JP2014199831A - Light-emitting device, phosphor sheet, backlight system, and process of manufacturing light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-emitting device using a phosphor sheet, with reduced loss of light emitted from a fluorescent material, excellent in ideal color rendering and color reproducibility.SOLUTION: The light-emitting device includes: a light-emitting element that emits primary light; and a phosphor sheet that absorbs part of the primary light and emits secondary light. A light reflection member is disposed at a side part of the phosphor sheet.

Description

  The present invention relates to a light-emitting device used for lighting or a display, and in particular, light emission using a phosphor sheet containing light directly output from a light source and a phosphor excited by a part of the light output from the light source. The present invention relates to a device and a backlight system using the same.

  In recent years, attention has been focused on LED backlights and LED bulbs of liquid crystal displays as light emitting devices using light emitting diodes (hereinafter referred to as LEDs). LEDs have excellent characteristics such as low power consumption, long product life, and small influence on the environment. The light emitting part of the LED backlight or the LED bulb emits a combination of light obtained by wavelength-converting part of the LED light and light not wavelength-converted by the LED phosphor. Various light different from light can be emitted. Such a light-emitting device is highly expected as a light-emitting device that replaces the conventional lighting and backlights of displays, and various developments have been made.

  In general, when a light emitting device is configured with a blue LED chip and a phosphor, a first method is to cover the blue LED chip by mixing the phosphor with a resin material, and a second method is a light emitting surface of the blue LED chip. There are various methods such as a method of directly applying the phosphor and a third method such as a method of placing a phosphor-containing sheet on a blue chip. The most commonly used method is the first method. However, in the case of the first method and the second method, heat due to the light emission of the blue LED directly affects the phosphor, so that depending on the type of the phosphor, the heat may cause deterioration. In particular, the nanocrystalline phosphor has high emission intensity and excellent color rendering and color reproducibility, but has a low heat-resistant temperature and is easily affected by heat. In addition, the surface where the phosphor is in contact with the outside is easily affected by oxygen and moisture, causing deterioration of the phosphor. Further, the resin may be deteriorated or discolored.

  For these reasons, a phosphor sheet in which a phosphor or a resin containing the phosphor is sandwiched by the third method, such as glass or organic glass, has attracted attention. The phosphor sheet is easy to handle and is not easily affected by oxygen or moisture, and can be provided separately from the light emitting element, so that it is not directly affected by heat.

  FIG. 12 is a schematic view of the light emitting device disclosed in Patent Document 1. The light emitting device 80 disclosed in the patent document includes a light emitting element 81 that emits primary light, and a silicone that includes a phosphor that absorbs part of the primary light and emits secondary light having a wavelength equal to or greater than the wavelength of the primary light. A phosphor sheet 82 made of resin, and the phosphor sheet 82 includes two types of phosphors 83 and 84 having different excitation wavelength ranges.

  FIG. 13 is a schematic view of the light emitting device disclosed in Patent Document 2. As shown in FIG. The light emitting device 90 disclosed in the patent document is formed of a material in which a phosphor 94 is sandwiched between light-transmitting plate materials 93 and sealed with a sealing material 95 on an upper surface of a substrate 92 on which a light emitting element 91 is placed. A sheet-like phosphor is mounted via a reflection frame 96.

  With the above structure, a light-emitting device which is hardly affected by oxygen, moisture, or heat and has little deterioration can be obtained.

JP 2005-244075 (published September 8, 2005) JP2007-317787 (released on December 6, 2007)

  However, when the light-emitting device in Patent Document 1 or Patent Document 2 is actually made to emit light, the light emission from the phosphor is lower than the directivity of the light-emitting element, so that the light from the light-emitting element passes through the phosphor sheet. In doing so, the wavelength-converted light of the phosphor is emitted in all directions, and part of the light is emitted from the side surface of the phosphor sheet. For this reason, when it is desired to irradiate the light of the light emitting device in a desired direction and space, the amount of light emitted from the phosphor may be reduced. Further, since there is light leaking from the side, there is a possibility that the color balance may be lost, and it is not possible to obtain the originally required color shade. Therefore, it is difficult to obtain ideal color reproducibility and brightness.

