JPS6043619B2 - 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, in which an electron gun is enclosed in the neck of a bulb, and then the gas inside the bulb is discharged. This method provides a suitable method for machine picture tubes, oscilloscopes, etc.

Conventionally, when manufacturing a cathode ray tube for color television, first the panel part and funnel part were
400C) Construct a bulb by frit sealing with solder glass for 7 minutes. After that, the temperature of the furnace is lowered to room temperature or taken out of the furnace and lowered to room temperature, and then the electron gun is inserted into the neck of the valve and the neck and stem are welded together using a burner. is enclosed in the neck part. Then, the valve with the electron gun attached is placed in another furnace for evacuation, and the temperature of the valve is raised from room temperature to 380°C, which is necessary for evacuation, according to the temperature of this furnace.The evacuation process is performed for 60 minutes, and the gas inside the valve is removed. Drain and vacuum. In such conventional methods, the cathode material and getters are damaged at the sealing temperature between the panel part and the funnel part.
There was a very strong preconception that the temperature when the electron gun was sealed had to be lowered to room temperature.

Therefore, the thermal efficiency is very poor because the temperature of the valve must be lowered to room temperature and then raised again to the exhaust temperature.However, considering the time required for this cooling and the time required for heating up to the exhaust temperature, the working time is reduced. becomes noticeably longer. Also, because it takes time to exhaust the valve, gas in the air tends to get into the valve before exhausting.
The carbon coated on the inner surface of the valve adsorbs a large amount of this gas, which has a negative effect on the exhaust operation. Furthermore, since the valve is taken out of the furnace and then transferred to the furnace for exhaust, continuous operation is impossible. The present invention was invented in order to correct the above-mentioned defects, and provides a method for manufacturing a cathode ray tube in which an electron gun is enclosed in a bulb and the gas in the bulb is then discharged.(a) A temperature higher than 400° C., which is the temperature required to perform at least one of sealing the panel portion and the funnel portion and firing the fluorescent surface of the bulb without the electron gun sealed therein. (b) Then, by cooling the bulb to room temperature so that the temperature does not drop, the gas in the bulb is discharged. (c) maintaining the valve at a temperature range of 100 to 400° C. that is sufficient to prevent damage to the electron gun components;
enclosing the electron gun in the valve in this state;
(d) then maintaining the valve within the temperature range;
The present invention relates to a method for manufacturing a cathode ray tube, characterized in that each step includes discharging the gas inside the valve.

By this method, thermal efficiency can be greatly improved, workability can be greatly improved, and sufficient exhaust can be achieved. Next, an embodiment in which the present invention is applied to a cathode ray tube of a color television receiver will be described with reference to the drawings.

As shown in FIG. 1, the structure of the furnace according to this embodiment differs greatly from that of the conventional furnace. That is, this furnace 1 is almost tubular in shape, and includes a frit seal zone I between the panel section 3 and the funnel section 4 that constitute the valve 2, and an electron gun 6 enclosing zone at the neck section 5 of the valve 2! area■ and the exhaust zone of valve 2■
There are some that are arranged in succession. A rail 7 for guiding the valve 2 from the zone 1 to the zone (2) through the furnace 1 is provided almost horizontally. The relationship between the valve 2 and the rail 7 is as shown in FIG. When these wheels run on the rails 7, 13, the valve 2, which is held in position by the support ring 8, is guided along the rails 7, 13. Rails 7, 13
is slightly inclined toward the zone (2) at the boundary between zones 1 and (2), and an opening 14 is formed at the bottom of the furnace 1 from this inclined portion to zones (2) and (2).

This allows the neck portion 5 of the valve 2 to be exposed below the bottom girth of the furnace 1 when the valve 2 is lowered when moving from zone I to zone II and returned to the horizontal position. I'm getting tired. Although not shown, Band 1, ■ and ■
A heater made of a resistance wire is arranged around the outside of the furnace 1 in , which keeps zone (1) at a temperature of 430-440°C, which is necessary for frit sealing, and zones (2) and (2) at a temperature of 380-440°C, which is necessary for evacuation. The temperature is maintained uniformly at 39°C.

Next, a process of manufacturing a cathode ray tube using the furnace 1 configured as above will be explained.

First, in zone 1, the bulb 2 is guided with the panel part 3 and the funnel part 4 butted against each other using a jig (not shown), and during this time the solder glass is soldered at a temperature of 430 to 440'C. The panel portion 3 and funnel portion 4 are frit-sealed with about 7 coats of powder.

At this time, the fluorescent surface coated on the inner surface of the panel portion 3 is formed at the same time. Then, the bulb 2 is introduced into the zone (1), thereby lowering the temperature of the bulb 2 slightly from the temperature at the time of frit sealing to 380-3900C.

