JPH09259763A - Method for removing harmful matter from cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a harmful matter removing method by which a foreign matter can be efficiently removed from a cathode-ray tube bulb in which various tube inside members are arranged. SOLUTION: In a harmful matter removing method of a cathode-ray tube, a bulb 3 before an electron gun is sealed is formed so that an end part opening of a neck 6 turns downward, and a gas blowout nozzle 24 is inserted from its neck end part opening, and an ultrasonic vibrator 26 or a hammer ring device 25 or its both are arranged on the outside of the bulb. An annular magnetic filed generating coil 27 is arranged in the vicinity of a boundary part between the neck part 6 and a cone part 8 so that a coil surface is positioned on a surface vertical to the tube axis, and gas is blown out of the gas blowout nozzle, and at least one of the ultrasonic vibrator and a hammer ring is operated, and an alternating magnetic field is intermittently generated from the magnetic field generating coil.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a harmful substance removing method in a manufacturing process of a cathode ray tube such as a color picture tube, and more particularly to a harmful substance removing method of a cathode ray tube which applies an alternating magnetic field to remove the harmful substance.

[0002]

2. Description of the Related Art Generally, various in-tube members are arranged in a cathode ray tube. For example, as shown in FIG. 2, a color picture tube has a glass bulb 3 made up of a panel 1 and a funnel-shaped funnel 2, and the panel 1
A phosphor screen 4 made of a three-color phosphor layer is provided on the inner surface of the, and a shadow mask 5 having a large number of electron beam passage holes formed therein is arranged so as to face the phosphor screen 4. On the other hand, the electron gun 7 is arranged in the neck 6 of the funnel 2. A conductive film 9 formed by applying a conductive paint (aquadag) is provided from the inner surface of the cone portion 8 of the funnel 2 to the inner surface of the adjacent portion of the neck 6. Further, inside the large-diameter portion 8 of the funnel 2, a magnetic shield 10 attached to the shadow mask 5 is arranged. In addition to these in-tube members, a support means 12 for supporting the shadow mask 5, a PF connector (not shown) for guiding a high voltage to the phosphor screen 4 and the shadow mask 5, and the like are arranged.

As described above, since various tube inner members are arranged in the tube of the color picture tube, foreign matters (harmful substances) such as dust adhered to the tube inner member are brought into the valve in the manufacturing process. Alternatively, foreign matter may be generated from the tube inner member itself and fall off at some occasion to block the electron beam passage hole of the shadow mask 5 or adhere to the phosphor screen 4, resulting in a screen defect. In addition, it adheres to the electrodes of the electron gun 7 or in the vicinity thereof to cause defective withstand voltage such as inter-electrode touching and discharge, which not only lowers the manufacturing yield but also causes defects in the customer after shipping. Become.

Therefore, in the manufacturing process of the color picture tube,
The panel 1 having the phosphor screen 4 formed on the inner surface thereof and having the shadow mask 5 and the internal magnetic shield 10 disposed thereon and the funnel 2 having the conductive film 9 provided on the inner surface thereof are integrally joined and then obtained by this joining. Before the electron gun 7 is sealed in the neck 6 of the valve 3, the foreign matter generated by being attached to the inner member of the tube or generated from the inner member of the tube is removed.

As a method for removing the harmful substances, as shown in FIG. 3, the panel 1 and the funnel 2 which are integrally joined together are used.
Is supported by the neck end opening facing downward, and the gas injection nozzle 1 is introduced into the valve 3 from the neck opening.
4 is inserted to eject gas from the gas ejection nozzle 14, and a hammer ring device 15 disposed on the outer surface of the panel 1, an ultrasonic transducer 16 disposed outside the panel 1, and an outer side of the funnel 2. Any one of the arranged AC magnetic field generating coils 17 or any one of them 2
One or more of them are operated to drop foreign matter from the pipe inner member, and the dropped foreign matter is removed outside the pipe by the gas ejected from the gas ejection nozzle 14.

[0006]

As described above, the removal of harmful substances in the conventional cathode ray tube is carried out by supporting the valve with the neck end opening facing downward as described with respect to the color picture tube. Insert a gas jet nozzle into the valve from the opening to jet the gas, hammer ring device placed on the outer surface of the panel, ultrasonic transducer placed on the outside of the panel, alternating current placed on the outside of the funnel Any one of the magnetic field generating coils, or any two or more of them is operated to drop foreign matter from the pipe inner member, and the dropped foreign matter is removed from the pipe by the gas ejected from the gas ejection nozzle. Has been.

