JP3329598B2 - Phosphor, cathode ray tube, fluorescent lamp and phosphor manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spherical rare earth oxide phosphor and a cathode ray tube, a fluorescent lamp and a radiographic intensifying screen using the spherical phosphor.

[0002]

2. Description of the Related Art Phosphors used in cathode ray tubes, fluorescent lamps or radiographic intensifying screens have a thickness of several μm from the viewpoint of luminous efficiency when excited by electron beams, ultraviolet rays or radiation.
Is required. In order to obtain crystal grains having such a particle size, the phosphor is usually synthesized by a solid-phase reaction using a flux. However, the shape synthesized using the flux is not a perfect sphere, but a shape close to a polyhedron reflecting the shape and crystal structure of the raw material particles.

[0003] When a phosphor screen of a cathode ray tube is formed by using such a phosphor, for example, there is a disadvantage that light emission generated by electron beam excitation is not always sufficiently utilized as light output from the phosphor screen. That is, if the shape of the phosphor particles is close to a polyhedron, a dense phosphor film cannot be obtained, voids will be generated, and the smoothness of the aluminum back as the light reflection film will be inferior and irregularities will occur. For this reason, the diffuse reflection of the emitted light increases, which causes light loss. Similarly, even when the above-described phosphor is used for a fluorescent lamp, a dense phosphor film cannot be obtained, so that the light emission by ultraviolet excitation is not effectively used.

[0004] In some cases, it is effective to mix a plurality of phosphors in order to form a dense phosphor film and utilize light emission effectively. However, in this method, desired luminescence characteristics, for example, high luminous efficiency may not be realized because phosphors having different luminescence characteristics are mixed.

For example, a color cathode ray tube is manufactured by the following method. A suspension (slurry) composed of a phosphor and a photosensitive resin is applied to the entire inner surface of the glass to form a phosphor film, and ultraviolet rays are irradiated to polymerize only a desired region. Thereafter, the fluorescent film in the region not irradiated with the ultraviolet light is washed away. At this time, if the light scattering of the fluorescent film is large, ultraviolet rays do not enter the inside of the fluorescent film, so that the inside is hardly polymerized. Therefore, it is difficult to form a sufficiently thick film that maximizes the luminance of the fluorescent film. In addition, when the light scattering is large, a region other than a desired region is exposed and polymerized, and it is difficult to obtain a fluorescent film pattern as designed.

A cathode ray tube used in a projection type video device is
Usually, a phosphor is suspended in a barium aqueous solution in a cathode ray tube envelope, a potassium silicate aqueous solution is added thereto, and the phosphor is allowed to settle on the inner surface of the cathode ray tube face to produce a phosphor film. The red, green and blue light emitted in this manner 3
Attach an optical lens in front of each of the cathode ray tubes,
Enlarge and project the image on the screen. Large electron gun inputs are used to get sufficient brightness on the screen. Therefore, even if there are minute defects on the phosphor screen, a dense phosphor screen is required to be enlarged, especially with recent high-definition image fluorescence, and the light output is reduced and deteriorated even under high load conditions. Less is required.

On the other hand, in an X-ray image intensifier for medical use or material inspection, an image on an output surface is often photographed with a TV camera and observed in an enlarged manner. For this reason, a particularly uniform, dense and high-resolution phosphor screen is required.

Since the above-mentioned light scattering increases as the total surface area of the particles contained in the fluorescent film increases, it is desirable that the shape of the particles be spherical. Then, as an attempt to obtain phosphor particles having a shape as close as possible to a spherical shape, B.I. C. G
labmaier, W.C. Rossner, J .; Lepp
ert; Phys. Stat. Sol. (A) 130,
A method using an emulsion as shown in K183 (1992) is known. However, the phosphor obtained by this method is a collection of fine particles and has poor crystallinity, so that re-firing is required. The shape of the phosphor particles obtained as a result is not always perfect spherical and the particle size is small, which is not preferable as a phosphor used for a cathode ray tube or a fluorescent lamp.

As another attempt to obtain a spherical phosphor, Japanese Patent Application Laid-Open No. 62-201989 discloses a method of heating a phosphor material granulated in a high-temperature plasma, and rare earth oxides are also included in this phosphor. Included in. However, it is difficult to obtain a preferable particle size of the phosphor obtained by this method, there is a problem in dispersibility and adhesion, and it is possible to obtain a desired activator concentration as a practical phosphor in terms of emission color and emission efficiency. There were drawbacks such as not having.

Further, a phosphor that emits three colors of red, green and blue is used in the color display device. In this case, a deep red and bright phosphor is desired so that the color reproduction range of red is as large as possible. A representative red phosphor for a cathode ray tube closest to this condition is Y ₂ O ₃ S: Eu. However, since this phosphor has a polyhedral particle shape, it has a drawback caused by the above-described light scattering. Therefore, a phosphor which emits deep red light with a spherical particle shape that can be substituted for the phosphor has been demanded.

Next, a fluorescent lamp for lighting is required to have not only brightness but also good color appearance under the lighting, that is, both high efficiency and high color rendering, so that both are improved. These three-wavelength fluorescent lamps are widely used. This three-wavelength fluorescent lamp has, for example, an emission peak of 450 nm.
A divalent europium-activated barium / magnesium aluminate phosphor or a divalent europium-activated barium / calcium / strontium halophosphate that emits in the vicinity and emits blue light, with cerium / terbium that emits green light at an emission peak near 545 nm Active lanthanum phosphate phosphor, cerium / terbium activated magnesium aluminate phosphor, and europium activated yttrium oxide (Y ₂ O ₃₎ having a light emission peak near 611 nm and emitting red light:
Eu) It is obtained by mixing appropriate amounts of phosphors of three colors such as phosphors and applying the mixture in a glass bulb. The fluorescent color rendering index R _a one indicates a higher value of 84 to 88, are excellent in the effect to feel beautiful color of the irradiated body more naturally. However, the three-wavelength type fluorescent lamp has the drawback of the special color rendering index R ₉ for the high saturation of red is low as 20-40.

For the purpose of improving this, the present applicants have disclosed in Japanese Patent Application No. 5-24878 a gadolinium oxide activated with europium which emits deep red light having an emission peak near 623 nm in addition to the above three phosphors. (Gd ₂ O ₃ : E
u) discloses mixing phosphors. For example, 12% by weight of Gd ₂ O ₃ : Eu is added to the above three kinds of phosphors.
By mixing the phosphor, R ₉ could be improved by 18 points. However, the total luminous flux is 2.4%
It has decreased, the total flux decrease of about 1.3% in order to the R ₉ improved 10 points could not be avoided.

Further, R. C. Ropp: J. Elect
rochem. Soc. 112, 181 (196
5 years), Gd ₂ O ₃ : Eu belongs to a monoclinic crystal system. However, R. S. Roth et
al. : J. Res. National Bureau
of Standards, 64A, 309 (1
As shown in 960), Gd ₂ O ₃ is cubic at room temperature, and it is necessary to raise the temperature to 1200 ° C. or higher and then to rapidly cool it to obtain a monoclinic crystal which is a high-temperature stable phase. Therefore, it is difficult to manufacture the phosphor by the usual method of firing the phosphor in a crucible.

On the other hand, Arai et al. : J. Al
loys and Compounds, 192, 4
As shown on page 5 (1993), monoclinic Gd ₂ O ₃ activated with praseodymium has a green emission band that cannot be obtained with cubic Gd ₂ O ₃ , and therefore requires short afterglow green emission. Although there is a possibility that it can be used for various applications, it is required to solve the production problems for obtaining a monoclinic crystal which is a high-temperature stable phase as described above.

More recently, fluorescent lamps have been frequently used as backlights for liquid crystal displays.
In this case, the fluorescent lamp is used in combination with a light reflection film, a light guide plate and a diffusion plate. For the purpose of energy saving, it is desired that the luminous efficiency of the fluorescent lamp be as large as possible when the light reflection plate is combined. In the conventional fluorescent lamp, there is a problem that the light transmittance of the fluorescent film is low, and a large loss of light occurs when a part of emitted light is transmitted through the fluorescent lamp again by the reflective film and focused in one direction. In addition, the tube diameter is much smaller than the tube diameter of general lighting lamps of 25 to 35 mm from the viewpoint of emission luminance and compactness, and the phosphor application is not performed by the conventional phosphor slurry pouring but by the syringe injection method or the reduced pressure inhalation method. Are used. At this time, if the phosphor in the slurry is agglomerated or has poor fluidity, problems such as clogging of the phosphor at the injection nozzle and deterioration of the formed phosphor film surface occur.

On the other hand, in the case of a radiographic intensifying screen, in order to prevent a decrease in sensitivity, a fluorescent film is made thick to increase radiation absorption.
It is conceivable to increase the luminous efficiency. But in this case,
Since the particle layer of the phosphor has a large number of particle layers, scattering of light also increases, and sufficient sensitivity improvement cannot be obtained. On the other hand, if the average particle size of the phosphor used for the fluorescent film is increased, scattering of light is suppressed, but the sharpness of the obtained radiation image is reduced.
Therefore, in order to obtain an intensifying screen capable of obtaining a radiation image with high sensitivity and high sharpness, a method has been proposed in which phosphors having different average particle sizes are applied to form a two-layer phosphor film ( JP-A-1-57758). In this case, first, the particles produced by the wet precipitation / sintering method are classified by the precipitation method to produce phosphors having different average particle diameters. A binder is mixed with the phosphors having different average particle diameters (for example, CaWO ₄ having an average particle diameter of 4.2 μm and 9.6 μm), and a slurry is applied to the protective film by a knife coater. A slurry of a phosphor having a small average particle diameter (for example, CaWO ₄ having an average particle diameter of 4.2 μm) is similarly applied thereon. Next, a support is adhered to the fluorescent film to obtain an intensifying screen. However, since this manufacturing method has many steps and uses phosphors having different average particle diameters, it is difficult to set the particle diameter and the blending ratio, etc., so that a desired radiographic intensifying screen can be obtained. Hateful.

