JP2009242735A - Fluorescent material and fluorescence display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a CaTiO<SB>3</SB>:Pr based fluorescent material which has a brightness higher than conventional and to provide a fluorescence display device. <P>SOLUTION: A CaTiO<SB>3</SB>:Pr, Zn, Li, RE fluorescent material is a CaTiO<SB>3</SB>:Pr, Zn, Li based fluorescent material in which Pr, Zn and Li are added to CaTiO<SB>3</SB>as a first addition material and a second addition material, wherein one (RE) of Gd, La and Y is further added as a third addition material so that these Gd, La and Y enhance the brightness without preventing luminescence of other rear earth element and therefore the obtained brightness is higher than conventional. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a phosphor and a fluorescent display device including the phosphor as a light source.

For example, a Zn _1-x Cd _x S (hereinafter referred to as ZnCdS) system has conventionally been used as a red light emitting phosphor that emits light by excitation with a low-energy electron beam used in a fluorescent display device such as a fluorescent display (VFD). Phosphors have been used. In recent years, the use of harmful elements such as Cd has been regulated due to environmental problems, and ZnCdS phosphors are also subject to such regulation. In addition, when the ZnCdS phosphor, which is a sulfide, is decomposed by electron beam irradiation, there is a problem that the electron emission ability of the oxide cathode, which is an electron source, is reduced by the scattered S. In the present application, the “slow electron beam” means a beam accelerated at a voltage of about 10 to 200 (V) suitable for VFD unless otherwise specified.

In contrast, a red phosphor for oxide-based low-energy electron beams that does not contain Cd and S has been proposed in which rare earth elements and Group III elements are added to a matrix composed of an alkaline earth metal and Ti oxide. Yes. The alkaline earth metal is, for example, Mg, Sr, Ca, Ba, the rare earth element is, for example, Ce, Pr, Eu, Tb, Er, Tm, the group III element is, for example, Al, Ga, In, Tl, A typical composition example is, for example, SrTiO ₃ : Pr, Al (see, for example, Patent Documents 1 and 2). Here, the element (Pr, Al) on the right side of “:” is a component added to SrTiO ₃ which is the base material. In this composition, the preferable ranges of Pr and Al are 0.1 to 2 (mol%) and 1 to 50 (mol%), respectively (see Patent Document 1).
JP-A-8-85788 JP 2003-41246 A JP 2005-281507 A JP 2006-282703 A

By the way, the SrTiO ₃ : Pr, Al phosphor described in Patent Document 1 has a problem that the luminance is severely deteriorated and the lifetime is short. Patent Document 2 describes a technique for suppressing luminance deterioration by providing a protective film made of a host compound on the surface of phosphor particles. However, even if such a treatment is performed, a ZnCdS phosphor is used. In comparison, the lifetime is remarkably short. In addition, SrTiO ₃ : Pr, Al provided with the protective film had a lower luminance than the ZnCdS phosphor at the initial stage.

Therefore, the applicant of the present application previously uses CaTiO ₃ as a base, and Pr is added in a range of 0.003 to 0.05 (mol%) with respect to the base, and Al, Ga, In, Zn, Mg, Na, and CaTiO ₃ : Pr, M phosphor to which at least one kind of K (M) is added, or Ca _1-x Sr _x TiO ₃ (however, 0 <x ≦ 0.5) as a base material, and Pr and Li are added. Ca _1-x Sr _x TiO ₃ : Pr, Li phosphors have been proposed (see Patent Documents 3 and 4). According to these CaTiO ₃ phosphors, long-life and high-brightness oxide phosphors could be obtained.

  However, even the above phosphors still have low luminance as compared with conventional Cd phosphors. Therefore, with the demand for higher performance of the display, it has been required to further increase the brightness of the oxide phosphor.

The present invention has been made in the background of the above circumstances, and an object of the present invention is to provide a CaTiO ₃ : Pr phosphor and a fluorescent display device having higher luminance than those of the prior art.

In order to achieve such an object, the gist of the CaTiO ₃ : Pr, Zn, Li, RE phosphor of the first invention is that CaTiO ₃ is the base, Pr is the first additive, and Zn and Li are the first. As the second additive, at least one selected from Gd, La, and Y (RE) is added together as the third additive.

The gist of the fluorescent display device of the second invention resides in that the CaTiO ₃ : Pr, Zn, Li, RE phosphor of the first invention is provided as a light source.

