JP2021005524A - Illuminating device - Google Patents

Abstract

To provide an illuminating device that has high durability and emits desired output light.SOLUTION: An illuminating device 1 emits output light L5. The illuminating device 1 comprises an optical filter 50 comprising a transmitting/reflecting film layer 52 including a colloid crystal structure 53, and a light source 10 for emitting incident light L1 that is light incident on the transmitting/reflecting film layer 52. The incident light L1 is converted into reflected light L3 reflected by the transmitting/reflecting film layer 52, and transmitted light L2 transmitted by the transmitting/reflecting film layer 52, via the transmitting/reflecting film layer 52. The reflected light L3 is light including a reflection peak wavelength determined by the transmitting/reflecting film layer 52. The output light L5 includes the transmitted light L2.SELECTED DRAWING: Figure 1A

Description

The present invention relates to a lighting device.

Conventionally, a filter that absorbs or reflects light of a specific wavelength has been used in a light emitting device provided with a light source or the like. By using the above filter, the output light emitted by the light emitting device to the surroundings becomes light obtained by removing the light of the specific wavelength from the light emitted by the light source. That is, the above filter is used to make the output light emitted by the light emitting device a desired light (for example, light having high color rendering properties or light having low emission color variation). For example, as a light emitting device provided with the above filter, there is a light emitting device disclosed in Patent Document 1.

The light emitting device disclosed in Patent Document 1 includes a blue LED light source, a white conversion layer containing a phosphor, and a color correction filter that absorbs a specific wavelength. The white conversion layer emits white light based on the blue light emitted by the blue LED light source, and the color correction filter color-corrects the white light emitted by the white conversion layer. The color correction filter also contains a dye. For this reason, the light emitting device disclosed in Patent Document 1 is a light emitting device having excellent color reproducibility because the dye performs color correction of the emitted color, so that the emission color is less likely to vary.

JP-A-2017-54867

On the other hand, a filter that absorbs light of a specific wavelength by using a dye as disclosed in Patent Document 1 has a problem of low durability. This is because the organic molecules used as the dye are decomposed by heat or ultraviolet rays, and the wavelength of the light absorbed by the dye changes. Therefore, the light emitting device disclosed in Patent Document 1 also has a problem of low durability.

Therefore, an object of the present invention is to provide a lighting device having high durability and emitting a desired output light.

In order to achieve the above object, the illuminating device according to one aspect of the present invention is an illuminating device that emits output light, and includes an optical filter having a transmissive reflective film layer containing a colloidal crystal structure and the transmissive reflective film layer. A light source that emits incident incident light is provided, and the incident light is converted into reflected light reflected by the transmitted reflective film layer and transmitted light transmitted through the transmitted reflective film layer via the transmitted reflective film layer. The reflected light is light including a reflected peak wavelength determined by the transmitted reflecting film layer, and the output light includes the transmitted light.

According to the present invention, it is possible to provide a lighting device having high durability and emitting a desired output light.

FIG. 1A is a cross-sectional view showing the configuration of the lighting device according to the first embodiment. FIG. 1B is a cross-sectional view showing the configuration of an optical filter included in the lighting device according to the first embodiment. FIG. 2 is a diagram showing a visible light transmission spectrum of the optical filter according to the first embodiment. FIG. 3 is a diagram showing the relationship between the colloidal particle concentration and the reflection peak wavelength in the colloidal crystal structure according to the first embodiment. FIG. 4 is a diagram showing an emission spectrum of output light emitted by the lighting device according to the first embodiment. FIG. 5A is a cross-sectional view showing the configuration of the lighting device according to the second embodiment. FIG. 5B is a cross-sectional view showing the configuration of an optical filter included in the lighting device according to the second embodiment. FIG. 6A is a cross-sectional view showing the configuration of the lighting device according to the third embodiment. FIG. 6B is a cross-sectional view showing the configuration of an optical filter included in the lighting device according to the third embodiment. FIG. 7 is a cross-sectional view showing the configuration of the lighting device according to the fourth embodiment.

Hereinafter, the lighting device according to the embodiment of the present invention will be described in detail with reference to the drawings. In addition, all the embodiments described below show a specific example of the present invention. Therefore, the numerical values, shapes, materials, components, arrangement and connection forms of components, steps, order of steps, etc. shown in the following embodiments are examples, and are not intended to limit the present invention. Therefore, among the components in the following embodiments, the components not described in the independent claims will be described as arbitrary components.

Further, each figure is a schematic view and is not necessarily exactly illustrated. Therefore, for example, the scales and the like do not always match in each figure. Further, in each figure, substantially the same configuration is designated by the same reference numerals, and duplicate description will be omitted or simplified.

Further, in the present specification, terms indicating relationships between elements such as parallel or orthogonal, terms indicating the shape of elements such as squares or rectangles, and numerical ranges are not expressions that express only strict meanings, but are substantial. It is an expression meaning that the same range, for example, a difference of about several percent is included.

(Embodiment 1)
[Constitution]
First, the configuration of the lighting device 1 according to the present embodiment will be described with reference to FIGS. 1A and 1B. FIG. 1A is a cross-sectional view showing the configuration of the lighting device 1 according to the present embodiment. FIG. 1B is a cross-sectional view showing the configuration of an optical filter 50 included in the lighting device 1 according to the present embodiment. Further, the white arrows and the shaded arrows shown in FIG. 1A indicate the traveling direction of the light.

As shown in FIG. 1A, the lighting device 1 emits the output light L5. The lighting device 1 includes a light source 10, an optical filter 50, a housing 70, and a translucent member 80. The lighting device 1 according to the present embodiment is a lighting device that illuminates the surroundings with the output light L5.

In each figure, the plane parallel to the bottom surface of the housing 70 is an xy plane, and the x-axis direction and the y-axis direction are orthogonal to each other. The z-axis direction is a direction perpendicular to the x-axis and the y-axis.

Here, the elements included in the lighting device 1 will be described in order. First, the housing 70 will be described with reference to FIG. 1A.

The housing 70 is a member that houses the light source 10, the optical filter 50, and the translucent member 80. The housing 70 according to the present embodiment has a bottomed cylindrical shape. An opening is provided facing the bottom surface of the housing 70. The housing 70 according to the present embodiment is a case made of resin or metal. The internal space of the housing 70 is a closed space that houses the light source 10, the optical filter 50, and the translucent member 80. Further, the light source 10 is attached to the bottom surface of the housing 70. The translucent member 80 is attached to the opening. Further, the optical filter 50 is attached facing the bottom surface of the housing 70. Further, the optical filter 50 is attached between the light source 10 and the translucent member 80 in the housing 70. Further, the optical filter 50 is attached facing the bottom surface of the housing 70. Therefore, in the present embodiment, the light source 10, the optical filter 50, and the light transmitting member 80 are arranged in this order in the positive direction of the z-axis. Therefore, the incident light L1 emitted by the light source 10 is emitted from the housing 70 to the external space via the optical filter 50 and the light transmitting member 80. Further, as shown in FIG. 1A, the light emitted into the external space is the output light L5 emitted by the lighting device 1.

Next, the light source 10 will be described.

The light source 10 emits incident light L1 incident on the transmission / reflection film layer 52 included in the optical filter 50. Specifically, the light source 10 includes a light source substrate 11, a light emitting element 12, and a wavelength conversion layer 13.

The light source substrate 11 is a substrate on which the light source 10 is mounted, and has metal wiring for supplying electric power to the light source 10.

The light emitting element 12 is, for example, an LED (Light Emitting Diode). In the present embodiment, the light emitting element 12 is, for example, a blue LED that emits blue light. As the light emitting element 12, a laser diode can be used in addition to the LED.

The wavelength conversion layer 13 is a layer that converts the wavelength of the light emitted by the light emitting element 12. Specifically, the wavelength conversion layer 13 is made of a translucent resin material containing yellow phosphor particles as a wavelength conversion material. Further, the wavelength conversion layer 13 may be a sealing layer that seals the light emitting element 12. As the translucent resin material, for example, a silicone-based resin is used, but an epoxy-based resin, a urea-based resin, or the like may be used. Further, as the yellow phosphor particles, for example, YAG (Yttrium aluminum Garnet) -based phosphor particles are adopted.

With this configuration, a part of the blue light emitted by the light emitting element 12 is wavelength-converted to yellow light by the yellow phosphor particles contained in the wavelength conversion layer 13. Then, the blue light that has not been absorbed by the yellow phosphor particles and the yellow light that has been wavelength-converted by the yellow phosphor particles are diffused and mixed in the wavelength conversion layer 13. As a result, white light is emitted as diffused light from the wavelength conversion layer 13. That is, the light source 10 according to the present embodiment emits incident light L1 which is white light to the transmission / reflection film layer 52. Further, the light source 10 according to the present embodiment emits white light having a correlated color temperature of 2700 K.

As described above, the light source 10 according to the present embodiment is attached to the bottom surface of the housing 70 away from the opening. That is, the light source 10 is provided so that the surface of the light source substrate 11 on which the light emitting element 12 is not formed is in contact with the bottom surface of the housing 70. With such a configuration, the light source 10 can emit light from the bottom surface of the housing 70 toward the opening (the z-axis positive direction) of the housing 70. The light emitted from the light source 10 becomes incident light L1 and reaches the optical filter 50 having the transmission reflection film layer 52.

