JP2017033756A - Luminaire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bright luminaire with little luminance unevenness.SOLUTION: A luminaire 200 includes: a plurality of line-like light-emitting modules 210 arrayed at intervals; and a diffusion plate 204 arranged on the front side of the plurality of light-emitting modules 210. The light-emitting module includes: a plurality of semiconductor light-emitting elements; and a light wavelength conversion layer 118 excited by the light emitted by the semiconductor light-emitting elements, and for emitting visible light. The light wavelength conversion layer is constituted so as to cover the plurality of semiconductor light-emitting elements, and has an emission surface which is constituted so that the luminous intensity of the light toward a second irradiation region R2 between the front surface of a light source and the front surface of the adjacent light source becomes higher than the luminous intensity of the light toward a first irradiation region R1 on the front surface of the light source. The plurality of light sources are constituted so that a difference in luminance between the first irradiation region and the second irradiation region is alleviated by the light toward the second irradiation region from the light sources and the light toward the second irradiation region from the adjacent light sources.SELECTED DRAWING: Figure 11

Description

  The present invention relates to a lighting device.

  Conventionally, a planar substrate, a plurality of light emitting elements mounted on the substrate, a first transparent resin layer disposed so as to integrally cover and seal the plurality of light emitting elements, and the first transparent resin layer Has been devised (see Patent Document 1).

  In this planar light emitting module, phosphors that convert the wavelength of the light emitted from the light emitting element are dispersed in the first and second transparent resin layers, and the white light is visible when the second transparent resin layer is viewed from the outside. The phosphor is selected so that light is observed.

JP 2013-12536 A

  However, in the above planar light emitting module, a plurality of light emitting elements are integrally covered with the first transparent resin layer, and the light emitting surface of the first transparent resin layer is flat. Therefore, there is room for improvement in the difference between the luminance immediately above the light emitting elements and the luminance immediately above the light emitting elements on the emission side surface of the first transparent resin layer. If an attempt is made to reduce the difference in luminance, it is necessary to reduce the interval between the light emitting elements. In this case, it is difficult to achieve both improvement in output of the light emitting elements and heat dissipation.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a bright illumination device with less luminance unevenness.

  In order to solve the above problems, an illumination device according to an aspect of the present invention includes a plurality of linear light sources arranged at intervals, and a transmissive member disposed on the front side of the plurality of light sources. The light source includes a plurality of semiconductor light emitting elements and a light wavelength conversion layer that emits visible light when excited by light emitted from the semiconductor light emitting elements. The light wavelength conversion layer is configured to cover a plurality of semiconductor light emitting elements, and the light intensity of the light toward the first irradiation region on the front surface of the light source is larger than that of the front surface of the adjacent light source. And an exit surface configured to increase the luminous intensity of the light toward the second irradiation region. In the plurality of light sources, the difference in luminance between the first irradiation region and the second irradiation region is reduced by light traveling from the light source toward the second irradiation region and light traveling from the adjacent light source toward the second irradiation region. It is configured.

  According to this aspect, it is possible to realize an illuminating device with little luminance unevenness even if a plurality of line-shaped light sources are arranged at a certain interval. In addition, since the distance between the light sources is wide to some extent, the light source can be lightened, heat dissipation is good, a light source with high output can be used, and a bright lighting device can be realized.

  The transmissive member may be a diffusion plate provided at a position separated from the light wavelength conversion layer. Thereby, an illuminating device with less luminance unevenness can be realized.

  The plurality of light sources may be configured such that the luminance uniformity on the exit surface of the transmission member is 0.6 or more, preferably 0.9 or more. Thereby, the discomfort due to the graininess of the scattered light emitting elements is reduced, and an illumination device with less luminance unevenness can be realized.

  The optical wavelength conversion layer preferably satisfies H> 0.5 W, where W is the width in the direction intersecting the direction in which the semiconductor light emitting elements are arranged, and H is the height in the main direction of the light emitted from the semiconductor light emitting elements. . Thereby, the light flux of the light which goes to the 2nd irradiation field can be increased.

  The semiconductor light emitting device emits ultraviolet light or short wavelength visible light, and the light wavelength conversion layer is excited by ultraviolet light or short wavelength visible light and a first phosphor that emits visible light when excited by ultraviolet light or short wavelength visible light. The second phosphor that emits visible light having a different color from the visible light emitted from the first phosphor may be contained. As a result, white light can be realized by the color mixture of light emitted from a plurality of types of phosphors, so that an illumination device with little color misregistration and luminance unevenness can be realized.