According to the first invention, Pr in CaTiO _3, Zn, CaTiO addition of Li _3: Pr, Zn, in Li phosphor, Gd, La, and as either (RE) is a third additive Y Since it is added, it is possible to obtain higher brightness than in the past. The reason why such an effect can be obtained is not clear, but when the present inventors tested various rare earth elements generally used as phosphor additives, they do not interfere with the light emission of other rare earth elements. Is only Gd, La, Y, and Lu, and it has been found that the luminance of the phosphor can be dramatically increased only when Gd, La, and Y are added among these four types. The present invention has been made based on such knowledge.

According to the second invention, since the CaTiO ₃ : Pr, Zn, Li, RE phosphor of the first invention is provided as a light emitting source, it can be operated at a low voltage and has a long life. A high-luminance fluorescent display device is obtained.

In the present application, CaTiO ₃ is not limited to a stoichiometric composition having a Ca / Ti ratio of 1 except where otherwise specified, and the ratio is slightly larger or slightly smaller than 1. The composition is also included. For example, the ratio is within the range of 1.05 to 0.95.

  The phosphor of the first invention is capable of obtaining high brightness even with a low-speed electron beam used in VFD. However, it is excited by a high-speed electron beam of 1 (kV) or higher and ultraviolet light to emit light. The use is not limited to the case of excitation with a low-energy electron beam. That is, the phosphor of the present invention is an FED (Field Emission Display) that emits light by exciting the phosphor with an electron beam generated at a voltage of about 1 (kV) to 10 (kV), 10 It is also suitable for CRT (Cathode Ray Tube) that excites phosphors with an electron beam generated at a voltage of about (kV), PDP (Plasma Display Panel) that excites phosphors with ultraviolet light, etc. In addition, the display device of the second invention includes a fluorescent display tube and those having a phosphor as a light source.

  In the first invention, the first additive Pr functions as an emission center. Pr having a valence of +3 or +4 (especially +3 in the case of red light emission) is considered to replace the Ca site in terms of the ionic radius. However, since the valence of Ca is +2, Charge becomes excessive. Of the second additive, Zn is considered to replace the Ti site in terms of the ionic radius, but the Ti valence is +4 and the Zn valence is +2, so the excess charge due to the substitution of Pr. Can balance. In addition, Li in the second additive is considered to replace the Ca site in terms of the ionic radius, but since the valence of Li is +1, the balance of the charge that was excessive due to the Pr substitution also by this substitution Can take. Therefore, these Zn and Li are indispensable components for obtaining Pr with high brightness by stably presenting Pr.

  Here, in the first invention, preferably, the amount of the third additive added is 0.14 (mol%) or less with respect to the matrix 100 (mol%). If even a small amount of the third additive is added, the luminance enhancement effect can be obtained according to the amount of the third additive. However, since it tends to decrease in luminance when it is excessive, it is preferably kept at 0.14 (mol%) or less. In addition, although 2 or more types of 3rd additives may be added simultaneously, in that case, the range of the said addition amount is the total amount of the 2 or more types.

  Preferably, the amount of the third additive (Gd, La, Y) is in the range of 0.01 to 0.12 (mol%) with respect to the matrix 100 (mol%). In this way, even higher luminance can be obtained even in the case of low-energy electron beam excitation. More preferably, the added amount of the third additive is in the range of 0.07 to 0.11 (mol%) with respect to the base 100 (mol%).

  Preferably, the addition amount of the first additive is in the range of 0.003 to 0.05 (mol%) with respect to the base 100 (mol%). In this way, even higher luminance can be obtained in the case of low-energy electron beam excitation. If the amount of Pr, which is the emission center, is less than 0.003 (mol%) or exceeds 0.05 (mol%), high brightness may be obtained by excitation with ultraviolet light or a high-speed electron beam of 1 (kV) or more, but it is slow. With electron beam excitation, the brightness is low. If the Pr concentration becomes too high, the luminance decreases due to concentration quenching, and if the Pr concentration becomes too low, the number of emission centers decreases, so the luminance decreases. More preferably, the amount of Pr added is a value within the range of 0.008 to 0.023 (mol%).

  Preferably, the addition amount of the second additive is such that Zn and Li are each in the range of 1 to 5 (mol%), and the total is in the range of 1 to 10 (mol%). In this way, even higher luminance can be obtained in the case of low-energy electron beam excitation.