At this time, the electron gun 6 attached to the stem part 16 equipped with the exhaust pipe 15 is inserted from below into the neck part 5 exposed from the opening 14 of the furnace 1, and the stem part 6 and the neck part 5 are butted together. Then, heating is performed using a heating means 17, such as a heating furnace or a gas burner. When using a heating furnace, the stem portion 6
A frit glass is applied to the connector fixing portion with the neck portion 5 in the above, and the stem portion 6 is connected to the neck portion 5 via this frit glass, thereby enclosing the electron gun 6 within the neck portion 5. and fix it in about 1 inch. Note that during this sealing, the temperature of the bulb 2 is maintained at a level that will not damage the constituent parts of the electron gun 6. That is, the cathode material is not damaged by 38C, and the getter (oxidized at 400° C. or higher) disposed within the funnel portion 4 is also not damaged. Next, the valve 2 is introduced into the zone ■ which is maintained at the same temperature as the zone ■, and here the exhaust pipe 1 of the stem portion 16 is
5 is connected to a rubber tube 18 from a vacuum pump (not shown), and the inside of the valve 2 is evacuated at 380 to 3900C.

In this evacuation process, since the temperature in zone (2) and zone (2) are the same, the temperature in zone (2) has already reached the temperature required for evacuation, and the filling of the electron gun 6 and subsequent evacuation are performed continuously. It can be done. However, when going from zone 1 to zone ■, the temperature is slightly lowered to the exhaust temperature, so there is no need for the conventional cooling process, and the process from zone 1 to zone ■ is done in a continuous operation. It is possible to do so. Note that the above exhaust treatment does not necessarily mean that valve 2 is connected to rail 7.
It is not necessary to perform this while existing on the rail 7, and it may be performed in a separate band connected to band (3) by removing it from the rail 7. FIG. 3 shows the temperature profile of each process described in FIG. 1. According to this embodiment, after frit sealing in zone 1, the electron gun parts are temperature sufficient for exhaustion without damaging the
While the temperature was slightly lowered to ~390'C, the electron gun was subsequently filled in and evacuated, respectively.

Therefore, the thermal efficiency is very good, and it is greatly improved compared to the conventional method in which the power consumption and time required for cooling and reheating the furnace are large. Furthermore, since the valve is maintained at a temperature higher than the exhaust temperature during the period from the frit seal to the exhaust, the heating time of the valve can be greatly shortened. Moreover, since the work can be done continuously in one furnace, the work efficiency is significantly improved in addition to the above-mentioned time reduction. Furthermore, since the time required for evacuation is greatly shortened, it becomes difficult for gas in the air to enter the valve, and gas adsorption within the valve is greatly reduced. can be carried out completely and sufficiently, yet in a short period of time. Although the present invention has been described above based on one embodiment, it will be understood that further modifications can be made based on the technical idea of the present invention.

For example, the structure of the furnace 1 and the arrangement of each zone may be changed in various ways. In addition, the temperature of the valve 2 in zone ① is below 400℃, which is 100℃, which is the temperature at which gas, especially moisture, is exhausted.
℃ or 120°C or higher. In this case 100℃
Even if it is only a small amount, it is sufficient to exhaust moisture etc., and the heating time etc. are improved over the conventional method. It is also possible to apply the present invention to a black and white television picture tube, but in this case, the above-mentioned panel section 3 and funnel section 4 are integrated in advance and the fluorescent surface is fired. As described above, the present invention heats a bulb in which an electron gun is not enclosed to a temperature necessary for at least one of "sealing" the panel part and the funnel part and baking the fluorescent surface. After performing at least one of sealing and firing, the temperature was maintained at a temperature range that was sufficient for exhaust and did not damage the electron gun components by cooling to room temperature so that the temperature did not drop. Since the electron gun is sealed in the current state and is maintained within the above temperature range before being exhausted, there is no need to cool or reheat the valve as in the conventional method, and while protecting the electron gun, the exhaust temperature can be reduced. It can be easily obtained, and therefore the thermal efficiency can be very improved.In this case, the heating time up to the exhaust temperature can be greatly shortened, and continuous operation can be performed without taking the valve out of the furnace. This makes it possible to greatly improve work efficiency.

Furthermore, since the time required for evacuation is shortened by shortening the time, gases in the air are less likely to enter the valve and be adsorbed.

[Brief explanation of the drawing]

The drawings show an embodiment in which the present invention is applied to a cathode ray tube for a color television receiver, and FIG. A partial sectional view of the state when guiding,
FIG. 2 is a plan view of a valve guided on a rail, and FIG. 3 is a temperature profile in the process shown in FIG. 1.

Claims (1)

[Claims] 1. In a method for manufacturing a cathode ray tube, in which an electron gun is enclosed in a bulb, and then the gas in the bulb is discharged, (a) the bulb without the electron gun enclosed therein is separated from a panel portion and a funnel. heating to a temperature higher than 400°C, which is the temperature required to perform at least one of the sealing with the part and the firing of the fluorescent surface, and at least one of the sealing and the firing of the fluorescent surface. (b) then cooling the bulb to room temperature without dropping the temperature to a temperature sufficient to allow the gas in the bulb to be evacuated and not to damage components of the electron gun; (c) enclosing the electron gun in the bulb in this state; (d) then keeping the bulb within the temperature range and A method for manufacturing a cathode ray tube, comprising each step of discharging the gas inside the valve.