KR100492949B1 - Fluorescence film formation method of color cathode ray tube - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a fluorescent film of a color cathode ray tube, and an object thereof is to obtain excellent contrast characteristics and high luminance at the same time.

In order to achieve the above object, the present invention forms a red filter layer (or blue filter layer) on the inner surface of the panel on which the black matrix is formed, and a red phosphor (without a pigment) on the upper surface of the red filter layer (or blue filter layer) ( Or a blue phosphor (or blue phosphor) using a blue phosphor), and a blue phosphor (or red phosphor) with a blue pigment (or red pigment) to form a blue phosphor (or red phosphor) The green phosphor is formed by using the green phosphor that is not attached.

Description

Method for forming a fluorescent film of a color cathode ray tube.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color cathode ray tube, and more particularly to a method of forming a fluorescent film in which an image is reproduced by hitting an electron beam.

As shown in FIG. 1, a general color cathode ray tube includes a panel 2 having R, G, and B fluorescent films 1 coated on its inner surface, and a funnel 3 fused to a rear end of the panel 2. ), An electron gun 5 enclosed in the neck portion 4 of the funnel 3, and an electron beam 6 emitted from the electron gun 5 to strike the entire surface of the fluorescent film 1. A deflection yoke (7) for deflecting (6), a shadow mask (8) having a color discriminating function of the electron beam (6), and a frame (9) for supporting the shadow mask (8) on the surface of the panel (2). And, coupled to the frame 9 was configured as an inner shield 10 to shield the external magnetic field.

In the configuration of the fluorescent film 1, a black matrix layer 11, which is an external light absorbing film made of graphite, is formed on the inner surface of the panel 2 by a photosensitive method, and the pigment is deposited thereon. After forming the red fluorescent surface 1R and the blue fluorescent surface 1B and the green fluorescent surface 1G without a pigment in stripe or dot form, the electron beam 6 impinged on the fluorescent film 1 on it. A metal reflection film (not shown) was formed to reflect the light emitted to the secondary electrons and the rear surface generated later to the front portion of the cathode ray tube.

When power is applied to the color cathode ray tube in this configuration, the electron beam 6 is emitted from the electron gun 5, and the electron beam 6 passes through the shadow mask 7 to color discrimination. ) And the image is reproduced.

At this time, the pigment is attached to the black matrix 11 and the phosphor 1 in order to improve the contrast of the screen, and the color cathode ray tube having a higher definition and higher quality and a higher quality contrast cathode ray tube This is required.

However, in such a conventional color cathode ray tube, methods for improving contrast include a method of improving contrast by reducing reflection by external light by widening the area of the black matrix, and applying dark tint glass having a low light transmittance of panel glass. The method of improving the contrast is mainly used, but the former narrows the emission area and the luminance decreases. The latter absorbs the light in the red, blue, and green emission regions, and the luminance is proportional to the decrease in the light transmittance of the glass. There was a problem of deterioration.

The present invention has been made in view of the above-described problem by providing a red filter layer or a blue filter layer on the inner surface of a panel and then forming a red phosphor or a blue phosphor thereon to improve the contrast of the screen and at the same time obtain a high luminance characteristic.

Hereinafter, the embodiment according to the present invention will be described in detail.

3A shows a panel configuration of the cathode ray tube according to the present invention. A black matrix layer 102, which is an external light absorbing film, is formed on an upper surface of the panel 101, and the black matrix 102 and black are formed. Red, green, and blue three-color fluorescent surfaces 103R, 103G, and 103B are formed between the matrices 102 to realize color.

Before the red fluorescent surface 103R is formed on the inner surface of the panel 101, the red filter layer 104 is applied at the position, and the pigment is not attached to the upper surface of the red filter layer 104 to selectively reflect the external light. The red phosphor surface 103R is formed using the red phosphor.

