JP2015227252A - Glass composition for fluophor dispersion glass sheet and glass sheet using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glass composition used for production of a fluophor dispersion glass sheet having less included bubbles in the glass sheet, and having high LED light emission efficiency in burning under the atmosphere.SOLUTION: Provided is a glass composition for fluophor dispersion glass sheet including a glass powder and fluophor powder, in which difference (ΔTgs) between Ts and Tg calculated from a DTA curvature of the glass powder is 50-105°C.

Description

  The present invention relates to a light conversion member for converting blue light of a blue light source, particularly a blue light emitting diode (LED) element, into white.

  The white LED is used as a white illumination light source with a minute electric power, and is expected to be applied to illumination applications. The white light of the white LED is obtained by synthesizing blue light emitted from a blue LED element and yellow light obtained by converting a part of the blue light into yellow with a phosphor.

  Conventionally, as a light conversion member, a phosphor-dispersed glass sheet (hereinafter also referred to as a glass sheet) having a configuration in which an inorganic phosphor is dispersed in glass is known (for example, Patent Document 1). By adopting such a configuration, the high transmittance of the glass can be used, and furthermore, the heat generated from the element can be efficiently released to the outside of the member. Moreover, the damage of the member by light and a heat | fever is also low, and long-term reliability is acquired.

  The glass sheet is produced by mixing glass powder and phosphor powder and firing the mixture. Conventionally, there has been a problem that bubbles generated in the baking process remain in the glass. If there are bubbles in the glass (hereinafter referred to as encapsulated bubbles), the transmittance of the glass is lowered, causing a reduction in the luminous efficiency of the LED. In addition, the encapsulated foam may cause light to scatter in the glass and reduce the amount of light striking the phosphor.

Patent Document 2 describes a method of using a SiO ₂ —B ₂ O ₃ -based glass and a SnO—P ₂ O ₅ -based glass and performing a firing step under reduced pressure in order to reduce encapsulated bubbles. . However, in the baking under a reduced pressure atmosphere, the encapsulated foam can be reduced, but depending on the glass composition, the component may be volatilized. Further, in a glass having a high softening point such as SiO ₂ —B ₂ O ₃ glass, the firing temperature becomes high, and the phosphor may be deteriorated.

JP 2003-258308 A JP 2007-311743 A

In view of the above problems, the present inventors use a glass having a low glass softening point, thereby lowering the firing temperature to prevent the phosphor from being deteriorated, and exhibiting a glass having a steep viscosity curve in the firing temperature range. It has been found that the encapsulated foam in the glass sheet after firing can be reduced by using it, and the present invention has been achieved.
That is, this invention aims at provision of the glass composition which can manufacture the fluorescent substance dispersion | distribution glass sheet with few inclusion bubbles of a glass sheet, and high transmittance | permeability at low temperature.

  The glass composition of the present invention is a glass composition for a phosphor-dispersed glass sheet containing glass powder and phosphor powder, and the difference (ΔTgs) between Ts and Tg calculated from the DTA curve of the glass powder is 50 to 105 ° C.

  The glass composition for a phosphor-dispersed glass sheet of the present invention can lower the firing temperature and can further reduce the encapsulated foam of the glass sheet after firing. Due to the low temperature firing, it is possible to suppress the deterioration of the phosphor in the manufacturing process. Furthermore, light scattering inside the glass sheet can be suppressed, the transmittance of the glass sheet can be increased, and the luminous efficiency of the LED can be increased.

Sectional drawing of a fluorescent substance dispersion | distribution glass sheet.

  The influence on the light emission efficiency of the LED due to the presence of the encapsulated foam of the glass sheet will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view of a phosphor-dispersed glass sheet 2 on a light-emitting element 1.

  FIG. 1A shows a case where there are no encapsulated bubbles around the phosphor 3 and between the light emitting element 1 and the phosphor 3. Since the light emitted from the element is not scattered in the glass sheet, the decrease in the amount of light passing through the glass sheet is small. Therefore, the luminous efficiency of the LED is high. Further, the light 5 emitted from the light emitting element 1 efficiently hits the phosphor 3 and is converted into fluorescence 7. Therefore, a decrease in the conversion efficiency of the phosphor 3 is small.

