KR20000066869A - Blue phosphor complex having near ultraviolet-excited phosphors and cathode ray tube employing phosphor layer formed using the same - Google Patents

Abstract

PURPOSE: A fluorescent body and a CRT are provided to reduce electromagnetic wave produced from a near ultraviolet area while improving luminance. CONSTITUTION: A composite blue fluorescent body includes ZnS blue fluorescent body(110) and a near ultraviolet excitation fluorescent member(120) attached to the surface of the fluorescent body. The fluorescent body provides blue luminescence using, as an excitation source, a near ultraviolet ray generated from the fluorescence of the ZnS blue fluorescent body. With a near ultraviolet excitation fluorescent member or a composite blue fluorescent body, a CRT having a reduced electromagnetic wave produced from a near ultraviolet area with an improved blue luminance, can be obtained.

Description

Blue phosphor complex having near ultraviolet-excited phosphors and cathode ray tube employing phosphor layer formed using the same}

The present invention relates to a cathode ray tube, and more particularly, to a cathode ray tube that does not generate electromagnetic waves in the near ultraviolet region by including a composite blue light emitting phosphor including a near ultraviolet excitation phosphor and a fluorescent film manufactured using the same.

In the cathode ray tube, the phosphor constituting the fluorescent film emits light by collision with an electron beam emitted from an electron gun and is displayed as an image on the screen. Especially in the case of color cathode ray tubes, phosphors emitting red, green, and blue colors are applied to the inner surface of the panel in the form of dots or stripes, so that images of various colors are displayed by a combination of light emitted by each pixel when colliding with an electron beam. Done.

Fluorescent components commonly used for color cathode ray tubes include europium-activated yttrium sulfide phosphors (Y ₂ O ₂ S: Eu) as red light-emitting phosphors, copper, gold-activated zinc sulfide phosphors (ZnS :) as green light-emitting phosphors. Cu, Au, Al), zinc sulfide-based blue such as luminescent, chlorine zinc zinc sulfide phosphor (ZnS: Ag, Cl) or silver activator, aluminum zinc zinc sulfide phosphor (ZnS: Ag, Al) as blue light emitting phosphor Luminescent phosphors have generally been widely used.

However, the zinc sulfide-based blue light-emitting phosphor as described above has excellent fluorescence characteristics but emits light in the near ultraviolet region when emitting light. Such light in the near ultraviolet region (usually 360 to 400 nm) is harmful to the human body and emits electromagnetic waves. Generate.

The technical problem to be achieved by the present invention is to provide a composite blue light-emitting phosphor that does not generate electromagnetic waves in the near-ultraviolet region, including near-ultraviolet excitation phosphor.

Another object of the present invention is to provide a cathode ray tube which does not derive electromagnetic in the near ultraviolet region by providing a fluorescent film manufactured using the near ultraviolet excited phosphor or a composite blue light emitting phosphor including the same.

1 is a cross-sectional view of a composite blue light emitting phosphor according to the present invention.

2 is a cross-sectional view of a cathode ray tube according to an embodiment of the present invention.

* Brief description of symbols for the main parts of the drawings *

110 ... zinc sulfide blue light emitting phosphor 120 ... near ultraviolet excitation phosphor

200 ... glass panel 210 ... black matrix layer

220 ... Near ultraviolet absorbing filter layer 230 ... Red light emitting layer

240 ... green phosphor layer 250 ... blue phosphor layer

The technical problem of the present invention may be achieved by a composite blue light emitting phosphor including a zinc sulfide-based blue light emitting phosphor and a near-ultraviolet excitation phosphor attached to the surface thereof.

In another aspect of the present invention, there is provided a cathode ray tube including a glass panel, a black matrix layer formed on an inner surface of the glass panel, and a fluorescent film formed on the black matrix layer and formed of red, green, and blue phosphor layers. The blue phosphor layer can be made by a cathode ray tube, characterized in that it comprises a zinc sulfide-based blue light-emitting phosphor and a composite blue light-emitting phosphor comprising a near-ultraviolet excitation phosphor attached to the surface thereof.

Another technical problem of the present invention is to provide a cathode ray tube including a glass panel, a black matrix layer formed on an inner surface of the glass panel, and a fluorescent film formed on the black matrix layer and composed of red, green, and blue phosphor layers. The blue phosphor layer may be formed by applying a slurry composition for forming a fluorescent film including a zinc sulfide-based blue light emitting phosphor and a near-ultraviolet excitation phosphor, followed by drying and firing.

Another technical problem of the present invention is to provide a cathode ray tube including a glass panel, a black matrix layer formed on an inner surface of the glass panel, and a fluorescent film formed on the black matrix layer and composed of red, green, and blue phosphor layers. It may also be made by a cathode ray tube, characterized in that further comprising a near-ultraviolet absorption filter layer comprising a near-ultraviolet excitation phosphor between the black matrix layer and the fluorescent film.