  The semiconductor light emitting device emits ultraviolet light or short wavelength visible light, and the light wavelength conversion layer has a first layer and a second layer provided on the opposite side of the light emitting device with the first layer interposed therebetween. May be. The first layer and the second layer may include a red phosphor, a green phosphor, a yellow phosphor, and a blue phosphor. The first layer may include at least one of a red phosphor and a green phosphor. The second layer may include at least one of a yellow phosphor and a blue phosphor. Thereby, since the four phosphors having different colors of the excitation light are included, a novel illumination device with high color rendering properties can be realized. In addition, since the red phosphor or green phosphor whose excitation spectrum exists to a relatively long wavelength side is included in the first layer close to the light emitting element, yellow light or blue light excited in the second layer Re-absorption by the first layer is suppressed, and color misregistration and light flux reduction are reduced.

 It should be noted that any combination of the above-described constituent elements and a representation of the present invention converted between a method, an apparatus, a system, etc. are also effective as an aspect of the present invention.

  According to the present invention, it is possible to realize a bright illumination device with little luminance unevenness.

It is a top view which shows the outline of the illuminating device which concerns on this Embodiment. It is the side view which showed the outline of the light emitting module which concerns on this Embodiment typically. It is AA sectional drawing of the light emitting module shown in FIG. It is a figure which shows an example of the excitation spectrum and emission spectrum of red fluorescent substance used by embodiment. It is a figure which shows an example of the excitation spectrum and emission spectrum of the green fluorescent substance used by embodiment. It is a figure which shows an example of the excitation spectrum of the yellow fluorescent substance used by embodiment, and an emission spectrum. It is a figure which shows an example of the excitation spectrum of the blue fluorescent substance used by embodiment, and an emission spectrum. It is a figure which shows the emission spectrum of the light emitting module which concerns on embodiment. 9A is a cross-sectional view of the light-emitting module according to the present embodiment, FIG. 9B is a cross-sectional view of the dome-shaped light-emitting module, and FIG. 9C is an SMD (Surface Mount Device) type. It is sectional drawing of a light emitting module. It is a figure which shows each illumination intensity distribution of the light emitting module shown to Fig.9 (a)-FIG.9 (c). FIG. 11A is a top view of the lighting device, and FIG. 11B is a cross-sectional view taken along line BB of the lighting device in FIG. FIG. 12A is a diagram showing the luminance distribution of the diffusing plate exit surface of the illuminating device provided with a light emitting module whose H is 10 mm, and FIG. 12B is an illuminating device provided with the light emitting module whose H is 7.5 mm. FIG. 12C is a diagram showing the luminance distribution of the diffusing plate exit surface of the illuminating device provided with the light emitting module whose H is 5 mm.

  The present invention will be described below based on preferred embodiments with reference to the drawings. The same or equivalent components, members, and processes shown in the drawings are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate. Further, the embodiments do not limit the invention but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

  The present invention can be applied to all lamps and lighting fixtures, but is particularly suitable for lighting devices having a wide light emitting surface. In the following description, a lighting device used as studio lighting will be described as an example.

(Lighting device)
FIG. 1 is a top view schematically showing the lighting apparatus according to the present embodiment. In FIG. 1, illustration of a diffusion plate that becomes a light emitting surface of the illumination device is omitted.

  The lighting device 10 according to the present embodiment includes a rectangular resin casing 50, an aluminum bottom plate 52 laid on the bottom of the casing 50, and lines arranged on the bottom plate 52 at intervals. Light-emitting module 110 as a plurality of light sources, and a rectangular plate-shaped transmission member (not shown in FIG. 1) disposed on the front side of the light-emitting surface of light-emitting module 110.

(Light emitting module)
The light-emitting module according to this embodiment includes a plurality of light-emitting elements that emit ultraviolet light or short-wavelength visible light, and a light wavelength conversion layer that emits visible light when excited by light emitted from the light-emitting elements. The light wavelength conversion layer is configured to cover a plurality of light emitting elements. The light wavelength conversion layer includes a first layer and a second layer provided on the opposite side of the light emitting element with the first layer interposed therebetween. The first layer and the second layer include a red phosphor, a green phosphor, a yellow phosphor, and a blue phosphor. The first layer includes at least one of a red phosphor and a green phosphor. The second layer includes at least one of a yellow phosphor and a blue phosphor. The light wavelength conversion layer may be a single layer, and in that case, the light wavelength conversion layer only needs to contain a plurality of kinds (colors) of phosphors whose emission colors are complementary to each other. The light wavelength conversion layer may be, for example, a single layer containing a yellow phosphor and a blue phosphor.

(Light emitting element)
The emission spectrum of the light-emitting element according to this embodiment is not particularly limited as long as it emits at least ultraviolet light or short-wavelength visible light, but from the viewpoint of the light emission efficiency of the light-emitting device, the peak of the emission spectrum. Is preferably in the wavelength region of 350 nm to 430 nm.

  Further, as specific examples of the light emitting element, for example, various light sources such as a semiconductor light emitting element such as an LED, an LD, and an EL, a light source for obtaining light emission from vacuum discharge or thermoluminescence, and an electron beam excitation light emitting element are used. it can. By using a semiconductor light emitting element as the light emitting element, a light emitting device with a small size, power saving, and long life can be obtained. As a suitable example of such a semiconductor light emitting device, an InGaN-based LED or LD having good light emission characteristics in a wavelength region near 400 nm can be given.

