JP6401068B2 - Light source for painted surface inspection and lighting device for painted surface inspection - Google Patents

Description

  The present invention relates to a painted surface inspection light source and a painted surface inspection illumination device used for inspecting a painted surface coated with a paint.

  The surface is painted with paint from relatively small size products such as home appliances such as digital cameras and smartphones and toys, to relatively large size products such as motorcycles, passenger cars, and railway vehicles. Various functions such as design and weather resistance are provided.

  The finished surface of the product is required to have various finishing conditions such as a mirrored surface and a matte (matte) state. In particular, in the case of a mirrored surface, minute irregularities and minute scratches are conspicuous. is important.

  For example, an automobile body is coated by applying a rust preventive paint on the surface of a metal substrate, applying a color paint with a paint containing a pigment thereon, and then applying a clear paint with a transparent paint. Depending on the type of coating, such as pearl coating or metallic coating, additional coating may be performed between color coating and clear coating. After coating each paint, polishing such as buffing is performed to finish the painted surface in a mirror state. When a minute polishing flaw occurs on the surface of the clear layer, which is the outermost layer of the coating, the portion becomes poor in appearance.

  The painted surface of the automobile body is larger than the home appliances, etc., the outer shape is complicated, there are many curved parts, etc., and the inspection standards for appearance defects are strict, so images and other methods are used. It is difficult to inspect by using an automatic inspection, and a visual inspection by human eyes is required.

  As a visual inspection method, a painted vehicle is an inspection target, fluorescent lamps are arranged at regular intervals on a wall surface and a ceiling surrounding the vehicle, and light is irradiated to the vehicle surface. The inspector observes the light reflected by the vehicle surface and visually detects the presence or absence of appearance defects such as minute scratches.

  The illumination device described in Patent Document 1 uses parallel light as light to be irradiated on a surface to be irradiated such as a coating surface. In the irradiation apparatus for coating inspection described in Patent Document 2, as the measurement light to be irradiated on the inspection object. , Using focused light.

JP 2006-58032 A JP 2009-174931 A

  Since various color paints are used for color coating, white light is used as the inspection light. White light is light in which blue light, green light, and red light are mixed, but the emission spectrum differs depending on the light source. Patent Documents 1 and 2 describe the use of parallel light or focused light, but no consideration is given to the emission spectrum.

For example, the emission spectrum of a white fluorescent lamp used as a light source for visually inspecting the painted surface of an automobile body has peaks at 440 nm, 545 nm and 620 nm, and the half width of each peak is about 10 to 30 nm. It has a narrow and sharp peak.

  When the painted surface is irradiated with white light having such an emission spectrum, the inspector observes both the light reflected from the painted surface, that is, the surface of the clear layer and the light reflected from the surface of the color coating. Since there is no light absorption on the surface of the clear layer, the spectrum of the reflected light is almost the same as the spectrum of the irradiated white light. If there are minute scratches on the surface of the clear layer, white light is scattered on the surface of the clear layer, so scattered light is observed. It is easy for human eyes to distinguish between white scattered light and specularly reflected light, and when an inspector observes the scattered light, it is possible to detect an appearance defect as so-called white blur.

  Here, in the sensitivity curve with respect to the color of human photoreceptor cells, the red cone that senses red has a first sensitivity peak that is the maximum peak near 560 nm, and a second sensitivity peak that is also around 440 nm. With a sensitivity peak of. The second sensitivity peak on the short wavelength side has substantially the same wavelength as the sensitivity peak of the blue cone that feels blue. If it does so, the light which has a wavelength of 440 nm vicinity will stimulate not only a blue cone but a red cone.

  Since the emission spectrum of the fluorescent lamp as described above has a sharp peak at 440 nm, the fluorescent lamp stimulates the blue cone and the red cone at the same time. That is, the fluorescent lamp emits white light including red that is felt by a red cone stimulated by light having a sharp peak at 440 nm, and the white light reflected by the surface of the clear layer is 440 nm light. It becomes white light whose redness easily changes depending on the intensity.