In the composite blue light emitting phosphor according to the present invention, ZnS: Ag, Cl or ZnS: Ag, Al and the like may be used as the zinc sulfide-based blue light emitting phosphor, and the main ultraviolet peak of the excitation source may be used as the near-ultraviolet excitation phosphor. Phosphor is 360-400 nm, for example BaMgAl ₁₀ O ₁₇ : Eu, BaMg ₂ Al ₁₆ O ₂₇ : Eu, Sr ₅ (PO ₄ ) ₆ Cl: Eu, BaMgAl ₁₄ O ₂₃ : Eu, (Sr, Ca, Ba ) ₅ (PO ₄ ) ₆ Cl: Eu and the like can be used. In this case, the near-ultraviolet excitation phosphor preferably has an average particle diameter of 0.1 to 2.0 mu m.

On the other hand, the method of manufacturing a composite blue light emitting phosphor may be a method that can be commonly used in the field of phosphor manufacturing, for example, a method of producing a pigment with a phosphor, that is, near ultraviolet excitation to the aqueous dispersion of zinc sulfide-based blue light emitting phosphor By adding a phosphor and a binder and adjusting pH with moderate agitation, the composite blue light-emitting phosphor in which the near-ultraviolet-excited phosphor was uniformly adhered to the surface of a zinc sulfide type blue light-emitting phosphor can be obtained.

At this time, the coating amount of the near-ultraviolet excitation blue light-emitting phosphor is preferably about a single layer coverage that can cover the surface of the zinc sulfide-based blue light-emitting phosphor up to one layer.

1 is a cross-sectional view of a composite blue light emitting phosphor according to the present invention. Referring to FIG. 1, a near-ultraviolet excitation phosphor 120 is attached to a surface of a zinc sulfide-based blue light emitting phosphor 110.

Since the near-ultraviolet excitation phosphor 120 emits blue light by using near-ultraviolet rays generated when the zinc sulfide-based blue light-emitting phosphor emits light as an excitation source, the amount of near-ultraviolet radiation is reduced and blue light emission is improved.

On the other hand, the cathode ray tube according to the present invention can be provided in three aspects.

The first aspect thereof is a case where the blue phosphor layer of the fluorescent film comprises the composite blue light emitting phosphor according to the present invention, after preparing a slurry composition for forming a fluorescent film containing the composite blue light emitting phosphor, and then applying the slurry composition Obtainable by a step of drying and firing.

The second embodiment is a case where the blue phosphor layer of the fluorescent film is prepared by applying a slurry composition for forming a fluorescent film comprising an ultraviolet-excited blue light-emitting phosphor and a zinc sulfide-based blue light-emitting phosphor, followed by drying and baking.

In this case, ZnS: Ag, Cl or ZnS: Ag, Al and the like may be used as the zinc sulfide-based blue light-emitting phosphor, and the main ultraviolet peak of the excitation source is 360-400 nm as the near-ultraviolet excitation phosphor. Phosphors having an average particle diameter of 0.1 to 2.0 µm are specifically BaMgAl ₁₀ O ₁₇ : Eu, BaMg ₂ Al ₁₆ O ₂₇ : Eu, Sr ₅ (PO ₄ ) ₆ Cl: Eu, BaMgAl ₁₄ O ₂₃ : Eu, (Sr, Ca, Ba) ₅ (PO ₄ ) ₆ Cl: Eu, and the like.

In addition, in order to maximize blue light emission while minimizing the generation of near ultraviolet light, the content of the near-ultraviolet excitation phosphor in the slurry composition for forming a fluorescent film is preferably 0.1 to 3% by weight based on the total weight of the zinc sulfide-based blue light emitting phosphor. .

Lastly, the third embodiment is a case where a near-ultraviolet absorption filter layer including a near-ultraviolet excitation phosphor is formed on a glass panel before the fluorescent film is formed, and a cathode ray tube equipped with such a near-ultraviolet absorption filter layer can be manufactured according to the following method. have.

First, an undercoat is applied and dried on the inner surface of the glass panel, and then a slurry composition including a near ultraviolet excitation phosphor, a photosensitive agent, a binder, a surfactant, and a solvent is applied, exposed, and developed to form a near ultraviolet absorbing filter layer. Subsequently, a cathode ray tube according to the present invention can be prepared by applying a slurry composition each containing green and red phosphors in order according to a conventional method, and then exposing and developing the red and green phosphor layers to complete the phosphor film.