(Light wavelength conversion layer)
The light wavelength conversion layer according to the present embodiment is composed of a plurality of layers having different types and amounts of phosphors contained therein. The first layer close to the light emitting element preferably contains at least one of a red phosphor and a green phosphor. The second layer provided on the opposite side to the light emitting element with the first layer interposed therebetween preferably includes at least one of a yellow phosphor and a blue phosphor.

  Since the first layer and the second layer as a whole include at least four phosphors having different excitation light colors (for example, a red phosphor, a green phosphor, a yellow phosphor, and a blue phosphor), color rendering is performed. A highly efficient new light emitting module can be realized. In addition, since the red phosphor or the green phosphor having an excitation spectrum up to a relatively long wavelength side is included in the first layer close to the light emitting element, the first phosphor located farther from the light emitting element than the first layer. The yellow light or blue light excited by the second layer is suppressed from being reabsorbed by the first layer, and color misregistration and a decrease in luminous flux are reduced.

(First layer)
The first layer (i) contains mainly red phosphor and green phosphor, (ii) contains mainly red phosphor, (iii) contains mainly green phosphor, (iv) mainly red phosphor , Including green phosphor and yellow phosphor, (v) mainly including red phosphor, green phosphor and blue phosphor, (vi) mainly including red phosphor and yellow phosphor, (vii) mainly In the case of including a green phosphor and a yellow phosphor, Each phosphor is dispersed in a sealing resin such as silicone or a matrix phase of glass. In the light wavelength conversion layer according to the present embodiment, there may be a case where a phosphor having the same color as the phosphor included in the first layer is included in the second layer. For example, among phosphors of a certain color included in the entire light wavelength conversion layer, the first layer may contain 90% or more and the second layer may contain 10% or less. Alternatively, 95% or more may be contained in the first layer and 5% or less may be contained in the second layer. Alternatively, the first layer may contain 98% or more and the second layer may contain 2% or less.

  The density | concentration of the whole fluorescent substance contained in a 1st layer should just be 0.2 vol% or more, Preferably it is 0.5 vol% or more, More preferably, it is 0.8 vol% or more. When the concentration of the entire phosphor is 0.2 vol% or more, visible light with a sufficient luminous flux can be generated by the light emitted from the light emitting element. Moreover, the density | concentration of the whole fluorescent substance contained in a 1st layer should just be 1.5 vol% or less, Preferably it is 1.3 vol% or less, More preferably, it is 1.1 vol% or less. If the concentration of the entire phosphor is 1.5 vol% or less, the proportion of visible light that is excited by the phosphor is scattered and shielded by other phosphors is reduced, and the decrease in the luminous efficiency of the light emitting module is suppressed. .

(Second layer)
When the second layer includes (i) mainly a blue phosphor and a yellow phosphor, (ii) mainly includes a blue phosphor, a yellow phosphor and a green phosphor, (iii) mainly a blue phosphor and a yellow phosphor And (iv) a case where mainly a blue phosphor is included, and (v) a case where a yellow phosphor is mainly included. Each phosphor is dispersed in a sealing resin such as silicone or a matrix phase of glass. In the light wavelength conversion layer according to the present embodiment, there may be a case where a phosphor having the same color as the phosphor included in the second layer is included in the first layer. For example, among phosphors of a certain color contained in the entire light wavelength conversion layer, the second layer may contain 90% or more and the first layer may contain 10% or less. Alternatively, 95% or more may be contained in the second layer, and 5% or less may be contained in the first layer. Or you may make it contain 98% or more in a 2nd layer, and 2% or less in a 1st layer.

  The density | concentration of the whole fluorescent substance contained in a 2nd layer should just be 0.6 vol% or more, Preferably it is 0.8 vol% or more, More preferably, it is 0.9 vol% or more. When the concentration of the entire phosphor is 0.6 vol% or more, visible light with a sufficient luminous flux can be generated by the light emitted from the light emitting element. On the other hand, if the concentration of the whole phosphor is less than 0.6 vol%, the second layer (phosphor layer) becomes large (thick) in order to ensure sufficient conversion performance, and a large amount as a matrix phase Since materials are required, the cost is high. Moreover, the density | concentration of the whole fluorescent substance contained in a 2nd layer should just be 2.0 vol% or less, Preferably it is 1.5 vol% or less, More preferably, it is 1.2 vol% or less. If the concentration of the whole phosphor is 2.0 vol% or less, the ratio of the visible light excited by the phosphor being scattered and shielded by other phosphors is reduced, and the decrease in the luminous efficiency of the light emitting module is suppressed. .

