JPS635849B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a color cathode ray tube.

Conventionally, shadow mask type color cathode ray tubes have been manufactured using the following steps. A clip is welded and attached to a blackened mask frame, a blackened shadow mask is welded to this mask frame, and a hole provided in the clip is fitted into a panel pin embedded in the panel. and assemble the shadow mask into the panel. An example is shown in FIG. 1 is a mask frame, 2 is a clip, 3 is a shadow mask, 4 is a panel, and 5 is a panel pin. This mask-incorporated panel is stabilized, and then a fluorescent surface is formed on the inner surface of the panel 4, and a color cathode ray tube is obtained through the following predetermined steps.

In the above-mentioned stabilization process, the clip 2 welded to the frame 1 is In advance of the thermal deformation of the clip 2, the shadow mask 3 shifts its position due to the thermal deformation of the clip 2, which serves to prevent the electron beam from mislanding the phosphor dot. That is, as shown in FIG. 2, the outer side of the bimetal 6 of the clip 2 attached to the frame 1 is made of high expansion metal.
During the heat treatment process, the bimetal 6 of the clip 2 warps as shown in FIG. 3, causing permanent deformation in the part that contacts the frame 1. As a result, after the heat treatment, the clip 2 returns to its state before the heat treatment process, as shown in FIG. Therefore, the shadow mask 3 fixed to the mask frame 1 does not return to the original position A, so the position of the shadow mask 3 with respect to the phosphor surface changes, and the electron beam impinges on a predetermined phosphor. I won't. In other words, a mislanding phenomenon occurs. If a heat treatment step is performed for the first time after the step of applying the phosphor slurry in this way, mislanding will occur due to changes in the clip 2 and, in turn, the positional deviation of the shadow mask 3. The clip 2 is heat-treated to cause permanent thermal deformation in advance, and even if the heat treatment is performed after applying the phosphor slurry, the clip 2 will no longer be thermally deformed and mislanding will no longer occur. This is to prevent it from happening.

However, this stabilization process requires a considerable amount of thermal energy to carry out, and also requires a large amount of expense considering the furnace and labor required for the process, causing the price of cathode ray tubes to rise.
The disadvantage was that it was not economical.

This invention was made with this in mind.
Unlike conventional methods, this method provides an extremely efficient method for manufacturing color cathode ray tubes.

In other words, by focusing on the deformation mechanism of the clip attached to the mask frame, welded the clip without blackening the mask frame, then performed the blackening treatment, then attached the shadow mask to this frame, and then assembled it to the panel. The method is characterized in that a fluorescent surface is formed on the inner surface of the panel without any stabilization, and then a product is produced through predetermined steps.

The method of this invention will be explained below. A clip is attached to a predetermined position on the outer surface of a mask frame that is not subjected to blackening treatment. As shown in FIG. 5, a mask frame 13 to which a clip 12 made of bimetal 11 is attached is held at a temperature of 550 to 620 degrees Celsius by holding means such as a holding jig 14 while maintaining a predetermined shape. heat-treated in a steam or carbon dioxide atmosphere for 10 to 30 minutes (blackening treatment at the same time). Next, the shadow mask, which has been formed into a spherical shape by drilling holes and has been blackened, is attached to the blackened mask frame as described above.
Then, it is assembled into a panel. Next, without performing a stabilizing process, a phosphor slurry is applied to the inner surface of the panel to form a phosphor surface, and then predetermined processes such as aluminizing, sealing, and sealing are performed to complete the color cathode ray tube.

In the conventional stabilizing process described in the above-mentioned conventional example, it was carried out at about 450°C for 30 minutes, but this was because the upper limit was about 450°C due to the softening of the panel glass. However, in the method of this example, the mask frame 1 is
Since heat treatment is applied to 3, the temperature is about 100℃ higher than before.
The process can be carried out at temperatures as high as 550 DEG C. to 620 DEG C., thereby making it possible to cause permanent thermal deformation in the clip 12 in advance, thereby eliminating thermal deformation caused by subsequent heat treatment. Furthermore, when stabilizing at 450℃,
The problem of further deformation of the clip due to subsequent heat treatment such as the sealing process is eliminated by the method of this example, and the spring characteristics of the clip are not adversely affected at the temperature of this example. Therefore, a cathode ray tube in which such a shadow mask is incorporated into the panel does not cause mislanding due to thermal deformation during operation. Furthermore, in the past, the clips were welded after the mask frame was blackened, so splashes were always generated at the welded areas, which caused the blackened film to peel off and cause rust.
With the method of this example, there is no clogging of the holes in the shadow mask, and the excellent effect of improving the withstand voltage characteristics of the cathode ray tube is achieved.

In this way, it has become possible to blacken the mask frame after attaching the clip and eliminate the stabilizing process that was previously performed, making it possible to save resources and labor, and reduce the price of color cathode ray tubes. can greatly contribute to
It is extremely useful industrially.

It should be noted that the method for blackening the frame to which the clip is attached is not limited to the above-mentioned method, and may be appropriately applied depending on each type of product.

[Brief explanation of the drawing]

Figure 1 is a plan view of the mask frame with the shadow mask attached to the panel, Figure 2
3 and 4 show the state when the clip is attached to the mask frame and subjected to heat treatment, FIG. 2 shows the state before heat treatment, FIG. 3 shows the state during heat treatment, and FIG. 4 shows the state after heat treatment. FIG. 5 is a diagram showing a state in which a mask frame to which a clip is attached is held down by a jig during blackening processing. 1...Mask frame, 2...Clip, 3...Shadow mask, 4...Panel, 5...Panel pin, 11
...bimetal, 12...clip, 13...mask frame, 14...presser jig.

Claims (1)

[Claims] 1. When manufacturing a color cathode ray tube having a shadow mask attached to a mask frame, after attaching a clip to a predetermined position on the outer surface of the mask frame, the clip is attached to the mask frame before attaching the shadow mask to the mask frame. A method for manufacturing a color cathode ray tube, characterized in that the mask frame is blackened by holding the clip in a predetermined shape.