However, such a harmful substance removing method is shown in FIG.
As shown in FIG. 6, the inner surface of the cone portion 8 of the funnel-shaped funnel 2 has a relatively gentle inclined surface, and the surface of the conductive film 9 formed on the inner surface is a rough surface having fine irregularities, and thus is removed. The foreign matter 19 is caught in the concave portion on the surface of the conductive film 9,
Further, since the convex portion blocks the gas from the gas ejection nozzle with respect to the concave portion, it is difficult to remove the gas from the outside of the pipe, and there is a problem that the dust removal efficiency is poor.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a harmful substance removing method capable of efficiently removing foreign matters from a cathode ray tube valve in which various in-tube members are arranged.

[0009]

In a method for removing harmful substances in a cathode ray tube, a cathode ray tube valve in which various inner tube members before electron gun sealing are arranged is installed with a neck end opening facing downward. Insert a gas injection nozzle from the neck end opening of the, and place an ultrasonic transducer or hammer ring device or both on the outside of the cathode ray tube valve, and near the boundary between the neck and cone of the cathode ray tube valve. The annular magnetic field generating coil is arranged so that the coil surface is located on a plane perpendicular to the tube axis, and gas is ejected from the gas ejection nozzle, and at least one of the ultrasonic transducer and hammer ring is operated. Moreover, the alternating magnetic field is intermittently generated from the magnetic field generating coil.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a method for removing harmful substances from a color picture tube, which is one form of the method. The harmful substances in the color picture tube are removed before the electron gun is sealed in the neck 6 of the bulb 3 obtained by joining the panel 1 and the funnel-shaped funnel 2.

Inside the bulb 3, a phosphor screen 4 composed of a three-color phosphor layer that emits blue, green, and red is provided on the inner surface of the panel 1, facing the phosphor screen 4 and facing it. A plurality of stud pins 20 having a shadow mask 5 provided inside the panel 1 and the shadow mask 5
The mask frame 21 is supported by a supporting means composed of a plurality of elastic supports 22 which are attached to the stud pins 20. Also, the mask frame 21
A magnetic shield 10 attached to the inside of the cone portion 8 of the funnel 2 is arranged inside the cone portion 8. Further, a conductive film 9 formed by applying a conductive paint is provided on the inner surface of the funnel 2.

To remove harmful substances, the valve 3 in which the above-mentioned various pipe internal members are arranged is supported by a support base (not shown) with the neck end opening facing downward. Then, the gas injection nozzle 24 is inserted into the valve 3 through the neck end opening of the valve 3, the hammer ring device 25 is provided on the outer surface of the panel 1, the ultrasonic transducer 26 is provided outside the panel 1, and the neck 6 of the funnel 2 is provided. An alternating magnetic field generating coil 27 is arranged outside the vicinity of the boundary between the cone portion 8 and the cone portion 8 so that the coil surface is located on a plane perpendicular to the tube axis. In particular, the alternating magnetic field generating coil 27 is formed in an annular shape surrounding the outer periphery near the boundary between the neck 6 and the large diameter portion 8.

While ejecting the gas from the gas ejection nozzle 24, the hammer ring device 25 strikes the outer surface of the panel 1, and the ultrasonic vibrator 26 applies ultrasonic vibration to the outside of the panel 1. Further, an alternating current of 50 to 60 Hz is applied to the alternating magnetic field generating coil 27 at 0.5 to
It is made to flow with an index of about 2 seconds, and an alternating magnetic field is repeatedly generated intermittently.

While ejecting the gas from the gas ejection nozzle 24 in this way, mechanical impact and vibration are applied by the hammer ring device 25 and the ultrasonic transducer 26, and the vicinity of the boundary between the neck 6 and the cone portion 8 is applied. When the alternating magnetic field is repeatedly generated intermittently from the annular alternating magnetic field generating coil 27 surrounding the outer circumference, foreign matter is dropped from the pipe inner member by the mechanical shock and vibration, and in particular, it is effective from the pipe inner member made of magnetic metal by the alternating magnetic field. The foreign matter can be dropped out effectively, and the dropped foreign matter can be effectively removed from the neck end opening to the outside of the tube by the alternating magnetic field which is repeated intermittently.