  On the surface of the color coating, a part of the white light having a wavelength is absorbed according to the color of the paint, and the remaining light is reflected. In particular, when the color coating is blue, the white light emitted from the fluorescent lamp passes through the clear layer, and the reflected light reflected by the surface of the color coating becomes blue light having an emission spectrum of 440 nm.

  When a fluorescent lamp is used as a light source for visual inspection, the inspector changes the redness that is scattered and reflected by minute scratches formed on the surface of the clear layer as reflected light of the light irradiated on the painted surface. Since white light from easy fluorescent lamps and specular reflected light reflected on the surface of color coating will be observed, it is difficult to distinguish between scattered light and specular reflected light by visual observation, and the detection accuracy of appearance defects will be reduced. End up.

  An object of the present invention is to provide a light source for paint surface inspection and an illumination device for paint surface inspection that can easily detect an appearance defect of a paint surface in visual inspection.

  The light source for coating surface inspection according to one aspect of the present invention has one valley peak in a wavelength region of 400 to 500 nm, a first peak on a shorter wavelength side than the valley peak, and the valley A second peak at a wavelength longer than the peak, the peak wavelength of the valley peak is λ0 [nm], the peak wavelength of the first peak is λ1 [nm], and the peak of the second peak When the wavelength is λ2 [nm], 420 nm ≦ λ0 ≦ 440 nm, 400 nm ≦ λ1 ≦ 410 nm, and a light emitting portion that emits white light having an emission spectrum of 450 nm ≦ λ2 ≦ 470 nm is included.

  An illumination device for painted surface inspection according to one aspect of the present invention includes a plurality of light sources for painted surface inspection.

  According to the light source for coating surface inspection according to one aspect of the present invention, white light is emitted in which a change in redness in reflected light of light irradiated on the coating surface is suppressed. It is possible to easily detect an appearance defect of a painted surface such as a blur.

  According to the illumination device for coating surface inspection according to one aspect of the present invention, the illumination device for coating surface inspection includes the light source for coating surface inspection that emits white light in which a change in redness in reflected light of light irradiated on the coating surface is suppressed. Therefore, it is suitable for visual inspection of the painted surface.

It is an external appearance perspective view of the photosynthesis promotion light source which concerns on one Embodiment of this invention. It is sectional drawing when the photosynthesis promotion light source shown in FIG. 1 is cut | disconnected by the plane shown with a virtual line. It is a figure which shows the emission spectrum of the photosynthesis promotion light source which concerns on one Example. It is an external appearance perspective view of an illuminating device provided with the photosynthesis promotion light source which concerns on this invention. It is a disassembled perspective view of the illuminating device shown in FIG. It is a perspective view which shows the state which removed the translucent board | substrate from the housing | casing of the illuminating device shown in FIG.

  Embodiments of a light synthesis promoting light source according to the present invention will be described below with reference to the accompanying drawings. In addition, this invention shall not be limited to the following embodiment.

<Configuration of light source for painted surface inspection>
FIG. 1 is an external perspective view of a painted surface inspection light source according to an embodiment of the present invention. 2 is a cross-sectional view of the painted surface inspection light source shown in FIG. 1 cut along a plane indicated by phantom lines.

  The painted surface inspection light source 1 is surrounded by a substrate 2, a light emitting element 3 provided on the substrate 2, a frame 4 provided on the substrate 2 so as to surround the light emitting element 3, and the frame 4. Inside the frame body 4 along the upper surface of the sealing member 5, the sealing member 5 filled with the inner space leaving a part of the upper part and the upper part of the inner space surrounded by the frame body 4 And a wavelength conversion member 6 provided so as to be within the range. The light emitting element 3 is, for example, a light emitting diode (LED), and emits light toward the outside by recombination of electrons and holes in a pn junction using a semiconductor.

  The substrate 2 is an insulating substrate and is made of, for example, a ceramic material such as alumina or mullite, or a glass ceramic material. Or it consists of a composite material which mixed several materials among these materials. The substrate 2 can be made of a polymer resin in which metal oxide fine particles capable of adjusting the thermal expansion of the substrate 2 are dispersed.

