JPH05266795A - Manufacture of color cathode ray tube - Google Patents

Abstract

PURPOSE:To totally improve the brightness, contrast characteristic and color purity by coating the inner surface of a faceplate with fine grain pigment dispersed solution, and coating this pigment layer with fluorescent body suspension, and exposing and developing the pigment layer and the fluorescent body layer through a shadow mask. CONSTITUTION:The inner surface of a faceplate is formed with a light absorbing layer, to which patterning is performed. Next, predetermined quantity of polyvinyl alcohol is added to the cobalt blue fine grain dispersed solution, and the light absorbing layer is coated with this solution, and is dried to form a pigment layer. Thereafter, the pigment layer is coated with blue fluorescent body suspension, and is exposed and developed through a shadow mask to obtain a blue fluorescent body stripe with blue front surface filter. Next, a green fluorescent body stripe with green front surface filter is formed similarly by using cobalt green fine grain dispersed solution. A filter layer is thereby formed in the inner surface to improve the brightness, contrast and color purity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a color cathode ray tube, and more particularly to a method for manufacturing a phosphor screen for the purpose of improving the contrast of the phosphor screen or improving the color purity of the phosphor.

[0002]

2. Description of the Related Art Various conventional methods have been proposed as methods for improving the contrast or color purity of a cathode ray tube. As an example thereof, there is a method of using a phosphor with a pigment for a phosphor film, but this method has a problem that the brightness of the phosphor decreases if the pigment concentration is too high. There is also a method of using colored glass for the face plate as a method of increasing the contrast by reducing the reflection of external light, but when the coloring amount is increased, the transmittance of the glass is lowered and the contrast is lowered. ..

In order to solve such a problem, Japanese Patent Laid-Open No.
No. 7457 discloses a method in which a pigment layer having the same body color as the emission color of the phosphor film is provided between the face plate and the phosphor layer. However, in the method of manufacturing a phosphor screen disclosed in JP-A-64-7457, since the pigment layer is formed by the slurry method and then the phosphor surface is further formed by the slurry method, the number of steps is double that of the conventional method. Therefore, there is a drawback that the manufacturing cost becomes high.

[0004]

As described above, in the method using the pigmented phosphor, the brightness is lowered, and in the method of coloring the face plate, the transmittance of the glass is changed and the contrast is lowered in some cases. .. Therefore, there is a method of providing a pigment layer between the face plate and the phosphor, but there is a problem that the manufacturing cost becomes high.

The present invention provides a color cathode-ray tube having a phosphor screen in which a pigment layer having a body color similar to the emission color of the phosphor film is provided between the face plate and the phosphor, while the manufacturing cost is almost the same as the conventional one. It is intended to provide a manufacturing method.

[0006]

In order to solve the above problems, the present invention provides a method for manufacturing a color cathode ray tube having a fluorescent surface on the inner surface of a face plate, wherein an ultrafine particle pigment dispersion liquid is present on at least the inner surface of the face plate of the color cathode ray tube. Is applied to form a pigment layer, a second step of applying a phosphor suspension on the pigment layer to form a phosphor layer, and a shadow mask of the pigment layer and the phosphor layer. It is characterized by comprising a third step of simultaneously exposing and developing via

In the method for manufacturing a color cathode ray tube, the ratio A / B of the resin component A and the pigment component B in the ultrafine pigment dispersion is 0.1 ≦ A / B ≦ 10. To do. Further, in the method for producing a color cathode ray tube, the particle diameter of the pigment in the ultrafine particle pigment dispersion is 1 nm to 150 nm.

[0008]

Description of the conventional method of manufacturing a color cathode ray tube will be omitted, and the main part of the present invention will be described.

As the pigment dispersion liquid used in the present invention, in order to have transparency, a liquid liquid in which ultrafine pigment particles having a particle diameter of 1 nm or more and 150 nm or less are dispersed is used. This is because when a pigment dispersion liquid having no transparency is used, the transmittance is lowered and the contrast characteristic is lowered.

Further, in the present invention, in order to apply a phosphor slurry directly on the pigment layer to form the phosphor layer and perform patterning by a single exposure, the conditions required for the pigment dispersion are: It looks like this: That is, 1. Give the face plate and pigment a proper binding property,
2. 2. Do not disturb the phosphor layer film on the pigment layer; 3. Being bound to the phosphor layer, 4. That is, the pigment dispersion layer can be easily peeled off at the time of development to perform patterning.

As a result of various studies on methods satisfying these conditions, the inventors have added a specific resin to a pigment dispersion liquid,
It was found that the problem can be solved by controlling the amount.

A method of manufacturing a color cathode ray tube according to the present invention will be described. First, a light absorption layer such as black matrix is patterned by a conventionally known method. Next, the pigment dispersion liquid is applied to the face plate and appropriately dried to form a pigment layer. Here, since the pigment in the dispersion has a binding property with the face plate,
As the resin in the dispersion liquid, a resin that is easily separated from the face plate is used. A phosphor slurry containing a resist is applied onto this pigment layer. Therefore, it is desirable to use a resin having a binding property with the phosphor slurry as the resin in the dispersion liquid. When exposure is performed in this state, the pigment layer is held by the cured film of the phosphor slurry, and predetermined patterning is performed. That is, it is desirable that the resin in the dispersion liquid does not have much binding property with the face plate but has binding property with the phosphor slurry. Here, if the amount of resin in the pigment dispersion is too large, the binding force between the face plate and the pigment layer is reduced, so that the developability is good, but the binding force at the exposed portion is weak, and so-called peeling occurs. On the other hand, if the amount of resin is too small, the pigment layer is not peeled off from the face plate in the developing process, and desired patterning cannot be performed.
That is, in the present invention, it is important to control the amount of resin contained in the ultrafine particle pigment dispersion liquid, and the resin / pigment ratio is preferably 0.1 ≦ resin / pigment ≦ 10.