[0017]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and provides a rare-earth oxide phosphor having a small particle size and a shape close to a true sphere. An object of the present invention is to obtain a cathode ray tube or a fluorescent lamp having a high luminance by forming a phosphor screen.

[0018]

Means for Solving the Problems The phosphor of the present invention is Ln.
₂ O ₃ : represented by a composition formula of R (where Ln is at least one element selected from the group consisting of La, Gd, Lu and Y, and R is at least one element selected from the lanthanide group). A transparent spherical particle having an average particle diameter of 0.5 to 15 μm and a ratio of a major axis to a minor axis of 1.0 to 1.5, and the transparent spherical particle having a ratio of 0.001 to 0.5% by weight; Ultrafine particles having a particle diameter of 0.2 μm or less and containing the same constituent elements as the transparent spherical particles adhered to the surface of the particles. Method for producing a phosphor of the present invention, Ln ₂ O _3:
R (where Ln is at least one element selected from the group consisting of La, Gd, Lu, and Y, and R is at least one element selected from the lanthanide group), and the resulting fluorescence The raw material phosphor particles having an activator concentration different from that of the body and having a primary particle diameter of 2 to 20 μm and not being granulated are supplied together with a carrier gas into the thermal plasma to form the raw material phosphor particles. By melting and quenching, Ln ₂ O ₃ : R (where Ln is at least one element selected from the group consisting of La, Gd, Lu and Y, and R is at least one element selected from the lanthanide group) Element), having an average particle size of 0.5 to 15 μm
And transparent spherical particles having a ratio of major axis to minor axis of 1.0 to 1.5, and the transparent spherical particles adhered to the surface of the transparent spherical particles at a ratio of 0.001 to 0.5% by weight. And a superfine particle having a particle diameter of 0.2 μm or less containing the same constituent element as described above.

The cathode ray tube according to the present invention is characterized in that Ln ₂ O ₃ : R (where Ln is at least one element selected from the group consisting of La, Gd, Lu and Y, and R is at least one selected from the lanthanide group). A transparent spherical particle having an average particle size of 0.5 to 15 μm and a ratio of the major axis to the minor axis of 1.0 to 1.5. A phosphor layer containing, as at least one component, a phosphor containing not more than 0.5% by weight of ultrafine particles having a diameter of not more than 0.2 μm is formed. The cathode ray tube of the present invention is represented by a composition formula of Gd ₂ O ₃ : R (where R is at least one element selected from the lanthanide group), and at least a part of the crystal system is a monoclinic system. And transparent spherical particles having an average particle diameter of 0.5 to 15 μm and a ratio of the major axis to the minor axis of 1.0 to 1.5.
A phosphor layer containing a phosphor containing 0.5% by weight or less of ultrafine particles of 2 μm or less is formed.

The fluorescent lamp according to the present invention is composed of Ln ₂ O ₃ : R
(Where Ln is at least one element selected from the group consisting of La, Gd, Lu and Y, and R is at least one element selected from the lanthanide group). It is composed of transparent spherical particles having a diameter of 0.5 to 15 μm and a ratio of the major axis to the minor axis of 1.0 to 1.5, and contains 0.5% by weight or less of ultrafine particles having a particle diameter of 0.2 μm or less. A phosphor layer containing a phosphor as at least one component is formed on the inner surface of the glass bulb. Further, the fluorescent lamp of the present invention has a Gd ₂ O ₃ : E
u, and the proportion of monoclinic crystals is 5 to 10
0%, ultrafine particles having an average particle diameter of 0.5 to 3 μm and a ratio of the major axis to the minor axis of 1.0 to 1.5, and having a particle diameter of 0.2 μm or less. A phosphor containing 0.5% by weight or less, a europium-activated yttrium oxide phosphor that emits red light with an emission peak near 611 nm, a phosphor that emits green light with an emission peak at 540 to 570 nm, and a light emission peak A phosphor layer mainly composed of a phosphor near 450 nm and mixed with a phosphor that emits blue light is formed on the inner surface of the glass bulb.

The cathode ray tube according to the present invention has a transparent spherical shape having an average particle diameter of 0.5 to 15 μm and a ratio of the major axis to the minor axis of 1.0 to 1.5, regardless of the kind of the phosphor. It is characterized in that a phosphor composed of particles and containing 0.5% by weight or less of ultrafine particles having a particle diameter of 0.2 μm or less is applied.
The cathode ray tube is used for a direct-view type color cathode ray tube having a shadow mask or a projection type video apparatus. When the cathode ray tube is an X-ray image intensifier, the phosphor used preferably has an average particle size of 0.5 to 3 μm.

Further, the fluorescent lamp of the present invention has a transparent spherical shape having an average particle size of 0.5 to 15 μm and a ratio of the major axis to the minor axis of 1.0 to 1.5, regardless of the kind of the phosphor. A fluorescent substance comprising particles and containing 0.5% by weight or less of ultrafine particles having a particle diameter of 0.2 μm or less is applied to the inner surface of a glass tube. Of these, a glass tube in which at least one-third or more of the outside area is covered with a reflective material having a light reflectance of 50 to 98% and a glass tube forming a fluorescent lamp having an inner diameter of 8 mm or less are preferable. Characteristic can be obtained.

The phosphor used in the phosphor screen of the present invention has an average particle diameter of 0.1 to 20 μm and a ratio of the major axis to the minor axis of 1 regardless of the kind of the phosphor. .
Consisting of transparent spherical particles having a particle diameter of 0.2 to 1.5
m, a phosphor containing 0.001 to 5% by weight, preferably 0.01 to 1% by weight of ultrafine particles.

Hereinafter, the present invention will be described in more detail.

The phosphor of the present invention comprises a rare earth oxide,
Ln ₂ O ₃ : R (where Ln is at least one element selected from the group consisting of La, Gd, Lu and Y;
R is at least one element selected from the lanthanide group), the average particle diameter is 0.5 to 15 μm, and the ratio between the major axis and the minor axis is 1.0 to 1.5. It is composed of transparent spherical particles and contains ultra-fine particles having a particle size of 0.2 μm or less by 0.5% by weight or less.

Among them, a composition formula of Gd ₂ O ₃ : R (where R is at least one element selected from the lanthanide group), wherein at least a part of the crystal system is monoclinic, 0.5% by weight of ultrafine particles composed of transparent spherical particles having an average particle diameter of 0.5 to 15 μm and a ratio of the major axis to the minor axis of 1.0 to 1.5, and having a particle diameter of 0.2 μm or less. Phosphors that emit red or green light, including the following, are suitably used for cathode ray tubes. R represents a lanthanide group element. Among them, elements particularly useful as phosphors are Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, and E.
r, Tm, and Yb.

The composition is represented by a composition formula of Gd ₂ O ₃ : Eu, in which the proportion of monoclinic crystals is 5 to 100%, the average particle size is 0.5 to 3 μm, and the major and minor axes are And transparent spherical particles having a particle diameter of 1.0 to 1.5.
Phosphors containing 0.5% by weight or less of ultrafine particles of 2 μm or less and exhibiting a red emission color are suitably used for fluorescent lamps. Here, the concentration range of Eu is preferably 1 to 6 mol%. If the Eu concentration is outside the above range,
The luminous efficiency decreases.

In the present invention, the average particle diameter of the phosphor particles is defined as 0.5 to 15 μm because the average particle diameter is 0.5 μm.
This is because, when it is smaller than m or larger than 15 μm, the luminance of the phosphor screen is reduced.

More specifically, G used for a cathode ray tube
The average particle diameter of the d ₂ O ₃ : R phosphor is preferably 1 to 10 μm. Such an optimal range for the average particle size is known empirically.

The reason why the average particle size of the Gd ₂ O ₃ : Eu phosphor particles exhibiting a red emission color suitably used for a fluorescent lamp is defined as 0.5 to 3 μm is as follows. That is, when a mixed phosphor is used in a fluorescent lamp, since the phosphor such as the red component acts disadvantageously with respect to the total luminous flux in terms of luminosity, it is empirically determined that the smaller the particle size is, the higher the total luminous flux becomes. Are known. For this reason,
The average particle size is preferably 3 μm or less. On the other hand, if the particle size is extremely small, it becomes difficult to handle the powder. Therefore, the average particle size is preferably 0.5 μm or more.

In the phosphor of the present invention, the ratio (aspect ratio) between the major axis and the minor axis of each phosphor particle, that is, the ratio between the largest diameter part and the smallest diameter part of each phosphor particle is 1. It is in the range of 0 to 1.5 and has a shape close to a sphere without any protrusions such as edges. The ratio between the major axis and the minor axis of the phosphor particles is more preferably 1.0 to 1.2.

The phosphor of the present invention contains 0.5% by weight or less of ultrafine particles having a particle diameter of 0.2 μm or less. When ultra-fine particles of 0.5% by weight or more adhere to or coexist on the surface of transparent spherical particles of several μm, light scattering increases, so that the light transmittance of the spherical particles and thus the fluorescent film formed therefrom decreases. Further, since the ultrafine particles have a low luminous efficiency, if transparent spherical particles of several μm are mixed, the luminous efficiency of the entire phosphor is reduced. on the other hand,
When the amount of the ultrafine particles is 0.5% by weight or less, the ultrafine particles adhere to the surface of the spherical particles, which is effective in improving the fluidity and dispersibility of the phosphor and enhancing the adhesion of the phosphor film. However,
When the content is less than 0.001% by weight, it can be said that the ultrafine particles are not substantially present, and the above-mentioned effect is lost.

Regarding the composition of the phosphor of the present invention, R is E
u and its atomic ratio to Ln is 1 to 6%, and R is Tb
And the atomic ratio to Ln is 0.1 to 6%, and R is P
r and its atomic ratio to Ln is 0.01 to 0.5%
It is desirable that Outside of these ranges,
This is because it is not practical for application to a cathode ray tube or a fluorescent lamp in terms of emission color and emission efficiency. The reason why the range of the atomic ratio is wide in the case of Tb is that the emission color becomes blue at a low density and the emission color becomes green at a high density, but either case can be used depending on the purpose.

