JPH056732A - Manufacture of color picture tube - Google Patents

Abstract

(57) [Summary] [Construction] To manufacture a color picture tube in which an internal magnetic shield 20 having an oxide film formed on the surface thereof is attached to a mask frame 10 of a shadow mask 8 mounted on a panel 1. At this time, an internal magnetic shield having no oxide film formed is attached to the mask frame, and an oxide film is formed on the surface of the internal magnetic shield by heating when the panel and the funnel 2 are integrally joined by frit glass. I did it. [Effect] It is possible to reduce the deterioration of withstand voltage characteristics due to the clogging of the shadow mask hole due to the peeling of the oxide film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a color picture tube having an internal magnetic shield.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 2, a color picture tube has an envelope composed of a panel 1 and a funnel 2 integrally joined to the panel 1, and is arranged in a neck 3 of the funnel 2. The three electron beams 5B, 5G, 5R emitted from the provided electron gun 4 are deflected by the magnetic field generated by the deflection yoke 6 mounted outside the funnel 2, and the three electron beams 5B, 5G, 5R are By facing the phosphor screen 7 formed of the three-color phosphor layer formed on the inner surface of 1 and selecting by the shadow mask 8 disposed inside the phosphor screen 7, the phosphor screen 7 is horizontally and vertically scanned. A structure for displaying a color image is formed on the phosphor screen 7.

In such a color picture tube, in order to correctly display a color image on the phosphor screen 7, the shadow mask 8 and the electron gun 4 are properly arranged in a predetermined relationship with respect to the phosphor screen 7. It is necessary. However, even if the shadow mask 8 and the electron gun 4 are correctly arranged with respect to the phosphor screen 7, the three electron beams 5B, 5G, and 5R emitted from the electron gun 4 are different from the outside due to geomagnetism or the like, which varies depending on the region, the installation direction, or the like. Due to the influence of the magnetic field, it is difficult to correctly display a color image on the phosphor screen 7. Therefore, in general, in a color picture tube, a magnetic shield (internal magnetic shield) 9 that surrounds a passage region of the three electron beams 5B, 5G, and 5R is arranged inside the funnel 2 that is most susceptible to the external magnetic field. There is.

The inner magnetic shield 9 is usually made of a ferromagnetic material such as a carbon steel plate, and has an external magnetic field of electron beams 5B, 5G,
In order to adjust the influence on 5R, there are various structures conventionally. FIG. 3 shows an example thereof. This internal magnetic shield 9
Has a rectangular trapezoidal shape, and an inwardly extending portion 12 for attaching to the mask frame 10 (see FIG. 1) of the shadow mask 8 is provided at the end portion on the larger diameter side thereof. Further, in order to adjust the influence of the external magnetic field on the electron beam, a V-shaped notch 14 is formed in the edge 13 of the short side on the small diameter side, and an opening 15 is formed in the long side surface. ..

Conventionally, the internal magnetic shield 9 is arranged in the pipe as follows.
A pair of divided pieces 16a and 16b having the shape shown in Fig. 4 are formed in advance, and heated to about 580 ° C for the purpose of preventing rusting as a pipe inner member and improving emissivity, and the surface thereof is subjected to tetra-sodium oxide. A relatively thick oxide film containing iron as a main component is formed. Then, before joining the panel on which the phosphor screen is formed and the shadow mask is attached to the funnel, the pair of divided pieces 16 is welded or fixed to a mask frame of the shadow mask attached to the panel by a clip or the like. It is arranged by fixing by means.

[0006]

As described above, the internal magnetic shield of the color picture tube is formed into a predetermined shape in advance, and the surface thereof is heated at a high temperature so that iron trioxide (Fe ₃ O _{3) is used.
4} ) Attaching a relatively thick oxide film, whose main component is ( ₄ ), to the mask frame of the shadow mask attached to the panel before combining the panel and funnel together and joining them together. Is placed in the pipe by. However, as described above, if a relatively thick oxide film is formed on the internal magnetic shield before attaching to the shadow mask,
Causes of oxide film peeling due to contact or deformation when the internal magnetic shield is transported or when it is attached to the shadow mask, which peels off after assembling the color picture tube and causes clogging of the shadow mask and deterioration of withstand voltage characteristics. There is a problem that becomes.

The present invention has been made in order to solve the above-mentioned problems, and peeling of the oxide film on the surface of the internal magnetic shield necessary for the purpose of preventing rusting as an inner member of the tube and improving emissivity. It is intended to manufacture a color picture tube by a method capable of reducing

[0008]

In manufacturing a color picture tube in which an internal magnetic shield having an oxide film formed on the surface thereof is attached to a mask frame of a shadow mask mounted on a panel, the mask frame is used. An internal magnetic shield having no oxide film formed thereon was attached, and an oxide film was formed on the surface of the internal magnetic shield by heating when the panel and the funnel were integrally joined by frit glass.