  The substrate 2 is formed with a wiring conductor that electrically connects the inside and outside of the substrate 2. The wiring conductor is made of a conductive material such as tungsten, molybdenum, manganese, or copper. When the substrate 2 is made of a ceramic material, for example, a metal paste obtained by adding an organic solvent to a powder such as tungsten is printed in a predetermined pattern on the ceramic green sheet to be the substrate 2, and a plurality of ceramic green sheets are laminated. And obtained by firing. For example, a plating layer such as nickel or gold is formed on the surface of the wiring conductor to prevent oxidation. Further, on the upper surface of the substrate 2, in order to reflect light efficiently above the substrate 2, a metal reflective layer such as aluminum, silver, gold, copper, or platinum is provided with a space between the wiring conductor and the plating layer. Form.

The light emitting element 3 is mounted on the substrate 2. The light emitting element 3 is electrically connected to, for example, a brazing material or solder on a plating layer that adheres to the surface of the wiring conductor formed on the substrate 2.
The light emitting element 3 has a translucent base and an optical semiconductor layer formed on the translucent base. The translucent substrate may be any substrate that can grow an optical semiconductor layer using a chemical vapor deposition method such as a metal organic chemical vapor deposition method or a molecular beam epitaxial growth method. As a material used for the light-transmitting substrate, for example, sapphire, gallium nitride, aluminum nitride, zinc oxide, zinc selenide, silicon carbide, silicon, or zirconium diboride can be used. In addition, the thickness of a translucent base | substrate is 50 micrometers or more and 1000 micrometers or less, for example.

  The optical semiconductor layer includes a first semiconductor layer formed on the translucent substrate, a light emitting layer formed on the first semiconductor layer, and a second semiconductor layer formed on the light emitting layer. . The first semiconductor layer, the light emitting layer, and the second semiconductor layer are, for example, a group III nitride semiconductor, a group III-V semiconductor such as gallium phosphide or gallium arsenide, or a group III nitride such as gallium nitride, aluminum nitride, or indium nitride. A physical semiconductor or the like can be used. The thickness of the first semiconductor layer is, for example, 1 μm to 5 μm, the thickness of the light emitting layer is, for example, 25 nm to 150 nm, and the thickness of the second semiconductor layer is, for example, 50 nm to 600 nm. In addition, the light emitting element 3 configured in this way can emit excitation light in a wavelength range of, for example, 370 nm to 420 nm.

  For example, the frame 4 is mixed with a ceramic material such as aluminum oxide, titanium oxide, zirconium oxide or yttrium oxide, or a porous material, or a powder made of metal oxide such as aluminum oxide, titanium oxide, zirconium oxide or yttrium oxide. Made of a resin material. The frame body 4 is laminated on the upper surface of the substrate 2 and connected via, for example, a resin. The frame body 4 is provided so as to surround the light emitting element 3 with a space from the light emitting element 3. Further, the frame body 4 is formed such that an inclined inner wall surface spreads outward from the lower end according to the upper end. The inner wall surface of the frame 4 functions as a reflection surface for the excitation light emitted from the light emitting element 3. Note that when the shape of the inner wall surface of the frame 4 is circular in plan view, light emitted from the light emitting element 3 can be reflected in all directions by the reflecting surface.

  In addition, the inclined inner wall surface of the frame body 4 is, for example, a metal layer made of tungsten, molybdenum, copper, silver, or the like on the inner peripheral surface of the frame body 4 made of a sintered material, and nickel or gold that covers the metal layer. A plated metal layer made of may be formed. The plated metal layer has a function of reflecting light emitted from the light emitting element 3. The inclination angle of the inner wall surface of the frame body 4 is set to an angle of 55 degrees or more and 70 degrees or less with respect to the upper surface of the substrate 2, for example.