The phosphor of the present invention can be produced by melting and quenching the raw phosphor particles. In particular,
For example, it is possible to use a method in which the raw material phosphor particles are supplied into a high-temperature thermal plasma together with a carrier gas, and are then taken out of the thermal plasma after a short time. Here, the thermal plasma means a high temperature ionization state of the gas. Thermal plasma is a few ~
It can be generated by gas discharge by high-frequency electromagnetic waves of several tens of megahertz or direct current, and the gas temperature of the so-called torch or frame reaches several thousands to 10,000 ° C. High-frequency thermal plasma devices are described, for example, by Yoshida et al .:
"Iron and Steel", Vol. 68, No. 10, page 20 (1982
Year).

In the present invention, JP-A-62-2019
Unlike the manufacturing method of JP-A-89-89, a phosphor having an activator concentration different from that of the obtained phosphor and not being granulated is used as a raw material. Such a raw material phosphor may be produced using a flux or may be produced by decomposing an oxalate coprecipitated product. By treating the particle surface of the raw phosphor with an acid or applying a trace amount of an organic surfactant to improve its dispersibility and fluidity, the average particle size of the raw phosphor and the resulting spherical phosphor can be reduced. The difference can be kept within 50%. It is desirable that the particle size of the primary particles of the raw phosphor is about 2 μm or more. This is because when the primary particles have a small particle diameter, even if the secondary particles in which the primary particles are agglomerated have a diameter of 2 μm or more, the whole is vaporized in the thermal plasma and quenched. This is because particles often have a size of 0.2 μm or less. On the other hand, when the diameter of the primary particles or the secondary particles is too large, the particle diameter of the obtained phosphor becomes large, which is not suitable for practical use. It is desirable that the primary particles and the secondary particles have a particle size of 20 μm or less. Even when the primary particle diameter is 2 μm or more, part of the phosphor is vaporized and cooled during the thermal plasma treatment, and contains ultrafine particles having a particle diameter of 0.2 μm or less. The amount of the ultrafine particles varies depending on the output of the thermal plasma, the supply position of the raw phosphor, and the method of collecting the treated phosphor. In the present invention,
When extra ultrafine particles are contained, the ultrafine particles are removed by sonication in a liquid, for example, water, and the content is adjusted to 0.5% by weight or less. After performing the thermal plasma treatment,
When refired at 800 to 1200 ° C., the aggregated ultrafine particles regrow and have a somewhat larger particle size and adhere to the surface of the spherical particles.

In the present invention, the crystal system of the obtained phosphor can be both a high-temperature phase and a low-temperature phase. For example,
Gd ₂ O ₃ when the phosphor, even raw crystal system of a stable cubic at lower temperatures, the raw material particles in the thermal plasma is Gd ₂
Since it is exposed to a temperature higher than the cubic to monoclinic transition temperature of O ₃ and then rapidly cooled, monoclinic crystals, which are high-temperature stable phases, are easily formed. On the other hand, when the spherical phosphor containing the ultrafine particles of the present invention is further fired at 800 to 1200 ° C., it can be easily changed to a cubic crystal system which is stable at a low temperature while maintaining the spherical shape.

In the present invention, the activator concentration of the spherical phosphor obtained by the thermal plasma treatment is different from that of the raw phosphor.
For example, in the case of using Y ₂ O ₃ : Eu of a red phosphor for a lamp as a raw material, even if the atomic ratio of Eu / Y is 4.4% in the raw material, it is 3.5 in a spherical phosphor subjected to thermal plasma treatment. %. On the other hand, Eu / Y is about 2
It reaches 0%. As a result, the emission color of the spherical phosphor is shifted from the desired red color to an orange color, and the emission efficiency is reduced by about 20%. Tb activated monoclinic Gd ₂ O ₃
In the case of the phosphor, when the Tb concentration decreases, 4% of the green component represented by the emission line of 544 nm is emitted in the emission spectrum.
A blue component represented by a 15-nm emission line becomes strong. In order to obtain a desired green light emitting phosphor, the atomic ratio of Tb / Ln needs to be a certain value of 2 to 6%, but the thermal plasma treatment causes the atomic ratio of Tb / Ln to change from the value of the raw material. I will. The degree of change in the activator concentration varies depending on the thermal plasma processing conditions, for example, the supply amount of the raw material phosphor,
Changes in activator concentration cannot be eliminated at all. Therefore, in order to obtain an activator concentration in the spherical phosphor that can obtain a desired emission color, the activator concentration of the raw phosphor is adjusted.

Since the phosphor of the present invention has a substantially spherical particle shape, when it is used to form a phosphor film by sedimentation in a liquid or by application of a slurry, a phosphor film close to the closest packing can be obtained. Also, since the total surface area of the phosphor film formed using phosphor particles having such a particle shape is small, light scattering is reduced as compared with the case where a conventional phosphor is used even at the same coating amount, and light transmission is reduced. The amount increases. Therefore, for example, when the fluorescent screen of a color cathode ray tube is formed by an optical printing method, since the light transmittance of the fluorescent screen is large, the light is exposed up to the deep portion of the fluorescent film, and therefore, compared to the case where a conventional phosphor is used. The thickness can be increased, and the thickness can be easily controlled. In addition, since the light transmittance is large and the film is dense, a good quality fluorescent film pattern without unevenness or unevenness at the end portion due to light scattering can be obtained. Further, in both the color cathode ray tube and the monochromatic cathode ray tube, since the fluorescent film is close to the closest packing, the smoothness of the light reflecting metal film formed on the fluorescent screen is improved. For this reason, of the light emitted from the phosphor screen, the light traveling toward the electron beam excitation side can be efficiently reflected, and the luminance can be improved. In addition to this, since the light transmittance of the fluorescent film is large, the proportion of the light emitted from the fluorescent screen that travels in the direction opposite to the electron beam excitation side (the side observed by humans) increases, and the luminance increases. Contribute to improvement.

Since the phosphor of the present invention contains 0.5% by weight or less of ultrafine particles mainly in a state of being attached to the particle surface,
It is excellent in fluidity and can easily obtain a uniform phosphor when mixed with other phosphors. This is particularly useful for lamps often used as mixed phosphors. Further, when a fluorescent film is used for a fluorescent lamp and a cathode ray tube, the adhesive force between the glass substrate and the fluorescent material is larger than that in a case where the ultrafine particles are not substantially contained. One of the reasons for this is
400 to 400 in the manufacturing process of the fluorescent lamp and the cathode ray tube
It is considered that the ultrafine particles play a role of a low melting point binder in the heating step at 700 ° C.

In the present invention, the monoclinic Gd ₂ O ₃ : R phosphor used for the cathode ray tube has a different emission color depending on the type of R, and therefore, the suitable use thereof is also different. That is,
In the case of monoclinic Gd ₂ O ₃ : Eu, the emission color is deeper red than that of the cubic crystal which is a low-temperature stable type, and is suitable for a red component of a color cathode ray tube or a projection type cathode ray tube. In the case of monoclinic Gd ₂ O ₃ : Pr, its emission color changes from low-temperature stable cubic red to yellow-green containing a green emission band. Since this light emission has an extremely short afterglow time of about 10 μs, it is suitable for a special cathode ray tube requiring a short afterglow. Monoclinic Gd ₂ O ₃ : Tb is suitable for a green component of a projection CRT because it emits green light with high efficiency.

As described above, the monoclinic Gd ₂ O ₃ : Eu phosphor used in the fluorescent lamp according to the present invention has an emission peak at around 623 nm, which has an emission peak at around 611 nm and a red emission peak at around 611 nm. Europium-activated yttrium oxide phosphor that emits light with an emission peak of 540-
By forming a phosphor layer mainly composed of a phosphor which emits green light at 570 nm and a phosphor having a light emission peak near 450 nm and emits blue light on the inner surface of the glass bulb, a fluorescent lamp is formed. R ₉ can be improved.

The green light-emitting phosphor is at least one selected from the group consisting of cerium / terbium-activated lanthanum phosphate phosphor and cerium / terbium-activated barium / magnesium aluminate phosphor, and emits the blue light. The phosphors to be formed include a divalent europium-activated barium / magnesium halophosphate phosphor, a divalent europium / manganese co-activated barium / magnesium halophosphate phosphor, and a divalent europium-activated barium / calcium / strontium halophosphate phosphor. At least one selected from the group is included.

Although the mixing ratio of the above-mentioned phosphor varies depending on how many times the correlated color temperature of the fluorescent lamp is set,
Normally, the blue-emitting phosphor 10 to 50 wt%, the green light emitting phosphor 20 to 45 wt%, Gd ₂ O _3: Eu phosphor and Y
_{If the 2} O ₃ : Eu phosphor is blended in a total range of 30 to 76% by weight, a desired fluorescent lamp can be obtained.

However, cubic Gd ₂ O ₃ : Eu is Y ₂
O _3: Eu phosphor as well as Y ₂ O for having an emission peak in the vicinity of 611 nm _3: Eu phosphor and alternatively it can be used, it does not adversely affect the color rendering properties of the fluorescent lamp. Therefore, Gd ₂ O ₃ : Eu does not need to be completely monoclinic, and if there is about 5% or more of monoclinic, the remainder is cubic, and there is no problem.

The fluorescent screen of the direct-view type color cathode ray tube having the shadow mask according to the present invention is easy to control the film thickness and high in brightness because the fluorescent film has little light scattering and high light transmittance. Further, the fluorescent film pattern can be easily formed close to the design. The phosphor has an average particle size of 0.5 to 15 μm,
And ultrafine particles having a particle diameter of 0.2 μm or less, which are composed of transparent spherical particles having a ratio of a major axis to a minor axis of 1.0 to 1.5,
This effect can be obtained as long as the content is not more than 10% by weight. Phosphor species include ZnS: Ag and Z in addition to rare earth oxides.
a zinc sulfide based phosphor such as nS: Cu or ZnS: Cu, Au; Ln ₂ O ₂ S: R (where Ln is La,
At least one element selected from the group consisting of Gd, Lu and Y, and R is at least one element selected from the lanthanide group). Good.