In addition, the phosphor of the present invention preferably includes (a) a base material for constituting a base made of CaTiO ₃ , a first additive material containing Pr, and at least one second material containing Zn and Li. A mixing step of mixing the additive raw material with at least one third additive raw material containing at least one of Gd, La, and Y; and (b) the obtained mixture is preferably in the range of 1050 to 1250 (° C.). Is manufactured by a process including a baking step of baking at a predetermined baking temperature within a range of 1050 to 1200 (° C.), more preferably within a range of 1100 to 1150 (° C.).

  In this way, the base material, the first additive material, the second additive material, and the third additive material are mixed in the mixing step, and the mixture is in the range of 1050 to 1250 (° C.) in the firing step. It is baked at the temperature inside. Therefore, an oxide phosphor that has a long life and emits light with high brightness even when excited by a low-speed electron beam can be obtained.

Preferably, the method includes a primary firing step of firing the mixture at a predetermined temperature lower by 50 to 150 (° C.) than the firing temperature prior to the firing step, and the firing step is obtained by the primary firing step. The calcined product is subjected to a firing treatment. In this way, the additive element diffuses more uniformly into the base CaTiO ₃ . For this reason, there exists an advantage which a brightness | luminance is raised further compared with the case where a primary baking process is not implemented. Note that if the Pr concentration distribution is biased, concentration quenching is likely to occur in the high concentration portion, while the luminance is lowered in the low concentration portion due to the lack of the emission center, so that the overall emission intensity is reduced.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios, shapes, and the like of the respective parts are not necessarily drawn accurately.

FIG. 1 is a process diagram for explaining an outline of a method for producing a phosphor according to an embodiment of the present invention. A method for producing a CaTiO ₃ : Pr, Gd, Zn, Li phosphor, which is an example of the phosphor of the present invention, will be described with reference to FIG. First, in the raw material mixing step P1, the composition of the phosphor to be produced is prepared as an appropriate compound, for example, CaCO ₃ , TiO ₂ , PrCl ₃ , GdCl ₃ , ZnS, Li ₂ CO _3, which is the starting material of this phosphor. According to the above, weigh each and mix well using a ball mill or mortar. The mixing ratio is, for example, Ca / Ti = 0.99 (molar ratio), with respect to CaTiO ₃ , the Pr addition amount is in the range of 0.003 to 0.05 (mol%), and the Zn addition amount is in the range of 1 to 5 (mol%). Of these, the Li addition amount is in the range of 1 to 5 (mol%), and the Gd addition amount is in the range of 0.01 to 0.14 (mol%).

  Next, in the primary firing step P2, the mixed raw material (mixture) is placed in an alumina crucible having a purity of, for example, 99.5 (%) or higher, and the primary is maintained in the atmosphere at a maximum holding temperature of about 1100 (° C) for about 6 hours. A firing (calcination) treatment is performed.

Next, in the firing step P3, the calcined product is directly subjected to a firing treatment for about 3 hours at a maximum holding temperature of about 1150 (° C.). Thereby, CaTiO ₃ : Pr, Gd, Zn, Li is synthesized from the starting material by the chemical reaction shown in the following (1). In the pulverization step P4, the synthesized phosphor is pulverized to an average particle size of about 3 (μm) using, for example, an alumina mortar.
CaCO ₃ + TiO ₂ + PrCl ₃ + GdCl ₃ + ZnS + Li ₂ CO ₃ → CaTiO ₃ : Pr, Gd, Zn, Li (1)

Next, in the water washing step P5, the water-soluble residue is dissolved by dispersing the pulverized phosphor powder in water. Among the starting materials, PrCl ₃ , GdCl ₃ , Li ₂ CO ₃ are soluble in water, while synthesized phosphors and other raw materials are insoluble, so unreacted PrCl ₃ , GdCl ₃ , Li ₂ Only CO ₃ will dissolve.

Next, in the sieving step P6, while the phosphor is dispersed in water, coarse particles are removed, for example, by passing through a sieve of about # 305, and thereafter, the phosphor particles are allowed to stand for an appropriate time to settle. Let After a predetermined time, the supernatant is removed by sucking with a pipette. Thereby, the water-soluble residue (that is, the soluble component in the raw material) contained in the supernatant is removed. This treatment is performed a plurality of times as necessary so that the water-soluble residue is completely removed. After removing the supernatant, the remaining phosphor particles are dried for about 5 hours at a temperature of, for example, 120 (° C.) in the drying step P7, and then the obtained solid is pulverized in an alumina mortar in the crushing step P8. Etc. to obtain a CaTiO ₃ : Pr, Gd, Zn, Li phosphor powder by crushing to a particle size of about 3 (μm).

