 45 ° and 75 °, and the angle of one optical axis plane N is set by an operation button (not shown).

  When adjusting the position of the two-dimensional color meter 2a, the rotating member 9 rotates integrally with the two-dimensional color meter 2a. However, when one of the light shielding members 8 contracts in the clockwise direction R or the counterclockwise direction L. The other is expanded by following one movement, and when one of the light shielding members 8 is expanded in the clockwise direction R or the counterclockwise direction L, the other is contracted following the one movement, thereby The rotation range of the two-dimensional colorimeter 2a that can secure the shielding property of S can be up to 170 °. The angle of the optical axis L of the two-dimensional colorimeter 2a may be 30 ° or more on the left and right with reference to at least horizontal. When the rotating member 9 rotates, the light shielding member 8 supports the rotating member 9 so that the position of the two-dimensional colorimeter 2a can be adjusted smoothly.

  As described above, when the angles of the optical axis L and the optical axis plane N are fixed to a predetermined angle, the angle of the optical axis L is also fixed, and the shutter is turned off to perform imaging. Further, the mounting angle of the imaging unit 2 is changed, and imaging is performed from other different angles. In this way, it is possible to accurately evaluate the metallic feeling by providing the imaging data in which the metallic feeling of the colored surface (painted surface or the like) to be photographed appears.

  According to this embodiment, it is possible to accurately evaluate a metallic feeling associated with a flip-flop phenomenon that changes depending on an angle, and it is easy to analyze and evaluate an accurate color / texture distribution.

  The embodiments of the present invention are not limited to the above-described embodiments, and modifications and the like can be made without departing from the technical idea of the present invention. Needless to say, objects and the like are also included in the technical scope of the present invention and can take various forms as long as they belong to the technical scope. For example, with respect to a method for photographing an object with an oblique illumination from an arbitrary angle in the imaging unit 2, the method and structure given in the present embodiment are merely examples, and the present invention is not limited to these, and other methods may be used. However, the technical idea of the present invention is implemented. Furthermore, it is also possible to attach an encoder to the rail 7b and record the mounting angle position of the imaging unit 2 in a computer and associate it with image data. The rotating member 9 has a U shape, but may have other shapes such as a U shape or an arc shape. A handle may be provided in the imaging unit 2 to improve operability.

  The oblique illumination imaging device of the present invention has great applicability in color inspection and other industrial applications in production sites such as vehicles, electrical appliances, and housing building materials. Car paint inspection (color shift, color unevenness, quantification of metallic feeling, color shift between different materials, numerical analysis of flip-flop phenomenon), car grain inspection, car leather seat inspection (complex Inspection of color unevenness and color misalignment of textured materials, inspection of color misalignment and color unevenness of printed materials, inspection of flooring of cosmetics containing lame and pearl pigments, color matching of tiles (accurate photography of colors and textures) ), Color matching inspection of cosmetics (skin gloss, etc.), sportswear, shoes, golf balls, and the like.

DESCRIPTION OF SYMBOLS 1 ... Oblique illumination imaging device 2 ... Imaging part 2a ... Two-dimensional color meter 2b ... Finder 3 ... Opening 4 ... Housing 5 ... Window 6 ... Covering material 7 ... Side plate 7a ... Hole 7b ... Rail 8 ... Light shielding material 9 ... Rotating members 10a to 10d ... Lighting part 10e ... Fixing member L ... Optical axis N ..Optical axis surface

Claims (5)

An imaging unit including a two-dimensional colorimeter having three spectral sensitivities (S1 (λ), S2 (λ), S3 (λ)) linearly converted equivalently to the CIE XYZ color matching function;
A housing having a predetermined shape, having an opening, rotatably supporting the imaging unit, and providing a rotating track,
A window is provided in the center, and through the window, light is allowed to pass through, and a covering material that covers the opening of the housing
With
The housing is
A pair of light-shielding side plates facing each other at an interval;
An elastic sheet-like light shielding material having an arc-shaped cross section that covers the end face of the space between the side plates and shields light;
A rotating member provided in an intermediate portion of the light shielding material, the two-dimensional colorimeter being fixed, and rotating in a predetermined rotating direction within an angular range of 180 ° or less along the end surface of the space;
A plurality of lights arranged symmetrically with respect to the two-dimensional colorimeter at a position arranged in the space and avoiding the optical axis of the two-dimensional colorimeter, and obliquely illuminate the light to the window With an illumination part,
An oblique illumination imaging apparatus, wherein an optical axis of the two-dimensional colorimeter and an optical axis of an illumination unit are arranged toward the window, and an imaging target is imaged under the oblique illumination.   The oblique illumination imaging apparatus according to claim 1, wherein the rotating member has a U-shape, and a pair of base portions are pivotally attached to the center of rotation and move along an arcuate track.   The oblique illumination imaging device according to claim 1 or 2, wherein the light shielding material is a light-shielding bellows or a stretchable sheet member that can move along an arcuate path, and has a structure that prevents disturbance light.   4. The lighting device according to claim 1, wherein the illumination unit is a bar-shaped LED illumination unit, and is disposed symmetrically at a plurality of locations in the space, and the LED illumination unit performs oblique illumination on the window. Oblique illumination imaging device.   5. The oblique illumination imaging apparatus according to claim 1, wherein the covering material is made of a porous sponge.

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