JPH0329236A - Manufacture of anti-static treatment type cathode-ray tube - Google Patents

Abstract

PURPOSE:To apply overall with good efficiency while removing stains due to the stuck dirty drops by dipping a face plate part of a cathode-ray tube face down into a coating liquid tank for applying a coating liquid followed by pulling it up and rotating the cathode-ray tube at full speed to unify a film. CONSTITUTION:A face plate part 4 of a cathode-ray tube 3 is dipped into a coating liquid tank 1 housing the coating liquid 2 able to give conductivity such as an alcohol solution of Si alkoxide in the state of face down. Thereby, the coating liquid 2 is applied to the outer surface of the face plate part 4 overall and uniformly. By making the whole of the cathode-ray tube 3, to whose face plate part 4 the coating liquid 2 is applied, to rise together with a spin coating machine 16, the face plate part 4 is pulled up from the tank 1, while in this state the cathode-ray tube 3 is rotated at full speed accompanying with full speed rotation of the spin coating machine 16. Thereby, the film thickness of a transparent conductive film 11 is unified.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention provides an antistatic treatment that forms a transparent conductive film on the surface of the face plate in order to prevent dust from adhering to the surface of the face plate and causing discomfort to the human body due to the electrostatic charge on the surface of the face plate. This paper concerns a method for manufacturing type cathode ray tubes.

[Conventional technology]