Next, the results of evaluating the characteristics of the phosphor synthesized as described above will be described. In this evaluation, a phosphor paste is prepared by mixing an appropriate amount of In ₂ O ₃ powder to supplement the conductivity of the phosphor powder and further mixing with a vehicle composed of an organic binder, an organic solvent, and the like. The mixing amount of In ₂ O ₃ is appropriately determined according to the conductivity of the phosphor powder itself and the conductivity required of the phosphor layer. For example, the amount of In ₂ O ₃ is 100% (by weight) with respect to the phosphor powder 100 (% by weight). It is about 5-15 (weight%). The prepared paste was applied with a suitable thickness on a display surface arranged in the electron emission direction in a display device, for example, and a phosphor layer was formed for evaluation. The evaluated display device is, for example, a fluorescent display tube 10 having a structure as shown in FIGS.

  FIG. 2 is a perspective view showing a fluorescent display tube 10 which is an example of the fluorescent display device of the present invention with a part cut away. In FIG. 2, the fluorescent display tube 10 is formed in a frame shape with a substrate 12 made of an insulating material such as glass, ceramics, and cocoons provided with a plurality of phosphor layers 22 formed in a predetermined light emission pattern. A glass spacer 14, a transparent cover / glass plate 16, a plurality of anode terminals 18p, a plurality of grid terminals 18g, and a cathode terminal 18k are provided. The substrate 12 and the cover / glass plate 16 are glass-sealed with each other via the spacers 14 to form a longitudinal flat box-like airtight container, and a vacuum space surrounded by these members is formed therein. ing.

  The display surface 20 of the substrate 12 is provided with a large number of phosphor layers 22 formed in various shapes, each surrounded by a grid electrode 24 and an auxiliary grid electrode 26. For example, the auxiliary grid electrode 26 is electrically insulated from the grid electrode 24 and is provided in common over the entire surface. The grid electrode 24 and the auxiliary grid electrode 26 are connected to the grid terminal 18g via grid wirings 30 and 32 provided on the display surface 20 and a number of terminal pads provided along the long sides thereof. Has been.

  A pair of terminal members 34 having the cathode terminals 18k are fixed to both ends of the substrate 12, and a direct heating cathode (cathode) is provided between an anchor 36 fixed to the terminal member and a support (not shown). A plurality of fine filament-like filaments (filaments / cathodes) 38 functioning are stretched so as to be in a predetermined height position parallel to the longitudinal direction of the substrate 12 and separated from the display surface 20 of the substrate 12 (that is, fluorescent light). (Built over the body layer 22). The filament 38 is made of tungsten (W) wire or the like whose surface is coated with an alkaline earth metal oxide solid solution having a low work function such as (Ba, Sr, Ca) O as an electron emission layer. The fluorescent display tube 10 is provided with a getter for increasing the degree of vacuum in the hermetic container, an exhaust pipe or an exhaust hole for evacuating and vacuuming the interior after the hermetic container is formed. However, these were omitted.

  FIG. 3 is an enlarged view showing a part of the display surface 20 in detail, and FIG. 4 is an enlarged view showing an essential part of the cross section. An anode wiring 40 made of, for example, a thick film conductor is provided on the display surface 20 so as to be connected to the anode terminal 18p, and an insulating material made of a thick film glass material or the like appropriately provided with a through hole 42 thereon. The body layer 44 is fixed. On the insulator layer 44, an anode 46 made of graphite having a planar shape slightly larger than that of the phosphor layer 22 is formed at a position where it is electrically connected to the anode wiring 40 through the through hole 42. In the fluorescent display tube 10, the phosphor layer 22 is formed on the anode 46. In addition, rib-like walls 48 and 50 made of, for example, a thick film glass material are erected around the phosphor layer 22. The grid electrode 24 and the auxiliary grid electrode 26 are made of, for example, thick film conductors, and are provided on top of the rib-like walls 48 and 50.

  In the fluorescent display tube 10 configured in this way, the thermoelectrons emitted from the filament 38 are applied to the zero (V) filament 38 by applying a positive voltage of about 20 (V) to the grid electrode 24. Thus, for example, when an acceleration voltage is sequentially applied to the grid electrode 24 for scanning and a positive voltage is applied to the anode wiring 40 to which the desired phosphor layer 22 is connected in synchronization with the scanning, Thermal electrons collide with the phosphor layer 22 to cause the phosphor layer 22 to emit light. Therefore, a desired light-emitting display can be obtained by changing the anode wiring 40 to which a positive voltage is applied every scanning cycle of the grid electrode 24. In the evaluation of the phosphor, the luminance was measured in a state where the phosphor layer 22 was constantly lit by applying a positive voltage to the phosphor layer 22 constantly.

