JPH07201278A - Manufacture of cathode ray tube, and its heating device - Google Patents

Abstract

PURPOSE:To prevent the remaining of water in a cone graphite film and prevent the occurrence of a blistering phenomenon in a frit sealing process. CONSTITUTION:The heater 3a of a heating device 3 provided in opposition to an area of a funnel glass 1 where a cone graphite film is applied is used for heating so as to increase temperature to apply the cone graphite film. Therefore, drying process is started from a funnel foundation so as to remove moisture by increasing the temperature of the funnel glass.

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 cathode ray tube and a heating device therefor, and more particularly to a method of applying an internal conductive film of the cathode ray tube.

[0002]

2. Description of the Related Art FIG. 1 shows a funnel after coating of an internal conductive film. In this figure, 1 is a funnel glass,
1a is a funnel neck portion, 1b is a funnel yoke portion, and 1c is a funnel cone portion. Reference numeral 2a is a neck graphite film, 2b is a soft graphite film, and 2c is a cone graphite film, and is composed of three kinds of graphite films as an internal conductive film of the funnel glass 1.

The purpose of the graphite film applied to the inner surface of the funnel glass 1 is to transfer the high voltage applied to the anode button (not shown) through the conduction spring (not shown) attached to the mask frame (not shown). Panel phosphor screen (not shown)
To the electron gun (not shown) through the neck graphite film 2a. Also,
It also has a getter effect of adsorbing the glass inside the cathode ray tube as a secondary effect. The purpose of applying the three types of graphite is that the graphite applied to the funnel neck portion 1a is applied with emphasis on strong adhesion. This is because even if the contact spring of the electron gun comes into contact, it does not come off.

Next, in order to minimize gas contamination of the cathode ray tube, the funnel cone portion 1c is coated with a material having a weak adhesive force but little gas generation. This distinction has the advantages of both. Also,
The soft part between the two is coated with a material having a very high resistance value, and the purpose is to suppress the spark current and prevent the failure of the TV set.

Next, a method of applying the internal conductive film will be described. First, the funnel glass 1 for forming the internal conductive film
The inner surface of is washed with an aqueous solution of ammonium fluoride, caustic soda and pure water. Next, the funnel glass 1 after cleaning is dried using a gas furnace or the like. If the temperature of the dried funnel glass 1 is high, cracks may occur in the graphite film when the graphite film is applied, so the temperature of the dried funnel glass 1 is 4%.
Set so that it becomes a little over 0 ° C.

Next, a neck graphite film 2a is applied to a predetermined area on the inner surface of the funnel glass 1. Similarly, the soft graphite film 2b is applied to a predetermined area on the inner surface of the funnel glass 1, and finally the cone graphite film 2c is applied to a predetermined area. The funnel glass 1 after coating is dried with a dehumidified air or the like to dry the graphite film, and the internal conductive film coating step is completed.

[0007]

In the drying of the graphite film in the above method, the influence on the funnel glass 1 is different due to the change of the atmosphere in the room, that is, the room temperature and the humidity, and the influence on the inner surface of the funnel glass 1 is different. In some cases, only the surface of the graphite film was dried and only the water content of the graphite remained, which also affected the drying speed of the graphite film. This is more likely to be affected by the cone graphite film 2c farther from the opening, and the water partially remaining on the cone graphite film 2c becomes a blistering phenomenon in the subsequent frit sealing step, which peels off and becomes a mask. If it adheres, it causes clogging of the mask, and if it adheres to the electron gun, it causes sparks.

The present invention has been made to solve the above-mentioned conventional drawbacks, and an object thereof is to obtain a method for manufacturing a cathode ray tube which forms a good cone graphite film. It is another object of the present invention to provide a heating device that raises the temperature of the funnel glass in the area where the cone graphite film is applied when the cone graphite film is applied.

[0009]

According to the method of manufacturing a cathode ray tube according to claim 1 of the present invention, in a cathode ray tube having a cone graphite film as an internal conductive film on the inner surface of the funnel, at least the cone graphite film of the funnel glass is provided. The cone graphite film is applied by raising the temperature of the area to which is applied.

According to the method of manufacturing a cathode ray tube according to claim 2 of the present invention, in the method of manufacturing a cathode ray tube according to claim 1, the temperature of at least a region of the funnel glass to which the cone graphite film is applied is raised to about 50.degree. It was done like this.

According to the method of manufacturing a cathode ray tube according to claim 3 of the present invention, the step of cleaning the inner surface of the funnel glass, the step of drying the funnel glass after cleaning, and the application of at least the neck graphite film and the soft graphite film of the funnel glass. The temperature of the region to be heated is maintained at about 40 ° C. or higher, the process of applying the neck graphite film and the soft graphite film, the process of drying the neck graphite film and the soft graphite film, the region of the funnel glass to which at least the cone graphite film is applied. The temperature is maintained at about 50 ° C. and the cone graphite film is applied, and at least the above process of drying the applied cone graphite film is performed.

According to the heating device of claim 4 of the present invention,
The heating means is provided facing the outside of the area of the funnel glass on which the cone graphite film is applied.

[0013]

According to the method of manufacturing a cathode ray tube according to claims 1 to 3 of the present invention, the temperature of at least the area of the funnel glass to which the cone graphite film is applied is raised to apply the cone graphite film to form the cone graphite film. Prevents residual water.

According to the heating device of claim 4 of the present invention,
Only the area of the funnel glass on which the cone graphite film is applied is heated to prevent cracks occurring in the soft graphite film.