Subsequently, the optical filter 50 will be described.

The optical filter 50 has a substrate 51 and a transmission / reflection film layer 52.

The substrate 51 is used as a support substrate for supporting the transmissive reflective film layer 52. Further, in the present embodiment, since various kinds of light pass through the substrate 51, it is preferable that the substrate 51 has high translucency. For example, the visible light transmittance of the substrate 51 is preferably 80% or more and 100% or less, and more preferably 85% or more and 100% or less.

As the substrate 51, for example, a glass plate such as soda-lime glass, low-alkali borosilicate glass, and non-alkali aluminoborosilicate glass can be used. Further, resin plates such as polycarbonate, acrylic resin and polyethylene terephthalate can also be used. Further, as the substrate 51, in addition to a hard material such as a glass plate and a resin plate, a flexible material such as a film can be used. The substrate 51 according to this embodiment is an acrylic substrate.

Further, for example, the substrate 51 may be, for example, a resin film or the like. As the material of the resin film, PET (polyethylene terephthalate), PE (polyethylene), PP (polypropylene), PVC (polyvinyl chloride), PS (polystyrene), PVAc (polyvinyl acetate) and the like can be used. The size and shape of the substrate 51 are not particularly limited. The substrate 51 has an appropriate size and shape according to the purpose of use, the environment of use, and the like. In the present embodiment, the substrate 51 has a disk shape, and the circumferential portion of the substrate 51 is held by the housing 70.

Further, the incident light L1 emitted by the light source 10 is incident on the transmission / reflection film layer 52. The incident light L1 is converted into the reflected light L3 reflected by the transmitted reflecting film layer 52 and the transmitted light L2 transmitted through the transmitted reflecting film layer 52 via the transmitted reflecting film layer 52. That is, the transmission / reflection film layer 52 reflects light in the wavelength region of the reflected light L3, and the transmission / reflection film layer 52 transmits light other than the wavelength region of the reflected light L3. At this time, the light transmitted through the transmission / reflection film layer 52 is the transmitted light L2. As described above, the transmissive reflective film layer 52 according to the present embodiment reflects a part of the incident light L1 and transmits the other part of the incident light L1. That is, the transmitted light L2 is light obtained by removing the wavelength region of the reflected light L3 from the incident light L1 emitted by the light source 10.

More precisely, the transmitted light L2 is light obtained by removing the wavelength region of the reflected light L3 and the absorption wavelength region of the transmitted reflection film layer 52 from the incident light L1 emitted by the light source 10. However, since the absorption of the transmissive reflective film layer 52 according to the present embodiment is so small that it can be ignored, the transmitted light L2 is the light obtained by removing the wavelength region of the reflected light L3 from the incident light L1 emitted by the light source 10. It is written that.

Further, the reflected light L3 is light including a reflected peak wavelength determined by the transmission reflective film layer 52 (the reflected peak wavelength will be described later with reference to FIG. 2).

Here, the colloidal crystal structure 53 included in the transmissive reflective film layer 52 will be described with reference to FIG. 1B.

The transmissive reflective film layer 52 contains a colloidal crystal structure 53. The transmissive reflective film layer 52 according to the present embodiment is a colloidal crystal structure 53.

The colloidal crystal structure 53 includes colloidal particles 54 and a matrix material 55. The matrix material 55 is arranged between the colloidal particles 54. In the colloidal crystal structure 53 according to the present embodiment, the colloidal particles 54 having the size of the colloidal dimension are regularly arranged three-dimensionally at intervals of the center-to-center distance d1 of the colloidal particles 54. However, the arrangement of the colloidal particles 54 does not need to have strict regularity as long as the object of the present embodiment is not impaired. As shown in FIG. 1B, a plurality of colloidal particles 54 are present in the matrix material 55. The thickness of the colloidal crystal structure 53 is not particularly limited, but is preferably 1 μm or more and 500 μm or less, and more preferably 5 μm or more and 100 μm or less.

The shape of the colloidal particles 54 is spherical, and the central particle size of the colloidal particles 54 is 150 nm or more and 300 nm or less. The central particle size of the colloidal particles 54 may be 160 nm or more and 250 nm or less, and may be 170 nm or more and 200 nm or less. The central particle size is a maximum value in the particle size distribution. Further, the particle size distribution may be measured by an image analysis method, a Coulter method, a centrifugal sedimentation method, a laser diffraction / scattering method, or the like.

The colloidal particles 54 include at least one of an inorganic material and a resin material. As described above, the colloidal particles 54 may be formed only from the inorganic material or may be formed only from the resin material. Further, the colloidal particles 54 may be formed of both an inorganic material and a resin material.

As the inorganic material, for example, metals such as gold and silver, and metal oxides such as silica, alumina and titania can be used. Further, as the resin material, a styrene resin, an acrylic resin, or the like can be used. These materials may be used alone or in combination of two or more. The colloidal particles 54 according to the present embodiment are made of an inorganic material and contain silicon and oxygen. The colloidal particles 54 according to the present embodiment are silica particles.

The matrix material 55 is composed of an organic substance. In the present embodiment, as the matrix material 55, a resin having a high light transmittance in a wavelength region in the range of 300 nm or more and 800 nm or less can be used. The resin used for the matrix material 55 is selected from the group consisting of acrylic resin, polycarbonate resin, cycloolefin resin, epoxy resin, silicone resin, acrylic-styrene copolymer, styrene resin and urethane resin. It is preferable to contain at least one. The matrix material 55 according to the present embodiment is made of an acrylic resin.

The ratio of the volume of the colloidal particles 54 to the total volume of the colloidal crystal structure 53 is preferably, for example, 10% by volume or more and 60% by volume or less. Further, the ratio of the volume of the colloidal particles 54 to the total volume of the colloidal crystal structure 53 is more preferably 20% by volume or more and 50% by volume or less, and more preferably 25% by volume or more and 40% by volume or less. More preferred. The ratio of the volume of the matrix material 55 to the total volume of the colloidal crystal structure 53 is preferably, for example, 40% by volume or more and 90% by volume or less. Further, the ratio of the volume of the matrix material 55 to the total volume of the colloidal crystal structure 53 is more preferably 50% by volume or more and 80% by volume or less, and more preferably 60% by volume or more and 75% by volume or less. More preferred. Within such a range, the light transmittance and shape stability of the colloidal crystal structure 53 can be improved.

The average value of the center-to-center distance d1 of the colloidal particles 54 is preferably 150 nm or more and 400 nm or less. The average value of the center-to-center distance d1 of the colloidal particles 54 is more preferably 190 nm or more and 390 nm or less, and further preferably 220 nm or more and 330 nm or less. By controlling the average value of the center-to-center distance d1 of the colloidal particles 54, it is possible to reflect light having a target wavelength. The average value of the center-to-center distance d1 of the colloidal particles 54 can be obtained by observing the surface of the colloidal crystal structure 53 with a scanning electron microscope.

In the present embodiment, the ratio of the volume of the colloidal particles 54 to the total volume of the colloidal crystal structure 53 is 26% by volume, the central particle size of the colloidal particles 54 is 180 nm, and the center of the colloidal particles 54. The average value of the distance d1 is 290 nm.

As shown in FIG. 1B, the colloidal crystal structure 53 may be arranged on the substrate 51. The colloidal crystal structure 53 may be in contact with the surface of the substrate 51 as shown in FIG. 1B, but an intervening layer (not shown) may be arranged between the colloidal crystal structure 53 and the substrate 51.

Here, a method for producing the colloidal crystal structure 53 will be described. The method for producing the colloidal crystal structure 53 according to the present embodiment is not particularly limited as long as the colloidal crystal structure 53 can be formed. Specifically, the colloidal crystal structure 53 is manufactured by dispersing the colloidal particles 54 in the raw material of the matrix material 55 such as the acrylic resin described above, applying the obtained dispersion liquid to the substrate 51 and the like and curing the colloidal particles 54. can do.

The method of applying the dispersion is not particularly limited, and for example, a spray coating method, a spin coating method, a slit coating method, a roll coating method and the like can be used. Further, the method for polymerizing the monomer is not particularly limited, and the monomer may be polymerized by heating, or may be polymerized by active energy rays (electromagnetic waves, ultraviolet rays, visible rays, infrared rays, electron beams, γ rays, etc.). When the monomer is polymerized by the active energy ray, a photopolymerization initiator or the like may be added to the dispersion liquid. As the photopolymerization initiator, known photopolymerization initiators such as radical photopolymerization initiators, cationic photopolymerization initiators, and anionic photopolymerization initiators can be used.

By having such a colloidal crystal structure 53, a part of the incident light L1 incident on the colloidal crystal structure 53, that is, the transmission reflection film layer 52 is Bragg-reflected, and a part of the light that is not reflected is reflected. It permeates the colloidal crystal structure 53.

As described above, since the transmission / reflection film layer 52 contains the colloidal crystal structure 53, the optical filter 50 according to the present embodiment has higher durability than the case where the conventional dye is used. This high durability is due to the fact that the structure of the colloidal crystal structure 53 is difficult to change due to heat, ultraviolet rays, or the like, and the change in the wavelength of the light reflected by the transmissive reflective film layer 52 can be suppressed.