FIG. 5 shows that for CaTiO ₃ 100 (mol%), the Pr addition amount is 0.011 (mol%), the Zn addition amount is 3 (mol%), the Li addition amount is 2 (mol%), and the Gd addition amount is It represents the result of evaluating the luminance of the phosphor obtained by changing the content in the range of 0 to 0.25 (mol%). In the measurement, the filament voltage of the fluorescent display tube 10 is 3.5 (V), the anode voltage is 26 (V), the duty ratio is 1/12, and the visible light peak wavelength of the phosphor of this embodiment is 614 ( The initial brightness of red light of about nm) was measured. In addition, In ₂ O ₃ for supplementing conductivity is added to the phosphor in the range of 6 to 10 (wt%), the luminance is measured, and the luminance when Gd is not added is 100 (%) The relative luminance was evaluated. Note that the luminance of the composition without adding Gd is, for example, about 120 (cd / m ² ). In addition, although the life evaluation results are omitted, each of the following evaluation examples has a life equivalent to the conventional one.

As shown in FIG. 5 above, it is clear that the luminance is improved by adding Gd. In the case of In ₂ O ₃ amount 6 (wt%) where the effect was remarkable, at least under the evaluated conditions, if the amount of Gd added was 0.14 (%) or less, the luminance was higher than when no additive was added. improves. In particular, when the amount of Gd added is in the range of 0.01 to 0.12 (mol%), a relative luminance of 130 (%) or higher is obtained, and in the range of 0.06 to 0.11 (mol%), a relative luminance of 150 (%) or higher is obtained. It is done. The reason why the brightness improvement effect stopped low when the amount of In ₂ O ₃ was 8 (wt%) or 10 (wt%) is considered to be because the amount of In ₂ O ₃ was excessive.

Incidentally, the amount of Gd added is more than 0.14 (mol%), even when In ₂ O ₃ amount is 6 (wt%) as compared to the case of no addition, but becomes low brightness, In ₂ O ₃ amount There is room for improvement, such as determining the measurement conditions and so on.

FIG. 6 shows the results of evaluating the luminance of a CaTiO ₃ : Pr, La, Zn, Li phosphor added with La instead of Gd in the same manner as the phosphor. In manufacturing this phosphor, LaCl ₃ is used as a starting material in place of GdCl ₃ in the manufacturing process shown in FIG. The reaction in the firing process is as follows (2).
CaCO ₃ + TiO ₂ + PrCl ₃ + LaCl ₃ + ZnS + Li ₂ CO ₃ → CaTiO ₃ : Pr, La, Zn, Li (2)

  As shown in FIG. 6, the same tendency as in the case of adding Gd is observed in the composition to which La is added. That is, by adding La, the luminance is improved as compared to the case of no addition, but at least in the evaluated range, the luminance is decreased when the addition amount is excessive. The brightness improvement effect is recognized when the La amount is 0.14 (mol%) or less, in the range of 0.01 to 0.12 (mol%), 30 (%) or more, and in the range of 0.08 to 0.1 (mol%), 50 (% ) The above brightness improvement was confirmed.

FIG. 7 shows the results of evaluating the luminance of a CaTiO ₃ : Pr, Y, Zn, Li phosphor added with Y in place of Gd and La in the same manner as the phosphor. When manufacturing this phosphor, in the manufacturing process shown in FIG. 1, YCl ₃ is used as a starting material instead of GdCl ₃ . The reaction in the firing process is as follows (3).
CaCO ₃ + TiO ₂ + PrCl ₃ + YCl ₃ + ZnS + Li ₂ CO ₃ → CaTiO ₃ : Pr, Y, Zn, Li (3)

  As shown in FIG. 7, even in the composition in which Y is added, the luminance is improved as compared with the case in which Y is not added, as in the case of Gd addition and La addition. In addition, at least in the evaluated range, when the addition amount is excessive, the luminance is decreased. The brightness improvement effect is observed when the Y amount is in the range of 0.14 (mol%) or less, in the range of 0.01 to 0.12 (mol%), 30 (%) or more, and in the range of 0.06 to 0.11 (mol%), 50 (% ) The above brightness improvement was confirmed.

