JPH03187121A - Electrification removing device for color cathode-ray tube bulb - Google Patents

Abstract

PURPOSE:To remove the electrification of a glass bulb by sliding a high- elasticity conductive-fiber-made electrification removing brush, which is in a well grounded state, in contact with the whole outside of the bulb. CONSTITUTION:An electrification removing brush 2 is made of high-elasticity strong carbon fiber which is given good conductivity by mixing good conductor powder such as Al in. A column 3 is made from a normal iron pipe or, etc., because it requires enough strength. A conductor often has floating potential near a high-voltage generator or a high-voltage charged subject and so an insulating coat is applied to the periphery of the column 3 to be insulated from the electrification removing brush 2. The electrification removing brush 2 is directly grounded with a fully sized cooper wire instead. The electrification removing brush 2 is slided in contact with the whole outside of the bulb of a color cathode ray tube 1 several times at preset intervals. It is thus possible to remove the electrification of a glass bulb in production.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is designed to prevent the glass bulb from being charged during the manufacturing process of color cathode ray tubes, which may clog the electron passage hole of the shadow mask and cause discomfort to the operator. This invention relates to technology for removing and eliminating static electricity.

[Prior Art] In color cathode ray tubes, before sealing the stem that supports the electrodes, the panel and funnel are fused and sealed using frit glass (low melting point crystallized powder glass), which is a unique process for color cathode ray tubes. and then apply a voltage of, for example, 30kV to this melted part.
A similar high voltage is applied to inspect the melted part for foreign matter, etc.

This high voltage application causes the glass bulb of the color cathode ray tube to become electrically charged, and this electrically charged state does not disappear for a considerable period of time, such as during winter when the humidity of the ambient air is low. Not only does this electrostatic charge on the valve cause discomfort to the operator, but when the neck tube end is open before the stem is sealed and air is flowing into the valve, dust in the air may It adheres to the shadow mask, which is charged to the same potential as the panel and has an electrostatic adsorption force, and blocks the small-diameter electron passage hole drilled in the mask, causing a frequent occurrence of so-called clogging defects. In general, even if the amount of electric charge is small, it is quite unpleasant for the person who comes into contact with it, although it varies from person to person.Therefore, it is important to prevent the valve from being charged even after the stem is sealed. It is.

Conventionally, in order to eliminate the charged state of the valve.

We have tried humidifying the ambient air around the work location and using static neutralizing air blowers to blow ionized air, but no significant effects have been found.

As a countermeasure against such a situation, for example,
Publication No. 455 discloses that an ion supply device is used to attenuate the output voltage of a high voltage generator within a predetermined time, and to neutralize the ionic current of a bulb near a color cathode ray tube to which high voltage is being applied for inspection. A technique for supplying ions is disclosed.

[Problems to be Solved by the Invention] However, the above-mentioned conventional techniques have not been able to eliminate the charged state to a sufficiently satisfactory degree.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the conventional technology and to provide a charge removal device for a color cathode ray tube bulb that can sufficiently remove the static charge accumulated on the bulb.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes forming a panel on which a fluorescent surface has been formed and a shadow mask etc. attached, and an internal conductive film connected to an anode terminal embedded in a wall surface. The finished funnel is melt-sealed with frit glass, and the outside of the funnel is placed on the outside of the bulb of the color cathode ray tube whose neck tube end is opened before the stem sealing process, and the withstand voltage test for the frit-sealed part has been completed. A static elimination brush made of highly elastic conductive fiber that is in good ground condition is brought into contact with the entire surface of the wall, including near the anode terminal, intermittently several times at predetermined time intervals. I decided to remove the electrical charge from the glass bulb.

[Effect] Even if the amount of charge on the bulb is not large,
Its removal is not easy. This is because the glass that makes up the bulb has fairly good insulating properties, and even if a grounded conductor is brought into contact with the grounded conductor, the electric charge on the contact point and the area very close to it will be removed, but the electric charge on other parts will be removed. Due to the good insulating properties of the glass, it is not prevented from moving and removed. Generally, if the charge is large enough to cause a problem, the voltage generated by the charge is high, so after a certain amount of time, the charge will be removed and the area where the voltage has become lower will be charged to another higher voltage. As a result, the voltage at the area where the voltage has already dropped becomes considerably high, even though it was not very high before, due to charge migration from the area where the voltage is, or induced by residual charge at the high voltage area. It will recover to. You can see a phenomenon as if an electric charge was flowing out. Therefore, even if a well-grounded static elimination brush is used, one simple stroke is not enough, and it is necessary to slide the static elimination brush over the entire surface over a period of time. In addition, the anode terminal embedded in the funnel wall of the bulb, together with the internal graphite coated and connected to it on the inner surface of the funnel, forms the electrode on the inner wall of the bulb (of a capacitor whose dielectric is the glass wall of the funnel). Is there anything inside the valve? Since it is impossible to insert a static elimination brush through the neck tube, it is necessary to keep the static elimination brush in contact with the anode terminal on the outside of the funnel wall and its vicinity for a relatively long period of time in order to remove the charge on the inner wall side of the bulb. There is. In addition, as mentioned above, since a phenomenon in which electric charges appear, the outer surface of the bulb and the anode terminal, which serves as the terminal representing the inner wall surface of the bulb, are connected multiple times, either alternately or simultaneously. , it is necessary to slide the static elimination brush into contact with it in a sweeping motion.