  The present invention has been made in view of the above-mentioned problems, and its purpose is to reduce loss of light amount emitted from the phosphor in a light emitting device using the phosphor sheet, and to achieve ideal color rendering and color reproduction. The object is to provide a light emitting device having excellent properties.

  A light-emitting device according to the present invention includes a light-emitting element that emits primary light and a phosphor sheet that absorbs part of the primary light and emits secondary light, and includes a side portion of the phosphor sheet. A light reflecting member is disposed on the surface. The phosphor sheet may be characterized in that a phosphor is sandwiched between transparent plate-like members. The area of the emission surface of the phosphor sheet may be larger than the area of the incident surface of the primary light. The phosphor sheet includes at least two kinds of phosphors, and the phosphors are arranged from the side closer to the light emitting element in order of phosphors emitting secondary light having a relatively long wavelength. This may be a feature. Further, at least one of the phosphors may be a phosphor made of nanocrystals.

  The phosphor sheet according to the present invention is a phosphor sheet used in a light emitting element that emits primary light and a light emitting device that absorbs a part of the primary light and emits secondary light. A light reflecting member is disposed on the side portion of the first member. The phosphor sheet may be characterized in that a phosphor is sandwiched between transparent plate-like members. The area of the emission surface of the phosphor sheet may be larger than the area of the incident surface of the primary light. The phosphor sheet includes at least two kinds of phosphors, and the phosphors are arranged from the side closer to the light emitting element in order of phosphors emitting secondary light having a relatively long wavelength. This may be a feature. Further, at least one of the phosphors may be a phosphor made of nanocrystals.

  In addition, a backlight system according to the present invention uses any of the light emitting devices described above.

  ADVANTAGE OF THE INVENTION According to this invention, in the light-emitting device using a fluorescent substance sheet, the loss of the light quantity emitted from a fluorescent substance can be reduced, and the light-emitting device excellent in ideal color rendering properties and color reproducibility can be obtained.

1 is a cross-sectional view of a light emitting device according to Embodiment 1. FIG. It is the schematic and sectional drawing of a fluorescent substance sheet. It is a figure which shows the manufacturing method of a fluorescent substance sheet. It is sectional drawing which shows the example of installation of a fluorescent substance sheet. It is a figure explaining the motion of the light of a fluorescent substance sheet. 6 is a cross-sectional view of a light emitting device according to Embodiment 2. FIG. It is a figure which shows the manufacturing method of a fluorescent substance sheet. It is sectional drawing which shows the example of installation of a fluorescent substance sheet. It is sectional drawing of the light-emitting device which concerns on Embodiment 3. FIG. It is sectional drawing of the light-emitting device which concerns on Embodiment 4. FIG. 6 is a cross-sectional view of a light emitting device according to Embodiment 5. FIG. It is the schematic of the conventional light-emitting device. It is the schematic of the conventional light-emitting device.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. In the drawings of the present invention, the same reference numerals represent the same or corresponding parts. In this specification, “nanocrystal” refers to a crystal in which the crystal size is reduced to about the exciton Bohr radius, and exciton confinement or band gap increase due to the quantum size effect is observed.

<Embodiment 1>
FIG. 1 is a cross-sectional view of a light emitting device 10 according to the present embodiment. The light emitting device 10 faces the substrate 2 on which the electrode 1 is formed, the package 3 and the light emitting element 4 provided on the electrode 1, the wire 5 that connects the light emitting element 4 and the electrode 1, and the light emitting element 4. The phosphor sheet 6 is arranged. And the fluorescent substance sheet 6 concerning a present Example is comprised by the transparent plate-shaped members 61 and 63, the fluorescent substance layer 62, and the light reflection member 64, It is characterized by the above-mentioned.