  An inner space surrounded by the frame body 4 is filled with a light-transmitting sealing member 5. The sealing member 5 has a function of sealing the light emitting element 3 and transmitting light emitted from the light emitting element 3. The sealing member 5 is filled in the inner space surrounded by the frame body 4 while leaving a part of the space surrounded by the frame body 4. For the sealing member 5, for example, a translucent insulating resin such as a silicone resin, an acrylic resin, or an epoxy resin is used. The refractive index of the sealing member 5 is set to 1.4 or more and 1.6 or less, for example.

  The wavelength conversion member 6 is provided along the upper surface of the sealing member 5 in the upper part of the inner space surrounded by the frame body 4. The wavelength conversion member 6 is formed so as to be accommodated in the frame body 4. The wavelength conversion member 6 has a function of converting the wavelength of light emitted from the light emitting element 3. The wavelength conversion member 6 emits light when the light emitted from the light emitting element 3 enters the inside and the phosphor 7 contained therein is excited. The wavelength conversion member 6 is made of, for example, a translucent insulating resin such as fluororesin, silicone resin, acrylic resin, or epoxy resin, or translucent glass, and the phosphor 7 is contained in the insulating resin or glass. ing. The phosphor 7 is uniformly dispersed in the wavelength conversion member 6.

<About phosphor>
The phosphor 7 contained in the wavelength conversion member 6 is, for example, 420 nm or more and 490 nm or less so that the spectrum of light emitted from the paint surface inspection light source 1 is a suitable spectrum in the inspection of the paint surface by visual inspection. One or more phosphors are selected from blue phosphors that emit fluorescence, for example, green phosphors that emit fluorescence of 490 nm to 539 nm, for example, red phosphors that emit fluorescence of 540 nm to 700 nm.

  It is important that the emission spectrum of a white light source suitable for coating surface inspection satisfies at least the following requirements. That is, in the wavelength region of 400 to 500 nm where both the blue cone and the red cone have sensitivity peaks, one valley peak, the first peak on the shorter wavelength side than the valley peak, and longer than the valley peak The peak wavelength of the valley peak is λ0 [nm], the peak wavelength of the first peak is λ1 [nm], and the peak wavelength of the second peak is λ2 [nm]. In this case, the emission spectrum is 420 nm ≦ λ0 ≦ 440 nm, 400 nm ≦ λ1 ≦ 410 nm, and 450 nm ≦ λ2 ≦ 470 nm. The emission spectrum is not particularly limited with respect to the wavelength region other than the wavelength region of 400 to 500 nm as long as the emission spectrum of white light is taken into consideration when the entire wavelength region is considered. In addition, the emission spectrum has two types of peaks, a peak that protrudes upward and a peak that protrudes downward. When distinguishing two types of peaks, as described above, a peak that protrudes upward is described as a “mountain peak”, and a peak that protrudes downward is described as a “valley peak”. In the present specification, the simple description of “peak” means “mountain peak”.

  In the conventional white light source including the aforementioned fluorescent lamp, the emission spectrum has a peak in the vicinity of 430 nm in the wavelength region of 400 to 500 nm in consideration of the sensitivity peak of the blue cone. However, the mountain peak near 430 nm also stimulates the red cone. That is, a conventional white light source including a fluorescent lamp is white light including red that is felt by a red cone having a second sensitivity peak at around 430 nm. Therefore, the light from the white light source is around 430 nm. When the intensity of the emission spectrum changes, redness changes and the white color changes, which is not a preferable light source. Therefore, the light source for coating surface inspection of the present embodiment has a valley peak in the wavelength region of 400 to 500 nm, and the peak wavelength λ0 is set to 420 nm ≦ λ0 ≦ 440 nm, so that the second sensitivity peak is around 430 nm. A white light source in which stimulation to the red cone is suppressed. And simply suppressing the stimulus to the red cone will also suppress the stimulus to the blue cone, so each side of the valley peak has a mountain peak to suppress the stimulus to the blue cone. I'm trying not to be.

