JPH0628974A - Conductive material applying method to cathode-ray tube body neck part - Google Patents

Abstract

PURPOSE:To provide a conductive material applying method to a cathode-ray tube body neck part by which film thickness becomes uniform and a paint film having no defect of such as a projecting part and an excellent surface characteristic can be formed. CONSTITUTION:In a conductive material applying method to a neck tube 11 part of a funnel 10 constituting a cathode-ray tube, sponge (applying means) 6 which has an outside diameter approximately equal to or larger than an inside diameter of the neck tube 11 part and is impregnated with the conductive material, is used. The conductive material is applied to the neck tube 11 part by moving the means 6 in parallel with the major axis direction of the neck tube 11 part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for applying a conductive material to a neck portion of a cathode ray tube for forming a more uniform conductive film.

[0002]

2. Description of the Related Art A cathode ray tube (CRT) used as a cathode ray tube of a television is composed of a panel on the image screen side and a funnel funnel in which an electron gun is arranged. In the CRT during operation, if a discharge sometimes occurs and a large current flows, a problem such as damage to the set circuit components occurs. In order to avoid this inconvenience, the discharge current is set to, for example, 20
It is necessary to suppress it to 0 A or less. As a method of suppressing this discharge current, a method of providing a resistor of a conductive material film on the neck portion of the funnel tube is known.

As a method of forming a conductive material film serving as a resistor on the funnel neck tube, conventionally, a sponge or the like is impregnated with a conductive material paint such as carbon (graphite), and the inner wall of the neck of the funnel tube is treated as described above. A method of adhering a sponge and rotating it in the circumferential direction of the inner wall has been proposed.

[0004]

In the above-described method for forming a conductive film, since the formed film thickness is less likely to be uniform and a plurality of protrusions along the rotation direction are likely to occur, a creeping discharge that propagates between the protrusions during operation of the CRT. Occurs. Therefore, the effect of suppressing the discharge current cannot be sufficiently obtained.

Therefore, the present invention provides a method for applying a conductive material to the neck portion of a cathode ray tube body, which is capable of forming a coating film having a uniform film thickness and having no surface defects such as protrusions. With the goal.

[0006]

According to the present invention, there is provided a method for applying a conductive material to a neck portion of a funnel which constitutes a cathode ray tube, wherein the inner diameter of the neck tube portion is substantially equal to or more than that. A cathode wire having an outer diameter of and a conductive material is applied to the neck tube portion by moving a sponge applying means impregnated with the conductive material in parallel with the long axis direction of the neck tube portion. The problem is solved by the method of applying the conductive material to the neck portion of the tube body.

[0007]

According to the present invention, the neck tube 1 is used as the coating means 6.
Using a sponge having an outer diameter substantially equal to or larger than the inner diameter of one part, the film formation of the conductive material is performed not by rotation but by vertical movement of the neck tube 11 along the long axis direction. It is possible to have properties that are uniform and have excellent surface properties. The sponge of the application section is preferably cylindrical,
It is configured to allow uniform penetration from the inside of the sponge to the outside.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a partial schematic view for carrying out the method of the present invention, and FIG. 2 is a schematic cross-sectional view of a coating support shaft and a sponge portion attached to its tip.

As shown in FIGS. 1 and 2, the carbon paint 2 contained in the carbon tank 1 is supplied to a sponge 6 attached to the tip of a coating support shaft 5 via a microtube pump 3 and a supply tube 4. And impregnated. 6a is a sponge support. The coating support shaft 5 can move up and down as shown by an arrow A in FIG.

This embodiment using the above apparatus will be described below with reference to FIG.

First, the funnel 10 and the coating support shaft 5 are arranged so that the funnel 10 faces downward so that the tube axis 11a of the neck tube 11 of the funnel and the axis 5a of the coating support shaft 5 coincide with each other.

Next, using the microtube pump 3,
The carbon coating material 2 is supplied from the carbon tank 1 to the sponge 6 at the tip of the coating / supporting shaft 5 so as to be impregnated, and the coating / supporting shaft 5 is funneled with the coating / supporting shaft 5 once the supply is stopped.
Of the sponge 6 so that the upper end of the sponge 6 is approximately 1 from the lower end P of the neck pipe where the application is prescribed, or the lower end P thereof.
The ascending is stopped at the time point Z when it reaches below mm (Fig. 3).
(A)).

Simultaneously with the stop of the elevation of the coating support shaft, the carbon paint 2 is supplied again to the sponge 6 and the coating support shaft 5 is raised again to raise the funnel neck tube 1.
Apply carbon paint up to the specified upper end Q of 1 (Fig. 3
(B)).

Next, the supply of the carbon paint to the sponge 6 is stopped, the coating support shaft 5 is lowered at a constant speed so that the sponge does not shift (FIG. 3 (c)), and the coating is stopped at the prescribed coating lower end P (FIG. 3). 3 (d)).

In this way, the carbon coating film can be formed on the neck tube 11 of the funnel 10 by reciprocating the coating support shaft 5 up and down once without inserting a drying step in the middle, and more uniformly than before. A carbon coating film having a film thickness was obtained. The thickness of the carbon coating film is preferably 6 to 10 μm,
The viscosity of the carbon paint is preferably low.

[0017]

As described above, according to the present invention, the effect of suppressing the discharge current due to the creeping discharge can be ensured.

[Brief description of drawings]

FIG. 1 is a partial schematic view of an apparatus for carrying out the method of the present invention.

FIG. 2 is a schematic cross-sectional view of the coating support shaft of FIG. 1 and a sponge portion attached to the tip thereof.

FIG. 3 is a process sectional view showing an example of the present invention.

[Explanation of symbols]

 1 Carbon Tank 2 Carbon Paint 3 Micro Tube Pump 4 Supply Tube 5 Coating Support Shaft 5a Shaft 6 Sponge (Coating Means) 6a Sponge Support 10 Funnel 11 Neck Tube 11a Tube Shaft

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] June 2, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction content]

This embodiment using the above apparatus will be described below with reference to FIGS. 3 and 4.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0015

[Correction method] Change

[Correction content]

Next, the supply of carbon paint to the sponge 6 is stopped, the coating support shaft 5 is lowered at a constant speed so that the sponge does not shift (FIG. 4 (a)), and it stops at the prescribed coating lower end P (FIG. 4). 4 (b)). ─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] August 12, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a partial schematic view of an apparatus for carrying out the method of the present invention.

FIG. 2 is a schematic cross-sectional view of the coating support shaft of FIG. 1 and a sponge portion attached to the tip thereof.

FIG. 3 is a first-half process sectional view showing an embodiment of the present invention.

FIG. 4 is a sectional view of a second half process showing an embodiment of the present invention.

[Explanation of reference numerals] 1 carbon tank 2 carbon paint 3 micro tube pump 4 supply tube 5 application support shaft 5a shaft 6 sponge (application means) 6a sponge support 10 funnel 11 neck tube 11a tube axis

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

[Figure 3]

[Figure 4]

Claims (1)

[Claims] 1. A method for applying a conductive material to a neck portion of a funnel forming a cathode ray tube, the method having an outer diameter substantially equal to or larger than an inner diameter of the neck tube portion and impregnated with the conductive material. A method for applying a conductive material to a neck portion of a cathode ray tube body, characterized in that the conductive material is applied to the neck tube portion by moving the sponge applying means described above in parallel with the long axis direction of the neck tube portion.