JPS6357903B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a cathode ray tube phosphor surface, and more particularly to a method for forming a black matrix type phosphor surface that simplifies the manufacturing process.

In general, the phosphor surface of a black matrix cathode ray tube is formed by regularly arranging phosphor picture elements in stripes that emit light in each color of green, blue, and red. Here, these phosphor picture elements are usually formed by a photographic printing method that utilizes the photocurability of a photosensitive resin. That is, as shown in FIG. 1a, this formation method involves coating the inner wall surface of the cathode ray tube panel 1 with a photocurable photoresist 2, and applying a shadow mask so that the light 3 hits the position where each color's phosphors should emit light. 4, a predetermined position is exposed to light by a point or linear light source (not shown). In this case, in order to approximate the trajectory of the electron beam and the trajectory of the light source, the light source is placed at the deflection center of the electron gun, and a correction lens usually made of glass or plastic is placed between the light source and the shadow mask 4. . When the photoresist film 5 is developed after exposure, a photoresist film 5 is formed at a predetermined position since the exposed portion is insolubilized by a photocrosslinking reaction. Next, as shown in Figure b, a light-absorbing substance 6 such as graphite is coated on the surface of the panel 1 including this photoresist film 5, and after drying, an oxidizing agent such as hydrogen peroxide is applied to form a photoresist film. The light-absorbing substance attached to the surface of the photoresist film 5 is removed by etching to form a black matrix stripe 6 as shown in FIG.
As shown in Figure d, phosphor stripes 7g, 7b, and 7r of each color of green, blue, and red were formed by a conventional slurry method or dusting method. After that, these phosphor stripes 7g, 7b, 7r
Filming film 8 on the inner surface of panel 1 including the top surface of
After forming the metal backing film 9, a metal backing film 9 is deposited on the upper surface thereof, and a cathode ray tube is formed through the next baking process.

However, in the method for forming a fluorescent surface using the above method, the manufacturing process of the color cathode ray tube fluorescent surface is extremely complicated as described above, and is a lengthy process that involves repeating wet coating, washing, development, and drying many times. Since it requires a process, it is extremely difficult to rationalize its workability, production process, etc., making production costs high.
Furthermore, this lengthy process also uses a large amount of energy such as electricity and water, as well as various materials, making the production cost even higher.

Therefore, the present invention eliminates the above-mentioned conventional drawbacks,
It is an object of the present invention to provide a method for forming a fluorescent surface of a cathode ray tube, which reduces production costs and allows a black matrix surface to be obtained at low cost.

In order to achieve this object, the present invention omit the step of forming a black matrix as a light absorbing layer, and form the light absorbing layer using a metal back vapor deposited film.

That is, as shown in FIG. 2, a polyethylene emulsion liquid having particles of about 1 μm or less is applied to the inner wall of the panel 1 to form a resin coating 10, and then phosphor stripes 7g, 7b, and 7r of each color are formed. After that, this phosphor stripe 7g, 7
Filming film 8 selectively only on the upper surfaces of b and 7r
Further, a metal back film 9 made of an aluminum vapor-deposited film is formed on the upper surface thereof and on the resin film 10 between the phosphor stripes 7g, 7b, and 7r.

According to this method, the phosphor stripe 7
Since the metal back film 9 between g and 7b, between 7b and 7r, and between 7r and 7g is formed on the resin film 10, the adhesive surface of the metal back film 9 is attached to the resin film 1.
A light absorption film is formed with an uneven surface corresponding to the external shape of the fine particles. Furthermore, since the filming film 8 is formed on the three-color phosphor stripes 7g, 7b, and 7r, a film that is smooth and has a high reflectance is formed. Therefore, an excellent black matrix phosphor surface using the metal back film 9 can be easily manufactured without using a conventional light absorption film using a graphite film.

Specific examples will be described in detail below.