In this case, the blue fluorescent surface 103B uses the blue fluorescent surface 103B using a blue phosphor having a pigment adhesion amount of about five times that of the conventional blue phosphor, that is, a pigment coverage of 5wt%, so that the reflectance at 600 nm is 30% or less. To form.

In another embodiment according to the present invention, as shown in (b) of FIG. 3, the blue filter layer 204 is applied at the position before the blue fluorescent surface 203B is formed on the inner surface of the panel 101, and the external light is selectively reflected. The blue fluorescent surface 203B is formed using a blue phosphor that does not have a pigment attached to the upper surface of the blue filter layer 204.

At this time, the red fluorescent surface 203R uses a red phosphor having a pigment adhesion amount of about three times that of the conventional red phosphor, that is, 0.3 wt% of pigment coverage, so that the reflectance at 500 nm is 30% or less. ).

In the same manner as described above, the green fluorescent surfaces 103G and 203G are formed using green phosphors to which no pigment is attached.

Its formation method is as follows.

First, a photoresist {pure (H ₂ O) + polyvinyl alcohol (PVA) + sodium bichromate (SDC) + butanediol} is applied to the inner surface of the glass of the panel 101 on which the black matrix 102 is formed, followed by drying. Then, the red fluorescent surface 103R (203R) or the blue fluorescent surface 103B (203B) and the green fluorescent surface 103G (203G) positions are exposed to light by photophotographing, and developed by pure water and airborne.

The developed panel 101 is coated with a slurry obtained by dispersing iron oxide (Fe ₂ O ₃ ), which is a red inorganic pigment, or cobalt blue (Co0Al ₂ O ₃ ), which is a blue inorganic pigment, and dried, followed by etching solution {hydrogen peroxide (H ₂ O). ₂ ) + ammonia water (NH ₄ OH)} dissociates the photocured position and develops with pure water to form a red filter layer 104 or a blue filter layer 204.

A red phosphor slurry or a blue phosphor sludge having no pigment attached to the upper surface of the red filter layer 104 or the blue filter layer 204 is coated and dried, and then the red phosphor surface 103R or the blue phosphor surface 203B is photographed. The position is exposed and photocured, and then developed with pure water to complete the red fluorescent surface 103R or the blue fluorescent surface 203B.

At this time, the blue fluorescent surface 103B of the panel 101 in which the red fluorescent surface 103R is formed using the red filter layer 104 has a blue inorganic pigment cobalt blue such that the reflectance becomes 30% or less at 600 nm. the pigment covering rate is as 5wt% exposure by applying to the inner surface of the pigment coating weight is five times as much blue phosphors slurry panel 101 than the conventional blue phosphor, dried photosensitive method of (Co0 · Al ₂ O ₃₎ Photocuring is followed by development with pure water.

Here, when the pigment coating amount is 5wt% or less, it may not have a contrast improving effect. On the contrary, when the pigment coating amount is more than that, there is a problem that the emission luminance of the phosphor is greatly reduced.

The red fluorescent surface 203R of the panel 101 on which the blue fluorescent surface 203B is formed using the blue filter layer 204 is formed of iron oxide as a red inorganic pigment such that the reflectance becomes 30% or less at 500 nm. Fe ₂ O ₃ ) with a 0.3 wt% pigment coverage, a red phosphor slurry having three times the amount of pigment adhered to the inner surface of the panel 101 compared to the conventional red phosphor, was applied to the inner surface of the panel 101, dried, and then exposed to light by photo-sensitization. It is then developed as pure water and completed.

Here, if the pigment coating amount is 0.3wt% or less, it may not have a contrast enhancement effect. On the contrary, if the pigment coating amount is more than that, there is a problem that the light emission luminance of the phosphor is drastically reduced.

The green fluorescent surfaces 103G and 203G, which have the greatest influence on the luminance in the same manner as in the above two embodiments, have high luminous efficiency, i.e., no pigments attached to them, so as to minimize the luminance degradation which may be caused by the contrast enhancement. The green phosphor slurry is applied to the inner surface of the panel 101 on which the red phosphor surface 103R or the blue phosphor surface 203B is formed, is exposed to light by photo-sensitization, and then developed by pure water.