  The conductor forming the electrode 1 has a function as a conductive path for electrically connecting the light emitting element 4, and is electrically connected to the light emitting element 4 by a wire 5. As the conductor, for example, a metallized layer containing metal powder such as W, Mo, Cu, or Ag can be used. Since the substrate 2 is required to have high thermal conductivity and a high total reflectance, for example, a polymer resin in which metal oxide fine particles are dispersed in addition to a ceramic material such as alumina or aluminum nitride is suitable. Used.

  The package 3 is made of polyphthalamide or the like having high reflectance and good adhesion to the sealing resin. The light-emitting element 4 is used as a light source and preferably has a peak wavelength in the range of 360 nm to 470 nm. For example, a GaN-based light-emitting diode, a ZnO-based light-emitting diode, or an organic EL having a peak wavelength at 450 nm can be used. .

  2A is a perspective view of the phosphor sheet 6, and FIG. 2B is a cross-sectional view. The phosphor sheet 6 includes transparent plate members 61 and 63, a phosphor layer 62, and a light reflecting member 64.

  The transparent plate-like members 61 and 63 are transparent in the visible region and desirably have high strength, and organic glass such as glass mainly composed of silicate and polycarbonate can be used. Since glass containing silicic acid as a main component has a high barrier property against gas moisture, it is possible to suppress deterioration of the phosphor and resin due to oxygen and moisture adhering to the phosphor layer 62. Moreover, organic glass has a softness | flexibility and can provide the flexible fluorescent substance sheet 6. FIG. The transparent plate members 61 and 63 may be formed of the same material or different materials.

  Of the glass containing silicate as a main component, quartz glass is preferably used. This is because quartz glass has a transmittance of about 95% in a wavelength region of 250 nm or more, and thus easily transmits LED light and fluorescence. Moreover, in the said organic glass, it is preferable to use PMMA (polymethyl methacrylate). PMMA has high weather resistance among organic glasses, so that deterioration such as coloring hardly occurs and it can be used for a long time.

  The phosphor layer 62 is composed of a resin layer containing a phosphor. Any phosphor may be used as long as it is a general phosphor. For example, a phosphor made of nanocrystals, a rare earth activated phosphor or a transition metal element activated phosphor can be used.

  Among these, it is particularly preferable to use a phosphor made of nanocrystals. The reason is that the nanocrystal is smaller than the wavelength of visible light and does not scatter the primary light emitted by the light emitting element (Mie scattering), so the directivity of the primary light is not lowered. For example, an InP-based nanocrystal can be used as the phosphor made of nanocrystals. When the particle size of InP is reduced (nanocrystallization), the band gap can be controlled in the range from blue to red by the quantum effect. For example, an InP-based nanocrystal having a particle size that emits green light and a particle size that emits red light is mixed and cured in a silicone resin or an acrylic resin.

  In addition, as a phosphor material, a phosphor that is a nanocrystal made of a group III-V compound semiconductor or II-VI compound semiconductor other than InP may be used. For example, as a nanocrystalline compound semiconductor composed of a II-VI group compound semiconductor or a III-V group compound semiconductor, in a binary system, as a II-VI group compound semiconductor, CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgSe, HgTe, PbSe, PbS etc. are mentioned. Examples of the III-V group compound semiconductor include GaN, GaP, GaAs, AlN, AlP, AlAs, InN, InP, InAs, and the like.

  In ternary and quaternary systems, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgSe, CdHgSe, CdHgSe, CdHgSe, CdHgSe, CdHgSe, CdHgSe, CdHgSe, CdHgSe , CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTTe, HgZnSeS, HgZnSeTe, HgZnSTe, GaNP, GaNAs, GaPAs, AlNP, AlNAs, AlPAs, InNP, InNAs, InPAs, InGaN, GaAlNP , InAlPAs etc. It is.

  And as said fluorescent substance, it is preferable to use the nanocrystal containing In and P or the nanocrystal containing Cd and Se. This is because a nanocrystal containing In and P or a nanocrystal containing Cd and Se can easily produce a nanocrystal having a particle size that emits light in the visible light region (380 nm to 780 nm). Among them, it is particularly preferable to use InP or CdSe. The reason for this is that InP and CdSe are easy to manufacture because of the small amount of constituent materials, and also show high quantum yield, and show high luminous efficiency when irradiated with LED light. Here, the quantum yield is the ratio of the number of photons emitted as fluorescence to the number of absorbed photons. Furthermore, it is preferable to use InP which does not contain Cd which shows strong toxicity as the phosphor.