In this case, ZnS: Ag, Cl, or ZnS: Ag, Al and the like may be used as the zinc sulfide-based blue light-emitting phosphor. As the near-ultraviolet excitation phosphor, the main emission peak of the excitation source is 360 to 400 nm and the average particle diameter is 0.1. As a phosphor of ˜2.0 μm, for example, BaMgAl ₁₀ O ₁₇ : Eu, BaMg ₂ Al ₁₆ O ₂₇ : Eu, Sr ₅ (PO ₄ ) ₆ Cl: Eu, BaMgAl ₁₄ O ₂₃ : Eu, (Sr, Ca, Ba ) ₅ (PO ₄ ) ₆ Cl: Eu and the like can be used.

In addition, in order to improve luminance while suppressing generation of near ultraviolet rays as much as possible, the thickness of the near ultraviolet absorption filter layer is preferably in the range of 0.1 to 3 µm.

FIG. 2 illustrates a film structure of the cathode ray tube according to the third embodiment. Referring to FIG. 2, a black matrix layer 210 is formed on an inner surface of the glass panel 200, and an upper portion of the black matrix layer 210 is formed. A near ultraviolet absorbing filter layer 220 made of a near ultraviolet excitation phosphor is formed on the upper surface of the near ultraviolet absorbing filter layer 220, and a fluorescent film including blue, green, and red phosphor layers 230, 240, and 250 is formed on the near ultraviolet absorbing filter layer 220.

The near-ultraviolet absorption filter layer 220 absorbs and filters near-ultraviolet rays generated from the blue light emitting layer 250 to significantly reduce the amount of generated near-ultraviolet rays. As a result, the amount of near ultraviolet rays is reduced and blue light emission is improved.

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Example 1

First, 0.5 g BaMgAl ₁₀ O ₁₇ : Eu and 0.2 g gelatin having an average particle diameter of 1 μm were added to an aqueous dispersion of 100 g of ZnS: Ag, Cl, and then the pH of the dispersion was adjusted to 3 to 4 to ZnS :: A composite blue light emitting phosphor having BaMgAl ₁₀ O ₁₇ : Eu attached to the surface of Ag and Cl was obtained.

Then, the obtained composite blue light-emitting phosphor, polyvinyl alcohol (PVA), sorbitan monolaurate sulfonate (SLS), propylene oxide ethylene oxide sulfide (PES), dinaphthalene-disulfonic acid soda sulfide (NSS), ethylene A blue phosphor slurry composition was prepared comprising glycol, ammonium dichloride (ADC) and pure water.

A fluorescent film was formed on the inner surface of the glass panel using the prepared blue phosphor slurry composition.

A cathode ray tube employing the above-mentioned fluorescent film was produced and its near ultraviolet generation amount and luminance were measured.

Example 2

A blue phosphor slurry composition including ZnS: Ag, Cl, BaMg ₂ Al ₁₆ O ₂₇ : Eu, PVA, SLS, PES, NSS, ethylene glycol, ADC, and pure water was prepared.

A fluorescent film was formed on the inner surface of the glass panel according to a conventional method using the prepared blue phosphor slurry composition.

A cathode ray tube employing the above-mentioned fluorescent film was produced and its near ultraviolet generation amount and luminance were measured.

Example 3

A slurry composition A comprising Sr ₅ (PO ₄ ) ₆ Cl: Eu, PVA, SLS, PES, NSS, ethylene glycol, ADC, and pure water having an average particle diameter of 0.1 μm was prepared.

A slurry composition B was then prepared comprising ZnS: Ag, Cl, PVA, SLS, PES, NSS, ethylene glycol, ADC and pure water.

Next, the prepared slurry composition A is applied to the inner surface of the glass panel on which the black matrix layer is formed, and then exposed and developed to form a near ultraviolet absorbing filter layer. Then, the slurry composition B is applied onto the near ultraviolet absorbing filter layer, and then exposed and developed. A blue phosphor layer was obtained by forming a blue light emitting layer. The fluorescent film was completed by further forming the red and green phosphor layers according to a conventional method.

A cathode ray tube employing the above-mentioned fluorescent film was produced and its near ultraviolet generation amount and luminance were measured.

Comparative Example 1

Except not adding BaMg ₂ Al ₁₆ O ₂₇ : Eu in preparing the slurry composition, a fluorescent film was formed according to the same method as in Example 2, and then a cathode ray tube employing the same was manufactured. Subsequently, the amount of generated near ultraviolet rays and the luminance of the prepared cathode ray tube were measured.

As a result of measuring the near-ultraviolet generation amount and the luminance of the cathode ray tubes obtained from the above examples and comparative examples, the cathode ray tubes (Examples 1 to 3) employing the fluorescent film produced according to the present invention are cathode ray tubes employing ordinary fluorescent films ( Compared with Comparative Example 1), the generation of near ultraviolet rays was reduced by 70% or more, and the luminance was increased by 5% or more.