In recent years, as color cathode ray tubes have become larger, the voltage applied to the phosphor screen has become higher in order to improve brightness and focus performance. For example, in a 21-inch class color cathode ray tube, the high voltage applied to the phosphor screen is 25 to 2
7 kV, but in recent years the applied voltage for color cathode ray tubes of 30 inches or larger is as high as 30 to 34 kV. Therefore,
In particular, when the TV set is turned on and off, the outer surface of the face plate of the color eyelid tube is charged up, and fine dust in the air adheres to the outer surface of the face plate, making it conspicuous. As a result, the capacitance performance of the color cathode ray tube may be deteriorated, and the outer surface of the face plate may be charged up.
When a viewer's body approaches the outer surface of the face plate, an electrical discharge phenomenon often occurs, causing discomfort to the viewer. Figure 5 shows the potential change on the outer surface of the face plate when the power of the television set is turned ON and OFF.
Immediately after FF, the charge ● increase is particularly remarkable. In order to reduce this charge build-up phenomenon on the outer surface of the cathode ray tube's face plate, a smooth transparent conductive film is formed on the outer surface of the cathode ray tube's face plate to allow the charge to escape to the ground. Cathode ray tubes with antistatic treatment are now being used. FIG. 4 is an external side view illustrating the principle of this antistatic cathode ray tube. The antistatic cathode ray tube (3) uses a deflection yoke (7) to electromagnetically deflect an electron beam emitted from an electron gun (l9) built into the neck part (8), while a high voltage button (5) ) is applied to the phosphor screen (not shown) provided on the inner surface of the face plate section 0) to accelerate the electron beam, and the energy excites the phosphor screen to emit light to extract optical output. As a measure to prevent the above-mentioned charge-up phenomenon that occurs due to the high voltage applied to the phosphor screen on the inner surface of the face plate section (4), and the various adverse effects that occur along with it, the face plate section A smooth transparent conductive film (11) is formed on the outer surface of (4), and by dropping this transparent conductive Im (11) to the ground, the charge is constantly released to the ground and the charge ●7 is suppressed. The specific means for grounding the transparent conductive film (11) is as shown in Figure 4, by electrically connecting the transparent conductive film (1l) and a metal explosion-proof band (8) with a conductive tape (12). This is achieved by connecting the above-mentioned metal explosion-proof band (8) to the ground wire (lO) that is in contact with the mounting ear (8). Song M (
Ill) and U2), as shown in Figure 4 above,
O of the antistatic treated cathode ray tube (3) with a smooth transparent conductive film (1l) formed on the outer surface of the face plate (0)
It shows the potential change on the outer surface of the face plate part 0) when it is N-OFF, and as is clear from the figure, the charge is much greater than that on which the transparent conductive film (l1) is not formed.
You can see that the close-up has become smaller. Since a smooth transparent conductive film (1l) as described above is required to have a certain degree of hardness and adhesion, a silica (S i 02 )-based film is generally formed. Conventionally, this silica-based smooth transparent conductive I
As a method for forming I (11), an alcohol m solution of Si (silicon) alkoxide having a -OH group, -OR group, etc. as a functional group is added to the face plate part (4) of a cathode ray tube.
The method used was to coat the outer surface uniformly and smoothly using a spin coating method or the like, dry it, and then bake it at a temperature of 80 to 200°C. Also. From the viewpoint of manufacturing efficiency and ease of handling the cathode ray tube, coating using the Subin coating method is recommended by attaching a metallic explosion-proof band (
This is done after completing the explosion-proofing process in step 8). Figure 3 is a side view showing the conventional coating liquid application method using the Subin coat method. As is clear from the figure, the cathode ray tube (3), which has been subjected to explosion-proof treatment with a metal explosion-proof band (8) and whose outer surface of the face plate (0) has been cleaned, is placed in its funnel m (13). By placing the spin coating a (1B) on the support stand (10) and fixing the mounting ears (3) to the upper end of the support column (15), spin the spin coating a (1B) with the face plate part (4) facing upward. Set Coating It (1B). Note that (l8) in Figure 3 is a salvage cap that stops the coating liquid from scattering outward.Next, with the above setting, initially Cathode ray tube (3
), apply a predetermined amount of coating liquid (2) from the injection nozzle (l7) placed above the face plate (0).
is poured onto the outer surface of the face plate part (0), and this poured coating liquid (2) reaches a certain extent on the face ◆ plate part (0
When the coating has spread over the entire outer surface of the coating, the rotation speed of the spin coating machine (IB) is increased to a high speed (100 to 150
r. p. m) and rotate the cathode ray tube (3) at high speed to spread the coating liquid (2) evenly and make the coating film uniform and stable. [Problems to be Solved by the Invention] Since the conventional manufacturing method for antistatic cathode ray tubes consists of the steps described above, the coating liquid is placed in the center above the face and the top part. It is difficult for the coating liquid to spread because it is supplied from a fixed injection nozzle.Also, if you increase the amount of coating liquid injected to improve the spreading, the droplets of the coating liquid shaken off during high-speed rotation will bounce off the salvage cap and cause cathode rays. There were problems such as adhesion to the face plate of the tube and near the high-pressure button in the funnel, causing dirt and deterioration of quality. This invention was made to solve the above-mentioned problems, and it is possible to efficiently apply a conductive coating liquid to the entire outer surface of the face plate when applying it to the face plate. , and there is no stain due to adhesion of droplets.
The purpose of this paper is to provide a manufacturing method for antistatically treated cathode ray tubes that can produce high quality cathode ray tubes. [Means for Solving the Problems] A method for manufacturing an antistatic cathode ray tube according to the present invention includes:
The face of the cathode ray tube is placed in a coating liquid tank containing conductive coating liquid.
After applying the coating liquid by dipping the plate part downward,
The feature is that the face plate is lifted out of the coating liquid tank and the cathode ray tube is rotated at high speed to make the coating uniform. [Function] According to the present invention, in order to apply a coating liquid by dipping the cathode ray tube with its face plate facing downward in a coating liquid tank,
The coating liquid is evenly supplied to the entire outer surface of the face plate section, eliminating the occurrence of uneven coating in some areas, and also supplying more coating liquid than necessary to the outer surface of the face plate section. Therefore, it is possible to eliminate stains on the face plate portion and the funnel portion due to splashing of droplets during high-speed rotation. [Embodiment of the Invention] An embodiment of the present invention will be described below based on the drawings. ．The configuration of the cathode ray tube and the configuration of the spin coating machine are the same as the conventional example shown in Figure 3, so the corresponding parts are given the same reference numerals and their explanation will be omitted. FIG. 2 is a side view showing the liquid coating process, and as clearly shown in the figure, the interior of the coating liquid tank (1) containing a coating liquid (2) capable of imparting conductivity such as an alcoholic solution of Si (silicon) alkoxide. By immersing the face plate fi (4) of the cathode ray tube (3) in a face-down state, the coating liquid (2) is uniformly applied to the entire outer surface of the face plate part 0). Then, by raising the entire cathode ray tube (3) whose face plate part (i) is coated with the coating liquid (2) together with the spin coating machine (10), the face plate part 0) is coated with the coating liquid (2) as shown in FIG. As shown in , the coating liquid is lifted from the coating tank (1), and in this state, the cathode ray tube (3) is rotated at high speed as the spin coating machine (1B) rotates at high speed, thereby forming a coating film, that is, a transparent conductive film (11). [Advantageous Effects of the Invention] As described above, according to the present invention, the coating liquid is applied to the face plate by immersing the cathode ray tube in the coating liquid tank with the face plate facing downward. Since the coating liquid is applied to the entire outer surface of the face plate, it is possible to uniformly supply the coating liquid to the entire outer surface of the face plate without causing uneven coating. Since there is no need to supply more coating liquid than necessary, there is no splashing of liquid droplets during high-speed rotation to make the film thickness uniform.Therefore, there is no adhesion of splashed liquid droplets, and there is no need to apply liquid to the face plate or funnel. It is possible to manufacture high-quality antistatic treated cathode ray tubes by eliminating contamination.

[Brief explanation of drawings]

FIG. 1 is a side view showing a coating liquid coating process in a method for manufacturing an antistatic cathode ray tube according to an embodiment of the present invention;
Fig. 2 is a side view showing the process of uniformizing the coating film, Fig. 3 is a side view showing the conventional method of applying waste liquid, Fig. 4 is a diagram explaining the principle of antistatic treatment type cathode ray tube, Fig. 5 is This is a diagram showing changes in potential at the face plate of a cathode ray tube. (1)...Coating liquid tank, (2)...Coating liquid, (3)...
Antistatic treated cathode ray tube, 0)...face plate part, (1l)...transparent conductive film, (l3)...funnel, (l8)...spin coating machine. Note that the same symbols in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) The process of applying the coating liquid by dipping the face plate of the cathode ray tube downward into a coating liquid tank containing a coating liquid capable of imparting conductivity, and the process of applying the coating liquid to the face plate of the cathode ray tube after application. 1. A method for manufacturing an antistatic cathode ray tube, comprising the steps of: lifting the tube from a coating liquid tank and rotating it at high speed to make the coating uniform.