  The light reflecting member 64 can be made of silver or aluminum having a high reflectance. Silver has a light reflectance of about 98% in the wavelength region of 450 nm to 700 nm, and aluminum has a light reflectance of about 90% in the wavelength region of 280 nm to 1000 nm, both of which have a high reflectance. Light and secondary light can be reflected without waste.

  Next, a method for manufacturing the light emitting device 10 will be described below. FIG. 3 is a diagram illustrating a manufacturing process of the phosphor sheet 6 used in the light emitting device 10. First, as shown in FIG. 3A, a silicone resin containing a predetermined amount of a nanocrystalline phosphor emitting red light and a nanocrystalline phosphor emitting green light is applied to the transparent plate member 61 to a thickness of 300 μm. Layer 62 is formed. This time, the transparent plate-like member 61 is made of quartz glass having a thickness of 1 mm. SCR1011 manufactured by Shin-Etsu Chemical Co., Ltd. was used as the silicone resin. Other than SCR 1011, any resin can be used as long as it is a resin in which the nanocrystalline phosphor is uniformly dispersed and is transparent and resistant to heat and light.

  Next, as shown in FIG. 3B, a transparent plate member 63 is placed on the phosphor layer 62 and cured at room temperature. This time, the transparent plate-like member 61 is made of quartz glass having the same thickness as the transparent plate-like member 63. In this way, the phosphor sheet 6 is formed.

  Next, as shown in FIG.3 (c), the light reflection member 64 is formed in the side surface of the fluorescent substance sheet 6 by forming silver into a film using a resistance heating type vacuum evaporation system. This time, the thickness of silver was 200 nm.

  Next, as shown in FIG. 1, an LED package including an electrode 1, a substrate 2, a package 3, a light emitting element 4, and a wire 5 is prepared, and the phosphor sheet prepared by the above method on the LED package. 6 is installed.

  FIG. 4 shows a state in which the phosphor sheet 6 is installed in the package 3. FIG. 4A shows an example in which an adhesive 31 is applied to the upper surface of the package 3 and the phosphor sheet 6 is placed thereon. The adhesive 31 may be any adhesive as long as the phosphor sheet 6 and the package 3 are securely fixed, but a silicone adhesive is preferable. Alternatively, as shown in FIG. 4B, a method may be used in which a base 32 on which the phosphor sheet 6 is accommodated is installed on the upper surface of the package 3 and the phosphor sheet 6 is fitted into the base 32. Alternatively, the surface in contact with the side surface of the phosphor sheet 6 in the base 32 may have a shape that covers all the side surfaces of the phosphor sheet 6, and this surface may be covered with a light reflecting member 64 such as silver. In this case, in the production of the phosphor sheet 6 shown above, the step of forming the light reflecting member 64 can be omitted. Further, as shown in FIG. 4 (c), the upper surface of the package 3 may be processed in advance so that the phosphor sheet 6 can be accommodated, and the phosphor sheet 6 may be fitted into that portion. The light emitting device 10 is manufactured by the above procedure.

  According to this embodiment, among the secondary light emitted from the phosphor, the component irradiated in the unnecessary direction is reflected by the light reflecting member 64, so that the secondary light is irradiated in the direction of the target without waste. Can be made.

  Here, the effect of the light reflecting member 64 will be described in detail. FIG. 5 schematically shows the movement of light on the upper surface portion of the phosphor sheet 6 when the phosphor 65 that has absorbed the primary light emitted from the light emitting element 4 emits secondary light. In practice, light refraction occurs between the phosphor layer and the transparent plate-like member, and between the transparent plate-like member and the outside air. However, in this schematic diagram, the light refraction at this portion is omitted. Yes.