The fluorescent screen of the cathode ray tube used in the projection type image apparatus of the present invention has a high packing density because spherical phosphor particles do not agglomerate and has good dispersibility, and contains ultrafine particles having a particle size of 0.2 μm or less. It has a film with strong adhesion to the substrate glass because it contains. As a result, when the image is enlarged and projected, the roughness of the phosphor screen due to the phosphor is not conspicuous. In addition, since the thermal conductivity of the film is improved, a large electron beam input, that is, the temperature rise is small even under high load, and the electron beam does not directly irradiate the substrate glass, so that the phosphor is deteriorated and the glass is colored. Light output is less when operated for a long time. The phosphor used has an average particle size of 0.5 to 15
μm and a ratio of a major axis to a minor axis of 1.0 to 1.5, and is composed of transparent spherical particles containing 0.5% by weight or less of ultrafine particles having a particle diameter of 0.2 μm or less. The effect can be obtained. Examples of the phosphor species include zinc sulfide phosphors such as ZnS: Ag, Ln ₂ , in addition to rare earth oxides.
O ₂ S: R (where Ln is La, Gd, Lu and Y
At least one element selected from the group consisting of: R is at least one element selected from the lanthanide group), a rare earth oxysulfide-based phosphor represented by a composition formula: Y
_{3 (Al, Ga) 5 O} 12: Tb, Y 2 SiO 5: Tb,
InBO ₃ : Tb, Zn ₂ SiO ₄ : Mn, LaOC
l: Tb, Ti, (La, Gd) OBr: Ce.

The X-ray image intensifier according to the present invention has a structure as shown in FIG. Here, 11 is an input fluorescent screen, and X
Converts line input to visible light. Reference numeral 12 emits electrons at the position where light is received by the photocathode. A focusing electrode 13 forms an electron lens in the tube. Reference numeral 14 denotes an anode, and 25 to 25
A 30 kV potential difference is created to accelerate the electrons emitted at the cathode. Reference numeral 15 denotes an output phosphor screen on which a phosphor layer and an aluminum metal film are formed in this order on a glass substrate. 16 is a vacuum container. In the present invention, since the spherical phosphor used for the output phosphor screen has good dispersibility, a homogeneous phosphor screen having a high packing density can be obtained, and thereby the resolution can be increased. At this time, in order to further increase the resolution, it is desirable that the particle size is as small as possible. In particular, since the phosphor particles are spherical, the contact with the glass substrate is close to point contact, and the degree of optical coupling between the glass substrate and the phosphor is low. Of the light-emitting component is reduced, and the resolution, contrast and output are improved. However, if the particle size is too small, the luminous efficiency decreases, so that the average particle size is desirably 0.5 to 3 μm.
The dispersibility and fluidity required for forming a film by the sedimentation method, the centrifugal method, or the electrodeposition method, and the adhesion of the formed film are sufficient due to the presence of ultrafine particles having a particle diameter of 0.2 μm or less adhered to the phosphor surface. Things are obtained. The phosphor used may be a conventional (Zn, Cu) S: Ag-based zinc sulfide phosphor,
When the particle size of the phosphor of this type is smaller than 1 μm, there is a disadvantage that the luminous efficiency is reduced. In addition, the rare earth oxide phosphor of the present invention and Ln ₂ O ₂ S: R (where Ln is L
a rare earth oxysulfide-based phosphor represented by a composition formula of at least one element selected from the group consisting of a, Gd, Lu and Y, and R is at least one element selected from the lanthanide group. be able to.

The fluorescent lamp of the present invention has good dispersibility without agglomerated spherical phosphors and good fluidity including ultrafine particles, so that when two or more phosphors are mixed, uniform mixing can be easily obtained. And a dense fluorescent film can be obtained. For this reason, color shift at both ends of the fluorescent lamp is small. The phosphor used at this time is composed of transparent spherical particles having an average particle diameter of 0.5 to 15 μm and a ratio of a major axis to a minor axis of 1.0 to 1.5, and a particle diameter of 0.2 μm or less. Any kind of phosphor can be used as long as the phosphor satisfies the condition of containing 0.5% by weight or less of ultrafine particles. For example, as blue, CaWO ₄ , CaWO ₄ : Pb, BaMg ₂ Al
₁₆ O ₂₇ : Eu, (Sr, Ca) ₁₀ (PO ₄ ) ₆ Cl ₂ :
Eu, green, LaPO ₄ : Ce, Tb, CeMgA
l ₁₁ O ₁₉ : Tb, Zn ₂ SiO ₄ : Mn, Y as red
₂ O ₃ : Eu and Y (P, V) O ₄ : Eu.

The effect of the fluorescent lamp of the present invention is particularly remarkable when the tube diameter is 8 mm or less. That is, since the phosphor has good dispersibility and fluidity, a uniform phosphor screen can be easily obtained without clogging the nozzle when the phosphor is applied by a syringe injection method or a reduced pressure suction method.

The fluorescent lamp of the present invention exhibits a greater effect when used in combination with a reflector as in the case of a light guide type backlight of a liquid crystal display. FIG. 2 shows the structure of a liquid crystal display provided with a light guide type backlight incorporating the fluorescent lamp for a liquid crystal backlight of the present invention. Here, 21 is a fluorescent lamp, 22 is a light reflection film, 23 is a light guide plate, 24 is a diffusion plate, 25 is a liquid crystal display panel, and 26 is a lamp cover. The light output emitted from the fluorescent lamp for the liquid crystal backlight in a direction other than the direction of the light guide plate is reflected by the reflection film and is focused in the direction of the light guide plate. At this time, one outside the glass tube
It is preferable that an area of or more is covered with a reflective material having a light reflectance of 50 to 98%. Area less than 1/3 or 5
When the light reflectance is 0% or less, the light condensing effect is small, and this structure using the reflecting material becomes meaningless. Light reflectance is 98
% Of the material is practically nonexistent, but if present, the effect of the fluorescent lamp coated with the spherical phosphor described below is reduced. Most of the reflected light is focused towards the diffuser across the fluorescent lamp. Since the fluorescent film of the fluorescent lamp of the present invention is coated with a spherical fluorescent material, it has a higher light transmittance than a film made of a normal fluorescent material. For this reason, the light output focused in the direction of the light guide plate can be increased by 10% or more as compared with a fluorescent lamp having the same total light output coated with a phosphor. Further, at this time, the fluorescent lamp of the present invention has a tube diameter of 8 to apply a spherical phosphor with good dispersibility.
mm or less, it can be easily manufactured, and is effective in reducing the thickness of the liquid crystal display device.

Since the intensifying screen of the present invention uses spherical particles, a dense and uniform fluorescent film with little light scattering can be obtained.
The phosphor used has an average particle size of 0.1 to 20 μm,
It is composed of transparent spherical particles having a ratio of the major axis to the minor axis of each particle of 1.0 to 1.5, and 0.001 to 5% by weight, preferably 0.1 to 5% by weight of ultrafine particles having a particle diameter of about 0.2 μm. Any kind of phosphor can be used as long as the phosphor contains 01 to 1% by weight. For example,
CaWO ₄ , CaWO ₄ : Pb, Ln ₂ O ₂ S: R (where Ln is at least one element selected from the group consisting of La, Gd, Lu and Y, and R is at least one element selected from the lanthanide group) A rare-earth oxysulfide-based phosphor represented by a composition formula of Ln ₂ O ₃ : R (where Ln is at least one element selected from the group consisting of La, Gd, Lu and Y; R is at least one element selected from the lanthanide group), a rare earth oxide-based phosphor represented by a composition formula, Ba _1-x Sr _x FCl _1-y Br
_y : Eu (x = 0 to 1, y = 0 to 1), BaSO ₄ : E
u, LaOBr: R (R = Tb, Tm), HfP
₂ O ₇ , Hf ₃ (PO ₄ ) ₄ , YTaO ₄ , GaTaO
There are _four .

FIG. 3 shows the structure of the radiation intensifying screen of the present invention. Here, 31a and 31b are radiation intensifying screens (31a is a front intensifying screen, 31b is a back intensifying screen), 32 is a radiation film, and 33 is radiation transmitted through an image to be copied. The radiographic intensifying screens 31a and 31b are composed of 35 fluorescent films on 34 supports and 36 protective films. 31a and 31b depending on the incident radiation
The phosphor of the intensifying screen emits light, and the emitted light allows the radiation film to be efficiently exposed from both sides. At this time, the particle size is 2
If a photograph is taken with an intensifying screen using a phosphor of 0 μm or more, the homogeneity of the image is impaired. The phosphor particles of the present invention contain ultrafine particles having a particle size of 0.2 μm or less in a range of 0.001 to 5 μm.
%, Preferably 0.01 to 1% by weight, but if more than 5% by weight contains ultrafine particles, light scattering increases. Therefore, the light transmittance of a phosphor film made of this phosphor is increased. And the utility becomes poor. On the other hand, when ultrafine particles in the above range are included, the fluidity and dispersibility of the phosphor are improved. For this reason, when the phosphor film is produced by sedimentation of the phosphor in the liquid or application of the phosphor slurry, the phosphor film approaches close packing. For this reason, irregular reflection in the fluorescent film, which was large when a conventional phosphor is used, is reduced, and the ratio of light emission used as light output from the fluorescent screen is increased (the transmittance of the fluorescent film is improved). The brightness of the film is improved. For example, using a raw material phosphor having the same average particle diameter and the spherical particle phosphor according to the present invention to produce and compare the same amount of applied phosphor film, a thinner phosphor film can be obtained with the spherical particle phosphor. Therefore, a radiation image with high sharpness can be obtained.