  Furthermore, in the emission spectrum of the present embodiment, when the light intensity at the peak wavelength λ2 of the second peak at a wavelength longer than the valley peak is 1, the light intensity at the peak wavelength λ0 of the valley peak is a relative value. It is preferable that the light intensity at the peak wavelength λ1 of the first peak on the shorter wavelength side than the valley peak is 0.4 or more and 0.8 or less in relative value.

  By setting it as such an emission spectrum, the stimulation to the red cone at the second sensitivity peak is effectively suppressed, and the stimulation to the blue cone is not suppressed, which is preferable.

  Furthermore, the emission spectrum of the present embodiment has a third peak in the wavelength region of 500 to 600 nm, and 515 nm ≦ λ3 ≦ 545 nm when the peak wavelength of the third peak is λ3 [nm]. The light intensity at the peak wavelength λ3 of the third peak is 0.7 or more and 0.9 or less as a relative value when the light intensity at the peak wavelength λ2 of the second peak is 1.

  Such an emission spectrum is preferable because an appropriate stimulus can be given to the green cone.

  Further, the emission spectrum of the present embodiment has a fourth peak in the wavelength region of 600 to 700 nm, and 605 nm ≦ λ4 ≦ 635 nm when the peak wavelength of the fourth peak is λ4 [nm]. . The light intensity at the peak wavelength λ4 of the fourth peak is a relative value of 0.6 or more and 0.8 or less when the light intensity at the peak wavelength λ2 of the second peak is 1.

  Such an emission spectrum is preferable because an appropriate stimulus can be given to the red cone.

  Furthermore, in the emission spectrum of the present embodiment, when the light intensity at the peak wavelength λ2 of the second peak is 1, the maximum value of the light intensity in the wavelength region of 390 nm or less is a relative value of 0.1 or less. is there. That is, in the near-ultraviolet light region of 390 nm or less, the relative intensity does not exceed 0.1, and the amount of near-ultraviolet light contained in the light emitted from the paint surface inspection light source of this embodiment is very small. Such a light source having an emission spectrum is less affected by near-ultraviolet light and is preferable as a light source for an inspector to visually inspect.

  The color temperature of the light emitted from the paint surface inspection light source 1 is in the range of 6400 to 6600 K, the average color rendering index Ra is in the range of 80 to 97, and the CIE chromaticity coordinates x and y are 0. It is preferable to satisfy the relationship of 3 ≦ x ≦ 0.4 and 0.3 ≦ y ≦ 0.4.

As an example of the phosphor 7 that satisfies the above-mentioned requirements, (Sr, Ba, Ca) ₅ (PO ₄ ) ₃ Cl: Eu is used as the blue phosphor, and (BaSr) ₂ SiO ₄ as the green phosphor. : Eu, CaAlSi (ON) ₃ : Eu as red phosphor, and realized by setting the blend ratio of blue phosphor, green phosphor, yellow phosphor and red phosphor to 2: 1: 25 it can.

  FIG. 3 shows an emission spectrum S of the coating surface inspection light source 1 configured by uniformly dispersing the phosphor 7 according to the above example in the wavelength conversion member 6. According to the emission spectrum S shown in FIG. 3, in the wavelength region of 400 to 500 nm, the peak wavelength λ0 has a valley peak of 430 nm, and the short wavelength side thereof has a first peak having a peak wavelength λ1 of 407 nm. The second peak has a peak wavelength λ2 of 460 nm on the long wavelength side.

  Further, when the light intensity at the peak wavelength λ2 of the second peak is 1, the light intensity at the peak wavelength λ0 of the valley peak is 0.358 as a relative value, and the light intensity at the peak wavelength λ1 of the first peak. Is a relative value of 0.697.

  Further, in the wavelength region of 500 to 600 nm, the peak wavelength λ3 has a third peak at 529 nm, and the light intensity at the peak wavelength λ3 of the third peak is the light intensity at the peak wavelength λ2 of the second peak. The relative value when set to 1 is 0.820.

