JP3039945B2 - Color cathode ray tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a color cathode-ray tube provided with a conductive film on the face plate surface for the purpose of preventing static electricity and increasing contrast, and particularly has a sufficient antistatic function. Also, the present invention relates to a color CRT capable of exhibiting excellent contrast even when external light is bright.

[Prior art] As a prior art relating to this kind of contents, there are (a) a dye which has an alkali ion as a conductive substance and has an absorption between green and red luminescence in order to enhance contrast, and a hydrolyzed solution of alkylsilane. A method of forming a conductive high-contrast film by mixing it into a cathode ray tube and forming a conductive high-contrast film. A method of coloring glass (JP-A-63-30346); (c) a glass containing neodymium oxide as a CRT face glass having sufficiently satisfactory conductivity; and an emission spectrum of the CRT between the CRT and an observer. A method of increasing contrast by interposing an organic film containing a substance having absorption (organic dye or the like) in two or more regions other than the above
-221943).

[Problems to be Solved by the Invention] However, the above-mentioned conventional methods have disadvantages, and cannot be said to show sufficiently satisfactory performance. Hereinafter, each problem will be briefly described.

First, in the method (a), since alkali ions are used as the conductive material, moisture in the film is lost due to long-term use, the conductivity is reduced, and the antistatic function is deteriorated. Further, since an organic dye is used, the dye is deteriorated by ultraviolet rays and the like contained in sunlight, fluorescent light, and the like, and may be discolored.

Further, the method (b) is a method of simply coloring the glass surface, which may hinder the emission of the CRT and may cause a change in the emission color or a decrease in luminance.

In the method (c), the use of neodymium oxide-containing glass as the face glass leads to an increase in cost, and a high-contrast image is obtained by mixing a substance having absorption in a region other than the CRT emission spectrum into the organic film. Is given to an observer, but the organic film has a disadvantage that the strength is small and the durability is not high. further,
Even if an appropriate dye is selected as the organic dye, no substance completely absorbs only the region other than the CRT emission spectrum. There is a risk that the color will be dark and the brightness (clearness) of the color will be lost. This phenomenon is particularly noticeable when the external light is bright.

An object of the present invention is to provide a high-contrast conductive film having a sufficient antistatic function and capable of exhibiting excellent contrast even when external light is bright, by solving the problems of the above-described conventional technology. To provide.

[Means for Solving the Problems] The object of the present invention is to provide a conductive film provided on the surface of a color cathode-ray tube face plate for the purpose of preventing static electricity and increasing contrast, wherein the conductive film is formed of a conductive substance and a green and blue emission spectrum. This can be achieved by forming a conductive film composed of a mixture of a dye or pigment having absorption between the two and a dye or pigment having absorption between green and red emission spectra.

[Function] By using a conductive film having the above structure, the conductive film exhibits sufficient conductivity and absorbs light between the green and blue emission spectra and between the green and red emission spectra. Thus, a high-contrast conductive film in which reflection of external light is reduced can be obtained.

[Examples] Hereinafter, formation of the conductive film for high contrast of the present invention will be described with reference to examples.

Example 1 After thoroughly washing the surface of a 29-inch color CRT face plate and drying it with clean hot air, gently pour a liquid having the following composition into the center of the face plate while rotating horizontally at 70 rpm for 120 seconds. The film was rotated to form a film having a uniform thickness.

Conductive coating solution (Sumifine Fine AS-1) 99.94% Sulforhodamine (Acid Red) 0.03% Acridine orange 0.03%
ATO (Antimony Tin Oxide) film. This cathode ray tube was placed in a firing furnace and fired at 130 ° C. for 20 minutes to obtain a cathode ray tube having a conductive film having a thickness of about 0.4 μm.

The conductive film thus obtained is a conductive film having a surface gloss (gloss value) of 98, a surface resistance of 5 × 10 ⁸ Ω / □, and an absorption characteristic as shown in FIG. And exhibited sufficient antistatic performance and high contrast function. In the figure, the curve shown by the solid line is the curve showing the emission spectrum of the color CRT.

Example 2 First, solutions A and B2 having the following compositions were prepared.