The phosphor of the present invention containing ultrafine particles is easy to mix because of its good dispersibility, and is used for preparing a two-layer coated radiographic intensifying screen using a phosphor having a different average particle size. Fabrication of the film is easy. In addition, since it contains ultrafine particles, a two-layer fluorescent film intensifying screen can be produced without using phosphors having different average particle sizes. That is, using the phosphor of the present invention containing a large amount of ultrafine particles (about 1% by weight), ultrasonic cleaning is performed to disperse the particles having a particle size of several μm and the ultrafine particles, and then the fluorescent film is formed on the support by a sedimentation method. Is produced, a layer of ultrafine particles is formed on the support side, and a dense mixed film of particles having a particle diameter of several μm and ultrafine particles is formed thereon. In this case, it is possible to obtain a radiographic intensifying screen capable of obtaining a radiographic image with high sensitivity and sharpness in a smaller number of steps as compared with the conventional example.

[0054]

Embodiments of the present invention will be described below.

Example 1 A Y ₂ O ₃ : Eu phosphor was used as a raw material. The average particle size of the raw phosphor was measured by the Blaine method and found to be 4.5 μm. This raw material phosphor was supplied into a high-frequency plasma using argon gas as a carrier gas, melted and rapidly cooled to obtain a phosphor according to the present invention. When the average particle size of the obtained phosphor was measured by the Blaine method, it was 4.8 μm. An electron micrograph of the obtained phosphor is shown in FIG. The ratio between the major axis and the minor axis of each phosphor particle determined from the electron micrograph was in the range of 1.00 to 1.10. Further, the phosphor X-ray diffraction pattern of is the same as that of Y ₂ O _3, also the composition Y ₂ O _3: It has been confirmed is Eu. The phosphor was accelerated at an acceleration voltage of 10 kV and a current density of 1 μA / cm ^2.
When the powder luminance was measured by excitation with the electron beam, the value was 98% of that of the raw phosphor.

Next, a phosphor screen having a coating weight of 7 mg / cm ² was formed by a sedimentation method using the obtained phosphor, and an aluminum bag was provided.
It sealed and produced the 7-inch projection type cathode ray tube. The brightness of this cathode ray tube measured at a voltage of 30 kV and a beam current of 200 μA was 790 ft-L. This value was 5% higher than the luminance 750 ft-L of the cathode ray tube manufactured similarly using the raw phosphor.

(Example 2) The oxalate coprecipitated product was
After decomposing and firing at 0 ° C., firing was performed at 1100 ° C. using an alkaline earth halide as a flux to obtain a La ₂ O ₃ : Pr phosphor having a Pr concentration of 0.1 mol%. The average particle size of this raw material phosphor was 6.8 μm as measured by the Blaine method. This raw material phosphor was supplied into high frequency plasma using argon gas as a carrier gas in the same manner as in Example 1, melted, and rapidly cooled to obtain a phosphor according to the present invention. When the average particle size of the obtained phosphor was measured by the Blaine method, it was 7.3 μm. The ratio of the major axis to the minor axis of each phosphor particle determined from the electron micrograph was in the range of 1.00 to 1.15, and contained 0.3% by weight of ultrafine particles. When the powder luminance of this phosphor was measured under the same conditions as in Example 1, it was 78% of the raw material phosphor. It is considered that the powder luminance was significantly reduced as described above because Pr was somewhat oxidized. The emission color at this time was green, and showed a spectrum having peaks near 510 nm and 670 nm. The emission color was the same as that of the raw phosphor and the composition was also the same.

Next, a phosphor screen having a coating weight of 11 mg / cm ² was formed by a sedimentation method using the obtained phosphor, and an aluminum bag was applied. An inch projection cathode ray tube was manufactured. For this cathode ray tube, a voltage of 30 kV and a beam current of 200 μA
Was 300 ft-L when the luminance was measured under the following conditions. This value was 20% higher than the luminance of 250 ft-L of a cathode ray tube manufactured similarly using the raw phosphor. As described above, the phosphor of the present embodiment has a higher luminance as a cathode ray tube than the raw phosphor, despite the lower powder luminance. This is due to the fact that the particle shape of the phosphor of this embodiment is a shape close to a true sphere.

Example 3 An oxalate co-precipitated product was treated with 90
After decomposition and firing at 0 ° C., 1400 without flux
C., the Eu concentration is 5 mol% Gd ₂ O
₃ : Eu phosphor was obtained. When the X-ray diffraction of this raw material phosphor was measured, most was monoclinic Gd ₂ O ₃ , but a pattern of cubic Gd ₂ O ₃ having a strongest peak ratio of 5% was also observed. Was. When the average particle size of the raw phosphor was measured by the Blaine method, it was 3.5 μm, but it was slightly aggregated. This raw material phosphor was supplied into high frequency plasma using argon gas as a carrier gas in the same manner as in Example 1, melted, and rapidly cooled to obtain a phosphor according to the present invention. When the average particle size of the obtained phosphor was measured by the Blaine method, it was 4.2 μm. The ratio between the major axis and the minor axis of each phosphor particle determined from the electron micrograph was 1.
It was in the range of 00 to 1.18. The X-ray diffraction of the obtained phosphor were measured, consistent with Gd ₂ O ₃ monoclinic, not observed pattern of Gd ₂ O ₃ cubic, monoclinic almost completely It was confirmed that the phosphor was Gd ₂ O ₃ : Eu phosphor. The obtained phosphor was used at a wavelength of 254 nm.
When the powder luminance was measured by excitation with ultraviolet light, the value was 95% of the raw material phosphor.

Next, the obtained phosphor is applied to the inner surface of a glass tube using a nitrocellulose binder, whereby
A 40 W rated fluorescent lamp was produced. A similar fluorescent lamp was manufactured using the raw phosphor. When the luminous flux of both fluorescent lamps was measured under the rated input, the fluorescent lamp of Example 3 showed a value 3% higher than the fluorescent lamp of the raw material phosphor.

(Example 4) A Gd ₂ O ₃ : Eu phosphor belonging to a cubic crystal system was used as a raw material. When the average particle size of the raw phosphor was measured by the Blaine method, it was 3.4.
μm. This raw material phosphor was supplied into a high-frequency plasma torch using a mixed gas of argon and oxygen as a carrier gas, melted and rapidly cooled to obtain a powder sample. This phosphor was suspended in water, ultrasonically washed and allowed to stand, the upper layer portion was removed, and after suction filtration, dried at 100 ° C. to obtain a phosphor according to the present invention. When the average particle size of the obtained phosphor was measured by the Blaine method, it was 3.6 μm. An electron micrograph of the obtained phosphor is shown in FIG. The ratio of the major axis to the minor axis of each phosphor particle determined from the electron micrograph was 1.00.
１．１1.10. This phosphor has a particle size of 0.2μ.
m and 0.02% by weight of ultrafine particles. The X-ray diffraction pattern of this phosphor was completely different from that of the raw phosphor, indicating that the phosphor was monoclinic. The phosphor was excited with an electron beam having an accelerating voltage of 10 kV and a current density of 1 μA / cm ² or an ultraviolet ray having a wavelength of 254 nm, and the emission spectrum was measured. The main emission wavelength was 623 nm, and the emission chromaticity value was x = 0. 63, y = 0.35. These values are the main emission wavelength 611 nm and emission chromaticity value x of the raw phosphor.
= 0.62 and y = 0.36.

Next, a phosphor screen having a coating amount of 7 mg / cm ² was formed by a sedimentation method using the obtained phosphor, an aluminum bag was applied, an electron gun was mounted, and the air was exhausted and sealed. An inch projection cathode ray tube was manufactured. About this cathode ray tube,
When the luminance was measured under the conditions of a voltage of 29 kV and a beam current of 1500 μA, it was 3500 ft-L. This value is the monoclinic Gd obtained by firing at 1300 ° C. and quenching.
The luminance was 30% higher than the luminance of 2700 ft-L of a cathode ray tube manufactured similarly using a ₂ O ₃ : Eu phosphor.

Example 5 As a raw material, a Y ₂ O ₃ : Eu phosphor belonging to a cubic crystal system was used. The Eu / Y atomic ratio was 4.4%. The average particle size of this raw material phosphor was 3.2 μm as measured by the Blaine method. This raw material phosphor was supplied into a high-frequency plasma torch using a mixed gas of argon and oxygen as a carrier gas, melted, rapidly cooled, and collected by a cyclone to obtain a phosphor composed of particles close to a true sphere. This phosphor was suspended in water, ultrasonically washed and allowed to stand, the upper layer was removed, and suction filtration and drying were performed. This phosphor contained particles of a slightly monoclinic crystal system in addition to the cubic crystal system. Further, 0.1% of ultrafine particles having a particle size of 0.2 μm or less were contained. The phosphor obtained by calcining the phosphor in air at 1100 ° C. for 2 hours was composed of only cubic crystal particles.
The average particle size of this phosphor was 3.8 μm as measured by the Blaine method. The ratio between the major axis and the minor axis of each phosphor particle determined from the electron micrograph was 1.00 to 1.10.
Was in the range. The ultrafine particles melted and crystallized somewhat and adhered to the particle surface, but the amount was about 0.1%. The Eu / Y atomic ratio was 3.5%. When this phosphor was excited with an electron beam having an acceleration voltage of 10 kV and a current density of 1 μA / cm ² or an ultraviolet ray having a wavelength of 254 nm, and the emission spectrum was measured, the main emission wavelength was 611 nm, which was the same as the raw material phosphor. However, the luminous efficiency is 110% when excited by an electron beam and 80% when excited by an ultraviolet ray as compared with the raw phosphor.
%Met.