Further, in the present embodiment, the shape of the colloidal particles 54 is spherical, and the central particle size of the colloidal particles 54 is 150 nm or more and 300 nm or less. Therefore, it is possible to reflect light having a target wavelength.

Further, in the present embodiment, the colloidal particles 54 are composed of an inorganic material and contain silicon and oxygen. As described above, the colloidal particles 54 made of the inorganic material can further enhance the durability.

Further, in the present embodiment, the colloidal crystal structure 53 includes a matrix material 55 composed of an organic substance. By controlling the volume ratio of the matrix material 55 including the matrix material 55 in this way, the center-to-center distance d1 can be easily controlled and light of a target wavelength can be reflected.

Further, the full width at half maximum of the reflection peak caused by the colloidal crystal structure 53 configured as described above is 30 nm or less.

In the present embodiment, the colloidal crystal structure 53, that is, the reflected light L3 reflected by the transmission reflection film layer 52, goes toward the light source 10 side (z-axis negative direction). Further, in the present embodiment, the light transmitted through the colloidal crystal structure 53, that is, the transmission / reflection film layer 52 is the transmitted light L2, and the transmitted light L2 is directed to the light transmitting member 80 side (the z-axis positive direction). Head to.

Here, the translucent member 80 will be described with reference to FIG. 1A.

The light transmitting member 80 is a member that transmits light. The light transmitting member 80 according to the present embodiment is a member that transmits transmitted light L2. As shown in FIG. 1A, the light emitted from the translucent member 80 is the output light L5 emitted by the illuminating device 1. Therefore, the output light L5 includes the transmitted light L2 which is the light transmitted through the transmission reflection film layer 52.

Further, the light transmitting member 80 is a member made of a material having high light transmission. Further, the light transmitting member 80 may be a member that transmits light without scattering it. For example, the translucent member 80 is composed of a translucent resin material such as acrylic or polycarbonate, or a translucent material such as glass material. Further, the translucent member 80 of the present embodiment is made of a glass material.

In the present embodiment, the translucent member 80 has a disk shape, and the circumferential portion of the translucent member 80 is attached to the opening of the housing 70. That is, the opening of the housing 70 is closed by the translucent member 80. Therefore, the housing 70 and the translucent member 80 protect the light source 10 and the optical filter 50. The lighting device 1 may be configured not to include the translucent member 80.

[Light emission characteristics]
Here, the light emitting characteristics of the lighting device 1 according to the present embodiment will be described.

First, the characteristics of the optical filter 50 according to the present embodiment will be described. FIG. 2 is a diagram showing a visible light transmission spectrum of the optical filter 50 according to the present embodiment. More specifically, FIG. 2 shows a visible light transmission spectrum of an optical filter 50 having a transmission reflection film layer 52 including the colloidal crystal structure 53 according to the present embodiment and a dye-containing optical filter of Comparative Example 1. It is a figure which shows. The plastid-containing optical filter of Comparative Example 1 is an optical filter including a substrate equivalent to the substrate 51 according to the present embodiment and a dye using an organic molecule. The dye according to Comparative Example 1 includes a porphyrin-based dye.

First, the optical filter 50 according to the present embodiment will be described. In the visible light transmission spectrum of the optical filter 50, there is a wavelength region (575 nm or more and less than 605 nm) having a low transmittance of less than 80%. This low transmittance wavelength region includes a downwardly convex peak wavelength (585 nm). This is because the colloidal crystal structure 53 according to the present embodiment reflects light including a peak wavelength. That is, since the colloidal crystal structure 53 reflects the reflected light L3, the transmittance of the reflected light L3 in the wavelength region of the optical filter 50 decreases.

Further, in a wavelength region other than the above-mentioned low transmittance wavelength region (380 nm or more and less than 575 nm, and 605 nm or more and less than 780 nm), there is a high transmittance wavelength region having a transmittance of 80% or more. That is, the optical filter 50 transmits light other than the wavelength region of the reflected light L3. That is, the transmitted light L2 is light obtained by removing the wavelength region of the reflected light L3 from the incident light L1 emitted by the light source 10. Therefore, the optical filter 50 can transmit only desired light.

Next, the plastid-containing optical filter of Comparative Example 1 will be described. In the visible light transmission spectrum of the plastid-containing optical filter of Comparative Example 1, there is a wavelength region (540 nm or more and less than 615 nm) having a low transmittance of less than 80%. This low transmittance wavelength region includes a downwardly convex peak wavelength (590 nm). This is because the light is absorbed by the dye contained in the plastid-containing optical filter.

Further, in a wavelength region other than the above-mentioned low transmittance wavelength region (380 nm or more and less than 540 nm, and 615 nm or more and less than 780 nm), there is a high transmittance wavelength region having a transmittance of 80% or more. That is, the plastid-containing optical filter of Comparative Example 1 transmits light other than the light absorbed by the dye. Therefore, the plastid-containing optical filter of Comparative Example 1 can transmit only desirable light, like the optical filter 50 according to the present embodiment.

On the other hand, comparing the low transmittance wavelength region of the optical filter 50 according to the present embodiment with the low transmittance wavelength region of the dye-containing optical filter of Comparative Example 1, the optical filter according to the present embodiment is compared. The wavelength region with a low transmittance of 50 has a narrower wavelength region. That is, the optical filter 50 according to the present embodiment has a feature of not transmitting light in a narrower wavelength region. That is, the optical filter 50 according to the present embodiment can transmit only light in a more target wavelength region.

FIG. 3 is a diagram showing the relationship between the colloidal particle concentration and the reflection peak wavelength in the colloidal crystal structure 53 according to the present embodiment. More specifically, FIG. 3 is a diagram showing the relationship between the colloidal particle concentration and the reflection peak wavelength when the central particle size of the colloidal particles 54 is changed from 161 nm to 316 nm. The colloidal particle concentration is the ratio of the volume of the colloidal particles 54 to the total volume of the colloidal crystal structure 53. Further, the reflected peak wavelength is the wavelength at the reflected peak of the reflected light L3.

The reflection mechanism of the colloidal crystal structure 53 according to the present embodiment is due to Bragg reflection. Therefore, the reflected peak wavelength of the reflected light L3 depends on the center-to-center distance d1 of the colloidal particles 54. As described above, as the colloidal particle concentration increases, the center-to-center distance d1 decreases. Therefore, as the colloidal particle concentration increases, the reflected peak wavelength shifts to the short wavelength side. As the colloidal particle concentration decreases, the reflected peak wavelength shifts to the longer wavelength side. Further, as the center particle size increases, the center-to-center distance d1 increases. Therefore, as the central particle size increases, the reflected peak wavelength shifts to the longer wavelength side. As the central particle size decreases, the reflected peak wavelength shifts to the shorter wavelength side.

In the present embodiment, the colloidal particle concentration is 26% by volume and the central particle size is 180 nm, so that the reflected peak wavelength of the reflected light L3 is 585 nm. That is, the peak wavelength of the reflected light L3 coincides with the center wavelength in the wavelength region of low transmittance shown in FIG.

Next, the output light L5 of the lighting device 1 according to the present embodiment will be described. FIG. 4 is a diagram showing an emission spectrum of output light L5 emitted by the lighting device 1 according to the present embodiment. More specifically, FIG. 4 relates to the lighting device 1 according to the present embodiment, the lighting device including the plastid-containing optical filter according to Comparative Example 1, and the lighting device without the optical filter according to Comparative Example 2. It is a figure which shows the emission spectrum. The illuminating device according to Comparative Example 1 is provided with the plastid-containing optical filter shown in FIG. 2 instead of the optical filter 50 included in the illuminating device 1 according to the present embodiment. It is different from the lighting device 1. Further, the lighting device according to Comparative Example 2 is different from the lighting device 1 according to the present embodiment in that the lighting device 1 according to the present embodiment does not include the optical filter 50.

First, the lighting device according to Comparative Example 2 will be described. Since the output light in the lighting device according to Comparative Example 2 is the same light as the incident light L1 emitted by the light source 10 according to the present embodiment, it is white light having a correlated color temperature of 2700 K.

Subsequently, the lighting device 1 according to the present embodiment will be described. Compared with the lighting device according to Comparative Example 2, the light emitting spectrum of the lighting device 1 according to the present embodiment has a wavelength region centered on 585 nm in which the light emission intensity is reduced. This coincides with the low transmittance wavelength region of the optical filter 50 according to the present embodiment shown in FIG. The optical filter 50 (transmissive reflection film layer 52) according to the present embodiment reflects a part of the incident light L1 and transmits the other part of the incident light L1. The transmitted light L2 is light obtained by removing the wavelength region of the reflected light L3 from the incident light L1 emitted by the light source 10. As described above, the output light L5 according to the present embodiment includes the transmitted light L2. Therefore, the output light L5 emitted by the illuminating device 1 includes light obtained by removing the wavelength region of the reflected light L3 from the incident light L1 emitted by the light source 10. That is, the optical filter 50 according to the present embodiment can use the output light L5 emitted by the lighting device 1 as desired light.