(First resin layer)
The first resin layer is a matrix phase in which various phosphors contained in the first layer are dispersed. Specifically, as the first resin layer, a silicone resin having a storage elastic modulus of 10 ⁴ to 10 ⁵ Pa at least at any temperature included in the range of −40 to 100 ° C. is preferable. Moreover, the 1st resin layer may be provided so that a conducting wire (bonding wire) may be sealed. Thereby, the stress acting on the conductor can be relaxed.

(Second resin layer)
The second resin layer is a matrix phase in which various phosphors contained in the second layer are dispersed. Specifically, the second resin layer is preferably a silicone resin having a Shore A hardness of 30 to 80. Thereby, the light emitting element is protected in the light emitting module covered with the second resin layer.

(Red phosphor)
The red phosphor emits light having an emission spectrum peak wavelength in the range of 620 nm to 750 nm.
(I) (Ca _1−x Sr _x ) AlSiN ₃ : Eu ²⁺ (0 ≦ x <0.4)
(Ii) Sr ₂ Si ₅ N ₈ : Eu ²⁺
(Iii) (Ca, Sr, Ba) ₃ SiO ₅ : Eu ²⁺
The substance represented by the composition formula of

(Green phosphor)
The green phosphor emits light having an emission spectrum peak wavelength in the range of 495 nm to 570 nm.
(I) (Ba, Sr, Ca) ₂ SiO ₄ : Eu ²⁺
(Ii) (Ba, Sr) ₂ SiO ₄ : Eu ²⁺
(Iii) Sr ₂ SiO ₄ : Eu ²⁺
(Iv) Eu-activated β sialon (v) Ba ₃ Si ₆ O ₁₂ N ₂ : Eu ²⁺
(Vi) SrGa ₂ S ₄ : Eu ²⁺
(Vii) SrSi ₂ O ₂ N ₂ : Eu ²⁺
(Viii) (Ba, Sr) Si ₂ O ₂ N ₂ : Eu ²⁺
(Ix) SrAlO ₄ : Eu ²⁺
(X) (Sr, Ba) Al ₂ Si ₂ O ₈ : Eu ²⁺
(Xi) (Ba, Sr, Ca) ₂ (Mg, Zn) Si ₂ O ₇ : Eu ²⁺
_{(Xii) Sr 2 Si 3 O} 8 -2SrCl 2: Eu 2+
The substance represented by the composition formula of

(Yellow phosphor)
The yellow phosphor emits light having an emission spectrum peak wavelength in the range of 570 nm to 590 nm. For example, the general formula is (M ² x, M ³ y, M ⁴ z) _m M ¹ O ₃ X _{( 2 / n)}
(Here, M ¹ is at least one element including Si selected from the group consisting of Si, Ge, Ti, Zr and Sn, and M ² is at least Ca selected from the group consisting of Ca, Mg, Ba and Zn. M ³ is one or more elements containing at least Sr selected from the group consisting of Sr, Mg, Ba and Zn, X is at least one halogen element, M ⁴ is a rare earth element and Mn 1 or more elements including at least Eu ²⁺ selected from the group consisting of: m is in the range of 0.11 ≦ m ≦ 8/6, n is in the range of 5 ≦ n ≦ 7, and x and y , Z is a range satisfying x + y + z = 1, 0 <x <1, 0 <y <1, 0.01 ≦ z ≦ 0.3).

(Blue phosphor)
The blue phosphor emits light having an emission spectrum peak wavelength in the range of 435 nm to 495 nm, for example,
(I) BaMgAl ₁₀ O ₁₇ : Eu ²⁺
_{(Ii) (Sr, Ca,} Ba) 10 (PO 4) 6 C l2: Eu 2+
(Iii) Ba ₃ MgSi ₂ O ₈ : Eu ²⁺
(Iv) Sr ₃ MgSi ₂ O ₈ : Eu _{2+
(V) SiO 2 -CaI 2:} Eu 2+
(Vi) Sr ₄ Al ₁₄ O ₂₄ : Eu ²⁺
(Vii) (Ba, Sr, Ca) ₂ (B ₅ O ₉ ) X ₂ : Eu ²⁺ (X is a halogen element)
(Viii) (Sr, Ba) ₃ MgSi ₂ O ₈ : Eu ²⁺
The substance represented by the composition formula of

(Other phosphors)
In addition to the above-described phosphors, or in place of some phosphors, an orange phosphor or another color phosphor may be used. The orange phosphor emits light having an emission spectrum peak wavelength in the range of 590 nm to 620 nm.

(Light emitting module manufacturing method)
Next, an example of a method for manufacturing the light emitting module according to the present embodiment will be described. First, one or a plurality of LED chips that emit near-ultraviolet rays or short-wavelength visible light are mounted on a substrate made of alumina, aluminum, glass-reinforced epoxy resin, or the like on which a circuit pattern is formed in advance. The mounting method is performed by, for example, a method in which an LED chip is packaged in advance and then solder-mounted, or a chip-on-board mounting in which an LED chip is bonded to a substrate with a die bonding material and then bonded to a gold wire.