  FIG. 1B shows a case where the enclosing bubble 4 is in contact with the phosphor 3. In this case, light is easily reflected at the interface between the encapsulated bubble 4 and the glass 6, and part of the light 5 becomes scattered light 8. Furthermore, if the encapsulated foam 4 is present, multiple scattering tends to occur within the glass sheet. When multiple scattering is performed, the optical path length becomes long, light is attenuated in the glass sheet, the amount of light transmitted through the glass sheet is reduced, and the light emission efficiency of the LED may be lowered. Further, when the amount of light hitting the phosphor 3 is reduced, the amount of the fluorescence 7 is reduced, and the conversion efficiency may be reduced.

  FIG. 1 (c) shows a case where there is an encapsulated bubble but it does not contact the phosphor 3 and there is an encapsulated bubble 4 between the light emitting element 1 and the phosphor 3. Similar to FIG. 1B, when the encapsulated foam 4 enters the glass 6 and when the encapsulated foam 4 exits the glass 6, the light 5 is reflected at the interface. That is, light is scattered and part of the encapsulated foam 4 becomes scattered light 8. If the light is scattered in the glass sheet, the light emission efficiency of the LED may be reduced as in the case of FIG. Further, when the amount of light hitting the phosphor 3 is reduced, the amount of the fluorescence 7 is reduced, and the conversion efficiency may be reduced.

  Light 5 and fluorescence 7 emitted from the element are transmitted through the glass sheet and emitted. When these light is multiple-scattered and back-reflected by the encapsulated bubbles, there is a possibility that the light is attenuated in the glass sheet. The degree of multiple scattering and back reflection can be evaluated by the total light transmittance. That is, if excessive multiple scattering and back reflection do not occur, the total light transmittance is high and the loss of light while passing through the glass sheet is small.

  From the above, if the encapsulated foam 4 is present in the glass sheet 2, the light is attenuated in the glass sheet and the transmittance is lowered, and the light striking the phosphor 3 is reduced and the conversion efficiency of the phosphor is lowered. Thereby, the luminous efficiency of LED falls. Therefore, the LED conversion member is required to reduce the encapsulated foam 4 of the glass sheet 2.

  Next, embodiments of the glass composition of the present invention (hereinafter referred to as the present glass composition) will be described. This glass powder has the characteristics that the rate of change in viscosity at the softening point is large and the viscosity curve is steep. Since such glass powder has low glass viscosity at the firing temperature, it can be sufficiently defoamed in the firing step.

In the present invention, the rate of change of the viscosity curve at the softening point of the glass powder is evaluated by the magnitude of the difference ΔTgs between the glass softening point Ts and the glass transition point Tg measured by DTA (differential thermal analysis). Ts and Tg are both temperatures determined by the viscosity of the glass. Specifically, Ts is a temperature at which the viscosity of the glass is 10 ^7.5 dPa · s, and Tg is a temperature at which the viscosity of the glass is about 10 ^13.3 dPa · s. Therefore, the smaller the ΔTgs, the greater the rate of change in viscosity and the steeper curve.

  ΔTgs of the glass powder used in the present glass composition is 50 to 105 ° C. If ΔTgs is less than 50 ° C., the glass may become unstable. On the other hand, if ΔTgs exceeds 105 ° C., the encapsulated foam of the glass sheet after firing may increase. ΔTgs is preferably 80 to 100 ° C., and more preferably 85 to 95 ° C.

  The Ts of the glass powder is preferably 700 ° C. or lower. If Ts is high, the firing temperature becomes high, and thus the phosphor powder may be deteriorated in the firing step. Ts is more preferably 650 ° C. or lower, and further preferably 620 ° C. or lower.

Examples of the glass in which ΔTgs and Ts are in the above range include a glass mainly composed of Bi ₂ O ₃ —ZnO—B ₂ O ₃ . Among them, as represented by mol% based on _{oxides, Bi 2 O 3 3~30%,} B 2 O 3 10~50%, the glass containing 0 to 45% ZnO is more preferable. _{Bi 2 O 3 3~30%, B} 2 O 3 10~50%, ZnO 0~45%, SiO 2 5~35%, BaO 0~20%, MnO 2 0~1%, CeO 2 0~1% The glass containing is more preferable. As glass mainly composed of Bi ₂ O ₃ —ZnO—B ₂ O ₃ , Bi ₂ O ₃ 3-30%, B ₂ O ₃ 10-50%, ZnO 0-45%, SiO ₂ 5-35 %, BaO 0-20%, MnO ₂ 0-1%, CeO ₂ 0-1%. In the present specification, “consisting essentially of” means that inevitable impurities other than the components described are allowed.