Further, a lighting device including a plastid-containing optical filter according to Comparative Example 1 will be described. Compared with the lighting device according to Comparative Example 2, the light emitting spectrum of the lighting device according to Comparative Example 1 has a wavelength region having a reduced emission intensity centered on 590 nm. This coincides with the low transmittance wavelength region of the plastid-containing optical filter according to Comparative Example 1 shown in FIG. The plastid-containing optical filter of Comparative Example 1 transmits light other than the light absorbed by the dye. Therefore, in the dye-containing optical filter of Comparative Example 1, the output light emitted by the light emitting device according to Comparative Example 1 can be the desired light, as in the optical filter 50 according to the present embodiment.

Here, the emission characteristics obtained from the emission spectrum of FIG. 4 will be described with reference to Table 1. Table 1 shows the color rendering properties of the output light L5 emitted by the illuminating device 1 according to the present embodiment calculated from the emission spectrum of FIG. More specifically, Table 1 shows the lighting device 1 according to the present embodiment, the lighting device provided with the plastid-containing optical filter according to Comparative Example 1, and the lighting device not provided with the optical filter according to Comparative Example 2. Shows the color rendering properties of the output light. In the present embodiment, the color rendering property is represented by the average color rendering index.

It can be seen that the output light L5 emitted by the lighting device 1 according to the present embodiment has improved color rendering properties as compared with the output light emitted by the lighting device according to Comparative Example 2. As described above, in the present embodiment, the output light L5 emitted by the illuminating device 1 by the optical filter 50 includes the incident light L1 emitted by the light source 10 minus the wavelength region of the reflected light L3. Therefore, the lighting device 1 according to the present embodiment can emit the output light L5 having high color rendering property as the desired output light L5. On the other hand, also in Comparative Example 1, similarly to the present embodiment, the plastid-containing optical filter of Comparative Example 1 sets the output light emitted by the light emitting device according to Comparative Example 1 as desired light, thereby producing output light. The color rendering property of is improved.

In the present embodiment, the light source 10 emits light having a correlated color temperature of 2700 K as incident light L1 and the reflected peak wavelength is 585 nm, so that the color rendering property of the output light L5 can be improved. Further, the color rendering property of the output light L5 can be improved if the reflected peak wavelength is 580 nm or more and 590 nm or less regardless of the correlated color temperature of the incident light L1 emitted by the light source 10. In order to improve the color rendering property of the output light L5, the reflected peak wavelength is preferably 560 nm or more and 620 nm or less, more preferably 570 nm or more and 610 nm or less, and as described above, 580 nm or more and 590 nm or less. More preferred.

[Effects, etc.]
As described above, the illuminating device 1 according to the present embodiment is the illuminating device 1 that emits the output light L5, and has an optical filter 50 having a transmission / reflection film layer 52 including a colloidal crystal structure 53 and a transmission / reflection film. A light source 10 that emits incident light L1 incident on the layer 52 is provided. The incident light L1 is converted into the reflected light L3 reflected by the transmitted reflecting film layer 52 and the transmitted light L2 transmitted through the transmitted reflecting film layer 52 via the transmitted reflecting film layer 52, and the reflected light L3 is a transmitted reflecting film. The light includes the reflected peak wavelength determined by the layer 52, and the output light L5 includes the transmitted light L2.

As a result, since the transmission / reflection film layer 52 contains the colloidal crystal structure 53, the optical filter 50 according to the present embodiment has higher durability than the case where a conventional dye is used. This high durability is due to the fact that the structure of the colloidal crystal structure 53 is difficult to change due to heat, ultraviolet rays, or the like, and the change in the wavelength of the light reflected by the transmissive reflective film layer 52 can be suppressed.

Further, the transmission / reflection film layer 52 according to the present embodiment reflects a part of the incident light L1 and transmits the other part of the incident light L1. At this time, the light reflected by the transmission / reflection film layer 52 is the reflected light L3, and the light transmitted through the transmission / reflection film layer 52 is the transmitted light L2. That is, the transmitted light L2 is light obtained by removing the wavelength region of the reflected light L3 from the incident light L1 emitted by the light source 10. The output light L5 according to the present embodiment includes transmitted light L2. Therefore, the output light L5 emitted by the illuminating device 1 includes light obtained by removing the wavelength region of the reflected light L3 from the incident light L1 emitted by the light source 10. That is, the optical filter 50 according to the present embodiment can use the output light L5 emitted by the lighting device 1 as desired light.

As a result, it is possible to realize the lighting device 1 which has high durability and emits a desired output light L5.

The lighting device 1 according to the present embodiment can emit the output light L5 having high color rendering property as the desired output light L5 by having the above-described configuration.

Further, the lighting device 1 according to the present embodiment further includes a light transmitting member 80 that transmits transmitted light L2, and a housing 70 that houses a light source 10, an optical filter 50, and a light transmitting member 80.

As a result, the light source 10 and the optical filter 50 can be protected by the housing 70 and the translucent member 80.

Further, the colloidal crystal structure 53 according to the present embodiment includes colloidal particles 54 having a spherical shape, and the central particle size of the colloidal particles 54 is 150 nm or more and 300 nm or less.

As a result, light of the target wavelength can be reflected.

Further, the colloidal particles 54 according to the present embodiment contain silicon and oxygen.

As a result, the durability can be further enhanced by the colloidal particles 54 composed of the inorganic material.

Further, the colloidal crystal structure 53 according to the present embodiment contains a matrix material 55 composed of an organic substance.

Thereby, by controlling the volume ratio of the matrix material 55 including the matrix material 55, the center-to-center distance d1 can be easily controlled and the light of the target wavelength can be reflected.

(Embodiment 2)
In the first embodiment, there is only one transmission / reflection film layer 52 included in the optical filter 50, but the present invention is not limited to this. The second embodiment is different from the first embodiment in that the transmission / reflection film layer 52a included in the optical filter 50a includes the first transmission / reflection film layer 521a and the second transmission / reflection film layer 522a. Further, the second embodiment is different from the first embodiment in that the lighting device 1a includes the fluorescent member 90a. In the second embodiment, detailed description of the components common to the first embodiment will be omitted.

[Constitution]
First, the configuration of the lighting device 1a according to the present embodiment will be described with reference to FIGS. 5A and 5B. FIG. 5A is a cross-sectional view showing the configuration of the lighting device 1a according to the present embodiment. FIG. 5B is a cross-sectional view showing the configuration of the optical filter 50a included in the lighting device 1a according to the present embodiment. Further, the white arrow, the shaded arrow, and the dot-marked arrow shown in FIG. 5A indicate the traveling direction of the light.

As shown in FIG. 5A, the lighting device 1a emits output light L5a. The lighting device 1a includes a light source 10a, an optical filter 50a, a housing 70a, a translucent member 80a, and a fluorescent member 90a. The lighting device 1a according to the present embodiment is a lighting device that illuminates the surroundings with the output light L5a.

The light source 10a and the translucent member 80a in the present embodiment have the same configuration as that in the first embodiment. Further, the light source substrate 11a, the light emitting element 12a, and the wavelength conversion layer 13a included in the light source 10a are also the same as those in the first embodiment.

First, the housing 70a will be described.

The housing 70a is a member that houses the light source 10a, the optical filter 50a, the translucent member 80a, and the fluorescent member 90a. In the present embodiment, the light source 10a, the optical filter 50a, and the translucent member 80a are attached in the same manner as in the first embodiment. Further, the fluorescent member 90a is attached to the bottom surface of the housing 70a. Further, the fluorescent member 90a is also attached to the inner peripheral surface of the cylinder of the housing 70a on the bottom surface side of the optical filter 50a.

Subsequently, the optical filter 50a will be described.

The optical filter 50a has a substrate 51a and a transmission / reflection film layer 52a. The transmission / reflection film layer 52a according to the present embodiment includes a first transmission / reflection film layer 521a and a second transmission / reflection film layer 522a. Further, the first transmissive reflective film layer 521a and the second transmissive reflective film layer 522a are laminated. In the present embodiment, the lamination means the first transmissive reflective film layer 521a when the first transmissive reflective film layer 521a and the second transmissive reflective film layer 522a are viewed in a plan view (when viewed from the negative z-axis direction). Refers to a structure in which all of the above and all of the second transmissive reflective film layer 522a overlap.

The substrate 51a according to the present embodiment is the same as that of the first embodiment.

Further, the incident light L1a emitted by the light source 10a is incident on the transmission / reflection film layer 52a. The incident light L1a is converted into the reflected light L3a reflected by the transmitted reflecting film layer 52a and the transmitted light L2a transmitted through the transmitted reflecting film layer 52a via the transmitted reflecting film layer 52a. That is, the transmission / reflection film layer 52a reflects light in the wavelength region of the reflected light L3a, and the transmission / reflection film layer 52a transmits light other than the wavelength region of the reflected light L3a. At this time, the light transmitted through the transmission / reflection film layer 52a is the transmitted light L2a. As described above, the transmissive reflective film layer 52a according to the present embodiment reflects a part of the incident light L1a and transmits the other part of the incident light L1a. That is, the transmitted light L2a is light obtained by removing the wavelength region of the reflected light L3a from the incident light L1a emitted by the light source 10a.