Next, a phosphor screen having a coating amount of 7 mg / cm ² was formed by a sedimentation method using the obtained phosphor, and an aluminum bag was applied. An inch projection cathode ray tube was manufactured. There were no problems such as film peeling at the time of formation of the sedimentation film and poor pressure resistance caused by the film formation method due to vibration after the cathode ray tube formation. The brightness of this cathode ray tube measured at a voltage of 29 kV and a beam current of 1500 μA was 5300 ft-L. This value is 1 compared with the luminance of 4700 ft-L of a cathode ray tube similarly manufactured using the raw material phosphor before the thermal plasma treatment.
The value was 3% higher.

(Example 6) Blue and green light-emitting phosphor stripes were formed on a 25-inch color cathode ray tube panel, and the phosphor obtained in Example 4 was applied as a red light-emitting phosphor by a usual procedure. did. After the phosphor screen was exposed and developed, the coating amount was measured to be 4.0 mg / c
m ² . Irregularities on the edges of the phosphor screen stripes
Was visually determined to be the best 10 points. on the other hand,
Monoclinic Gd ₂ O ₃ : E obtained by firing at 1300 ° C. and quenching
In the case of using the u phosphor, the coating amount is 3.1 mg / cm.
^{2. The} score was 7 points. Next, a cathode ray tube was produced through the steps of organic filming, aluminum film deposition, baking, attachment of a funnel and an electron gun, and exhaust / sealing.
The red light emission luminance of this cathode ray tube was 120% of the luminance of a cathode ray tube similarly prepared using a monoclinic Gd ₂ O ₃ : Eu phosphor obtained by firing at 1300 ° C. and quenching.

The width of the color reproduction range of this cathode ray tube is determined by using the cubic Gd ₂ O ₃ : Eu phosphor as the raw material of the fourth embodiment or the cubic Y ₂ O ₃ : Eu phosphor as the raw material of the fifth embodiment. It was confirmed that the width was approximately 7% wider than any of the cathode ray tubes manufactured in the same manner.

(Example 7) A Gd ₂ O ₃ : Eu phosphor belonging to the same cubic crystal system as in Example 4 was used as a raw material. The raw material phosphor was supplied to a direct current plasma torch for plasma spraying using argon gas as a carrier gas to be melted, blown into water and rapidly cooled to obtain a phosphor according to the present invention. When the average particle size of the obtained phosphor was measured by the Blaine method, it was 4.2 μm, and the average particle size was 0.2 μm.
It contained 0.05% of ultrafine particles of not more than μm. FIG. 6 shows an electron micrograph of the obtained phosphor. This phosphor is
Compared with the phosphor produced by the high-frequency thermal plasma method of Example 4, the sphericity was slightly inferior, and the ratio between the major axis and the minor axis of each phosphor particle was in the range of 1.00 to 1.30. But,
It could be regarded as close to a true sphere. Also,
The X-ray diffraction pattern of this phosphor was completely different from that of the raw phosphor, indicating that the phosphor was monoclinic.

Next, a phosphor screen having a coating amount of 7 mg / cm ² was formed by a sedimentation method using the obtained phosphor, and an aluminum bag was applied. An inch projection cathode ray tube was manufactured. About this cathode ray tube,
When the luminance was measured under the conditions of a voltage of 29 kV and a beam current of 1500 μA, it was 3400 ft-L. This value was 6% higher than the luminance of 3200 ft-L of a cathode ray tube manufactured similarly using the raw phosphor.

Example 8 Gd ₂ O containing 5 mol% of Tb and belonging to a cubic crystal system as a raw material for thermal plasma treatment
₃ : Tb phosphor was used. The average particle size of the raw phosphor was 3.5 μm. The raw material phosphor was supplied to a high-frequency plasma torch using an argon gas as a carrier gas, melted, quenched, and then recovered by a cyclone to obtain a phosphor according to the present invention. The average particle size of the obtained phosphor was 4.2 μm. The ratio between the major axis and the minor axis of each phosphor particle determined by an electron microscope is in the range of 1.0 to 1.10, and 0.2% by weight of ultrafine particles having a particle size of 0.2 μm or less.
Included. The X-ray diffraction pattern of this phosphor was completely different from that of the raw phosphor and was monoclinic.

When this phosphor was excited by an electron beam having an acceleration voltage of 10 kV and a current density of 1 μA / cm ² , it emitted green light, and its luminous efficiency was at least three times that of the cubic phosphor as a raw material. Indicated.

Next, a 7-inch projection cathode ray tube was manufactured in the same manner as in Example 4 by using the obtained phosphor by a sedimentation method. The luminance under the conditions of a voltage of 29 kV and a beam current of 1500 μA was 3.5 times or more that of the raw phosphor.

Example 9 A Gd ₂ O ₃ : Pr phosphor belonging to a cubic crystal system was used as a raw material for the thermal plasma treatment. The average particle size of this raw material phosphor was 3.2 μm as measured by the Blaine method. This raw material phosphor was supplied into a high-frequency plasma torch using argon gas as a carrier gas, melted and rapidly cooled to obtain a phosphor according to the present invention. When the average particle size of the obtained phosphor was measured by the Blaine method, it was 3.8 μm. The ratio between the major axis and the minor axis of each phosphor particle determined from the electron micrograph was in the range of 1.00 to 1.10. Further, the X-ray diffraction pattern of this phosphor was completely different from that of the raw phosphor, indicating that the phosphor was monoclinic. This phosphor is accelerated at an accelerating voltage of
kV, electron beam with current density of 1 μA / cm ² or wavelength 25
When the emission spectrum was measured by excitation with ultraviolet light of 4 nm, it showed a green emission color, and the emission chromaticity value was x = 0.3.
1, y = 0.51. This emission characteristic shows that the raw material phosphor shows a red emission color, emission chromaticity value x = 0.64, y
It was significantly changed as compared with 0.28.

Next, a phosphor screen having a coating amount of 7 mg / cm ² was formed by a sedimentation method using the obtained phosphor, and an aluminum bag was applied. An inch projection cathode ray tube was manufactured. About this cathode ray tube,
When the luminance was measured under the conditions of a voltage of 29 kV and a beam current of 1500 μA, it was 580 ft-L. This value is
Monoclinic Gd ₂ O ₃ : P obtained by firing at 1300 ° C. and quenching
r The luminance of a cathode ray tube manufactured similarly using phosphor
The value was 16% higher than ft-L.

Comparative Example 1 A divalent europium-activated barium-calcium-strontium halophosphate phosphor, a cerium-terbium-activated lanthanum phosphate phosphor and a commercially available europium-activated yttrium oxide phosphor that is not spherical particles were mixed. It was applied to the inner surface of a glass bulb having a tube diameter of 32 mm to produce a conventional three-wavelength straight fluorescent lamp of 40 W type having a correlated color temperature of 5000 K and a chromaticity on a black spot locus. The total luminous flux at 0 hours of lighting of this lamp is 364
The special color rendering index R ₉ of 0 lumen and red was 35.

Comparative Example 2 After co-precipitation of gadolinium and europium oxalate was decomposed and calcined at 900 ° C., calcined at 1400 ° C. using an alkaline earth halide as a flux and Gd having a Eu concentration of 5 mol% was obtained. _{A 2} O ₃ : Eu phosphor was obtained. When the X-ray diffraction was measured, it was confirmed that it was almost completely monoclinic. When the average particle size of this phosphor was measured by the Blaine method, it was 3.5 μm.
Met.

Next, the three kinds of phosphors shown in Comparative Example 1 and this Gd ₂ O ₃ : Eu phosphor were mixed to obtain 5000K40W.
A straight tube fluorescent lamp of the shape was fabricated. The total luminous flux of this lamp at 0 hours of lighting was 3,580 lumens, and the red special color rendering index R ₉ was 47. Thus, compared with the fluorescent lamp of Comparative Example 1, the total luminous flux was reduced by 1.6%, and R ₉ was 12%.
The points have improved. In other words, to improve R ₉ by 10 points, the total luminous flux is reduced by 1.4%.

Example 10 The same oxalate coprecipitation of gadolinium and europium as in Comparative Example 2 was decomposed and fired at 1000 ° C. to obtain a Gd ₂ O ₃ : Eu powder. X of this powder
When the line diffraction was measured, a cubic diffraction pattern was obtained. Next, this powder is supplied into a high-frequency plasma torch using a mixed gas of argon and oxygen as a carrier gas,
The phosphor according to the present invention was obtained by melting and quenching.
The average particle size of this phosphor measured by the Blaine method was 1.
It was 5 μm. FIG. 7 shows an electron micrograph of the obtained phosphor. The ratio between the major axis and the minor axis of each phosphor particle determined from the electron micrograph was in the range of 1.00 to 1.15. Further, when the ratio between the cubic system and the monoclinic system was calculated from the ratio of the X-ray diffraction peaks of this phosphor, it was found that the monoclinic system was contained in approximately 80%.

Next, the three kinds of phosphors shown in Comparative Example 1 and this Gd ₂ O ₃ : Eu phosphor were mixed to obtain 5000K40W.
A straight tube fluorescent lamp of the shape was fabricated. At this time, Gd ₂ O ₃ :
The mixing ratio of the Eu phosphor was 20% by weight. The total luminous flux of this lamp at 0 hours of lighting was 3,570 lumens, and the special color rendering index R ₉ of red was 55. Thus, the total luminous flux was reduced by 2.0% as compared with the fluorescent lamp of Comparative Example 1, but R ₉ was improved by 20 points. That is, to improve R ₉ by 10 points, the total luminous flux is 1.0 point.
% Only decreases.