  Further, in the wavelength region of 600 to 700 nm, the peak wavelength λ4 has a fourth peak at 622 nm, and the light intensity at the peak wavelength λ4 of the fourth peak is the light intensity at the peak wavelength λ2 of the second peak. The relative value when 1 is 0.695.

  Furthermore, the maximum value of the light intensity in the near ultraviolet light region of 390 nm or less is 0.056 as a relative value when the light intensity at the peak wavelength λ2 of the second peak is 1.

  When the painted surface inspection light source 1 according to this embodiment is turned on with a current of 60 mA, the luminous flux is 19 lms, the color temperature is 6500 K, the average color rendering index Ra is 95, and the chromaticity of the CIE chromaticity coordinates. x was 0.31 and chromaticity y was 0.32.

  As a result of visual inspection by irradiating the painted surface of the automobile body with white light using the light source 1 for painted surface inspection according to the above embodiment, it occurs on the painted surface as compared with the case of using a conventional fluorescent lamp or the like. It has been found that it is easy to detect appearance defects due to fine scratches.

  When the painted surface inspection light source of this embodiment is used as an inspection light source for a painted automobile body, a plurality of painted surface inspection light sources are arranged in an automobile manufacturing factory, an automobile repair / maintenance factory, or an automobile inspection factory. It is used in the form of a lighting device constructed. Hereinafter, an example of an illuminating device including a paint surface inspection light source according to the present embodiment will be described with reference to the accompanying drawings.

<Configuration of lighting device>
FIG. 4 is an external perspective view of an illuminating device provided with a paint surface inspection light source according to the present embodiment, and FIG. 5 is an exploded perspective view of the illuminating device shown in FIG. FIG. 6 is a perspective view showing a state where the translucent substrate is removed from the housing of the lighting device shown in FIG.

  The illuminating device 10 includes a long casing 11 opened upward, a plurality of painted surface inspection light sources 1 arranged in a line in the longitudinal direction in the casing 11, and a plurality of painted surface inspections. A long wiring board 12 on which the light source 1 is mounted, and a long translucent board 13 that is supported by the housing 11 and closes the opening of the housing 11.

  The housing 11 has a function of holding the translucent substrate 13 and a function of dissipating heat generated by the paint surface inspection light source 1 to the outside. The housing 11 is made of, for example, a metal such as aluminum, copper, or stainless steel, plastic, resin, or the like. The housing 11 has a bottom portion 21a extending in the longitudinal direction and a pair of support portions 21b extending from both ends in the width direction of the bottom portion 21a, and is open on both the upper side and the longitudinal direction. The main body portion 21 includes a long main body portion 21 and two lid portions 22 that respectively close the openings on one side and the other side in the longitudinal direction of the main body portion 21. A holding portion is formed on the upper portion of each support portion 21b so that the recesses for holding the translucent substrate 13 are opposed to each other. The length of the casing 11 in the longitudinal direction is set to, for example, 100 mm or more and 2000 mm or less.

  The wiring board 12 is fixed to the bottom surface in the housing 11. As the wiring board 12, for example, a printed board such as a rigid board, a flexible board, or a rigid flexible board is used. The wiring pattern of the wiring board 12 and the wiring pattern of the board 2 in the painted surface inspection light source 1 are electrically connected via solder or a conductive adhesive. Then, a signal from the wiring board 12 is transmitted to the light emitting element 3 through the substrate 2, and the light emitting element 3 emits light. In addition, electricity is supplied to the wiring board 12 from the power supply provided outside via the wiring.

  The translucent substrate 13 is made of a material that transmits light emitted from the light source 1 for coating surface inspection, and is made of a light transmissive material such as acrylic resin or glass. The translucent substrate 13 is a rectangular plate, and the length in the longitudinal direction is set to, for example, 98 mm or more and 1998 mm or less. The translucent substrate 13 is inserted into a recess formed in each holding portion from an opening on one side or the other side in the longitudinal direction of the main body portion 21 and is slid along the longitudinal direction to thereby form a plurality of painted surfaces. It is supported by the pair of support portions 21b at a position separated from the inspection light source 1. And the illuminating device 10 is comprised by obstruct | occluding the opening of the longitudinal direction in the main-body part 21 with the cover part 22. FIG.