Bi ₂ O ₃ is a component that lowers Ts without lowering the chemical durability of glass, and is an essential component in this system. The content of Bi ₂ O ₃ is preferably 3 to 30%. If Bi ₂ O ₃ is less than 3%, Ts of the glass powder becomes high, which is not preferable. On the other hand, if it exceeds 30%, the glass becomes unstable, tends to crystallize, and the sinterability may be impaired. The content of Bi ₂ O ₃ is more preferably 5 to 25%, and further preferably 5 to 20%.

B ₂ O ₃ is a glass network former and is a component that can stabilize glass, and is an essential component in this system. The content of B ₂ O ₃ is preferably 10 to 50%. If the content of B ₂ O ₃ is less than 10%, the glass becomes unstable, tends to be crystallized, and the sinterability may be impaired. On the other hand, if the content of B ₂ O ₃ exceeds 50%, the chemical durability of the glass may be lowered. The content of B ₂ O ₃ is more preferably 15 to 45%, further preferably 20 to 45%.

  ZnO is a component that lowers Ts and is not an essential component in this system. The content of ZnO is preferably 0 to 45%. If the ZnO content exceeds 45%, it will be difficult to vitrify, and it will be difficult to produce glass. The lower limit of the ZnO content is more preferably 5% or more, and further preferably 10% or more. Further, the upper limit is more preferably 40% or less, and further preferably 35% or less.

SiO ₂ is a component that increases the stability of the glass and is not an essential component in this system. The content of SiO ₂ is preferably 0 to 35%. The content of SiO ₂ is at 35 percent, there is a possibility that Ts increases. The lower limit of the content of SiO ₂ is more preferably 5% or more, and further preferably 10% or more. The upper limit is more preferably 30% or less, and further preferably 25% or less.

  CaO, SrO, MgO or BaO alkaline earth metal oxides are components that increase the stability of glass and lower Ts, and are not essential components in this system. The total amount of alkaline earth metal oxide is preferably 0 to 20%. If the total amount exceeds 20%, the stability of the glass is lowered. More preferably, the total amount is 18% or less. Further, BaO is preferable as the alkaline earth metal oxide.

Neither MnO ₂ nor CeO ₂ is an essential component in this system, but is preferably contained because it functions as an oxidizing agent in the glass. In any case, reduction of Bi ₂ O ₃ in the glass can be prevented, so that this type of glass can be stabilized. Reduction of Bi ₂ O ₃ is not preferable because the glass is colored. Furthermore, the encapsulated foam of the glass sheet after baking may increase. Therefore, the content of MnO ₂ and CeO ₂ is preferably 0 to 1%. If the content exceeds 1%, coloring may increase.

Components are prepared and mixed so as to have predetermined thermal characteristics, melted in an electric furnace or the like, and rapidly cooled to produce glass. The glass powder is produced by pulverizing and classifying the glass. The average particle diameter (hereinafter, the particle diameter is abbreviated as particle diameter) D ₅₀ of the glass powder is preferably less than 2.0 μm. D ₅₀ is 2.0μm or more, the phosphor powder is not uniformly dispersed in the glass powder, it may decrease the conversion efficiency when the glass sheet. D ₅₀ is more preferably 1.5 μm or less, and still more preferably 1.4 μm or less.

The maximum particle size Dmax of the glass powder is preferably 30 μm or less. When Dmax is more than 30 μm, the phosphor powder is not uniformly dispersed in the glass powder, and when the glass sheet is produced, the conversion efficiency of the phosphor may be lowered. Dmax is more preferably 20 μm or less, and still more preferably 15 μm or less.
In the present specification, both D ₅₀ and Dmax is a value calculated by a laser diffraction type particle size distribution measurement.

  The phosphor powder used in the present glass composition is not limited as long as it can convert blue light into yellow light. Examples of the phosphor include oxides, nitrides, oxynitrides, sulfides, oxysulfides, halides, aluminate chlorides, and halophosphates, and particularly have an excitation band at a wavelength of 400 to 500 nm. Those having an emission peak at a wavelength of 500 to 700 nm are preferable.