[0009]

As described above, the inner magnetic shield having no oxide film is attached to the mask frame, and the surface of the inner magnetic shield is oxidized by heating when the panel and the funnel are integrally joined by the frit glass. By forming a film, even if contact or deformation occurs during transportation of the internal magnetic shield or attachment to the shadow mask, the adhesion of the oxide film formed thereafter is not affected, and the panel and the funnel are separated. The heating at the time of joining is lower than the conventional oxide film forming temperature (about 450 ° C.), and an oxide film containing FeO as a main component and having a relatively small thickness that is difficult to peel off is formed. The peeling of the oxide film can be greatly reduced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described based on embodiments with reference to the drawings.

FIG. 1 shows a method of manufacturing a color picture tube which is one of the embodiments. In the color picture tube, a panel and a shadow mask are combined in a predetermined relationship to assemble a panel / mask assembly.
As shown in (a), a phosphor screen 7 including a three-color phosphor layer that emits blue, green, and red is formed on the inner surface of the panel 1. Then, the shadow mask 8 is attached to the panel 1 on which the phosphor screen 7 is formed. Then, as shown in (b), the mask frame 10 of the shadow mask 8 is formed with a plate-like ferromagnetic material such as a carbon steel plate having no oxide film (blackening film) formed into a predetermined shape. The body 20 is attached by welding or fixing means such as a clip.

Next, frit glass is applied to the joining surface of the funnel with the panel 1, and the funnel and the panel 1 to which the frit glass is applied are attached to the shadow mask 8 as shown in (c). The inner magnetic shield 20 is placed inside the funnel 2 and positioned. Then, the funnel 2 and the panel 1 thus positioned are separated by 450
The frit glass applied to the funnel 2 is melted and joined together into a heating furnace having a maximum temperature of ℃, and the surface of the internal magnetic shield 20 inside the funnel 2 is oxidized.

Then, the electron gun is sealed in the neck 3 of the funnel 2 integrally joined to the panel 1, and the tube sealed with the electron gun is heated at a maximum temperature of 420 ° C. to evacuate the color image. Manufacture tubes.

By the way, as described above, in manufacturing the color picture tube, the internal magnetic shield 20 having no oxide film is attached to the shadow mask 8 incorporated in the panel 1,
When the panel 1 and the funnel 2 are integrally joined, peeling of the oxide film due to contact and deformation caused by conventionally mounting the internal magnetic shield having the oxide film formed on the shadow mask 8 can be prevented, and the carbon steel plate can be prevented. By heating at a relatively low oxide film forming temperature such as F
Since an oxide film containing eO as a main component is formed, the oxide film does not come off after manufacturing the tube as in the conventional case, and the shadow mask clogging and the deterioration of withstand voltage characteristics caused by the removal of the conventional oxide film are prevented. It can be greatly reduced.

[0015]

The internal magnetic shield having no oxide film formed is attached to the mask frame of the shadow mask mounted on the panel, and the internal magnetic field is generated by heating when the panel and the funnel are integrally joined by frit glass. Since an oxide film is formed on the surface of the shield, even if contact or deformation occurs before placing the internal magnetic shield in the tube, the oxide film formed after that does not affect the adhesion of the oxide film. Can be formed. Moreover, since the heating for joining the panel and the funnel is lower than the conventional oxide film formation temperature, a blackened film containing FeO as a main component and having a relatively small thickness is formed, and the conventional oxide film is prevented from peeling off. As a result, the clogging of the shadow mask and the deterioration of the withstand voltage characteristics caused by the above can be significantly reduced.

[Brief description of drawings]

FIG. 1 is an explanatory view of an embodiment of the present invention, FIG. 1 (a) shows a state in which a shadow mask is attached to a panel having a phosphor screen, and FIG. 1 (b) shows the shadow mask. The figure which shows the state which attached the internal magnetic shield, FIG.
FIG. 6C is a view showing a state in which the panel and the funnel are integrally joined with the inner magnetic shield inside.

FIG. 2 is a diagram showing a configuration of a color picture tube.

FIG. 3 is a view showing an internal magnetic shield of the color picture tube.

FIG. 4 (a) and FIG. 4 (b) are views showing a divided structure of the internal magnetic shield.

[Explanation of symbols]

 1 ... Panel 2 ... Funnel 7 ... Phosphor screen 8 ... Shadow mask 10 ... Mask frame 20 ... Internal magnetic shield

Claims (1)

Claim: What is claimed is: 1. When manufacturing a color picture tube, the internal magnetic shield having an oxide film formed on the surface thereof is attached to a mask frame of a shadow mask mounted on a panel. An internal magnetic shield having no oxide film formed is attached to the mask frame, and an oxide film is formed on the surface of the internal magnetic shield by heating when the panel and the funnel are integrally joined by frit glass. And a method of manufacturing a color picture tube.