Specific examples of the resin contained in the pigment dispersion include polyvinyl alcohol and polyvinyl bis azide. These resins are preferably the same substance as the resin contained in the phosphor slurry. If the same material as the resin in the phosphor slurry is used, it has a weak binding force with the face plate, has a binding property with the phosphor slurry, and satisfies the above-mentioned four conditions and can be subjected to predetermined patterning. It will be possible. The film thickness of the pigment layer can be easily adjusted by adjusting the specific gravity and viscosity of the dispersion, or by adding a surfactant to the dispersion.
By performing the above-described steps for each color, a color cathode ray tube having a filter layer on the inner surface can be easily manufactured.

[0014]

EXAMPLES The present invention will be described below with reference to examples.

First, a patterned light absorbing layer is formed by a conventionally known method. That is, a resist is applied to the inner surface of the face plate of the color cathode ray tube, exposed through a shadow mask, developed, and dried to leave a stripe-shaped or dot-shaped photo-cured film on the phosphor layer formation planned portion, After applying a light-absorbing substance such as graphite to bind it, wash it with hydrogen peroxide solution to dissolve the photo-cured film, and also remove the light-absorbing substance bound to it, and plan to form a phosphor layer. The part is exposed to form a patterned light absorbing layer. First color

Polyvinyl alcohol (PVA) (manufactured by Nippon Gosei Co., Ltd., EG-40) was added to a cobalt blue fine particle dispersion liquid (average particle diameter of about 40 nm) so that PVA / dispersion liquid = 5%, and the inner surface of the face plate was added. Was coated on the patterned light absorbing layer of, and dried by a heater to form a pigment layer. Then, a blue phosphor suspension containing a PVA / ADC resist was applied to obtain a laminated film that was a blue phosphor layer. Next, exposure and development were performed through a shadow mask to obtain a blue phosphor stripe with a blue front filter. Second color

Next, polyvinyl alcohol (PVA) was added to the cobalt green fine particle dispersion liquid (average particle diameter of about 40 nm).
(Nippon Gosei Co., Ltd. EG-40) PVA / dispersion liquid = 5
% So that it is applied to the face plate,
It was dried with a heater to form a pigment layer. Then PVA
A green phosphor suspension containing / ADC resist was applied to obtain a laminated film which is a green phosphor layer. Next, exposure and development were performed through a shadow mask to obtain a green phosphor stripe with a green front filter. Third color

Next, polyvinyl alcohol (PVA) (EG-40 manufactured by Nippon Gosei Co., Ltd.) was added to a red iron oxide fine particle dispersion liquid (average particle diameter of about 40 nm) so that PVA / dispersion liquid = 5%. It was applied on a plate and dried by a heater to form a pigment layer. After that, PVA / AD
A red phosphor suspension containing a C resist was applied to obtain a laminated film that was a red phosphor layer. Next, exposure and development were performed through a shadow mask to obtain a red phosphor stripe with a red front filter.

Using the face plate thus prepared, a color cathode ray tube was manufactured and its characteristics were evaluated.
As a result, a high-performance color cathode ray tube with a contrast ratio improved by 30% and a color purity improved by 14% is simply compared with the conventional large-scale process of increasing the number of (coating-exposure-developing) processes three times. It became possible to manufacture in a process in which the number of coating processes was increased three times.

[0020]

As described above, according to the method of the present invention, it is possible to manufacture a cathode ray tube in which brightness, contrast characteristics and color purity are comprehensively improved with almost the same manufacturing cost as that of the conventional one. It will be possible.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Michiyo Abe 1-9-2, Harara-cho, Fukaya-shi, Saitama Stock Company Toshiba Fukaya Electronics Factory

Claims (3)

[Claims] 1. A method of manufacturing a color cathode ray tube having a fluorescent surface on the inner surface of a face plate, comprising: a first step of applying an ultrafine pigment dispersion liquid to at least the inner surface of the face plate of the color cathode ray tube to form a pigment layer; It comprises a second step of applying a phosphor suspension onto the pigment layer to form a phosphor layer, and a third step of simultaneously exposing and developing the pigment layer and the phosphor layer through a shadow mask. And a method for manufacturing a color cathode ray tube. 2. The method for manufacturing a color cathode ray tube, wherein the ratio A / B of the resin component A and the pigment component B in the ultrafine pigment dispersion is 0.1 ≦ A / B ≦ 10. The method for manufacturing a color cathode ray tube according to claim 1. 3. The method of manufacturing a color cathode ray tube, wherein the particle size of the pigment in the ultrafine particle pigment dispersion is 1 nm to 1 nm.
The method for producing a color cathode ray tube according to claim 1 or 2, wherein the thickness is 50 nm.