Referring to the operation of the present invention configured as described above is as follows.

First, the red fluorescent surface 103R or the blue fluorescent surface 203B of the screen formed by the present invention forms a transmission spectrum, as shown in FIG. 4 or FIG. 6, so that the phosphor has a high transmittance in the red or blue phosphor light emitting region. By selectively absorbing a wavelength region other than the light emitting portion, contrast and high color purity are exhibited without loss of luminance.

In the case of the panel 101 in which the red fluorescent surface 103R is formed using the red filter 104, the blue fluorescent surface 103B forms a reflection spectrum having a reflectance of 30% or less at 600 nm, and is caused by external light of the phosphor emitting portion. The reflection can be selectively absorbed to improve the contrast.

In addition, in the case of the panel 101 in which the blue fluorescent surface 203B is formed using the blue filter 204, the red fluorescent surface 203R forms a reflection spectrum with a reflectance of 30% or less at 500 nm, and is caused by external light of the phosphor light emitting portion. The reflection can be selectively absorbed to improve the contrast.

The green fluorescent surfaces 103G and 203G, which have the greatest influence on the luminance, use a green phosphor having high luminous efficiency, i.e., no pigments attached, to minimize the luminance deterioration that may be caused by contrast enhancement. By forming, high luminance characteristics are exhibited.

As described above, in the present invention, the blue or red filter layer is formed on the inner surface of the panel, and the blue or red phosphor is formed thereon, thereby improving contrast and exhibiting high luminance characteristics.

1 is a block diagram of a general color cathode ray tube.

2 is a cross-sectional view of a panel portion of a conventional color cathode ray tube.

3 is a cross-sectional view of the panel portion of the color cathode ray tube according to the present invention;

(A) is the first embodiment.

(B) is the second embodiment.

Figure 4 is a graph showing the red fluorescent surface transmission spectrum of the first embodiment according to the present invention.

5 is a graph showing a blue fluorescent surface reflection spectrum of the first embodiment according to the present invention;

6 is a graph showing a blue fluorescent surface transmission spectrum of the second embodiment according to the present invention.

Fig. 7 is a graph showing the red fluorescent surface reflection spectrum of the second embodiment according to the present invention.

*** Explanation of symbols for the main parts of the drawing ***

101: panel 102: black matrix layer

103R, 203R: red fluorescent surface 103G, 203G: green fluorescent surface

103B and 203B: blue fluorescent surface 104: red filter layer

204: blue filter layer

Claims (2)

A first step of forming a red filter layer at a red phosphor installation position of a panel on which a black matrix is formed, a second step of forming a red fluorescent surface using a red phosphor having no pigment attached to an upper surface of the red filter layer; In a method of forming a fluorescent film of a color cathode ray tube comprising a third step of forming a blue fluorescent surface using a blue phosphor with a blue pigment, and a fourth step of forming a green fluorescent surface using a green phosphor without a pigment. In The pigment of said blue phosphor uses cobalt blue (Co0 * Al2O3), The coverage is 5 wt%, The fluorescent film formation method of the color cathode ray tube characterized by the above-mentioned. A first step of forming a blue filter layer at a blue phosphor installation position of a panel on which a black matrix is formed, a second step of forming a blue fluorescent surface using a blue phosphor having no pigment attached to an upper surface of the blue filter layer; In the method of forming a fluorescent film of a color cathode ray tube comprising a third step of forming a red fluorescent surface using a red phosphor with a red pigment, and a fourth step of forming a green fluorescent surface using a green phosphor without a pigment. In The pigment of the red phosphor is made of iron oxide (Fe ₂ O ₃ ), the coverage is 0.3wt% of the fluorescent film forming method of the color cathode ray tube, characterized in that.

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