Further, the reflected light L3a is light including a reflection peak wavelength determined by the transmission reflection film layer 52a. In the present embodiment, the reflected light L3a includes a first reflected light reflected by the first transmitted reflecting film layer 521a and a second reflected light reflected by the second transmitted reflecting film layer 522a. Further, each of the first reflected light and the second reflected light is light containing different reflected peak wavelengths. That is, in the present embodiment, the reflected light L3a is a combination of the first reflected light and the second reflected light. Therefore, the reflected light L3a is light containing two different reflected peak wavelengths.

Here, the first colloidal crystal structure 531a included in the first transmissive reflective film layer 521a and the second colloidal crystal structure 532a included in the second transmissive reflective film layer 522a will be described with reference to FIG. 5B.

The first transmissive reflective film layer 521a according to the present embodiment is the first colloidal crystal structure 531a, and the second transmissive reflective film layer 522a according to the present embodiment is the second colloidal crystal structure 532a.

The first colloidal crystal structure 531a contains first colloidal particles 541a and a first matrix material 551a. The second colloidal crystal structure 532a contains the second colloidal particles 542a and the second matrix material 552a.

The first colloidal crystal structure 531a, the first colloidal particles 541a, the first matrix material 551a, the second colloidal crystal structure 532a, the second colloidal particles 542a, and the second colloidal material 552a use the same configurations as in the first embodiment. be able to. However, the following points are different.

In the present embodiment, the central particle size of the first colloidal particles 541a is larger than the central particle size of the second colloidal particles 542a. Further, the center-to-center distance d2 of the first colloidal particles 541a is larger than the center-to-center distance d3 of the second colloidal particles 542a. As a result, the reflection peak wavelength of the first transmission reflection film layer 521a of the first colloid crystal structure 531a is longer than the reflection peak wavelength of the second transmission reflection film layer 522a of the second colloid crystal structure 532a. Is.

Here, a method for producing the first colloidal crystal structure 531a and the second colloidal crystal structure 532a will be described.

In the present embodiment, a dispersion liquid for obtaining the first colloidal crystal structure 531a is applied to the substrate 51a and cured to obtain the first colloidal crystal structure 531a. Next, a dispersion liquid for obtaining the second colloidal crystal structure 532a is applied to the first colloidal crystal structure 531a and cured to obtain the second colloidal crystal structure 532a. By using the above method, the first colloidal crystal structure 531a and the second colloidal crystal structure 532a are produced.

In the present embodiment, the second colloidal crystal structure 532a is directly provided on the first colloidal crystal structure 531a, but the present invention is not limited to this. For example, a flattening layer may be provided between the first colloidal crystal structure 531a and the second colloidal crystal structure 532a. The flattening layer is provided, for example, as follows. A flattening layer is produced by using the raw material of the matrix material 55 such as the acrylic resin described above as a dispersion liquid, applying the dispersion liquid to the first colloidal crystal structure 531a and curing it.

By providing such a flattening layer, the unevenness derived from the first colloidal particles 541a in the first colloidal crystal structure 531a can be flattened. As a result, the second colloidal crystal structure 532a can be provided on the flat surface of the flattening layer, so that the center-to-center distance d3 in the second colloidal crystal structure 532a can be controlled as designed.

As described above, the reflected light L3a includes the first reflected light reflected by the first transmitted reflecting film layer 521a and the second reflected light reflected by the second transmitted reflecting film layer 522a. Further, each of the first reflected light and the second reflected light is light containing different reflected peak wavelengths. Therefore, the transmission reflection film layer 52a can reflect light including a plurality of target reflection peak wavelengths.

Further, the first transmissive reflective film layer 521a and the second transmissive reflective film layer 522a are laminated. The transmitted light L2a is light obtained by removing the wavelength region of the reflected light L3a from the incident light L1a emitted by the light source 10a. Further, in the present embodiment, the output light L5a includes the transmitted light L2a as in the first embodiment. Therefore, the output light L5a emitted by the illuminating device 1a includes light obtained by subtracting the wavelength region of the reflected light L3a (that is, the wavelength region including a plurality of different reflected peak wavelengths) from the incident light L1a emitted by the light source 10a. That is, the optical filter 50a according to the present embodiment can use the output light L5a emitted by the lighting device 1a as desired light.

Subsequently, the fluorescent member 90a will be described. The fluorescent member 90a is a member having a fluorescent material that absorbs the reflected light L3a and emits the fluorescent L4a.

The fluorescent material is a material that absorbs the wavelength contained in the reflected light L3a and converts the wavelength. For example, as the fluorescent material, a material such as YAG-based material or TAG (Terbium aluminum Garnet) -based material can be used. However, fluorescent materials are not limited to these materials. In the present embodiment, the incident light L1a emitted by the light source 10a is white light, that is, light in the visible light region, so that the reflected light L3a is also light in the visible light region. That is, the fluorescent material according to the present embodiment absorbs light in the visible light region.

Further, the fluorescent material converts the reflected light L3a into wavelength and emits the fluorescent L4a. Therefore, the wavelength region of the fluorescence L4a is different from the wavelength region of the reflected light L3a. As described above, the fluorescent member 90a is attached to the bottom surface of the housing 70a and the inner peripheral surface of the cylinder of the housing 70a on the bottom surface side of the optical filter 50a. Therefore, the fluorescent member 90a emits the fluorescence L4a toward the optical filter 50a (that is, the transmission / reflection film layer 52a).

Here, the fluorescence L4a transmits through the transmission / reflection film layer 52a. This can be explained as follows.

The transmissive reflective film layer 52a reflects the reflected light L3a. That is, the transmission / reflection film layer 52a reflects light in the wavelength region of the reflected light L3a. On the other hand, the wavelength region of the fluorescence L4a is different from the wavelength region of the reflected light L3a. Therefore, the transmissive reflective film layer 52a does not reflect the fluorescence L4a. As a result, the fluorescence L4a transmits through the transmission / reflection film layer 52a. Further, since the light transmitted through the transmission / reflection film layer 52a is the transmitted light L2a, the fluorescence L4a transmitted through the transmission / reflection film layer 52a is also the transmitted light L2a.

Further, the light transmitting member 80a is a member that transmits light. In the present embodiment, the light transmitting member 80a is a member that transmits transmitted light L2a. As shown in FIG. 5A, the light emitted from the translucent member 80a is the output light L5a emitted by the illuminating device 1a. Therefore, the output light L5a includes the transmitted light L2a which is the light transmitted through the transmission / reflection film layer 52a. That is, in the present embodiment, the output light L5a includes a transmitted light L2a and a fluorescent L4a which is also a transmitted light L2a.

As a result, the fluorescent material contained in the fluorescent member 90a absorbs the reflected light L3a and emits the fluorescent L4a. Without the fluorescent material, the light in the wavelength region of the reflected light L3a cannot pass through the transmission-reflective coating layer 52a and is extinguished. That is, without the fluorescent material, the light in the wavelength region of the reflected light L3a cannot be used as the output light L5a. The fluorescent material converts the light in the wavelength region of the reflected light L3a into the fluorescent L4a, so that the illumination device 1a can use the fluorescent L4a as the output light L5a. That is, the luminous efficiency of the output light L5a emitted by the lighting device 1a can be increased. Further, since the output light L5a is light containing transmitted light L2a and further containing fluorescence L4a, the output light L5a becomes more desired light.

In the present embodiment, the reflected light L3a is light including two different reflected peak wavelengths. Therefore, it is desirable that the fluorescent material absorbs light containing at least one of the two different reflected peak wavelengths. Further, since the fluorescent member 90a has two different fluorescent materials, each fluorescent material may absorb light including each reflection peak wavelength of two different reflection peak wavelengths.

[Effects, etc.]
The lighting device 1a according to the present embodiment further includes a fluorescent member 90a having a fluorescent material that absorbs reflected light L3a and emits fluorescent L4a, and the output light L5a further includes fluorescent L4a.

As a result, the fluorescent material contained in the fluorescent member 90a absorbs the reflected light L3a and emits the fluorescent L4a. Without the fluorescent material, the light in the wavelength region of the reflected light L3a cannot be used as the output light L5a. The fluorescent material converts the light in the wavelength region of the reflected light L3a into the fluorescent L4a, so that the illumination device 1a can use the fluorescent L4a as the output light L5a. That is, the luminous efficiency of the output light L5a emitted by the lighting device 1a can be increased. Further, since the output light L5a is light containing transmitted light L2a and further containing fluorescence L4a, the output light L5a becomes more desired light.

The transmission / reflection film layer 52a according to the present embodiment includes a first transmission / reflection film layer 521a and a second transmission / reflection film layer 522a. Further, the reflected light L3a includes a first reflected light reflected by the first transmitted reflecting film layer 521a and a second reflected light reflected by the second transmitted reflecting film layer 522a, and includes the first reflected light and the second reflected light. Each is light with different reflected peak wavelengths.

This makes it possible to reflect light containing a plurality of different reflection peak wavelengths of interest.

In the present embodiment, the first transmissive reflective film layer 521a and the second transmissive reflective film layer 522a are laminated.

As a result, the output light L5a emitted by the illuminating device 1a includes light obtained by subtracting the wavelength region of the reflected light L3a (that is, the wavelength region including a plurality of different reflected peak wavelengths) from the incident light L1a emitted by the light source 10a. That is, the optical filter 50a according to the present embodiment can use the output light L5a emitted by the lighting device 1a as desired light.