  Immediately above each mounted LED chip, a phosphor that absorbs light emitted from the LED chip and converts it into green light, or a silicone resin that similarly contains a phosphor that converts into red light is mounted.

The mounting of the silicone resin as the first layer is (1) pre-molding the phosphor-containing silicone resin into a sheet and bonding the silicone resin to the substrate, or (2) applying the phosphor-containing silicone to the LED chip. It is carried out by curing after applying a constant amount of drop on the top. In this case, the resin (adhesion of (1), dripping of (2)) in contact with the LED chip has a storage elastic modulus of 10 ⁴ to 10 ⁵ Pa at at least one temperature included in the range of −40 to 100 ° C. A low modulus resin is preferred.

Next, a silicone resin (second layer) in which a blue phosphor or a yellow phosphor is dispersed is mounted. In particular,
(1) On the substrate on which the first layer described above is mounted, a silicone resin in which blue phosphor or yellow phosphor is dispersed is applied so as to have an appropriate thickness in the range of 3 to 15 mm. Heat cure.
(2) The mold is filled with a silicone resin in which a blue phosphor or a yellow phosphor is dispersed, a substrate on which the first layer is mounted is placed in the opening of the mold, and is cured by heating.
(3) Fill a mold with a silicone resin in which a blue phosphor or a yellow phosphor is dispersed, and heat cure. And the hardened | cured molded product is bonded together to the board | substrate which mounted the above-mentioned 1st layer using transparent resin.

  FIG. 2 is a side view schematically showing an outline of the light emitting module according to the present embodiment. FIG. 3 is a cross-sectional view of the light emitting module shown in FIG.

  The light emitting module 110 shown in FIG. 2 includes a ceramic substrate 112, a plurality of nUV-LED chips 14 mounted on the substrate 112 via a resin, a circuit pattern formed on the substrate 112, and the nUV-LED chip 14. A wire 16 made of pure gold and an optical wavelength conversion layer 118 are provided. The nUV-LED chip 14 is an LED chip that emits short-wavelength visible light having a peak in the vicinity of 405 nm.

  The light wavelength conversion layer 118 includes a first layer 120, a second layer 122 provided on the opposite side of the nUV-LED chip 14 across the first layer 120, a first layer 120, a second layer And a transparent layer 124 that joins the layer 122. The first layer 120 is obtained by dispersing the red phosphor 24 and the green phosphor 126 in the first resin layer 21. The second layer 122 is obtained by dispersing the yellow phosphor 30 and the blue phosphor 32 in the second resin layer 28. The transparent layer 124 may contain a phosphor used for the first layer 120 and the second layer 122.

In the present embodiment, the red phosphor 24 ((Ca, Sr) SiAlN is added to the relatively soft silicone resin (I) having a storage elastic modulus of 0.4 MPa so that the concentration of the entire phosphor becomes 1.0 vol%. ₃ : Eu ²⁺ ) and green phosphor 126 (β-sialon) at a weight ratio of 4: 1 and dispersed / vacuum defoamed to prepare a silicone resin (I) coating solution. The mixing ratio of the red phosphor 24 and the green phosphor 126 may be set as appropriate in the range of red phosphor: green phosphor = 65: 35 to 85:15 (weight ratio).

  The substrate 112 according to the present embodiment is a ceramic substrate having a length of 200 mm, and 24 nUV-LED chips 14 are mounted on the mounting surface at an 8 mm pitch. Next, using a dispenser, a silicone resin (I) coating solution in which the amount of the phosphor contained is adjusted is applied so that the nUV-LED chip 14 and the wire 16 on the substrate 112 are sealed, The first layer 20 having a height of 1 mm, a width of 3 mm, and a length of less than 200 mm is formed by heat curing at 150 ° C. for 1 hour. Thereby, the wire 16 is protected.

Next, the blue phosphor 32 ((Ca, Sr) ₅ (PO) is added to a relatively hard silicone resin (II) having a storage elastic modulus of 5.5 MPa so that the concentration of the entire phosphor becomes 1.0 vol%. ₄ ) ₃ Cl: Eu ²⁺ ), yellow phosphor 30 ((Ca, Sr) ₇ (SiO ₃ ) ₆ Cl ₂ : Eu ²⁺ ) are mixed at a weight ratio of 1: 1, and dispersed / vacuum defoamed to obtain a silicone resin. (II) was prepared. Note that the mixing ratio of the blue phosphor 32 and the yellow phosphor 30 may be appropriately set in the range of blue phosphor: yellow phosphor = 50: 50 to 90:10 (weight ratio).

  Next, the silicone resin (II) in which the amount of the contained phosphor is adjusted is formed into a mold having a substantially triangular prism-shaped cavity (see FIG. 3) having an opening width of 10 mm, a depth of 8 mm, and a length of 200 mm. Fill. At this time, vacuum filling may be performed so as not to entrain air.