[0015]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the flowchart of FIG. First, the funnel glass 1 is washed as in the conventional case (S1). Next, the drying process is completed (S2), and the process proceeds to the internal conductive film coating process. Here, the funnel glass temperature is set to about 40 ° C. or higher as in the conventional case. This is because when the funnel glass temperature is high, cracks are generated when the soft graphite film 2b is applied. Next, the neck graphite film 2a and the soft graphite film 2b are applied as in the conventional case (S3).

Next, by the heating device 3 shown in FIG. 3, only the outer surface of the predetermined area of the funnel glass 1 to which the cone graphite film 2c is applied is heated by the heater 3a, and the temperature of the funnel glass in this portion is about 50.degree. Raise to. Next, the cone graphite film 2c is applied (S4). In this way, the funnel glass temperature of the funnel glass 1 is increased only in a predetermined area to which the cone graphite film 2c is applied, and the funnel coated with the cone graphite film 2c is increased by the funnel glass itself. That is, it is possible to prevent the residual moisture in the graphite film by drying the cone graphite film 2c from the funnel base. Further, the funnel glass temperature can be raised without causing cracks in the soft graphite film 2b.

Example 2. The heating device of FIG. 3 used in Example 1 will be described. The heating device 3 is composed of the following.
The support portion 3b is provided on the base 3d, and the funnel glass 1 is placed in the hole provided in the support portion. At that time, the funnel neck portion 1a of the funnel glass 1 is locked and positioned by the positioning 3c. The heater 3a is provided outside the area of the funnel glass 1 where the cone graphite film is applied so as to heat only the area where the cone graphite film is applied. In this case, the soft graphite film portion is not excessively heated, and the soft graphite film is not cracked.

Although the heater 3a is used as the heating means in the above description, a warm air blower may be used, or another heating means may be used.

Example 3 In Example 1, only the area of the funnel glass 1 on which the cone graphite film 2c is applied is heated. However, when the soft graphite film is less likely to crack, the area other than the area where the cone graphite film 2c is applied is also used. You may heat. For example, the entire funnel glass may be heated.

Example 4 In the flowchart of FIG. 2 of Example 1, the neck applied between the step of applying the neck graphite film and the soft graphite film (step S4) and the step of applying the cone graphite film (step S5). A step of drying the graphite film and the soft graphite film may be included. In this case, drying is usually performed by natural drying.

[0021]

As described above, according to the present invention, the temperature of at least the area of the funnel glass to which the cone graphite film is applied is raised to apply the cone graphite film. , It has the effect of removing residual water of corn graphite and preventing the blistering phenomenon.

Further, since the heating device is used to heat only the region of the funnel glass having the cone graphite film applied, there is an effect that the soft graphite film is not cracked.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a funnel after completion of coating of an inner conductive film according to a first embodiment of the present invention.

2 shows a flow chart of the manufacturing method of FIG.

FIG. 3 is a cross-sectional view showing a funnel heating device according to Embodiment 1 of the present invention.

[Explanation of symbols]

 1 Funnel Glass 1a Funnel Neck Part 1b Funnel Yoke Part 1c Funnel Cone Part 2a Neck Graphite Film 2b Soft Graphite Film 2c Cone Graphite Film 3 Heating Device 3a Heater (Heating Means) 3b Supporting Part 3c Positioning 3d Base

[Procedure amendment]

[Submission date] September 5, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

The purpose of the graphite film applied to the inner surface of the funnel glass 1 is to transfer the high voltage applied to the anode button (not shown) through the conduction spring (not shown) attached to the mask frame (not shown). Panel phosphor screen (not shown)
And be conducted to, it is to conduct high voltage through the neck graphite film 2a to the electron gun (not shown). Also,
It also has a getter effect of adsorbing the gas inside the cathode ray tube as a secondary effect. The purpose of applying the three types of graphite is that the graphite applied to the funnel neck portion 1a is applied with emphasis on strong adhesion. This is because even if the contact spring of the electron gun comes into contact, it does not come off.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

[0007]

In the drying of the graphite film in the above method, the influence on the funnel glass 1 is different due to the change of the atmosphere in the room, that is, the room temperature and the humidity, and the influence on the inner surface of the funnel glass 1 is different. In some cases, only the surface of the graphite film was dried and only the water content of the graphite remained, which also affected the drying speed of the graphite film. This is a graph
Cone graphite film 2c that is likely to accumulate
However, the moisture left partially on the cone graphite film 2c becomes a blistering phenomenon in the subsequent frit sealing step, and if it peels off and adheres to the mask, the mask becomes clogged. If it adheres to the surface, it causes a problem such as sparking.

[Procedure 3]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

[Fig. 2]

Claims (4)

[Claims] 1. A cathode ray tube having a cone graphite film as an internal conductive film on the inner surface of a funnel, wherein the temperature of at least a region of the funnel glass to which the cone graphite film is applied is raised to apply the cone graphite film. A method of manufacturing a cathode ray tube, characterized in that 2. The method of manufacturing a cathode ray tube according to claim 1, wherein the temperature of at least a region of the funnel glass to which the cone graphite film is applied is raised to about 50 ° C. . 3. The step of cleaning the inner surface of the funnel glass, the step of drying the funnel glass after cleaning, the temperature of at least the neck graphite film and the soft graphite film of the funnel glass being maintained at about 40 ° C. or higher, The step of applying the neck graphite film and the soft graphite film, the step of drying the neck graphite film and the soft graphite film, the temperature of at least the cone graphite film of the funnel glass is maintained at about 50 ° C. A method of manufacturing a cathode ray tube, comprising at least the above-mentioned step of coating and drying the coated cone-graphite film. 4. A heating means is provided to face the outside of the area of the funnel glass on which the cone graphite film is applied,
A heating device characterized by increasing the temperature of the funnel glass.