(Embodiment 3)
In the second embodiment, the configuration in which the first transmissive reflective film layer 521a and the second transmissive reflective film layer 522a are laminated is shown, but the present invention is not limited to this. The third embodiment is different from the second embodiment in that the first transmissive reflective film layer 521b and the second transmissive reflective film layer 522b are arranged so as not to overlap when viewed in a plan view. More specifically, the transmissive reflective film layer 52b includes a first transmissive reflective film layer 521b, a second transmissive reflective film layer 522b, and a third transmissive reflective film layer 523b. Further, the first transmissive reflective film layer 521b, the second transmissive reflective film layer 522b, and the third transmissive reflective film layer 523b are arranged so as not to overlap when viewed in a plan view. Further, the third embodiment is different from the second embodiment in that the lighting device 1b does not include a fluorescent member. In the third embodiment, detailed description of the components common to the first and second embodiments will be omitted.

[Constitution]
First, the configuration of the lighting device 1b according to the present embodiment will be described with reference to FIGS. 6A and 6B. FIG. 6A is a cross-sectional view showing the configuration of the lighting device 1b according to the present embodiment. FIG. 6B is a cross-sectional view showing the configuration of the optical filter 50b included in the lighting device 1b according to the present embodiment. Further, the white arrow and the shaded arrow shown in FIG. 6A indicate the traveling direction of the light.

As shown in FIG. 6A, the illuminating device 1b emits output light L5b. The lighting device 1b includes a light source 10b, an optical filter 50b, a housing 70b, and a translucent member 80b. The lighting device 1b according to the present embodiment is a lighting device that illuminates the surroundings with the output light L5b.

The light source 10b, the housing 70b, and the translucent member 80b in the present embodiment have the same configurations as those in the first and second embodiments. Further, the light source substrate 11b, the light emitting element 12b, and the wavelength conversion layer 13b included in the light source 10b are the same as those in the first and second embodiments.

Next, the optical filter 50b according to the present embodiment will be described.

The optical filter 50b has a substrate 51b and a transmission / reflection film layer 52b. The transmissive reflective film layer 52b includes a first transmissive reflective film layer 521b and a second transmissive reflective film layer 522b. The second embodiment is different in that the first transmissive reflective film layer 521b and the second transmissive reflective film layer 522b are arranged so as not to overlap when viewed in a plan view. More specifically, the transmissive reflective film layer 52b according to the present embodiment includes a first transmissive reflective film layer 521b, a second transmissive reflective film layer 522b, and a third transmissive reflective film layer 523b. Further, the first transmissive reflective film layer 521b, the second transmissive reflective film layer 522b, and the third transmissive reflective film layer 523b are arranged so as not to overlap when viewed in a plan view.

Here, the arrangement without overlapping in the present embodiment will be described. The term “non-overlapping” means that when the first transmissive reflective film layer 521b, the second transmissive reflective film layer 522b, and the third transmissive reflective film layer 523b are viewed in a plan view, the first transmissive reflective film layer 521b and the second transmissive reflective film layer 521b. The structure is such that there is no region where the 522b and the third transmissive reflective film layer 523b overlap.

Further, in the present embodiment, the first transmissive reflective film layer 521b, the second transmissive reflective film layer 522b, and the third transmissive reflective film layer 523b are arranged without overlapping and without gaps when viewed in a plan view. Will be done. Arrangement without gaps means that when the first transmissive reflective film layer 521b, the second transmissive reflective film layer 522b, and the third transmissive reflective film layer 523b are viewed in a plan view, the first transmissive reflective film layer 521b and the second transmissive reflective film layer 521b. The structure is such that 522b and the third transmissive reflective film layer 523b are not separated and are in contact with each other.

The substrate 51b according to the present embodiment is the same as that of the first and second embodiments.

The incident light L1b emitted by the light source 10b is incident on the transmission / reflection film layer 52b included in the optical filter 50b. Further, the incident light L1b is converted into the reflected light L3b reflected by the transmitted reflecting film layer 52b and the transmitted light L2b transmitted through the transmitted reflecting film layer 52b via the transmitted reflecting film layer 52b. In the present embodiment, the transmissive reflective film layer 52b includes a first transmissive reflective film layer 521b, a second transmissive reflective film layer 522b, and a third transmissive reflective film layer 523b. Further, the first transmissive reflective film layer 521b, the second transmissive reflective film layer 522b, and the third transmissive reflective film layer 523b are arranged without overlapping and without gaps when viewed in a plan view. Therefore, the transmission / reflection film layer 52b to which the incident light L1b is incident differs depending on the traveling direction of the incident light L1b. Therefore, the reflected light L3b is the first reflected light L31b reflected by the first transmitted reflecting film layer 521b, the second reflected light L32b reflected by the second transmitted reflecting film layer 522b, and the third transmitted reflecting film layer 523b reflected by the third transmitted reflecting film layer 523b. 3 Includes reflected light L33b.

Further, since the reflected light L3b is light including a reflected peak wavelength determined by the transmitted reflecting film layer 52b, the first reflected light L31b, the second reflected light L32b, and the third reflected light L33b each have different reflected peak wavelengths. It is the light that contains. That is, each of the reflected light L3b becomes light in a wavelength region different depending on the traveling direction of the light.

Further, as described above, the light transmitted through the transmission reflection film layer 52b is the transmitted light L2b. The transmissive reflective film layer 52b according to the present embodiment reflects a part of the incident light L1b and transmits the other part of the incident light L1b. That is, the transmitted light L2b is light obtained by removing the wavelength region of the reflected light L3b from the incident light L1b emitted by the light source 10b. Further, the transmitted light L2b is a first transmitted light L21b which is light transmitted through the first transmitted reflective film layer 521b, a second transmitted light L22b which is light transmitted through the second transmitted reflective film layer 522b, and a third transmitted reflective film. The third transmitted light L23b, which is the light transmitted through the layer 523b, is included. Therefore, the first transmitted light L21b is light obtained by removing the wavelength region of the first reflected light L31b from the incident light L1b. The second transmitted light L22b is light obtained by removing the wavelength region of the second reflected light L32b from the incident light L1b. Further, the third transmitted light L23b is light obtained by removing the wavelength region of the third reflected light L33b from the incident light L1b. That is, each of the transmitted light L2b becomes light in a different wavelength region depending on the traveling direction of the light.

Here, the first colloidal crystal structure 531b included in the first transmissive reflective film layer 521b, the second colloidal crystal structure 532b included in the second transmissive reflective film layer 522b, and the third included in the third transmissive reflective film layer 523b. The colloidal crystal structure 533b will be described with reference to FIG. 6B.

The first transmissive reflective film layer 521b according to the present embodiment is a first colloidal crystal structure 531b. The second transmissive reflective film layer 522b according to the present embodiment is a second colloidal crystal structure 532b. The third transmissive reflective film layer 523b according to the present embodiment is a third colloidal crystal structure 533b.

The first colloidal crystal structure 531b contains first colloidal particles 541b and a first matrix material 551b. The second colloidal crystal structure 532b contains the second colloidal particles 542b and the second matrix material 552b. The third colloidal crystal structure 533b contains a third colloidal particle 543b and a third matrix material 553b.

The first colloidal crystal structure 531b, the first colloidal particles 541b, the first matrix material 551b, the second colloidal crystal structure 532b, the second colloidal particles 542b, and the second colloidal material 552b have the same configurations as those of the first and second embodiments. Can be used. Further, the third colloidal crystal structure 533b, the third colloidal particles 543b, and the third matrix material 553b can use the same configurations as those in the first and second embodiments. However, the following points are different.

In the present embodiment, the central particle size of the first colloidal particles 541b is larger than the central particle size of the second colloidal particles 542b. Further, the central particle size of the second colloidal particles 542b is larger than the central particle size of the third colloidal particles 543b. Further, the center-to-center distance d4 of the first colloidal particles 541b is larger than the center-to-center distance d5 of the second colloidal particles 542b. Further, the center-to-center distance d5 of the second colloidal particles 542b is larger than the center-to-center distance d6 of the third colloidal particles 543b. As a result, the reflection peak wavelength of the first transmission reflection film layer 521b of the first colloid crystal structure 531b is longer than the reflection peak wavelength of the second transmission reflection film layer 522b of the second colloid crystal structure 532b. Is. Further, the reflection peak wavelength of the second transmission reflection film layer 522b, which is the second colloid crystal structure 532b, is longer than the reflection peak wavelength of the third transmission reflection film layer 523b, which is the third colloid crystal structure 533b. is there.

Here, a method for producing the first colloidal crystal structure 531b, the second colloidal crystal structure 532b, and the third colloidal crystal structure 533b will be described.