  Next, the above-described cavity mold filled with the silicone resin (II) is used as a lower mold, and an upper mold that closes the cavity is prepared. The upper mold has a convex shape with a width of 4 to 8 mm and a height of 1 to 3 mm at the center. After these lower and upper molds are clamped, they are placed in a heating furnace and heat treated at 150 ° C. for 1 h to cure the silicone resin, and then demolded to obtain a phosphor-containing silicone molded body.

  Accordingly, the silicone molded body has a groove having a width of 4 to 8 mm and a depth of 1 to 3 mm formed on the lower surface. The groove is filled with an adhesive transparent resin (for example, dimethyl silicone resin is suitable) to be the transparent layer 124, and the substrate 112 on which the first layer 20 is formed is laminated on the transparent layer 124. The transparent resin is cured by heat treatment at 150 ° C. for 1 hour, and the light emitting module 110 is manufactured.

  FIG. 4 is a diagram illustrating an example of an excitation spectrum and an emission spectrum of a red phosphor used in the embodiment. FIG. 5 is a diagram illustrating an example of an excitation spectrum and an emission spectrum of the green phosphor used in the embodiment. FIG. 6 is a diagram illustrating an example of an excitation spectrum and an emission spectrum of a yellow phosphor used in the embodiment. FIG. 7 is a diagram illustrating an example of an excitation spectrum and an emission spectrum of a blue phosphor used in the embodiment.

  As shown in FIG. 4, the peak wavelength λp of the emission spectrum L1 of the red phosphor according to the embodiment is in the range of 625 nm to 635 nm. The excitation end wavelength λe of the excitation spectrum L2 is in the range of 530 nm to 540 nm. Here, the excitation end wavelength λe indicates a wavelength at which the decrease in excitation intensity on the long wavelength side in the excitation spectrum L2 starts to decrease rapidly. The half-value wavelength λh of the excitation spectrum L2 is in the range of 560 nm to 570 nm. Here, the half-value wavelength λh indicates a wavelength at which the intensity Ih is 50% of the peak intensity Imax on the long wavelength side of the excitation spectrum L2.

  As shown in FIG. 5, the peak wavelength λp of the emission spectrum L3 of the green phosphor according to the embodiment is in the range of 520 nm to 530 nm. The excitation end wavelength λe of the excitation spectrum L4 is in the range of 450 nm to 460 nm. The half-value wavelength λh of the excitation spectrum L4 is in the range of 470 nm to 480 nm.

  As shown in FIG. 6, the peak wavelength λp of the emission spectrum L5 of the yellow phosphor according to the embodiment is in the range of 570 nm to 580 nm. The excitation end wavelength λe of the excitation spectrum L6 is in the range of 410 nm to 420 nm. The half-value wavelength λh of the excitation spectrum L6 is in the range of 435 nm to 445 nm.

  As shown in FIG. 7, the peak wavelength λp of the emission spectrum L7 of the blue phosphor according to the embodiment is in the range of 455 nm to 465 nm. The excitation end wavelength λe of the excitation spectrum L8 is in the range of 390 nm to 400 nm. Further, the half-value wavelength λh of the excitation spectrum L8 is in the range of 400 nm to 410 nm.

(Characteristic evaluation)
In the light emitting module in the above-described embodiment, the average color rendering coefficient, color temperature, and chromaticity coordinates (cx, cy) were measured. As a result, a light emitting module having an average color rendering coefficient Ra of 97, a color temperature of 3208K, and chromaticity coordinates (cx, cy) of (0.424, 0.402) was obtained. Thus, the light emitting module 110 according to the embodiment realizes light with a light bulb color and high color rendering properties.

  FIG. 8 is a diagram showing an emission spectrum of the light emitting module according to the embodiment. As shown in FIG. 8, in the light emitting module 110 according to the embodiment, the intensity in the green or red wavelength range of the emission spectrum is larger than the intensity in the yellow or blue wavelength range, and the color rendering property is high and warm. It turns out that light emission of a certain light bulb color is realized.

  As described above, since the light emitting module according to the embodiment includes the red phosphor and the green phosphor in which the excitation spectrum exists up to a relatively long wavelength side in the first layer 20 close to the nUV-LED chip, The yellow light and blue light excited by the second layer are suppressed from being absorbed by the first layer, and color misregistration and a decrease in luminous flux are reduced.

  The first layer may include a red phosphor, and the second layer may include a green phosphor, a yellow phosphor, and a blue phosphor. As a result, the red phosphor having an excitation spectrum up to a relatively long wavelength side is included in the first layer close to the light emitting element, so that yellow light or blue light excited in the second layer is the first. Re-absorption by the layer is suppressed, and a color shift and a decrease in luminous flux are reduced.

  Next, the relationship between the cross-sectional shape of the light emitting module and the illuminance distribution will be described. 9A is a cross-sectional view of the light-emitting module according to the present embodiment, FIG. 9B is a cross-sectional view of the dome-shaped light-emitting module, and FIG. 9C is an SMD (Surface Mount Device) type. It is sectional drawing of a light emitting module.