When the excitation light is blue light having a wavelength of 440 to 480 nm, the phosphor is (Y, Gd) ₃ Al ₅ O ₁₂ : Ce ³⁺ , (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce ³⁺ , Ba ₅ (PO ₄ ) ₃ Cl: U and CaGa ₂ S ₄ : Eu ²⁺ are preferable. Among them, (Y, Gd) ₃ Al ₅ O ₁₂ or Ce ³⁺ , (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ is more preferable.

The average particle diameter _{D 50} of the phosphor powder is preferably 15μm or less. If D ₅₀ of the phosphor powder becomes large, the dispersion becomes poor glass sheet after firing, the conversion efficiency of light is degraded. D ₅₀ is more preferably 13 μm or less, and even more preferably 10 μm or less.

  In the present glass composition, in addition to the glass powder and the phosphor powder, those capable of defoaming the encapsulated foam may be further included. Examples of such elements include elements that can have a plurality of oxidation numbers by changing the valence, such as metal compounds having oxidation catalytic properties such as copper chloride and antimony oxide. On the other hand, from the viewpoint of production cost, the present glass composition is preferably composed of glass powder and phosphor powder.

  In the case where the present glass composition is composed of glass powder and phosphor powder, the mixing ratio of the glass powder and phosphor powder is volume%, glass powder 60 to 99.99%, and phosphor powder 0.01. ~ 40% is preferred. If the volume ratio of the glass powder is less than 60%, the sinterability of the mixture of the glass powder and the phosphor powder may be impaired, and the transmittance of the glass sheet may be lowered. Moreover, there is a possibility that yellow light increases and desired white light cannot be obtained. On the other hand, if the phosphor powder is less than 0.01%, the blue light cannot be sufficiently converted, and when the LED is used, desired white light may not be obtained. The mixing ratio is more preferably 70 to 95% glass powder and 5 to 30% phosphor powder, and more preferably 80 to 90% glass powder and 10 to 20% phosphor powder.

  The glass sheet is produced through a molding process and a baking process using the present glass composition. The molding method is not particularly limited as long as a desired shape can be imparted. Examples thereof include a press molding method, a roll molding method, and a doctor blade molding method. A green sheet manufactured by a doctor blade molding method is preferable because a glass sheet having a uniform film thickness can be efficiently manufactured in a large area.

  The green sheet can be manufactured, for example, by the following process. Glass powder and phosphor powder are kneaded in a vehicle and defoamed to obtain a slurry. The slurry is prepared on a transparent resin by a doctor blade method and dried. After drying, it is cut into a desired size and the transparent resin is peeled off to obtain a green sheet. Furthermore, a desired thickness can be ensured by pressing them into a laminate.

  The vehicle is obtained by dissolving a resin in an organic solvent. As the resin, ethyl cellulose, nitrocellulose, acrylic resin, vinyl acetate, butyral resin, melamine resin, alkyd resin, rosin resin and the like can be used. Moreover, as an organic solvent, ethyl cellulose and nitrocellulose can be used. In order to improve the strength of the green sheet, the vehicle may further contain a butyral resin, a melamine resin, an alkyd resin, a rosin resin, or the like.

  The transparent resin for applying the slurry is not limited as long as a green sheet having a uniform film thickness is obtained. For example, a PET film etc. are mentioned.

  When the glass sheet is produced, the firing temperature is 450 to 900 ° C., and the glass softening point Ts ± 50 ° C. is preferable. Usually, when glass powder is fired to form a sintered body, the encapsulated foam of the glass sheet can be reduced by setting the firing temperature in the vicinity of Ts. When fired at a temperature higher than Ts + 50 ° C., the encapsulated foam increases, and the phosphor powder may be deteriorated by reaction with heat or glass, and the conversion efficiency of the phosphor may be reduced. On the other hand, if it is fired at a temperature lower than Ts-50 ° C, the encapsulated foam of the glass sheet cannot be sufficiently reduced. The firing temperature is more preferably Ts ± 30 ° C., further preferably Ts ± 20 ° C.

When Bi ₂ O ₃ —ZnO—B ₂ O ₃ based glass is used, Ts is preferably 530 to 630 ° C. Therefore, the firing temperature is preferably 480 to 680 ° C. The firing temperature is more preferably 500 to 660 ° C, further preferably 530 to 630 ° C.

  The firing atmosphere is not particularly limited. If the ΔTgs of the glass is within the range of the present invention, the encapsulated bubbles of the glass sheet can be sufficiently reduced even in the atmosphere, and the conversion efficiency of the phosphor can be increased.