Specific example: First, a 2% solution of polystyrene emulsion containing particles with a particle size of about 0.3 μm, such as Morton Chemical's Opacifier E305 (trade name), is applied to the inner wall of the panel and dried to form a resin film. let Next, phosphor stripes of each color are formed on the upper surface of this resin coating by a conventional method. After forming the phosphor stripes, a photoresist having the composition ratio shown below is applied and dried.

Pure water 90.76% Polyvinyl alcohol 3% Ammonium dichromate 0.24% Surfactant and acrylic emulsion 6% Next, the phosphor stripes of each color were exposed and developed using the same method used to form the phosphor stripes above. By selectively forming a filming film and then forming a metal back film by vapor deposition of aluminum, a black matrix fluorescent film as shown in FIG. 2 is formed.

The light reflectance of the black matrix phosphor surface formed by such a method is approximately 28%, compared to approximately 27% by the conventional method shown in FIG.
We were able to obtain a light reflectance that was almost the same as the conventional one. In addition, the light absorption rate is determined by the particle size in the resin coating.
The maximum value was obtained at about 0.5 μm. Also, the minimum film formation temperature (MFT) of polystyrene emulsion
If the MFT is lower than the coating film drying temperature, a smooth film will be formed, so it is desirable that the MFT be higher than the drying temperature, that is, one that does not form a film when forming the resin film. In addition, silicates such as potassium silicate and colloidal silica are used to adhere polystyrene emulsion particles, and water-soluble resins such as polyvinyl alcohol are used as binders to prevent them from being washed away during the formation of a fluorescent film in the subsequent process. It is necessary. In addition, the amount of binder and adhesive added to the polystyrene emulsion particles must be an amount that does not impair the shape of the particles, that is, approximately 10% or less based on the weight of the emulsion particles. Absorption rate tends to decrease.

In the present invention, without any restrictions on the manufacturing method of the fluorescent surface, the fluorescent film can be formed by directly forming a metal back on the fluorescent film to make the reflectance of the metal back on the fluorescent film sufficiently high. This increases the luminance of the light emitted by the laser, making it possible to significantly shorten the process.

Furthermore, in the above embodiments, a case has been described in which a filming process is performed after the formation of a fluorescent film, but other printing methods such as gravure offset printing may also be used. In this case, if the amount of resin in the phosphor stripe is approximately 50% or more, the surface of the phosphor stripe will be smooth and the filming process will not be necessary. If this method is used, a fine particle coating will be formed on the inner wall surface of the panel. Then, by forming a phosphor film on the top surface using a gravure offset printing method using a mixture of a phosphor and polystyrene, and applying a metal back, it becomes possible to form a black matrix phosphor film. .

Further, in the above embodiments, the case where the phosphor film is formed into a stripe shape has been described, but it goes without saying that the same effect as described above can be obtained even when the phosphor film is formed into a dot shape.

As explained above, according to the method for forming a fluorescent surface of a cathode ray tube according to the present invention, by forming a fine particle coating on the inner wall surface of the panel before forming the phosphor film, the light of the black matrix is Since the absorption layer can be easily formed in an extremely simple process, the manufacturing process is simplified compared to conventional methods, which shortens the cathode ray tube manufacturing process and significantly reduces manufacturing costs. Extremely excellent effects can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a main part for explaining a conventional method for forming a fluorescent surface of a cathode ray tube, and FIG. 2 is a cross-sectional view of a main part for explaining an example of a method for forming a fluorescent surface of a cathode ray tube according to the present invention. It is a diagram. 1... Panel, 7g, 7b, 7r... Fluorescent stripe, 8... Filming film, 10... Resin coating.

Claims (1)

[Claims] 1 In the method for forming the fluorescent surface of a black matrix type color cathode ray tube, the particle size is
A step of forming a resin film using an emulsion liquid having particles of 0.05 μm to 5 μm, a step of forming a phosphor film of each color in a predetermined pattern on the upper surface of the resin film, and a step of forming a phosphor film of each color on the top surface of the resin film. A cathode ray tube fluorescent surface comprising the steps of selectively forming a filming film, and forming a metal back film on the exposed portion of the resin film and on the filming film on the phosphor film. Formation method.