  FIG. 5A shows a phosphor sheet 6 used in the light emitting device 10 according to this embodiment, and FIG. 5B shows a phosphor sheet 7 used in a conventional light emitting device 70. The only difference between the phosphor sheet 6 and the phosphor sheet 7 is whether or not the light reflecting member 64 is provided, and the other configuration is the same. In this embodiment, quartz is used for the transparent plate members 61 and 63, and silicone (SCR 1011) is used for the resin of the phosphor layer 62. Quartz has a refractive index of about 1.54 and silicone (SCR 1011) has a refractive index of about 1.53. Thus, in order to prevent a loss of light amount due to light refraction, it is desirable that the resin used in the phosphor layer and the transparent plate-like member have the same refractive index as close as possible. In addition, when the transparent plate-like members 61 and 63 are acrylic glass such as PMMA, the refractive index is the same or close if the resin used in the phosphor layer 62 is also made of the same acrylic. Specifically, PLMA (polylauryl methacrylate) or PMMA may be used.

  In FIG. 5A, the primary light L8 emitted from the light emitting element is absorbed by the phosphor 65, and the phosphor 65 emits secondary lights L1 to L5. Among these, the secondary lights L2 to L4 are emitted from the light emitting device 10 as they are. As an example, as shown in FIG. 5A, the secondary light L <b> 1 travels while reflecting inside the phosphor layer 62, is reflected by the light reflecting member 64, and is emitted from the light emitting device 10. As an example, as shown in FIG. 5A, the secondary light L5 travels while reflecting inside the upper and lower transparent plate-like members 61 and 63 and the phosphor layer 62 sandwiched therebetween, and the light reflecting member 64. And is emitted from the light emitting device 10.

  Here, FIG. 5B will be described as a comparative example. In FIG. 5B, the primary light L8 emitted from the light emitting element is absorbed by the phosphor 65, and the phosphor 65 emits secondary lights L1 to L5. Among these, the secondary lights L2 to L4 are emitted from the light emitting device 70 as they are. As an example, as shown in FIG. 5B, the secondary light L <b> 1 travels while reflecting the inside of the phosphor layer 62 and is emitted from the side surface of the phosphor sheet 7. As an example, as illustrated in FIG. 5B, the secondary light L <b> 5 travels while reflecting inside the upper and lower transparent plate-like members 61 and 63 and the phosphor layer 62 sandwiched therebetween, and the phosphor sheet 7. The light is emitted from the side surface.

  In this way, the secondary light L1 and L5 are not irradiated to the irradiated object provided facing the light emitting device 70, and the amount of light irradiated to the irradiated object is reduced. Therefore, by using the light reflecting member 64 in the immediate part of the phosphor sheet, it is possible to prevent a decrease in the amount of light applied to the irradiated object.

<Embodiment 2>
Next, Embodiment 2 will be described with reference to FIG. The present embodiment is different from the first embodiment in that the phosphor layer 62 is sandwiched between transparent plate-like members 61 and 63 having different areas. The light emitting device 20 shown in FIG. 6 has a configuration in which the area of the light emitting surface A in the transparent plate member 63 is larger than the area of the primary light incident surface B in the transparent plate member 61.

  Next, a method for manufacturing the light emitting device 20 will be described below. FIG. 7 is a diagram illustrating a manufacturing process of the phosphor sheet 6 used in the light emitting device 20. First, as shown in FIG. 7A, a metal mold 600 is prepared. The cross-sectional shape of the mold 600 has a trapezoidal shape with a wide upper portion and a narrow lower portion. The angle of the oblique side of the trapezoidal shape is determined by the required shape of the light emitting sheet 6. Next, as shown in FIG. 7B, a silicone resin is poured into the mold as the transparent plate member 61 and cured. In addition to this, organic glass is preferable as the transparent resin member 61 and the transparent resin member 63 described later. Organic glass, like resin, can be poured into a mold and cured.