  FIG. 8 shows the results of evaluating the Pr concentration dependence of the relative luminance change when the La addition amount is changed. The tendency of the relative luminance when the amount of added La was changed was confirmed by shaking the Pr concentration at three points of 0.005 (mol%), 0.011 (mol%), and 0.02 (mol%). Although the luminance differs depending on the Pr concentration, at least in the range of the above Pr concentration, no difference was observed in the change tendency of the relative luminance.

  FIG. 9 shows the results of evaluating the dependency of relative luminance on the Zn addition amount in the same manner as described above. The amount of Zn added was 1 (mol%), 3 (mol%), and 5 (mol%). In the evaluated range, the influence of the Zn addition amount is not recognized on the change tendency of the relative luminance.

  FIG. 10 shows the results of evaluating the dependency of relative luminance on the amount of added Li in the same manner as described above. The amount of Li added was 1 (mol%), 3 (mol%), and 5 (mol%). In the evaluated range, the influence of Li addition amount is not recognized on the change tendency of the relative luminance.

According to the evaluation results shown in FIG. 8 to FIG. 10, in the CaTiO ₃ : Pr, La, Zn, Li phosphor, the effect when the La addition amount is changed in the range up to about 0.3 (mol%) is as follows. It was confirmed that it was independent of the amount of other additives, ie, Pr, Zn, Li. The above-mentioned tendency is not limited to the case of adding La, and the same is true when either Gd or Y is added.

As described above, in this embodiment, Pr in CaTiO _3, Zn, CaTiO ₃ added with Li: Pr, Zn, in Li phosphor, Gd, that La, and one of Y is added further Therefore, higher brightness can be obtained as compared with the prior art.

  As mentioned above, although this invention was demonstrated in detail with reference to drawings, this invention can be implemented also in another aspect, A various change can be added in the range which does not deviate from the main point.

It is process drawing explaining the manufacturing method of the fluorescent substance of one Example of this invention. It is a figure which cuts off a part of cover glass and shows the whole structure of the fluorescent display tube which is an example of the fluorescent display apparatus of this invention. FIG. 3 is a plan view showing a fluorescent layer by enlarging a part of a display surface of the fluorescent display tube of FIG. 2. It is a figure which expands the principal part of the cross section of the fluorescent display tube of FIG. 2, and explains a structure. It is a figure which shows the relative luminance with respect to the case of no addition when changing the amount of Gd addition in the fluorescent substance of one Example of this invention. It is a figure which shows the relative luminance at the time of changing La addition amount. It is a figure which shows the relative luminance at the time of changing Y addition amount. It is a figure which shows the result of having evaluated the Pr density | concentration dependence of the relative luminance which changed La addition amount. It is a figure which shows the result of having evaluated the Zn addition amount dependence of the relative luminance which changed La addition amount. It is a figure which shows the result of having evaluated the Li addition amount dependence of the relative luminance which changed La addition amount.

Claims (7)

CaTiO ₃ is the base, Pr is the first additive, Zn and Li are the second additive, and at least one selected from Gd, La, and Y (RE) is added as the third additive. CaTiO ₃ : Pr, Zn, Li, RE phosphor characterized in that The CaTiO ₃ : Pr, Zn, Li, RE phosphor according to claim 1, wherein the addition amount of the third additive is 0.14 (mol%) or less with respect to 100 (mol%) of the base material. The CaTiO ₃ : Pr, Zn, Li, RE phosphor according to claim 1, wherein the amount of the third additive added is in the range of 0.01 to 0.12 (mol%) with respect to the matrix 100 (mol%). The CaTiO ₃ : Pr, Zn, Li, RE phosphor according to claim 1, wherein the amount of the third additive added is in the range of 0.07 to 0.11 (mol%) with respect to the matrix 100 (mol%). 5. The CaTiO ₃ : Pr, according to claim 1, wherein the amount of the first additive added is in the range of 0.003 to 0.05 (mol%) with respect to the matrix 100 (mol%). Zn, Li, RE phosphor. The CaTiO ₃ : Pr according to any one of claims 1 to 5, wherein the amount of the second additive added is in the range of 1 to 5 (mol%) with respect to the matrix 100 (mol%). Zn, Li, RE phosphor. A fluorescent display device comprising the CaTiO ₃ : Pr, Zn, Li, RE phosphor according to any one of claims 1 to 6 as a light source.

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