According to the present invention, a near-ultraviolet excitation blue light-emitting phosphor or a complex blue light-emitting phosphor including the same is used, and the near-ultraviolet excitation phosphor emits blue light using the near-ultraviolet light generated therefrom when an existing blue phosphor emits light as an excitation source. do. Accordingly, the cathode ray tube of the present invention employing such a near ultraviolet excitation phosphor or a fluorescent film manufactured using the composite blue light emitting phosphor including the same may generate less electromagnetic waves and further improve blue light emission.

Claims (15)

A composite blue light emitting phosphor comprising a zinc sulfide blue light emitting phosphor and an ultraviolet excitation blue light emitting phosphor attached to a surface of the zinc sulfide blue light emitting phosphor. The cathode ray tube according to claim 1, wherein the blue light-emitting phosphor is ZnS: Ag, Cl or ZnS: Ag. The method of claim 1, wherein the near-ultraviolet excitation phosphor is BaMgAl ₁₀ O ₁₇ : Eu, BaMg ₂ Al ₁₆ O ₂₇ : Eu, Sr ₅ (PO ₄ ) ₆ Cl: Eu, BaMgAl ₁₄ O ₂₃ : Eu and (Sr, Ca , Ba) ₅ (PO ₄ ) ₆ One or more selected from the group consisting of Cl: Eu, the cathode ray tube, characterized in that the average particle diameter of 0.1 to 2.0㎛. The cathode ray tube according to claim 1, wherein an adhesion amount of said near ultraviolet excitation phosphor is a monolayer coating amount. In the cathode ray tube comprising a glass panel, a black matrix layer formed on the inner surface of the glass panel, and a fluorescent film formed on the black matrix layer and composed of red, green and blue phosphor layers, And the blue phosphor layer comprises a composite blue light emitting phosphor comprising a zinc sulfide-based blue light emitting phosphor and a near ultraviolet excitation phosphor attached to the surface thereof. The cathode ray tube according to claim 5, wherein the blue light-emitting phosphor is ZnS: Ag, Cl or ZnS: Ag. The method of claim 5, wherein the near-ultraviolet excitation phosphor is BaMgAl ₁₀ O ₁₇ : Eu, BaMg ₂ Al ₁₆ O ₂₇ : Eu, Sr ₅ (PO ₄ ) ₆ Cl: Eu, BaMgAl ₁₄ O ₂₃ : Eu and (Sr, Ca , Ba) ₅ (PO ₄ ) ₆ One or more selected from the group consisting of Cl: Eu, the cathode ray tube, characterized in that the average particle diameter of 0.1 to 2.0㎛. The cathode ray tube according to claim 5, wherein an adhesion amount of said near ultraviolet excitation phosphor is a monolayer coating amount. In the cathode ray tube comprising a glass panel, a black matrix layer formed on the inner surface of the glass panel, and a fluorescent film formed on the black matrix layer and composed of red, green and blue phosphor layers, The blue phosphor layer is prepared by applying a slurry composition for forming a fluorescent film comprising a zinc sulfide-based blue light-emitting phosphor and a near-ultraviolet excitation phosphor, followed by drying and firing. 10. The cathode ray tube according to claim 9, wherein the blue light-emitting phosphor is ZnS: Ag, Cl or ZnS: Ag. The method of claim 9, wherein the near-ultraviolet excitation phosphor is BaMgAl ₁₀ O ₁₇ : Eu, BaMg ₂ Al ₁₆ O ₂₇ : Eu, Sr ₅ (PO ₄ ) ₆ Cl: Eu, BaMgAl ₁₄ O ₂₃ : Eu and (Sr, Ca , Ba) ₅ (PO ₄ ) ₆ One or more selected from the group consisting of Cl: Eu, the cathode ray tube, characterized in that the average particle diameter of 0.1 to 2.0㎛. The cathode ray tube according to claim 9, wherein the content of the near-ultraviolet excitation phosphor in the slurry composition for forming a fluorescent film is 0.1 to 3% by weight based on the total weight of the zinc sulfide-based blue light-emitting phosphor. In the cathode ray tube comprising a glass panel, a black matrix layer formed on the inner surface of the glass panel, and a fluorescent film formed on the black matrix layer and composed of red, green and blue phosphor layers, And a near-ultraviolet absorption filter layer including a near-ultraviolet excitation phosphor between the black matrix layer and the fluorescent film. The method of claim 13, wherein the near-ultraviolet excitation phosphor is BaMgAl ₁₀ O ₁₇ : Eu, BaMg ₂ Al ₁₆ O ₂₇ : Eu, Sr ₅ (PO ₄ ) ₆ Cl: Eu, BaMgAl ₁₄ O ₂₃ : Eu and (Sr, Ca , Ba) ₅ (PO ₄ ) ₆ One or more selected from the group consisting of Cl: Eu, the cathode ray tube, characterized in that the average particle diameter of 0.1 to 2.0㎛. The cathode ray tube according to claim 13, wherein the near ultraviolet absorbing filter layer has a thickness of 0.1 to 3 m.