In addition, as is often experienced at high voltage test sites, conductors near high voltage generators or objects charged with high voltage may become charged with so-called floating potential, causing a very troublesome phenomenon. . Therefore, if no action is taken, iron supports placed on the factory floor near locations where voltage resistance tests are performed on the frit-sealed parts of color cathode ray tubes are often at a floating potential. It is also necessary to pay sufficient attention to this aspect (generally, good grounding work) when installing and supporting the static elimination brush.

Embodiment FIG. 1 is a diagram showing a state in which the static elimination brush is brought into contact with the outside of a color cathode ray tube in an embodiment of the present invention.

The upper part of the figure is a color cathode ray tube, 2 is a static elimination brush, and 3 is a support for the static elimination brush. The static elimination brush is made of, for example, highly elastic and durable carbon fiber mixed with a good conductor powder such as aluminum powder to give it good conductivity. In addition, the support pillars need to have sufficient strength, so they are made of ordinary iron pipes, etc., and as mentioned above, the conductors may have a floating potential in the vicinity of high voltage generators or objects charged with high voltage. Because there are a lot of electrical conductors, the surroundings of this pillar should be covered with a material that has good insulation and is durable, such as vinyl chloride.In other words, although this pillar is made of iron and has conductivity, it is not reliable for grounding. On the contrary, it is insulated from the static elimination brush.

On the other hand, with the static elimination brush 5, it is necessary to pay close attention to the resistance value of the grounding point, which is directly grounded with a sufficiently thick copper wire.

FIG. 2 shows an example of a static elimination brush. When static electricity is removed near the anode terminal of the funnel, a plurality of such brushes may be attached around the support column, and the support column may be rotated while pressing the brushes against the valve surface.

As mentioned above, this is to ensure that the ends of the bristles of the brush come into full contact with the surface near the anode terminal.

In contrast to the above, the static elimination brush 2 for eliminating static electricity from the front surface (display surface) of the valve panel and the outer surface near the panel skirt has a shape as shown in Figure 1, for example. Therefore, it is necessary to perform a relative (reciprocating vibration, if necessary) RA motion with respect to the cathode ray tube. (The action of sweeping is expressed as sweeping).

FIG. 3 shows an example of a static eliminator system that uses static eliminator brushes to eliminate static electricity at a plurality of work positions. Currently, color cathode ray tubes are mass-produced products, and they are usually transported by a conveyor at a constant speed, and work is performed automatically and mechanically along the way.The time required for each task varies, so it is a task that requires a long time. will be divided into multiple work positions and receive work. In the example shown in Fig. 3, after the withstand voltage test of the frit-sealed part is completed, static electricity removal work is performed at the five positions shown in the figure while moving in the direction of the arrow.6 At the first position, the panel surface and Sweep the side surface (mainly the panel skirt surface), and in the 2nd and 3rd positions, lJh pole terminal (
Sweep only the area (cavity) and its vicinity. In the fourth position, the outer surface of the valve and the vicinity of the cavity are repeatedly swept simultaneously and individually for relatively short periods of time. In the fifth position, only the cavity is swept.

In addition, the direction of the conveyor in this diagram is helpful.
This is due to workplace layout requirements unrelated to static charge removal, and there is no problem in arranging them in a straight line.

[Effects of the Invention] As explained above, according to the present invention, defects such as shadow mask clogging and stray emissions are reduced, and the occurrence of unpleasant electric shocks to the operator is also reduced.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an example of the present invention in which a static eliminator brush is in contact with the outside of a color cathode ray tube, Fig. 2 is a diagram showing an example of a static eliminator brush, and Fig. 3 is a diagram showing how the static eliminator brush is used to remove static electricity. FIG. 2 is a diagram showing an example of a static eliminator integrated into a system that performs work at multiple work positions.

Claims (1)

[Claims] 1. The panel on which the fluorescent surface has been formed and the shadow mask etc. have been attached, and the funnel on which the interior conductive film has been formed, which is connected to the anode terminal embedded in the wall, are melt-sealed with frit glass to ensure resistance to the frit-sealed part. Ensure that the outside of the bulb of the color cathode ray tube, which has undergone voltage inspection and whose neck tube end is open before the stem sealing process, is well grounded over the entire area, including near the anode terminal on the outer funnel wall. A charge removal device for a color cathode ray tube bulb, characterized in that the charge removal device for a color cathode ray tube bulb is characterized in that the charge is removed from a glass bulb by sliding a charge removal brush made of a certain highly elastic conductive fiber into contact with the glass bulb.