  Next, as shown in FIG. 7C, a resin containing a nanocrystalline phosphor is applied on the transparent plate member 61 as the phosphor layer 62, and transparent as shown in FIG. 7D. Silicone resin is poured as the resin member 63. After the curing of the resin is completed, the mold is removed as shown in FIG. 7E, and silver is deposited as a light reflecting member 64 on the side surface as shown in FIG. 7F. The silver deposition method is the same as that of the first embodiment.

  In addition, without performing the process of vapor-depositing silver shown in FIG.8 (f), in the state which arrange | positioned materials, such as silver beforehand, as the light reflection member 64 in the side surface of the metal mold | die 600 in FIG. It does not matter if the method is used. In this case, by making the light reflecting member 64 longer than the thickness of the phosphor sheet 6, it is possible to irradiate the secondary light in the target direction more efficiently.

  FIG. 8 shows a state in which the phosphor sheet 6 is installed in the package 3. FIG. 8A shows the case where the adhesive 31 is applied to the upper surface of the package 3 and the phosphor sheet 6 is placed thereon. The adhesive 31 may be any adhesive as long as the phosphor sheet 6 and the package are securely fixed, but a silicone adhesive is preferable.

  Alternatively, as shown in FIG. 8B, a method may be used in which a base 33 on which the phosphor sheet 6 is accommodated is installed on the upper surface of the package 3 and the phosphor sheet 6 is fitted into the base 33. Alternatively, the surface of the table 33 that contacts the side surface of the phosphor sheet 6 may be covered with a light reflecting member 64 such as silver. In this case, in the production of the phosphor sheet 6 shown above, the step of forming the light reflecting member 64 can be omitted. Further, in this case, by making the surface in contact with the side surface of the phosphor sheet 6 longer than the side surface of the phosphor sheet 6 in the table 33, the secondary light can be irradiated in the target direction more efficiently.

  Further, as shown in FIG. 8 (c), the upper surface of the package 3 may be processed in advance so that the phosphor sheet 6 can be accommodated, and the phosphor sheet 6 may be fitted into that portion. The light emitting device 20 is manufactured by the above procedure.

  By adopting such a configuration, the component that is irradiated in the unnecessary direction among the secondary light of the phosphor is reflected by the light reflecting member 64, and the light of the secondary light is irradiated in the direction of the target without waste. Can do. Since the area of the light emitting surface A in the transparent plate-like member 63 is larger than the area of the incident surface B of the primary light in the transparent plate-like member 61, the light is converted downward in the light whose wavelength is converted by the phosphor. Since part of the traveling light can be reflected upward, a brighter light emitting device can be obtained as compared with the first embodiment.

<Embodiment 3>
Next, a third embodiment will be described with reference to FIG. This embodiment is different from Embodiments 1 and 2 in that two resin layers containing different nanocrystalline phosphors are laminated. In the light emitting device 30 illustrated in FIG. 9, a resin layer 621 including a nanocrystalline phosphor that emits red light and a resin layer 622 including a nanocrystalline phosphor that emits green light are stacked in the order of the optical path of the primary light emitted from the light emitting element 4. .

  The reason for this configuration is that the phosphor absorbs light having energy larger than the respective excitation energy, and develops secondary light as fluorescence. For example, secondary light emitted from a phosphor having a large excitation energy such as a blue phosphor is absorbed by a phosphor having a small excitation energy such as a red phosphor, and it becomes difficult to obtain a desired color balance. . In such a case, the secondary light emitted from each phosphor is mostly absorbed again by the phosphors emitting other colors by laminating in order of the phosphors having the long peak wavelengths in the order of the optical path of the primary light. The desired color balance can be easily obtained.

<Embodiment 4>
Next, a fourth embodiment will be described with reference to FIG. In the present embodiment, unlike the first and second embodiments, the phosphor layer is sandwiched between the transparent plate-like members 61 and 63 having different areas, in that two resin layers containing nanocrystalline phosphors are laminated. This is different from the first and third embodiments. In the light emitting device 40 illustrated in FIG. 10, a resin layer 621 including a nanocrystalline phosphor that emits red light and a resin layer 622 including a nanocrystalline phosphor that emits green light are stacked in the order of the optical path of the primary light emitted from the light emitting element 4. .