  The light wavelength conversion layer 118 of the light emitting module 110 shown in FIG. 9A has a width W in a direction intersecting the direction in which the nUV-LED chips 14 are arranged, and is in the main direction of light emitted by the nUV-LED chips 14. When the height is H, H> 0.5W is satisfied.

  The light wavelength conversion layer 132 of the light emitting module 130 shown in FIG. 9B has a width in the direction intersecting with the direction in which the nUV-LED chips 14 are arranged, and W in the main direction of the light emitted by the nUV-LED chips 14. When the height is H, H = 0.5 W is satisfied.

  The light emitting module 140 shown in FIG. 9C includes a blue LED chip 142, a transparent resin 144 in which a concave portion in which the blue LED chip 142 is mounted at the bottom is filled so as to cover the blue LED chip 142, and a transparent resin 144. And a yellow phosphor 146 dispersed in the liquid crystal. The thickness of the transparent resin 144 is about 0.4 mm.

  FIG. 10 is a diagram showing the illuminance distribution of each of the light emitting modules shown in FIGS. 9A to 9C.

  The line L11 shown in FIG. 10 is the illuminance distribution of the SMD type light emitting module shown in FIG. 9C, and the higher the illuminance on the front of the light emitting module and the larger the irradiation angle (the more inclined the front is). Illuminance decreases sharply. That is, the light emitting module 140 has a very high directivity of irradiation light.

  A line L12 illustrated in FIG. 10 is an illuminance distribution of the light emitting module 130 illustrated in FIG. 9B, and a decrease in illuminance when the irradiation angle is larger than that of the light emitting module 140 is reduced. However, there is still room for improvement.

  On the other hand, the line L13 shown in FIG. 10 is the illuminance distribution of the light emitting module 110 shown in FIG. The light wavelength conversion layer 118 of the light emitting module 110 is configured to cover the plurality of nUV-LED chips 14, and is based on the light intensity toward the first irradiation region (irradiation angle 0 degree) on the front surface of the light emitting module 110. In addition, the light emitting module 110 includes an emission surface 118a configured to increase the luminous intensity of light toward the second irradiation region (irradiation angle ± 60 degrees) between the front surface of the light emitting module 110 and the front surface of the adjacent light emitting module 110. Thereby, the light flux of the light which goes to the 2nd irradiation field can be increased.

  Next, characteristics of a lighting device including a plurality of the light emitting modules 110 described above will be described. The following description will be made based on the measurement results of the irradiation performance in the lighting device including the two light emitting modules in the same line form as the light emitting module 110, but the tendency of the irradiation performance is the same as that of the lighting device 10 shown in FIG. is there.

  FIG. 11A is a top view of the lighting device 200, and FIG. 11B is a cross-sectional view taken along line BB of the lighting device 200 in FIG.

  In the illumination device 200, two light emitting modules 210 having a length L of 150 mm are mounted on the bottom of a casing 202 having a width W 'of 50 mm, a length L' of 160 mm, and a height H 'of 15 mm. An interval G between the light emitting modules 210 is 20 mm. In addition, a diffuser plate 204 having a transmittance of 60% is mounted in a housing opening in front of the light emitting side of the light emitting module 210 and at a position away from the light wavelength conversion layer 118. Thereby, an illuminating device with less luminance unevenness can be realized.

  In the illuminating device 200 having such a configuration, the luminance distribution on the exit surface 204a of the diffusion plate 204 when the height H in the main direction of light emitted from the light emitting elements of the light wavelength conversion layer 118 is different was measured.

  FIG. 12A is a diagram showing the luminance distribution of the diffusing plate exit surface of the illuminating device provided with a light emitting module whose H is 10 mm, and FIG. 12B is an illuminating device provided with the light emitting module whose H is 7.5 mm. FIG. 12C is a diagram showing the luminance distribution of the diffusing plate exit surface of the illuminating device provided with the light emitting module whose H is 5 mm.

  As shown in FIG. 12A to FIG. 12C, the difference between the maximum luminance value and the minimum luminance value is about 0.036 to 0.063 when the region where the luminance is maximum is 1. Is kept small. Thereby, if at least the width W of the light wavelength conversion layer 118 is 10 mm and the height H is 5 mm to 10 mm or more, that is, by satisfying H> 0.5 W, the luminance of the emission surface 204a of the diffusion plate 204 is improved. It can be seen that the uniformity can be realized at 0.8 or more. Preferably, the height H should satisfy the range of 6.5 mm to 8.5 mm, that is, H ≧ 0.65. Here, the uniformity can be considered as a ratio between the maximum value of luminance and the minimum value of luminance on the light emitting surface. Alternatively, it may be regarded as the ratio of the average luminance of the light emitting surface to the maximum value of the luminance of the light emitting surface.