In the present embodiment, a dispersion liquid for obtaining the first colloidal crystal structure 531b is applied to a part of the substrate 51b and cured to obtain the first colloidal crystal structure 531b. Next, a dispersion liquid for obtaining the second colloidal crystal structure 532b is applied to a part of the substrate 51b on which the first colloidal crystal structure 531b is not provided and cured to obtain the second colloidal crystal structure 532b. obtain. At this time, the dispersion liquid for obtaining the second colloidal crystal structure 532b is applied so as not to overlap with the first colloidal crystal structure 531b and to be arranged without gaps. Further, a dispersion liquid for obtaining the third colloidal crystal structure 533b is applied to a part of the substrate 51b on which the first colloidal crystal structure 531b and the second colloidal crystal structure 532b are not provided and cured to obtain the third colloidal crystal structure. A tricolloid crystal structure 533b is obtained. At this time, the dispersion liquid for obtaining the third colloidal crystal structure 533b is applied so as not to overlap with the first colloidal crystal structure 531b and the second colloidal crystal structure 532b and to be arranged without gaps. .. By using the method of applying each dispersion liquid separately as described above, the first colloid crystal structure 531b, the second colloid crystal structure 532b, and the third colloid crystal structure 533b are produced.

Here, the translucent member 80b will be described with reference to FIG. 6A.

The light transmitting member 80b is a member that transmits transmitted light L2b. As shown in FIG. 6A, the light emitted from the translucent member 80b is the output light L5b emitted by the illuminating device 1b. Therefore, the output light L5b includes the transmitted light L2b which is the light transmitted through the transmission reflection film layer 52b. As described above, since each of the transmitted light L2b is light in a different wavelength region depending on the traveling direction of the light, the output light L5b emitted by the illuminating device 1b becomes light in a different wavelength region depending on the traveling direction of the light. ..

[Effects, etc.]
In the present embodiment, the first transmissive reflective film layer 521b and the second transmissive reflective film layer 522b are arranged so as not to overlap when viewed in a plan view.

As a result, the transmissive reflective film layer 52b according to the present embodiment reflects a part of the incident light L1b and transmits the other part of the incident light L1b. At this time, the light reflected by the transmission / reflection film layer 52b is the reflected light L3b, and the light transmitted through the transmission / reflection film layer 52b is the transmitted light L2b. That is, the transmitted light L2b is light obtained by removing the wavelength region of the reflected light L3b from the incident light L1b emitted by the light source 10b.

Further, in the present embodiment, the first transmissive reflective film layer 521b, the second transmissive reflective film layer 522b, and the third transmissive reflective film layer 523b are arranged so as not to overlap when viewed in a plan view. Therefore, the transmission / reflection film layer 52b into which the incident light L1b is incident differs depending on the traveling direction of the incident light L1b. Therefore, each of the transmitted light L2b is light obtained by subtracting each wavelength region of the reflected light L3b from the incident light L1b emitted by the light source 10b. That is, each of the transmitted light L2b becomes light in a different wavelength region depending on the traveling direction of the light. The output light L5b according to the present embodiment includes transmitted light L2b. Therefore, the output light L5b emitted by the illuminating device 1b becomes light in a different wavelength region depending on the traveling direction of the light. That is, the optical filter 50b according to the present embodiment can use the output light L5b emitted by the lighting device 1b as desired light.

The lighting device 1b according to the present embodiment can emit desired output light L5b by having the above-described configuration.

For example, the lighting device 1b according to the present embodiment can be used as a street light capable of suppressing light pollution to plants. It is known that the growth of certain plants is inhibited by irradiation with light of a specific wavelength. It is desirable that the lighting device 1b according to the present embodiment is provided at a place where a road through which a person or a car passes and a field in which the plant is grown are adjacent to each other. As a result, bright light is emitted from the lighting device 1b according to the present embodiment toward the road through which a person or a car passes, and the lighting device 1b according to the present embodiment is directed toward the field where the plant is grown. Therefore, light other than the above specific wavelength is irradiated. As described above, the lighting device 1b according to the present embodiment can be used as a street light capable of suppressing light pollution to plants.

(Embodiment 4)
In the first, second and third embodiments, the optical filter is attached facing the bottom surface, but the present invention is not limited to this. The fourth embodiment is different from the first, second, and third embodiments in that the optical filter 50c is provided on the inner peripheral surface of the cylinder of the housing 70c. Further, the fourth embodiment is different from the first, second and third embodiments in that the housing 70c is made of a translucent material. In the fourth embodiment, detailed description of the components common to the first, second, and third embodiments will be omitted.

[Constitution]
First, the configuration of the lighting device 1c according to the present embodiment will be described with reference to FIG. 7. FIG. 7 is a cross-sectional view showing the configuration of the lighting device 1c according to the present embodiment. Further, the white arrow and the shaded arrow shown in FIG. 7 indicate the traveling direction of the light. In addition, in FIG. 7, only a part of the incident light L1c emitted by the light source 10c is shown in order to avoid complicating the figure. Specifically, FIG. 7 shows only the light on the negative side of the x-axis with respect to the light having a light distribution angle (details will be described later) of 0 °. However, the light on the x-axis positive side of the light having a light distribution angle of 0 ° exhibits the same behavior as the light on the x-axis negative side of the light having a light distribution angle of 0 °.

As shown in FIG. 7, the illuminating device 1c emits output light L5c. The lighting device 1c includes a light source 10c, an optical filter 50c, a housing 70c, and a light transmitting member 80c. The lighting device 1c according to the present embodiment is a lighting device that illuminates the surroundings with the output light L5c.

The light source 10c and the translucent member 80c in the present embodiment have the same configurations as those in the first, second, and third embodiments. Further, the light source substrate 11c, the light emitting element 12c, and the wavelength conversion layer 13c included in the light source 10c are also the same as those in the first, second, and third embodiments.

First, the housing 70c according to the present embodiment will be described.

The housing 70c is a member that houses the light source 10c, the optical filter 50c, and the translucent member 80c.

The housing 70c according to the embodiment has a bottomed cylindrical shape. An opening is provided facing the bottom surface of the housing 70c. Further, the housing 70c transmits light. More specifically, the housing 70c transmits the transmitted light L2c. Therefore, the housing 70c is a member made of a material having high light transmission. Further, the housing 70c may be a member that transmits light without scattering it. For example, the housing 70c is made of a translucent resin material such as acrylic or polycarbonate, or a translucent material such as glass material. Further, the housing 70c of the present embodiment is made of a glass material.

The internal space of the housing 70c is a closed space that accommodates the light source 10c, the optical filter 50c, and the translucent member 80c. Further, the light source 10c is attached to the bottom surface of the housing 70c. The translucent member 80c is attached to the opening. Further, the optical filter 50c is attached to the inner peripheral surface of the cylinder of the housing 70c. More specifically, the optical filter 50c is attached to the inner peripheral surface of the cylinder between the light source 10c and the translucent member 80c in the housing 70c. Therefore, the incident light L1c emitted by the light source 10c is emitted toward the optical filter 50c and the light transmitting member 80c. The incident light L1c is emitted from the housing 70c to the external space via the optical filter 50c, the housing 70c, and the translucent member 80c, respectively. Further, as shown in FIG. 7, the light emitted into the external space is the output light L5c emitted by the lighting device 1c.

In the present embodiment, the output light L5c includes the first output light L51c and the second output light L52c. Here, a light distribution curve is defined in order to explain the first output light L51c and the second output light L52c. The light distribution curve is a curve showing the light distribution angle (traveling direction) of the light emitted by the light source 10c and the luminous intensity. In the present embodiment, the direction in which the light distribution angle is 0 ° is the traveling direction of the incident light L1c emitted from the light source 10c in the positive direction of the z-axis. Further, light having a small light distribution angle is defined as light having a narrow light distribution angle, and light having a large light distribution angle is defined as light having a wide light distribution angle. In the present embodiment, the first output light L51c is light having a narrow light distribution angle, and the second output light L52c is light having a wide light distribution angle. For example, the first output light L51c is light transmitted through the light transmitting member 80c. Further, for example, the second output light L52c is light that has passed through the optical filter 50c and the housing 70c.

Subsequently, the optical filter 50c according to the present embodiment will be described.

The optical filter 50c has a substrate 51c and a transmission / reflection film layer 52c. The transmission / reflection film layer 52c according to the present embodiment includes a first transmission / reflection film layer 521c, a second transmission / reflection film layer 522c, and a third transmission / reflection film layer 523c. The first transmissive reflective film layer 521c, the second transmissive reflective film layer 522c, and the third transmissive reflective film layer 523c are the same as those in the third embodiment.

Therefore, the reflected light L3c reflected by the transmitted reflective film layer 52c includes the first reflected light L31c, the second reflected light L32c, and the third reflected light L33c. Each of the first reflected light L31c, the second reflected light L32c, and the third reflected light L33c is light containing different reflected peak wavelengths. Further, the transmitted light L2c which is the light transmitted through the transmission / reflection film layer 52c includes the first transmitted light L21c, the second transmitted light L22c, and the third transmitted light L23c. Each of the first transmitted light L21c, the second transmitted light L22c, and the third transmitted light L23c becomes light in a different wavelength region depending on the traveling direction of the light. In the present embodiment, the transmitted light L2c transmits through the housing 70c. Further, the light transmitted through the housing 70c becomes the second output light L52c. Therefore, each of the second output lights L52c, which is light having a wide light distribution angle, becomes light in a different wavelength region depending on the traveling direction of the light. Further, as described above, the output light L5c includes the transmitted light L2c which is the light transmitted through the transmission reflection film layer 52c.

