JPS5810811B2 - Cathode ray tube manufacturing method - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing a cathode ray tube.

Conventionally, a cathode ray tube in which a flat face plate on which a fluorescent film has been formed in advance is hermetically sealed in a cone portion with a frit glass interposed therebetween has been manufactured as follows.

That is, as shown in FIG. 1, a fluorescent film 2 is formed on the inner surface of the face plate 1 by a precipitation method, etc., a binder (lacquer film) 3 is applied on the upper layer, and a thin aluminum film (metal back layer) is further applied on the upper layer. ) 4, the lacquer film 3 is decomposed by firing to form a fluorescent film 2 and a metal back layer 4, respectively.

Then, this face plate 1 was placed on the cone portion 5 with a frit glass 6 interposed therebetween and welded as shown in FIG.

However, the above manufacturing method requires two heating steps for firing and airtight sealing, which complicates the work process. Using plate 1,
Even if an attempt is made to perform airtight sealing at the same time as firing and perform the heating process in one time, there is no air permeability between the inner peripheral surface of the face plate 1 and the cone portion 5, so that the firing will not be performed sufficiently. In addition, there was a problem in that the generated gas adversely affected the frit glass, making it impossible to obtain sufficient airtightness, and it was not possible to perform the heating process only once.

In view of the above-mentioned problems, the present invention provides a manufacturing method that can melt the frit glass and decompose the lacquer film in one heating step.

That is, this invention has a frit glass 1 as shown in FIG.
2 is applied to the periphery of the opening of the cone portion 11 to form raised and raised portions 12a at multiple locations higher than others, and the face plate 10 on which the fluorescent film 13, lacquer film 14, and metal back layer 15 are formed is placed. However, a gap 16 is formed between the cone portion 11 and the face plate 10 to provide ventilation with the outside.

The frit glass 12 applied to the cone portion 11 has a melting point higher than that of the lacquer film 14 applied to the face plate 10.

After placing the face plate 10 on the frit glass 12 coated on the cone portion 11 so that a gap 16 is formed between the two, the face plate 10 is heated in a furnace, and the lacquer film 1
When the temperature is raised to the decomposition temperature of step 4 and maintained, the melting point of the frit glass 12 is higher than the decomposition temperature of the lacquer film 14, so the frit glass 12 does not soften and is sufficiently supplied with outside air from the gap 16 and the neck portion to be fired. is completely carried out.

After firing, when the temperature rises to the melting point of the frit glass 12, the frit glass 12 can be reliably sealed without being adversely affected by the lacquer film decomposition gas.

In this way, until the lacquer film 14 decomposes, a gap 16 is formed between the face plate 10 and the frit glass 12, and there is good ventilation with the outside air, so the lacquer film 14 completely decomposes and does not decompose. After the process is completed, the face plate 10 and the cone part 11 are welded together.
Firing and sealing can be performed in one heating step.

In addition, the face plate 1 remains until the lacquer film 14 decomposes.
A gap 16 is formed between 0 and the frit glass 12,
Another method for providing air permeability between the two is as shown in FIG.
A glass bulb 11 may be interposed between the two.

As a result, a gap 16 is formed between the face plate 10 and the frit glass 12 until the lacquer film 14 is decomposed, and after the lacquer film 14 is decomposed, the frit glass 12 is melted and the glass bulb 17 becomes a frit glass as shown in FIG. 1
2 and sealing is performed.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can be applied, for example, to a face plate in which a binder mixed with a phosphor is applied to the face plate by screen printing or the like, and a metal back layer is formed on the upper layer. Good too.

As explained above, this invention uses frit glass having a melting point higher than the decomposition temperature of the binder, and forms a gap between the cone portion and the face plate that communicates the inside and outside of the bulb until the decomposition of the binder is completed. The decomposition of the binder and the welding of the face plate to the cone portion can be performed in one heating process, thereby simplifying the work process.

[Brief explanation of the drawing]

1 and 2 are drawings showing a conventional face welding type cathode ray tube, Fig. 3 is a drawing showing a face welding type cathode ray tube according to the present invention, and Figs. 4 and 5 are drawings showing another embodiment of the present invention. It is a drawing showing an example. 10... Face plate, 11... Coin part, 12...
... Fritted glass, 12a ... Convex portion, 13 ... Fluorescent film,
14...Binder, 16...Gap, 17...Glass bulb.

Claims (1)

[Claims] 1. A flat face plate with a lacquer film formed on the fluorescent film or a fluorescent film containing a binder and a metal back layer formed on the soil layer is placed on the opening end surface of the cone part.
When airtightly sealing using frit glass with a melting point higher than the decomposition temperature of the lacquer film or binder, there is a gap between the cone and the face plate that communicates the inside and outside of the bulb until the decomposition of the lacquer film or binder is completed. A method of manufacturing a cathode ray tube, comprising: forming a cathode ray tube.