  In addition, when firing using an electric furnace, it is preferably performed in two stages: binder removal firing for removing the binder and the like in the vehicle and main firing for sintering the glass powder.

  Binder removal firing depends on the type and amount of binder in the vehicle used in the production of the green sheet. For example, it is preferable to carry out by using an electric furnace etc. and hold | maintaining at 400-480 degreeC for 1 to 6 hours.

  The glass sheet produced from the present glass composition has few encapsulated bubbles and can increase the conversion efficiency of the phosphor.

  Since there is a positive correlation with the porosity of the glass sheet, the amount of encapsulated foam can be evaluated by the porosity. The porosity of the glass sheet is preferably 5% or less. When the porosity is more than 5%, the glass sheet contains many bubbles and light is likely to be scattered by the glass sheet. The porosity is preferably as low as possible, more preferably 2.5% or less, and even more preferably 1% or less. In the present specification, the porosity means a value derived from the deviation of the measured specific gravity with respect to the theoretical specific gravity of the glass sheet.

  The glass sheet preferably has less internal scattering due to encapsulated foam and less absorption. If the glass sheet has a large amount of internal scattering, the glass becomes opaque, which is not preferable. Scattering of the glass sheet can be evaluated by measuring parallel light transmittance and measuring total light transmittance. In this specification, both the parallel light transmittance and the total light transmittance are values measured by a method according to JIS-K-7136.

  The parallel light transmittance is preferably 4% or more, and more preferably 5% or more. If the parallel light transmittance is less than 4%, blue light that is not converted into a phosphor is scattered inside the glass sheet, and the LED issuance efficiency may be reduced.

  The total light transmittance is preferably 70% or more, more preferably 75% or more, and even more preferably 80% or more. If the total light transmittance is less than 70%, the light emitted from the light emitting element is absorbed inside the glass sheet, and the luminance of the LED is lowered, that is, the luminous efficiency of the LED is not preferable.

  The conversion efficiency of the phosphor in the glass sheet can be evaluated by the quantum conversion efficiency. The quantum conversion efficiency is preferably 85% or more. If it is less than 85%, the incident blue light cannot be sufficiently converted to yellow light, and the light obtained by the synthesis may not be a desired white color. The quantum conversion efficiency is more preferably 86% or more. The quantum conversion efficiency is expressed as a ratio of the number of photons emitted from the sample as light emission when irradiated with excitation light and the number of photons absorbed by the sample. The number of photons is measured by an integrating sphere method. To do.

  Hereinafter, the present invention will be described based on examples. Examples 1 and 2 are examples of the present invention, and example 3 is a comparative example.

(Example 1)
Bi ₂ O ₃ 8.9%, SiO ₂ 15.2%, B ₂ O ₃ 31%, ZnO 33.5%, BaO 11.2%, MnO ₂ 0.1% in terms of mole% based on oxide. was mixed glass raw materials such that the _CeO 2 0.1%. This was heated in an electric furnace to 1200 to 1400 ° C. in a platinum crucible and melted, and the melt was quenched with a rotating roll to form a glass ribbon. The glass ribbon was pulverized by a ball mill, passed through a sieve having a mesh having an opening of 150 μm, and further classified by air flow to obtain glass 1 powder (glass powder 1).

The glass transition temperature Tg and the glass softening point Ts of the obtained glass powder 1 were measured using a differential thermal analyzer (trade name: TG8110, manufactured by Rigaku Corporation). D ₅₀ and Dmax were calculated by laser diffraction particle size distribution measurement (manufactured by Shimadzu Corporation, apparatus name: SALD2100). The results are shown in Table 1.

  The glass powder 1 thus obtained and the YAG phosphor powder are mixed with 84% by volume of the glass powder 1 and 16% by volume of the phosphor powder, kneaded with a vehicle, and defoamed to obtain a slurry. It was. This slurry was applied to a PET film (manufactured by Teijin Limited) by the doctor blade method. This was dried in a drying furnace for about 30 minutes, cut into a size of about 7 cm square, and the PET film was peeled off to obtain a green sheet having a thickness of about 0.5 mm.

  Two green sheets were laminated and pressed. This was placed on a mullite substrate coated with a release agent, deburied at 420 ° C. for 4 hours in the atmosphere, further baked at 550 ° C. under normal pressure for 1 hour, then mirror-polished on one side, and a glass sheet It was created. The thickness of the glass sheet measured with a micrometer was 135 μm.