  By adopting such a configuration, as in the third embodiment, the secondary light emitted from each phosphor is hardly absorbed again by the phosphors emitting other colors, and the desired color balance can be easily achieved. Can be obtained. Furthermore, as in the second embodiment, part of the light traveling downward in the secondary light of the phosphor can be reflected upward by the light reflecting member 64, so that a bright illumination device without loss can be obtained. Can do.

<Embodiment 5>
Next, a side edge type backlight system according to the present invention will be described with reference to FIG. The side edge type backlight system in the present embodiment includes a light emitting device 10, a light guide plate 7, and a reflection plate 8. In the present embodiment, the primary light and the secondary light emitted from the light emitting device 10 enter the light guide plate 7 and are reflected by the reflection plate 8, so that the primary light and the secondary light are transmitted from the surface facing the reflection plate 8. It has a structure to take out.

  By covering the cross section of the phosphor sheet with the light reflecting member 64, it is possible to reduce the loss of light emitted outside without being incident on the light guide plate 7, as compared with the conventional case. Therefore, for example, when this embodiment is adopted in a television backlight system, the brightness of the television can be improved. In the present embodiment, an example in which the lighting device of the present invention is used for a side-edge type backlight has been described. However, the present invention is not limited to this, and for example, it can be used as a direct type backlight. Although the light emitting device 10 is used in the present embodiment, any light emitting device described in the above embodiment may be used.

  As described above, in the light emitting device using the phosphor sheet, by using the light reflecting member, the loss of the amount of light emitted from the phosphor is reduced, and the light emitting device is bright and has excellent ideal color rendering and color reproducibility. Was able to be realized.

  The light emitting device according to the present invention can be suitably used for a light emitting device including a semiconductor light emitting element that emits primary light and a phosphor sheet that includes a phosphor that absorbs the primary light and emits secondary light.

DESCRIPTION OF SYMBOLS 1 Electrode 2 Board | substrate 3 Package 4 Light emitting element 5 Wire 6, 7 Phosphor sheet 7 Light guide plate 8 Reflecting plate 10, 20, 30, 40 Light emitting device 61, 63 Transparent plate member 62 Phosphor layer 64 Light reflecting member 600 Mold

Claims (11)

A light emitting element that emits primary light;
In a light emitting device including a phosphor sheet that absorbs a part of the primary light and emits secondary light,
A light-emitting device, wherein a light reflecting member is disposed on a side portion of the phosphor sheet.   The light emitting device according to claim 1, wherein the phosphor sheet has a phosphor sandwiched between transparent plate-like members.   The light emitting device according to claim 1 or 2, wherein an area of an emission surface of the phosphor sheet is larger than an area of an incident surface of the primary light. The phosphor sheet includes at least two kinds of phosphors,
The light emitting device according to any one of claims 1 to 3, wherein the phosphors are arranged in order of phosphors emitting secondary light having a relatively long wavelength from a side closer to the light emitting element. .   5. The light emitting device according to claim 1, wherein at least one of the phosphors is a phosphor made of nanocrystals. A light emitting element that emits primary light;
In the phosphor sheet used in the light emitting device that absorbs part of the primary light and emits secondary light,
A phosphor sheet, wherein a light reflecting member is disposed on a side portion of the phosphor sheet.   The phosphor sheet according to claim 6, wherein the phosphor sheet has a phosphor sandwiched between transparent plate-like members.   The phosphor sheet according to claim 6 or 7, wherein an area of an emission surface of the phosphor sheet is larger than an area of an incident surface of the primary light. The phosphor sheet includes at least two kinds of phosphors,
The phosphor according to any one of claims 6 to 8, wherein the phosphors are arranged in the order of phosphors emitting secondary light having a relatively long wavelength from the side closer to the light emitting element. Sheet.   The phosphor sheet according to claim 6, wherein at least one of the phosphors is a phosphor made of nanocrystals.   6. A backlight system for video equipment, wherein the light-emitting device according to claim 1 is used.