KR100403393B1 - Method for depositing conductive film for cathode ray tube - Google Patents

Abstract

PURPOSE: A method is provided to stabilize electrical characteristics of cathode ray tube by preventing concentration of high voltage on the anode terminal upon occurrence of arc. CONSTITUTION: A method comprises a step of spraying a second conductive material having a resistance relatively lower than the resistance of a first conductive material in the local part including a terminal of an anode(20) prior to the deposition of the first conductive material, and drying the resultant structure; and a step of spraying the first conductive material all over the inner surface of a funnel(10).

Description

Method of applying a built-in conductive film of a cathode ray tube

The present invention relates to a method of coating an inner film of a cathode ray tube, which prevents a high voltage from concentrating on an anode terminal when a cathode ray tube is manufactured, in particular, when an anode electrode is double coated and arc-

In general, in the manufacturing process of a cathode ray tube, as shown in Fig. 1, after the fin 10 is completed, the inner surface of the (10) is subjected to a process of applying it as a conductive film, mainly as graphite, An electron beam emitted from an electron gun (not shown) passes through the inside of the above-mentioned (10) and passes through a shadow mask not shown in the drawing to reach a fluorescent surface to induce a fluorescent action. .

That is, a positive power source is required to allow the electron beam emitted from the cathode of the electron gun to be attracted to the fin portion, which is applied from the anode 20. Therefore, the conductive material is evenly applied on the inner surface of the (10) so as to induce a positive power source from the terminal (20).

However, in the process of performing the above-described process, when the substrate 10 is transferred through the support 12 and is stably supported by the substrate 10, the substrate 10 is first preheated at a predetermined temperature to apply the conductive material , And then the process is completed by uniformly spraying the conductive material 10 on which the graphite is used, through the spray 30 rotating at high speed, and applying and drying the same.

However, due to the leakage current generated by applying the initial voltage to the cathode ray tube completed through the above-described process, a phenomenon such as arc or flash is often generated. In this case, the relatively weak anode terminal portion is coated with a conductive material There is a problem that the anode terminal is broken or the cathode tube is broken in case of a severe case where the high voltage is concentrated at the inner node portion.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cathode ray tube which is capable of eliminating defective factors such as breakage of the anode terminal by providing a terminal for preventing a high voltage from being concentrated on the anode terminal so as to solve the problem in the built- And to provide a method for applying a built-in conductive film.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic sectional view showing a conventional built-in conductive film coating method. Fig.

2 is a schematic cross-sectional view showing a method of applying an inner film according to the present invention.

3 is an enlarged cross-sectional view of a main part of the present invention.

Description of the Related Art [0002]

10: Finnel 20: Anode

30: Spray 33: Spray nozzle

80: Low resistance coating material 90: High resistance coating material

According to the present invention, the above-

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a schematic view of a first conductive material, such as graphite, applied in a conventional manner (10) according to the present invention, prior to application of a relatively low resistance second conductive material, And FIG. 3 is a cross-sectional view showing that the second conductive material is applied first and then the general first conductive material such as graphite is entirely coated as described above.

2 and 3, a high voltage of about 22 to 32 kilovolts is normally applied to the (20) terminal. When an arc is generated by the leakage current, a strong spark is generated around the terminal 20, Terminal or the cathode ray tube itself may be damaged, so that it is necessary to stabilize the electrical characteristics by preventing the damage.

For this purpose, as shown in the figure, in the method for applying a built-in conductive film, in a state where the portion (10) is first preheated to reach a certain temperature, usually, before the application of the first conductive material such as graphite applied to the inner surface of the finnel First, only a portion of the terminal (20) is coated with a material having a lower resistance than the first conductive material, that is, a second conductive material having better conductivity, and is dried with hot heating air.

A first conductive material, such as graphite, is then applied to the entire inner surface of the anode 10 along with the anode, through the injection nozzle 33 of the spray 30, as is typically done.

As described above, the present invention is characterized in that, before applying the first conductive material, which normally uses graphite, to the inner surface of the finnel, a second conductive material having relatively high conductivity is applied to the periphery of the anode and dried sufficiently, And dried by a conventional method.

As a result, when a voltage is applied to the anode, the current is applied to the aluminum layer applied to the fluorescent surface by the first conductive material through the second conductive material, so that the electron beam emitted from the electron gun is not impinged more on the fluorescent screen The hot electrons striking the new mask are absorbed by the first conductive material and leaked again through the anode where the second conductive material between the anode and the first conductive material can leak the hot electrons more smoothly, Can be smoothly applied to the first conductive material, thereby greatly reducing the possibility of occurrence of an arc, and thus the electrical characteristics of the cathode ray tube can be stabilized.

Claims (1)

(10), wherein the conductive material is applied to the inner surface of the (10) inner surface of the substrate (20) before the application of the first conductive material, Characterized in that a second conductive material having a resistance lower than that of the conductive material is sprayed and dried rapidly, and then a first conductive material is uniformly sprayed on the applied first conductive material and uniformly on the entire inner surface of the coated conductive material. Method of applying conductive film inside of pipe.