  The illumination device 10 is a linear light-emitting illumination device in which a plurality of painted surface inspection light sources 1 are arranged in a straight line. However, the illumination device 10 is not limited to this, and the plurality of painted surface inspection light sources 1 are arranged in a matrix or staggered pattern. It may be a surface emitting lighting device arranged in a child shape.

  By using the painted surface inspection light source 1 as a light source mounted on the illumination device 10, white light with reduced change in redness in reflected light of the light irradiated on the painted surface is irradiated. An inspector who observes the light reflected by the painted surface distinguishes the scattered light from the specularly reflected light by visual observation, so that it is easy to detect an appearance defect of the painted surface such as white blur.

<Other examples of phosphor>
Other materials of the blue phosphor, the green phosphor, and the red phosphor that can be used for the painted surface inspection light source 1 according to the present embodiment are exemplified below.

As the blue phosphor, BaMgAl ₁₀ O ₁₇ : Eu, (Sr, Ca) ₅ (PO ₄ ) ₆ Cl: Eu, and as the green phosphor, (Ba, Sr) MgAl ₁₀ O ₁₇ : Eu, Mn, SrAl ₂ As O ₄ : Eu ² and a red phosphor, phosphors such as (La ₂ O ₂ S: Eu), ZnS: Cu, and Mn can be used.

DESCRIPTION OF SYMBOLS 1 Light source for coating surface inspection 2 Board | substrate 3 Light emitting element 4 Frame body 5 Sealing member 6 Wavelength conversion member 7 Phosphor 10 Lighting device

Claims (7)

  In the wavelength region of 400 to 500 nm, it has one valley peak, has a first peak on the shorter wavelength side than the valley peak, has a second peak on the longer wavelength side than the valley peak, When the peak wavelength of the valley peak is λ0 [nm], the peak wavelength of the first peak is λ1 [nm], and the peak wavelength of the second peak is λ2 [nm], 420 nm ≦ λ0 ≦ 440 nm A light source for coating surface inspection, which emits white light having an emission spectrum of 400 nm ≦ λ1 ≦ 410 nm and 450 nm ≦ λ2 ≦ 470 nm. When the light intensity at the peak wavelength λ2 is 1, in the relative value to the light intensity at the peak wavelength λ2,
The light intensity at the peak wavelength λ0 is 0.4 or less,
The light intensity for coating surface inspection according to claim 1, wherein the light intensity at the peak wavelength λ1 is 0.4 or more and 0.8 or less. In the wavelength region of 500 to 600 nm, it has a third peak, and when the peak wavelength of the third peak is λ3 [nm], 515 nm ≦ λ3 ≦ 545 nm,
When the light intensity at the peak wavelength λ2 is 1, in the relative value to the light intensity at the peak wavelength λ2,
3. The light source for coating surface inspection according to claim 1, wherein the light intensity at the peak wavelength [lambda] 3 is 0.7 or more and 0.9 or less. In the wavelength region of 600 to 700 nm, it has a fourth peak, and when the peak wavelength of the fourth peak is λ4 [nm], 605 nm ≦ λ4 ≦ 635 nm,
When the light intensity at the peak wavelength λ2 is 1, in the relative value to the light intensity at the peak wavelength λ2,
The light intensity for coating surface inspection according to any one of claims 1 to 3, wherein the light intensity at the peak wavelength λ4 is 0.6 or more and 0.8 or less. When the light intensity at the peak wavelength λ2 is 1, in the relative value to the light intensity at the peak wavelength λ2,
The light source for coating surface inspection according to any one of claims 1 to 4, wherein the maximum value of light intensity in a wavelength region of 390 nm or less is 0.1 or less.   A lighting device for coating surface inspection, comprising a plurality of light sources for coating surface inspection according to any one of claims 1 to 5.   The illumination device for coating surface inspection according to claim 6, wherein the light source for coating surface inspection includes a light emitting diode.

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