Solution A Conductive coating solution (Sumisefine AS-1) 99.94% Sulforhodamine (acid red) 0.05% Phthalocyanine blue 0.01% Solution B Ethoxysilane hydrolysis solution (Elesan coat solution) 99.97% Acridine orange 0.03% On the other hand, Form 29 After sufficiently washing the surface of the color cathode ray tube face plate and drying with clean warm air, the above solution A is uniformly spray-painted at a pressure of 2.5 kg / cm ^{2 at} a flow rate of 8 / Hr. The spray coating was performed uniformly at a flow rate of 10 kg / cm ^{2 at} a flow rate of 10 kg / cm ² , and was placed in a firing furnace and fired at 130 ° C. for 20 minutes.

The conductive film thus obtained has a gloss value of 55, a surface resistance of 8 × 10 ⁸ Ω / □, and has an absorption characteristic as shown in FIG. 1 (b). The performance and high contrast function were shown. Further, since this film has fine irregularities on its surface, it is a film exhibiting a so-called non-glare effect that scatters light and reduces reflection of external light.

It should be noted that exactly the same effect was obtained when the paint / pigment components in the liquids A and B were exchanged.

Example 3 The solution A of Example 2 was applied to the face plate surface under the same conditions as in Example 1 and then the solution B of Example 2 was applied under the same conditions as in Example 1 to obtain a solution 2 When a layer film is provided, the second layer film does not contain a conductive substance as compared with the first layer film, so that the refractive index is lowered and a kind of antireflection effect is provided, so that the gross value is reduced to about 70. And the glare on the surface disappears. The effect is that the second layer has a pressure of 3.0k.
The same can be obtained by spray coating at g / cm ² and a flow rate of 3 / Hr.

The film obtained by this method is a film having a gloss value of 70, a surface resistance of 5 × 10 ⁸ Ω / □, and having an absorption characteristic as shown in FIG. there were.

In the case of the present embodiment, similarly to the case of the second embodiment,
Exactly the same effect was obtained when the dye / pigment components in both solutions A and B were exchanged.

As described in the above embodiments, the conductive film of the present invention has a contrast of about 15
% And a conductive film having a sufficient antistatic effect can be obtained, so that a clear and high-contrast image can be obtained. In particular, by employing the techniques of Embodiments 2 and 3, the number of steps is increased, but in addition to the above-described features, an easy-to-view screen with less reflection of external light can be obtained.

Note that the desired conductive film characteristics can be obtained with a relatively wide margin by a combination of the emission spectrum of the phosphor used for the color CRT and the above-mentioned dye or pigment.

[Effect of the Invention] As described above, by solving the problem of the prior art by using the conductive film provided on the surface of the color cathode ray tube face plate as the conductive film of the present invention,
A high-contrast conductive film having a sufficient antistatic effect and exhibiting excellent contrast even when external light is bright could be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing an emission spectrum of a color cathode ray tube fluorescent screen and an absorption spectrum of a conductive film of the example.

──────────────────────────────────────────────────続 き Continued from the front page (72) Inventor Toshio Tojo 3681 Hayano Mobara-shi, Chiba Hitachi Devices Engineering Co., Ltd. (72) Inventor Yoshifumi Tomita 3300 Hayano Mobara-shi Chiba Pref. 56) references Patent flat 1-311546 (JP, a) JitsuHiraku Akira 62-89756 (JP, U) real public Akira 48-33549 (JP, Y2) (58 ) investigated the field (Int.Cl. ^7, (DB name) H01J 29/28 H01J 29/32 H01J 29/89

Claims (4)

(57) [Claims] 1. A conductive film containing a pigment or a dye and a conductive material is formed on a face plate surface, an insulating film is formed on the conductive film, and the insulating film contains a pigment or a dye. Color CRT. 2. A color cathode ray tube according to claim 1, wherein said conductive film and said insulating film have different absorption spectra of pigments or dyes contained therein. 3. The pigment or dye having a different absorption spectrum comprises a pigment or dye absorbing light having a wavelength between the green and blue emission spectra of the color CRT, and a pigment or dye having a wavelength between the green and red emission spectra of the color CRT. 3. A color cathode ray tube according to claim 2, wherein the color cathode ray tube is a pigment or a dye absorbing light of a wavelength. 4. The color cathode ray tube according to claim 1, wherein said conductive film contains ATO.