  As described above, in the lighting device 200 according to the present embodiment, the plurality of light emitting modules 210 are adjacent to the light from the certain light emitting module 210 toward the second irradiation region (region R2 shown in FIG. 11B). The difference in luminance between the first irradiation region (region R1 shown in FIG. 11B) and the second irradiation region is alleviated by the light traveling from the first to the second irradiation region. Therefore, luminance unevenness on the exit surface 204a side of the diffusion plate 204 is also reduced.

  Thereby, even if a plurality of line-shaped light emitting modules are arranged at a certain interval, a lighting device with little luminance (illuminance) unevenness can be realized. Moreover, since the space | interval between light emitting modules is large to some extent, it is good in heat dissipation, and a bright illuminating device is realizable by using a light emitting module with high output.

  Further, the plurality of light sources may be configured such that the luminance uniformity on the exit surface of the transmission member is 0.6 or more. As a result, it is possible to realize an illumination device with less light emitting elements and less luminance unevenness that is more advantageous in terms of weight, size, and cost.

  In the illuminating device according to the present embodiment, a large and high luminous surface having a width of about 150 to 250 mm and a length of about 250 to 350 mm can be realized. Further, since the interval between the light emitting modules is increased to about 10 to 30 mm, heat dissipation is good, and the heat sink and other heat dissipation mechanisms can be omitted or simplified, which contributes to weight reduction and thinning of the apparatus. Moreover, since the mounting density of the light emitting modules is low and the temperature rise of the lighting device itself can be suppressed, a low-cost resin can be used for the housing, and the handling and transportability can be improved by reducing the weight.

  As described above, the present invention has been described with reference to the above-described embodiment. However, the present invention is not limited to the above-described embodiment, and the present invention can be appropriately combined or replaced with the configuration of the embodiment. It is included in the present invention. In addition, it is possible to appropriately change the combination and processing order in the embodiment based on the knowledge of those skilled in the art and to add various modifications such as various design changes to the embodiment. The described embodiments can also be included in the scope of the present invention.

  DESCRIPTION OF SYMBOLS 10 Illumination device, 14 nUV-LED chip, 16 wires, 20 1st layer, 21 1st resin layer, 24 red fluorescent substance, 28 2nd resin layer, 30 yellow fluorescent substance, 32 blue fluorescent substance, 50 housings Body, 52 bottom plate, 110 light emitting module, 112 substrate, 118 light wavelength conversion layer, 118a emission surface, 120 first layer, 122 second layer, 124 transparent layer, 126 green phosphor, 130 light emitting module, 132 light wavelength Conversion layer, 140 light emitting module, 200 lighting device, 202 housing, 204 diffuser plate, 204a emission surface, 210 light emitting module, R1, R2 region.

Claims (6)

A plurality of linear light sources arranged at intervals, and
A transmissive member disposed on the front side of the plurality of light sources, and a lighting device comprising:
The light source is
A plurality of semiconductor light emitting elements;
A light wavelength conversion layer that emits visible light that is excited by light emitted from the semiconductor light-emitting element,
The light wavelength conversion layer is
It is configured to cover the plurality of semiconductor light emitting elements,
The emission surface configured such that the luminous intensity of the light toward the second irradiation area between the front surface of the light source and the front surface of the adjacent light source is larger than the luminous intensity of the light toward the first irradiation area in front of the light source. Have
The plurality of light sources has a difference in luminance between the first irradiation region and the second irradiation region due to light traveling from the light source toward the second irradiation region and light traveling from the adjacent light source toward the second irradiation region. Is configured to be mitigated,
A lighting device characterized by that.   The lighting device according to claim 1, wherein the transmission member is a diffuser plate provided at a position separated from the light wavelength conversion layer.   The lighting device according to claim 2, wherein the plurality of light sources are configured such that a luminance uniformity on an emission surface of the transmission member is 0.6 or more.   The light wavelength conversion layer has a width H in the direction crossing the direction in which the semiconductor light emitting elements are arranged, and H> 0.5 W, where H is the height in the main direction of light emitted from the semiconductor light emitting elements. The lighting device according to claim 1, wherein the lighting device is satisfied. The semiconductor light emitting element emits ultraviolet light or short wavelength visible light,
The light wavelength conversion layer is
A first phosphor that emits visible light when excited by the ultraviolet or short wavelength visible light;
2. A second phosphor that emits visible light of a color different from the visible light that is excited by the ultraviolet light or short-wavelength visible light and that emits light from the first phosphor. The lighting device according to any one of 1 to 4. The semiconductor light emitting element emits ultraviolet light or short wavelength visible light,
The light wavelength conversion layer is
A first layer, and a second layer provided on the opposite side of the light emitting element across the first layer,
The first layer and the second layer include a red phosphor, a green phosphor, a yellow phosphor and a blue phosphor,
The first layer includes at least one of the red phosphor and the green phosphor,
The second layer includes at least one of the yellow phosphor and the blue phosphor.
The lighting device according to any one of claims 1 to 4, wherein

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