Further, the substrate 51c according to the present embodiment is the same as the first, second and third embodiments in that it has a high light transmittance and that a translucent material can be used. On the other hand, the substrate 51c is arranged on the inner peripheral surface of the cylinder of the housing 70c. Therefore, when the substrate 51c has a rigid property, the shape of the substrate 51c needs to be a cylindrical shape along the inner peripheral surface of the cylinder of the housing 70c. Further, when the substrate 51c has a flexible property, the shape of the substrate 51c is not particularly limited. In the present embodiment, the substrate 51c has a flexible property.

The optical filter 50c according to the present embodiment is produced by using a method of separately coating as in the third embodiment.

Further, when the optical filter 50c is attached to the housing 70c, the optical filter 50c is attached while bending the optical filter 50c along the inner peripheral surface of the cylinder of the housing 70c.

The light transmitting member 80c is a member that transmits light. The translucent member 80c according to the present embodiment is a member that transmits the incident light L1c and the reflected light L3c. The translucent member 80c may be composed of the same members as those in the first, second and third embodiments. As shown in FIG. 7, the light emitted from the translucent member 80c is the first output light L51c emitted by the illuminating device 1c. Therefore, in the present embodiment, the output light L5c includes the incident light L1c and the reflected light L3c. That is, the first output light L51c, which is light having a narrow light distribution angle, is light in which incident light L1c and reflected light L3c are combined.

In summary, in the present embodiment, the housing 70c transmits light, and the optical filter 50c is attached to the inner peripheral surface of the cylinder of the housing 70c. As a result, the first output light L51c, which is light having a narrow light distribution angle, is light in which incident light L1c and reflected light L3c are combined. That is, the composite illumination light in which the incident light L1c and the reflected light L3c are combined is irradiated from the illumination device 1c in the narrow light distribution angle direction. On the other hand, each of the second output lights L52c, which is light having a wide light distribution angle, is light in a different wavelength region depending on the traveling direction of the light. That is, gradation illumination light having a different light color depending on the traveling direction of the light is irradiated from the illumination device 1c in the wide light distribution angle direction.

(Other)
Although the lighting device according to the embodiment has been described above, the present invention is not limited to the above embodiment.

In the embodiment, the light source emits white light, that is, incident light which is light in the visible region, but the light source is not limited to this. For example, the incident light emitted from the light source may be light in the infrared region or light in the ultraviolet region. In this case, by controlling the distance between the centers of the colloidal particles and setting the wavelength region of the reflected light to the infrared region or the ultraviolet region, it is possible to realize a lighting device that emits desired output light as in the embodiment. In this case, the translucent member, the substrate that supports the transmissive reflective film layer, and the housing in the third embodiment are composed of a member that transmits light in the infrared region or light in the ultraviolet region.

Further, in the embodiment, the colloidal crystal structure includes, but is not limited to, a matrix material. The colloidal crystal structure does not contain a matrix material and may contain only colloidal particles. The distance between the centers of the colloidal particles at this time is, for example, equivalent to the center particle size of the colloidal particles.

In the embodiment, the transmissive reflective film layer is a colloidal crystal structure, but the present invention is not limited to this. The transmissive reflective film layer may include a colloidal crystal structure and may contain other components. For example, the transmission / reflection film layer may include a scattering layer containing scattered particles, a light guide layer for guiding light, and the like, in addition to the colloidal crystal structure.

In the first embodiment, an example in which the full width at half maximum of the reflection peak caused by the colloidal crystal structure is 30 nm or less is shown, but the present invention is not limited to this. The full width at half maximum of the reflection peak caused by the colloidal crystal structure may be 50 nm or less, 30 nm or less, or 20 nm or less.

Further, as shown in each figure, in the translucent member of the embodiment, an example in which the surface on which light is incident is smooth is shown, but the present invention is not limited to this. For example, a convex structure may be provided on the surface on which light is incident and / or on the surface opposite to the surface on which light is incident. In this case, the translucent member functions as a convex lens or a biconvex lens. Further, the translucent member may be a condenser lens. However, the translucent member is not limited to this, and may have other shapes.

In the second embodiment, the fluorescent material is a material that absorbs the wavelength contained in the reflected light and converts the wavelength, but more strictly speaking, it is desirable that the fluorescent material has the following properties.

It is desirable that the maximum excitation wavelength of the fluorescent material coincides with the reflected peak wavelength of the reflected light. As a result, the fluorescent material can absorb the reflected light and fluoresce more efficiently. That is, the luminous efficiency of the fluorescent material can be increased. The maximum excitation wavelength is a wavelength that gives the strongest fluorescence intensity in the excitation spectrum of the fluorescent material. For example, when the excitation maximum wavelength and the reflection peak wavelength match, the reflection peak wavelength is located within the region range of the excitation wavelength corresponding to the excitation intensity of 70% or more of the excitation maximum intensity (that is, the excitation peak intensity). To do. Further, for example, when the excitation maximum wavelength and the reflection peak wavelength match, when the excitation maximum wavelength is λ1 (nm) and the reflection peak wavelength is λ2 (nm), the relationship of λ1-10nm <λ2 <λ1 + 10nm is satisfied. It may be.

Further, as shown in the first embodiment, the wavelength region of the low transmittance of the optical filter having the transmissive antireflection film layer containing the colloidal crystal structure is compared with the dye-containing optical filter which is one of the comparative examples. , The wavelength range is narrower. That is, since the optical filter having the transmissive reflection film layer containing the colloidal crystal structure contains the colloidal crystal structure, the reflected light becomes light including a sharper reflected peak wavelength. As a result, the maximum excitation wavelength of the fluorescent material of the fluorescent material and the reflected peak wavelength of the reflected light can be more easily matched, so that the luminous efficiency of the fluorescent material can be further improved.

Further, in the second embodiment, an example in which the first transmissive reflective film layer 521a and the second transmissive reflective film layer 522a are laminated is shown, but the present invention is not limited to this. For example, when the first transmissive reflective film layer and the second transmissive reflective film layer are viewed in a plan view (when viewed from the negative z-axis direction), a part of the first transmissive reflective film layer and one of the second transmissive reflective film layers. The structure may be such that the parts overlap. As described above, a structure different from the laminated structure may be used.

In the embodiment, the configuration in which the optical filter is attached facing the bottom surface of the housing or the configuration in which the optical filter is attached to the inner peripheral surface of the cylinder of the housing is shown, but the present invention is not limited to this. The optical filter may be in any position as long as the incident light emitted by the light source is incident on the transmission / reflection film layer of the optical filter.

In the embodiment, the lighting device is used as a lighting device provided with a housing, but the present invention is not limited to this. For example, the illuminating device may be a light emitting package or an electronic component including a light source and an optical filter having a transmissive reflective film layer containing a colloidal crystal structure.

In addition, it is realized by arbitrarily combining the components and functions in each embodiment within the range obtained by subjecting various modifications to each of the above embodiments to those skilled in the art or the gist of the present invention. Forms are also included in the present invention.

1 Lighting device 10 Light source 50 Optical filter 52 Transmission reflective film layer 521a First transmission reflection film layer 522a Second transmission reflection film layer 53 Colloid crystal structure 54 Colloid particles 55 Matrix material 70 Housing 80 Translucency member 90a Fluorescent member L1 Incident Light L2 Transmitted light L3 Reflected light L31b First reflected light L32b Second reflected light L4a Fluorescent L5 Output light

Claims (9)

A lighting device that emits output light
An optical filter having a transmissive reflective film layer containing a colloidal crystal structure,
A light source that emits incident light incident on the transmission / reflection film layer is provided.
The incident light is converted into reflected light reflected by the transmitted reflective film layer and transmitted light transmitted through the transmitted reflective film layer via the transmitted reflective film layer.
The reflected light is light including a reflected peak wavelength determined by the transmitted reflective film layer.
The output light is a lighting device including the transmitted light. Further, a fluorescent member having a fluorescent material that absorbs the reflected light and emits fluorescence is provided.
The lighting device according to claim 1, wherein the output light further includes the fluorescence. The transmissive reflective film layer includes a first transmissive reflective film layer and a second transmissive reflective film layer.
The reflected light includes a first reflected light reflected by the first transmitted reflecting film layer and a second reflected light reflected by the second transmitted reflecting film layer.
The lighting device according to claim 1 or 2, wherein each of the first reflected light and the second reflected light is light containing different reflected peak wavelengths. The lighting device according to claim 3, wherein the first transmissive reflective film layer and the second transmissive reflective film layer are laminated. The lighting device according to claim 3, wherein the first transmissive reflective film layer and the second transmissive reflective film layer are arranged so as not to overlap when viewed in a plan view. Further, a translucent member that transmits the transmitted light and
The lighting device according to any one of claims 1 to 5, further comprising the light source, the optical filter, and a housing for accommodating the translucent member. The colloidal crystal structure contains colloidal particles having a spherical shape.
The lighting device according to any one of claims 1 to 6, wherein the central particle size of the colloidal particles is 150 nm or more and 300 nm or less. The lighting device according to claim 7, wherein the colloidal particles contain silicon and oxygen. The lighting device according to any one of claims 1 to 8, wherein the colloidal crystal structure contains a matrix material composed of an organic substance.

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