JPH01211828A - Manufacture of color cathode ray tube - Google Patents

Abstract

PURPOSE:To restrict a shadow mask from cooling rapidly so as to hold the initial tensile strength by performing a stabilization processing of the shadow mask structure prior to application of black lead and phosphor while putting the shadow mask surface in a close contact with a flat plate having a higher heat capacity than that of the mask. CONSTITUTION:Before being subjected to stabilization processing prior to application of black lead and phosphor a shadow mask 2 has its flat surface brought in close contact with a flat plate 5, to be fixed with a fixing jig 6. For this flat plate 5, a plate having higher heat capacity than that of the shadow mask 2 such as the one made of SUS 304 with 3mm in thickness should be used. Then, the shadow mask structure is set in the prescribed plate in a panel 4 by preparing a spring 3 fitted to a stud pin 7 mounted within the panel 4. Under this condition, the shadow mask structure and the panel 4 are heated in the atmosphere at 430 deg.C for 60min as stabilization processing, and later cooled gradually with practically no change imposed on tensile strength of the shadow mask 2. Then, after being removed from the panel 4 and then from the flat plate 5, the shadow mask structure has its surface applied with black lead and phosphor.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a color cathode ray tube equipped with a shadow mask structure in which a shadow mask made of a thin metal plate with a large number of holes is stretched over a frame under tension. Manufacturing method
In particular, it relates to a method for stabilizing a shadow mask structure before applying graphite or phosphor.

[Conventional technology]

The shadow mask structure used in color cathode ray tubes is
Although it has a color selection function using phosphors coated in a mojik-like manner on the phosphor surface, it may thermally expand and deform by colliding with the electron beam, which may impair its function.

Traditionally, this solution has been
As shown in No. 96 and JP-A No. 61-80735, the shadow mask is stretched on a frame under tension to absorb the elongation due to thermal expansion caused by the collision G of the electron beam and prevent deformation. are doing.

In US Pat. No. 4,547,696, since the shadow mask is directly fixed to a part of the bulb with frit glass, no stabilization treatment is required for the shadow mask structure.

JP-A No. 61-80735 discloses a shadow mask structure in which a shadow mask to which tension is applied is fixed by welding to a frame having a spring for fixing the panel. For color cathode ray tubes, it is necessary to stabilize the shadow mask structure before applying graphite or phosphor.

[Problem to be solved by the invention]

U.S. Pat. No. 4,547,696 does not require stabilization treatment for the shadow mask structure as described above, but since it uses frit glass to fix the shadow mask,
There were reliability issues.

A color cathode ray tube equipped with a shadow-thumb structure as disclosed in Japanese Patent Application Laid-open No. 61-80735 suffers from excessive tension as the shadow mask, which has a smaller heat capacity than the frame, cools down faster and shrinks during the stabilization process of the shadow mask structure. is applied, and there is a risk of breakdown, and the challenge was to solve this problem.

An object of the present invention is to provide a method for manufacturing a color cathode ray tube that can prevent the shadow mask from yielding due to stabilization treatment of the shadow mask structure and can maintain the initial tension of the shadow mask. .

[Means for solving the problem] The above problem can be solved by stabilizing the shadow mask structure before applying graphite or phosphor, by closely adhering a flat plate with a larger heat capacity than the shadow mask to the shadow mask surface. The problem can be solved by doing this.

[Effect]

In stabilizing the shadow mask structure, the flat plate closely attached to the shadow mask surface keeps the shadow mask warm, thereby preventing rapid cooling of the shadow mask and suppressing breakdown.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. The shadow mask structure has a structure as shown in FIG. 2Q. The material of frame 1 is 8U843
0 has an L-shaped cross section, and the width at the top of the cross section is 5 dragons, -F
The width at the end is 10mm, the diameter is 10mm, and the overall outer diameter is 279mm wide and 210mm long. Shadow mask 2 is
The jar is made of a copper plate with a thickness of 0.025 mm, and holes 2a with a hole diameter of 0.12 mm are arranged on the entire surface except for the periphery at an interval of approximately 0.261 ffI+, so that the mutual angle of the rows is 60 degrees. . The periphery of this shadow mask 2 is continuously welded 7 times around the entire circumference of the welding part 1b shown by the two-dot chain line that connects approximately the center of the upper end 1a of the frame 1, and the shadow mask 2 is welded under tension. It is stretched on frame 1. Note that the side wall of the frame 1 is the panel 4 shown in FIG.
A spring 3 is welded to the housing.

A shadow mask structure having such a structure (this is a flat plate 5e of the shadow mask 2, as shown in FIG.
VB is applied and fixed with fixed oil No. 46.Here, for the flat plate 5, use 808304, which has a heat capacity 1 larger than that of the shadow mask 2, and has a thickness of 3, for example. By attaching the spring 3 to the provided stud pin 7, the Yado mask structure is placed at a predetermined position within the panel 4.

In this state, the shadow mask structure and the panel are stabilized by heat treatment at 430° C. for 60 minutes in the atmosphere. At this time, the temperature decreasing rate after heating at 430°C is
6℃/m up to 300℃, 4℃/m up to 200℃
ix, 3° C./m up to 100° C. and 2° C./m up to room temperature, but almost no change was observed in the tension of the shadow mask 2 after the treatment. Note that when the flat plate 5 was not disposed, 40% of the initial tension was lost at the same cooling rate as above.

After the stabilization process, the shadow mask structure is removed from the panel 4, the fixing jig 6 is removed, and the flat plate 5 is removed. after that,
The process progresses to the coating of graphite and phosphor.

In the above embodiment, the flat plate 5 has a thickness of 3 JIi.
5U8304 of 1 was used, but it is not limited to this; it has a larger heat capacity than Shadow Mask 2, and
Needless to say, any material that is resistant to oxidation or deformation at about 30°C is suitable. Furthermore, if the seal 4a of the panel 4 is stabilized while it is placed on a flat table, the intrusion of air into the panel 4 will be reduced, so the rapid cooling of the shadow mask 2 will be further suppressed. , the temperature decreasing rate can be increased. Further, the same effect can be obtained by closely adhering a plate having the outer dimensions of the frame to the surface of the shadow mask of the frame 1 opposite to the welding surface.

〔Effect of the invention〕

According to the present invention, the shadow 7? Since rapid cooling of the shadow mask can be suppressed, yielding due to rapid contraction of the shadow mask can be prevented, and the initial tension of the shadow mask can be maintained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view f'' showing a method for manufacturing a color cathode ray tube according to an embodiment of the present invention, and FIG. 2 is a perspective view of a shadow mask structure. 1. Frame, 2. Shadow mask, 2a. ... ri (, 4... panel, 5 - flat plate, 6... fixing jig. na talent 6: solid danger figure 2 figure 1: frame 2: sha←°勺1 suf 20: generation

Claims (1)

[Claims] 1. In the method of manufacturing a color cathode ray tube, which has a shadow mask structure in which a shadow mask with many holes made in a thin metal plate is stretched over a frame under tension, the shadow mask structure is prepared before applying graphite or phosphor. A method for manufacturing a color cathode ray tube, characterized in that stabilization treatment is performed by closely contacting a flat plate with a larger heat capacity than the shadow mask to the shadow mask surface.