KR910007487B1 - Method of establishing screen of crt - Google Patents

Abstract

A screen film of CRT is formed by forming a black matrix, coating a undercoating soln., forming a fluorescent film, coating a filming soln., and depositing an aluminium. In the forming press of the fluorescent strip, the filming soln. composed of polyvinyl alcohol (PVA) and ammonium dichromate (ADC) is inserted in the inner side of the panel directly after the developing step of the final fluorescent strip.

Description

Screen Film Formation Method of Cathode Ray Tube

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a screen film of a cathode ray tube, and more particularly, to a method for forming a screen film of a cathode ray tube having an improved film screen forming process to reduce equipment and having a film structure free of film stains and coatings.

In the cathode ray tube screen forming method, the stepwise step is described in terms of the process of forming the black matrix, applying the undercoating solution, forming the fluorescent film, applying the film, and applying the aluminum vacuum deposition process. And the like, but additional processes are added, for example, drying by heaters and blowers.

Herein, the fluorescent film forming process and the peeling liquid coating process will be described in detail as follows.

The formation of three-color fluorescent stripes (or dots) on the inner surface of the panel is repeated three times in the order of slurry injection → expansion → exposure → developing, and after forming the final color fluorescent stripe, It will be working on the liquid solution application process.

The filming solution is a thin film layer formed on the surface of the fluorescent layer to flatten the deposition layer of the aluminum film through a subsequent deposition process to flatten the deposited film, and during vapor deposition, metal vapor penetrates between the particle layers of the fluorescent stripe. It is used to prevent that.

This peeling liquid is a mixed solution of polyvirin alcohol (PVA) and ammonium dichromate (ADC), which is conventionally injected into the completely dried panel surface. As the affinity between the dried fluorescent layer and the blooming liquid is strong, it is a strong adhesion from the injected part. It is spread by the centrifugal force applied to the panel which starts to attach and is rotated. In this case, a film defect of the local film is generated. In other words, partial injection marks of the filming solution are left, resulting in an excessive thickness. Eventually, non-flattening is caused by the film film applied to flatten the site where the deposited film is formed. As a result, localization of the aluminum deposited film or severe breakdown of the deposited film partially occurs. .

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems, and provides a method for forming a screen film of a cathode ray tube capable of forming a film layer free of coating marks with a uniform thickness on the inner surface of the panel by improving the injection coating method of the filming solution. do.

In order to achieve the above object, the present invention provides a screening film forming method having a fluorescent stripe forming process and a film layer forming process, so that a filming solution applying step is performed immediately after the fluorescent stripe developing step of the final color of the fluorescent stripe forming process. It is characteristic in that it does.

Hereinafter, the present invention will be described in more detail.

The fluorescent stripe is formed in the order of G.B.R through a conventional process. Immediately after the development step of the final R-fluorescent stripe, a filming solution of PVA and ADC is injected into the inner surface of the panel. At this time, the panel is rotated at a low speed, and after the injection is completed, the panel is rotated at a high speed to recover the excess peeling liquid. After the drying step, it is transferred to a conventional aluminum deposition step.

As described above, the present invention is characterized in that the peeling liquid injection step is performed after the R-fluorescent stripe developing step. In some cases, the water droplets condensed on the inner surface of the panel by rotating the panel at a high speed before applying the peeling liquid. It is preferable to remove the and to make the inner surface of the panel wet.

In this case, a water wall is formed between the peeling liquid and the fluorescent layer, so that the affinity between the peeling liquid and the fluorescent layer is weakened. Consequently, the marks of the initial injection do not remain, and a thin film is formed with a slight time delay. . As a result, the film layer is formed with a very even thickness, and a very smooth plane can be obtained with a very even thickness. Therefore, the thickness of the aluminum deposited film deposited later becomes very even and the gap with the fluorescent layer becomes very uniform as a whole. Even when the film film is removed through the post-firing process, the local lifting or partial peeling-off phenomenon of the aluminum deposited film is greatly reduced. do.

As described above, the present invention enables to maintain the screen film formation state at the best state, which can solve all the problems caused by the poor film film, thereby contributing to the improvement of productivity according to the reduction of the defective rate of the product.

Claims (2)

In the process of forming the screen film of the cathode ray tube, the film forming method of the cathode ray tube, characterized in that the step of applying the filming solution immediately after the development step of the fluorescent stripe of the final color of the fluorescent stripe forming process. The method of claim 1, wherein the step of rotating the panel at a low speed or a high speed to remove a part of the water condensed on the inner surface of the panel prior to the step of applying the filming solution.