(Example 11) Y ₂ O ₂ S: Eu produced by the same flux method as the red phosphor for color TV was used as a raw material. However, the Eu / Y atomic ratio was set to 8.0%. The average particle size of this raw material phosphor was 4.1 μm.
This raw material phosphor was stirred in a 1/40 diluted nitric acid solution for 20 minutes, washed with water, filtered by suction, replaced with alcohol, and dried. 2% by weight of sulfur was added to this sample, introduced into a 4 MHz high frequency plasma torch in an argon atmosphere, quenched, and collected by a cyclone. Ultrasonic waves were applied to the obtained sample in water and allowed to stand, and then the upper layer was removed to obtain spherical particles. The particle surface of this sample contained 0.05% of ultrafine particles having a size of about 0.1 μm. This sample had a gray purple body color and a visible light reflectance of 40%. Further, this sample was fired at 900 ° C. for 1 hour in a sulfur atmosphere to obtain a phosphor. FIG. 8 shows an electron micrograph of this phosphor. This phosphor consisted of spherical particles having an average particle size of 4.5 μm. The ratio between the major axis and the minor axis of each phosphor particle determined from the electron micrograph was in the range of 1.00 to 1.10. The body color of this phosphor is white and the visible light reflectance is 9
4%. When the X-ray diffraction of this phosphor was measured, it showed a diffraction pattern of oxysulfide. The Eu / Y atomic ratio of this phosphor was 3.7%. Acceleration voltage 1
The emission color by electron beam excitation under the conditions of 0 kV and a current density of 0.5 μA / cm ² was red suitable for color TV.

After blue and green phosphor stripes were formed on a 25-inch color cathode ray tube panel,
The phosphor obtained in Example 4 was applied as a red light-emitting phosphor by an ordinary procedure. At this time, 420 to 35 for exposure
The transmittance of 0 nm ultraviolet light was 3%. After the phosphor screen was exposed and developed, the coating amount was measured to be 4.0 mg.
/ Cm ² . When the unevenness (sharpness) at the end of the phosphor screen stripe was visually judged, the best 10 points were obtained. On the other hand, when a red phosphor for color TV, which is a raw material not subjected to thermal plasma treatment, was used, the transmittance of ultraviolet light was 1%, the coating amount was 3.5 mg / cm ² , and the number of sharp points was 9 points. Next, a cathode ray tube was produced through the steps of organic filming, aluminum film deposition, baking, attachment of a funnel and an electron gun, and exhaust / sealing. The red emission luminance of this cathode ray tube is as follows.
₂ O ₂ S: The luminance was 120% of the luminance of a cathode ray tube manufactured similarly using a red phosphor for Eu color TV.

Example 12 Y ₂ O ₂ S: Tb having an average particle size of 1.5 μm produced by a flux method was used as a raw material. The Tb / Y atomic ratio was 6.5%. A 1/100 diluted aqueous solution of tamol was added to the raw phosphor, suction filtered, replaced with alcohol, and dried. To this sample, 3% by weight of sulfur was added, introduced into a 4 MHz high frequency plasma torch in an argon atmosphere, rapidly cooled, and collected by a cyclone. Ultrasonic waves were applied to the obtained sample in water and allowed to stand, and then the upper layer was removed to obtain spherical particles. This phosphor contained 0.05% of ultrafine particles. This sample had a flesh color and a visible light reflectance of 50%. Further, this sample was fired at 900 ° C. for 1 hour in a sulfur atmosphere in the same manner as in Example 11 to obtain a phosphor. This phosphor was composed of white spherical particles having an average particle size of 1.2 μm and containing 0.02% of distinguishable ultrafine particles, and the visible light reflectance was 91%. Tb / Y
The atomic ratio was 3.5%. The emission spectrum by electron beam excitation showed that the 544 nm band was 10 times or more stronger than the 415 nm band and was green.

This phosphor was settled on a glass substrate having a diameter of 25 mm by a lithium sulfate-potassium silicate method to form a phosphor film. Next, organic filming, aluminum film deposition,
After baking, X with 9 inch X-ray input surface
A cathode ray tube was manufactured through the steps of evacuation and sealing, which were mounted as an output surface of a line image intensifier. This X-ray image intensifier is 25
When operated at a cathode voltage of kV, the resolution of the output surface is 55 line pairs / cm at the center, and the light output is 1 mR / s.
ec X-ray input was 80 nits. On the other hand, the resolution of an X-ray image intensifier manufactured in the same manner using a Y ₂ O ₂ S: Tb phosphor which is not a spherical particle was 40 line pairs / cm, and the light output was 75 nits.

Example 13 The Y ₂ O ₃ : Eu phosphor used as the raw material of Example 1 and the spherical phosphor of Example 1 were each placed in a glass tube having an inner diameter of 4.5 mm by a vacuum suction method at 6 mg / cm 2. A cold-cathode fluorescent lamp with a total length of 150 mm was prepared by coating with a coating weight of No. ² and covering an area of 50% of the outer surface of the glass tube with a film-like reflector having a reflectance of 80%. When these fluorescent lamps were turned on with an input power of 2 W, the difference in luminance between both ends of the fluorescent lamp using the raw material phosphor of Example 1 was 6%. The difference in luminance between both ends was 1.5%.

Next, in the liquid crystal display shown in FIG. 2, the above two types of fluorescent lamps are used in a state where the fluorescent lamp 21 and the reflecting plate 22 are combined, and the liquid crystal panel 25 is a monochrome TFT having no color filter. A red monochrome display liquid crystal display was fabricated using the liquid crystal panel. When illuminated with an input power of 2 W, the luminance of the display surface in the case of the fluorescent lamp using the spherical phosphor is 18 times smaller than the luminance of the display surface in the case of the fluorescent lamp using the raw material phosphor of Example 1. % Higher value.

Example 14 The same as Example 13 except that a coating weight of 5.5 mg / cm ² was used using a phosphor obtained by mixing commercially available phosphors of blue light emission, green light emission and red light emission for a fluorescent lamp. Fluorescent lamps of the same shape were produced by various methods. When this fluorescent lamp was lit with an input power of 2 W, the difference in luminance between both ends of the fluorescent lamp was 9%. The diffuse transmittance of the fluorescent film of this fluorescent lamp is 3
It was 0%.

Next, a commercially available phosphor for blue light emission, green light emission and red light emission for a fluorescent lamp was supplied into a high-frequency plasma using argon as a carrier gas, melted, and quenched.
By ultrasonic cleaning in water, the average particle size is 4.6 μm (the content of ultrafine particles of 0.2 μm or less is 0.08
%), An average particle size of 5.2 μm (0.06% by weight of ultrafine particles having a particle size of 0.2 μm or less), and an average particle size of 4.3 μm.
m (content of ultrafine particles of 0.2 μm or less: 0.01% by weight)
3 types of spherical phosphors were obtained. These fluorescent materials were mixed to produce a similar fluorescent lamp. This fluorescent lamp is 2W
When the lamp was turned on with the input power of, the difference in luminance between both ends of the fluorescent lamp was 2.5%. The diffused transmittance of the fluorescent film of this fluorescent lamp was 55%.
The value was 8 times.

A color liquid crystal display was manufactured in the same manner as in Example 13 except that these two types of fluorescent lamps were used and a TFT liquid crystal panel having a color filter was used as the liquid crystal panel. When illuminated with an input power of 2 W, the brightness of the display surface when displaying white when using a fluorescent lamp using a spherical phosphor is the white display when using the former fluorescent lamp using a raw material phosphor. The value was 12% higher than the brightness of the display surface at the time.

Example 15 A CaWO ₄ phosphor having an average particle size of 11.3 μm was produced by a usual wet sedimentation and firing method. This raw material phosphor was supplied into a high-frequency thermal plasma using a mixed gas of argon and oxygen as a carrier, melted, and then rapidly cooled to obtain a phosphor according to the present invention.
The average particle size of the obtained phosphor was 10.5 μm, and after ultrasonic cleaning, contained 0.05% by weight of ultrafine particles having a particle size of 0.2 μm or less. A slurry was prepared by mixing a binder with this phosphor, and the phosphor coating amount after drying was 40 mg / cm ² on a support by a doctor blade method.
After coating uniformly to form a fluorescent film, a protective film was adhered to obtain an intensifying screen. On the other hand, for comparison, a radiographic intensifying screen was obtained in the same manner as described above using the raw phosphor (Comparative Example 3). When the coating thickness of the phosphor film of each intensifying screen was measured, it was 149 μm in Comparative Example 3 and was 128 μm in Example 15.

Next, the obtained intensifying screens were superimposed on an X-ray film and subjected to X-ray photography by a conventional method, and the sensitivity and sharpness of the developed X-ray film were measured. The sensitivity of Example 15 was 104% with respect to Comparative Example 3. Also, MTF is measured by a contrast method,
When comparing the sharpness with the value of the MTF spatial frequency of 2 lines / mm, Example 15 was 109% of Comparative Example 3.

Example 16 A Gd ₂ O ₂ S: Tb phosphor having an average particle size of 4.9 μm was prepared by a usual wet precipitation / calcination method. This raw material phosphor was supplied into a high-frequency thermal plasma using a mixed gas of argon and oxygen as a carrier, melted, and then rapidly cooled. At this time, by changing the conditions, the average particle diameter according to the present invention is 2.4 μm and 9.5 μm.
Were obtained. After the ultrasonic cleaning, the phosphor is 0.05% by weight of ultrafine particles of 0.2 μm or less.
And 0.01% by weight. These phosphors are mixed with a binder to prepare a slurry of a small particle phosphor and two kinds of phosphor slurries. The slurries are successively used, and the film thickness after drying by a doctor blade method on a support is 25 μm.
After two layers were uniformly coated to a thickness of 0 μm to form a fluorescent film, a protective film was adhered to obtain a radiographic intensifying screen. On the other hand, for comparison, two types of G particles having an average particle size of 2.5 μm and 9.8 μm, manufactured by a usual wet precipitation / calcination method, were used.
A radiographic intensifying screen was obtained in the same manner as described above using d ₂ O ₂ S: Tb phosphor (Comparative Example 4). When the coating amount of the fluorescent film on each intensifying screen was measured, it was found to be 78 mg / cm ² in Comparative Example 4 and 96 mg / cm ² in Example 16.

Next, for each of the obtained radiographic intensifying screens,
The X-ray film was superimposed on the X-ray film and subjected to X-ray photography by a conventional method, and the sensitivity and sharpness of the developed X-ray film were measured. The sensitivity of Example 16 was 1 compared to Comparative Example 4.
09%. The MTF was measured by the contrast method, and the sharpness was compared with the value of the MTF spatial frequency of 2 lines / mm.