  The porosity, quantum conversion efficiency, and transmittance of the glass sheet thus obtained were measured. These results are shown in Table 1.

  The porosity of the glass sheet was measured by the Archimedes method. The quantum conversion efficiency was measured at an excitation light wavelength of 460 nm using an absolute PL quantum yield measuring apparatus (manufactured by Hamamatsu Photonics, trade name: Quantauru-QY). The haze and transmittance of the glass sheet were measured with a C light source using a haze measuring device (manufactured by Suga Test Instruments Co., Ltd., trade name: Haze Meter HZ-2).

(Example 2)
A green sheet was obtained by the same method as in Example 1 using glass powder 1. Two green sheets were laminated and pressed. This was placed on a mullite substrate coated with a release agent, deburied at 460 ° C. for 6 hours in the atmosphere, further baked at 570 ° C. for 1 hour under reduced pressure (about 60 Pa), and then single-sided mirror polishing And the glass sheet was created. The thickness of the glass sheet measured with a micrometer was 135 μm.

  About the obtained glass sheet, the porosity, the quantum conversion efficiency, and the transmittance | permeability were measured by the method similar to Example 1. FIG. These results are shown in Table 1.

(Example 3)
In terms of oxide-based mol%, SiO ₂ 21%, B ₂ O ₃ 31%, ZnO 2%, Li ₂ O 16%, MgO 9%, CaO 5%, BaO ₂ %, Al ₂ O ₃ 14%. The glass raw materials were mixed as described above. This was heated in an electric furnace to 1300-1500 ° C. in a platinum crucible and melted, and the melt was quenched with a rotating roll to form a glass ribbon. The glass ribbon was pulverized with a ball mill, passed through a sieve having a mesh having an opening of 150 μm, and further subjected to air classification to obtain glass 2 powder (glass powder 2).

  The characteristics of the glass were evaluated in the same manner as in Example 1. The results are shown in Table 1.

  A glass sheet was prepared in the same manner as in Example 1 using glass powder 2. The plate thickness of the glass sheet was 154 μm. Moreover, the porosity, the quantum conversion efficiency, and the transmittance | permeability were measured by the method similar to Example 1 about the glass sheet. These results are shown in Table 1.

  The glass composition for a phosphor-dispersed glass sheet of the present invention is used for producing a phosphor-dispersed glass sheet for converting a blue light source to obtain a white light source of a white LED.

1 LED light emitting element, 2 glass sheet, 3 phosphor, 4 encapsulated foam, 5 LED light,
6 Glass, 7 Fluorescence, 8 Scattered light

Claims (9)

  A glass composition for a phosphor-dispersed glass sheet comprising glass powder and phosphor powder, wherein the glass powder has a difference (ΔTgs) between Ts and Tg calculated from a DTA curve of 50 to 105 ° C. A glass composition for a phosphor-dispersed glass sheet. The glass composition for a phosphor-dispersed glass sheet according to claim 1, wherein the glass is a Bi ₂ O ₃ —ZnO—B ₂ O ₃ system. _{3. The} glass composition for a phosphor-dispersed glass sheet according to claim 2, wherein the glass contains, in mol%, Bi ₂ O ₃ 3 to 30%, ZnO 0 to 45%, and B ₂ O ₃ 10 to 50%. The glass is expressed in mol%, Bi ₂ O ₃ 3-30%, B ₂ O ₃ 10-50%, ZnO 0-45%, SiO ₂ 5-35%, BaO 0-20%, MnO ₂ 0 The glass composition for a phosphor-dispersed glass sheet according to claim 2 or 3 containing 1% and CeO ₂ 0 to 1%.   The glass sheet manufactured by baking the glass composition for fluorescent substance dispersion | distribution glass sheets of any one of Claims 1-4.   The phosphor-dispersed glass sheet according to claim 5, wherein the porosity is 5% or less.   The phosphor-dispersed glass sheet according to claim 5, wherein the total light transmittance is 70% or more.   The phosphor-dispersed glass sheet according to any one of claims 5 to 7, wherein the parallel light transmittance is 4% or more and the total light transmittance is 70% or more.   Quantum conversion efficiency is 85% or more, The fluorescent substance dispersion | distribution glass sheet of any one of Claims 5-8.

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