Example 17 A Gd ₂ O ₂ S: Tb phosphor having an average particle size of 8.1 μm was prepared by a usual wet precipitation / calcination method. This raw material phosphor was supplied into a high-frequency thermal plasma using a mixed gas of argon and oxygen as a carrier, melted, and then rapidly cooled to obtain a phosphor according to the present invention. The average particle size of the obtained phosphor was 7.6 μm. Perform ultrasonic cleaning and remove ultra-fine particles of 0.2 μm or less
The phosphor containing 5% by weight of the phosphor is deposited on the protective film by a sedimentation method such that the amount of the phosphor after drying becomes 80 mg / cm ² to form a phosphor film. Intensifying screen was obtained. A 1 cm ² specimen was cut out from the radiographic intensifying screen, and the SEM image of the cross section was observed. As a result, it was found that a fluorescent film having the same structure as the two-layer coated fluorescent film of Example 16 was obtained. .

Next, the obtained intensifying screen was superimposed on an X-ray film and subjected to X-ray photography by a conventional method, and the sensitivity and sharpness of the developed X-ray film were measured. The sensitivity of Example 17 was 112% with respect to Comparative Example 4. Also, MTF is measured by a contrast method,
Comparing the sharpness with the value of the MTF spatial frequency of 2 lines / mm, Example 17 was 118% of Comparative Example 4.

In the above embodiment, the phosphor according to the present invention is used for a projection tube, a color cathode ray tube or a straight tube type fluorescent lamp. A similar effect can be achieved when used in an annular or compact fluorescent lamp.

[0095]

As described in detail above, the phosphor of the present invention is:
Since it has a shape close to a true sphere with a small particle size, it is possible to form a dense, uniform, and highly adherent phosphor screen, and to obtain a cathode ray tube, a fluorescent lamp, or a radiographic intensifying screen with high brightness. Further, by utilizing the emission color peculiar to the phosphor of the present invention, a cathode ray tube suitable for various uses and R ₉
Can be obtained.

The fluorescent lamp of the present invention can increase the brightness when used as a light guide type backlight of a liquid crystal display, and also improves the yield when manufacturing a fluorescent lamp with a small tube diameter. It is effective for thinning.

On the other hand, when radiography is performed using the radiographic intensifying screen of the present invention, a radiograph with high sensitivity and high sharpness can be obtained.

[Brief description of the drawings]

FIG. 1 is a view showing the structure of an X-ray image intensifier according to the present invention.

FIG. 2 is a view showing the structure of a liquid crystal display device provided with a light guide type backlight incorporating a fluorescent lamp according to the present invention.

FIG. 3 is a diagram showing a structure of a radiographic intensifying screen according to the present invention.

FIG. 4 is an electron micrograph showing the particle structure of the rare earth oxide phosphor in Example 1 of the present invention.

FIG. 5 is an electron micrograph showing the particle structure of a rare earth oxide phosphor in Example 4 of the present invention.

FIG. 6 is an electron micrograph showing a particle structure of a rare earth oxide phosphor in Example 7 of the present invention.

FIG. 7 is an electron micrograph showing a particle structure of a rare earth oxide phosphor in Example 10 of the present invention.

FIG. 8 is an electron micrograph showing the particle structure of a rare earth oxysulfide phosphor in Example 11 of the present invention.

[Explanation of symbols]

11 input phosphor screen, 12 photocathode, 13 focusing electrode,
14 ... Anode, 15 ... Output phosphor screen, 16 ... Vacuum container, 21
... fluorescent lamp, 22 ... light reflection film, 23 ... light guide plate,
Reference numeral 24: diffusion plate, 25: liquid crystal display panel, 26: lamp cover, 31a, 31b: radiation intensifying screen, 32: radiation film, 33: radiation, 34: support, 35: fluorescent film,
36 ... Protective film.

Continued on the front page (72) Inventor Takeshi Takahara 72 Horikawa-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Prefecture Inside the Toshiba Horikawacho Plant (72) Inventor Takeo Ito 1-9-2 Hara-cho, Fukaya-shi, Saitama Examiner Hiroko Fujiwara, Toshiba Fukaya Electronics Factory (56) References JP-A-1-108294 (JP, A) JP-A-62-201989 (JP, A) JP-A-2-255891 (JP, A) JP 8-92552 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C09K 11/78 G21K 4/00 H01J 29/20 H01J 61/44

Claims (19)

(57) [Claims] 1. Ln ₂ O ₃ : R (where Ln is La, G
d, at least one element selected from the group consisting of Lu and Y, and R is at least one element selected from the lanthanide group), and has an average particle size of 0.5 to
15 μm and the ratio of the major axis to the minor axis is 1.0 to 1.5
And ultrafine particles having a particle diameter of 0.2 μm or less containing the same constituent element as the transparent spherical particles and attached to the surface of the transparent spherical particles at a ratio of 0.001 to 0.5% by weight. A phosphor comprising: 2. R is Eu and its atomic ratio to Ln is 1 to 6%, R is Tb and its atomic ratio to Ln is 0.1 to 6%, or R is Pr and its atomic ratio to Ln. 2. The phosphor according to claim 1, wherein is 0.01 to 5%. 3. The transparent spherical particles are represented by a composition formula of Gd ₂ O ₃ : R (where R is at least one element selected from lanthanide group), and at least a part of the crystal system is monoclinic. The phosphor according to claim 1, which is a system. 4. R is Eu and its atomic ratio to Ln is 1 to 6%, R is Tb and its atomic ratio to Ln is 0.1 to 6%, or R is Pr and its atomic ratio to Ln. The phosphor according to claim 3, wherein is 0.01 to 5%. 5. The transparent spherical particles are represented by a composition formula of Gd ₂ O ₃ : Eu, the proportion of monoclinic crystals is 5 to 100%, and the average particle size is 0.5 to 3 μm. The phosphor according to claim 1, wherein: 6. A cathode ray tube comprising a phosphor layer containing the phosphor according to claim 1. 7. A cathode ray tube comprising a phosphor layer containing the phosphor according to claim 3 as at least one component. 8. A fluorescent lamp comprising a phosphor layer containing the phosphor according to claim 1 as at least one component formed on an inner surface of a glass bulb. 9. The phosphor according to claim 5, a europium-activated yttrium oxide phosphor having an emission peak near 611 nm and emitting red light, and an emission peak of 540 to 57.
A phosphor that emits green light at 0 nm and has an emission peak of 4
A fluorescent lamp characterized in that a phosphor layer mainly composed of a phosphor mixed with a phosphor which emits blue light near 50 nm is formed on the inner surface of a glass bulb. 10. The phosphor emitting green light comprises at least one selected from the group consisting of a cerium / terbium-activated lanthanum phosphate phosphor and a cerium / terbium-activated barium / magnesium aluminate phosphor. A phosphor emitting blue light is a divalent europium-activated barium / magnesium halophosphate phosphor, a divalent europium / manganese co-activated barium / magnesium halophosphate phosphor and a divalent europium-activated barium / calcium / strontium halophosphate phosphor The fluorescent lamp according to claim 9, comprising at least one member selected from the group consisting of: 11. An average particle size of 0.5 to 15 μm,
Transparent spherical particles having a ratio of a major axis to a minor axis of 1.0 to 1.5, and the same as the transparent spherical particles adhered to the surface of the transparent spherical particles at a ratio of 0.001 to 0.5% by weight. A cathode ray tube coated with a phosphor containing ultrafine particles having a particle diameter of 0.2 μm or less containing the constituent elements of the above. 12. The cathode ray tube according to claim 11, wherein said cathode ray tube is a direct-view type color cathode ray tube having a shadow mask.
A cathode ray tube as described. 13. The cathode ray tube according to claim 11, wherein the cathode ray tube is used for a projection type video device. 14. The transparent spherical particles have an average particle size of 0.5.
The cathode ray tube according to claim 11, wherein the cathode ray tube is an X-ray image intensifier. 15. An average particle size of 0.5 to 15 μm,
Transparent spherical particles having a ratio of a major axis to a minor axis of 1.0 to 1.5, and the same as the transparent spherical particles adhered to the surface of the transparent spherical particles at a ratio of 0.001 to 0.5% by weight. A fluorescent lamp, characterized in that a fluorescent material containing ultrafine particles having a particle diameter of 0.2 μm or less containing the constituent elements described above is applied to the inner surface of a glass tube. 16. The fluorescent lamp according to claim 15, wherein at least one-third of the outside area of the glass tube is covered with a reflective material having a light reflectance of 50 to 98%. 17. The fluorescent lamp according to claim 15, wherein the inner diameter of the glass tube forming the fluorescent lamp is 8 mm or less. 18. Ln ₂ O ₃ : R (where Ln is La, G
at least one element selected from the group consisting of d, Lu and Y, and R is at least one element selected from the lanthanide group), and the activator concentration of the obtained phosphor is With different activator concentrations, primary particle size is 2 ~
Ln ₂ O ₃ : R (where Ln is La, Gd, Lu) by supplying raw phosphor particles, which are not granulated at 20 μm, together with a carrier gas into a thermal plasma to melt and quench the raw phosphor particles. At least one element selected from the group consisting of
Is at least one element selected from the lanthanide group)
A transparent spherical particle having an average particle diameter of 0.5 to 15 μm and a ratio of major axis to minor axis of 1.0 to 1.5, and 0.001 to 0.5% by weight A phosphor containing the same constituent elements as the transparent spherical particles and adhering to the surface of the transparent spherical particles at a ratio of ultrafine particles having a particle size of 0.2 μm or less. Production method. 19. After treating the raw material phosphor particles in thermal plasma, ultrasonic cleaning is further performed to reduce the ratio of the ultrafine particles attached to the surface of the transparent spherical particles to 0.001 to 0.5. 19. The method for producing a phosphor according to claim 18 , wherein the content is adjusted to a range of weight%.