That is, in the conventional harmful substance removing method, the inner surface of the cone portion of the funnel-shaped funnel is a relatively gentle inclined surface, and the surface of the conductive film applied and formed on the inner surface is a rough surface having fine irregularities. Therefore, it is difficult for the foreign matter that has fallen off to be caught in the concave portions on the surface of the fine irregularities and to be removed outside the tube. However, as described above, the alternating magnetic field generating coil 27 is used as a boundary between the neck 6 and the cone portion 8. By surrounding the outer periphery of the part with an annular shape and arranging its coil surface perpendicular to the tube axis, an alternating magnetic field can be uniformly applied to the entire circumference of the funnel, and by applying the alternating magnetic field intermittently repeatedly. , Foreign matter that has fallen off on the conductive film 9 on the inner surface of the funnel is sequentially moved in the opening direction of the neck end, and the gas ejection nozzle 34
With the gas ejected from it, it can be effectively excluded from the neck end opening.

Table 1 shows three 20-inch color picture tube valves before sealing with an electron gun, which were treated by the method of the present invention and compared with the conventional method. The evaluation result in Table 1 is that the treated valve was tapped with a wooden hammer and the result was 10 μm.
It is the average value of three valves for foreign matter of m or more. The numerical value in parentheses is the ratio of the number of foreign matters to the conventional method.

[0018]

[Table 1]

As shown in Table 1, when treated by the method of the present invention, the number of foreign matters is greatly reduced as compared with the conventional method, and in particular, the ratio of metallic foreign matters is 0.56.
It is halved, and various foreign substances can be removed efficiently.

In the above embodiment, the hammering device and the ultrasonic vibrator are used together with the gas ejection nozzle and the alternating magnetic field generating coil. Almost the same effect can be obtained by operating only one of them.

In the above embodiment, the removal of harmful substances from the color picture tube valve has been described.
It is also applicable to the removal of harmful substances from other cathode ray tube bulbs.

[0022]

EFFECTS OF THE INVENTION A cathode ray tube valve in which various kinds of internal members before electron gun sealing are arranged is installed with the neck end opening facing downward, and a gas injection nozzle is inserted from the neck end opening of this cathode ray tube valve. , An ultrasonic transducer and / or a hammering device is placed outside the cathode ray tube valve, and an annular magnetic field generating coil is placed near the boundary between the neck and cone of the cathode ray tube valve so that the coil surface is relative to the tube axis. And the gas is ejected from the gas ejection nozzle, at least one of the ultrasonic transducer and hammer ring is operated, and an alternating magnetic field is intermittently generated from the magnetic field generation coil. By doing so, foreign matter in the pipe can be efficiently removed. In particular, it has a great effect on metallic foreign substances, and can reduce image defects caused by clogging of the shadow mask due to falling foreign substances and adhesion to the phosphor screen. It is possible to prevent deterioration of withstand voltage characteristics such as discharge and discharge, and to manufacture a cathode ray tube with high quality and reliability.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a harmful substance removing method for a color picture tube valve that is an embodiment of the present invention.

FIG. 2 is a diagram for explaining the configuration of a color picture tube.

FIG. 3 is a diagram for explaining a conventional harmful substance removing method for a color picture tube valve.

FIG. 4 is a diagram for explaining a problem of a conventional harmful substance removing method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Panel 2 ... Funnel 3 ... Bulb 4 ... Phosphor screen 5 ... Shadow mask 6 ... Neck 8 Cone part 9 ... Conductive film 10 ... Magnetic shield 24 ... Gas ejection nozzle 25 ... Hammer ring device 26 ... Ultrasonic transducer 27 … Alternating magnetic field generating coil

Claims (1)

[Claims] 1. A cathode ray tube valve, in which various in-tube members are arranged before the electron gun is sealed, is installed with a neck end opening facing downward, and a gas injection nozzle is inserted from the neck end opening of the cathode ray tube valve. , An ultrasonic transducer or a hammering device or both are arranged outside the cathode ray tube valve, and an annular magnetic field generating coil is provided near the boundary between the neck and the cone portion of the cathode ray tube valve. Is arranged so as to be positioned on a plane perpendicular to the above, ejects gas from the gas ejection nozzle, operates at least one of the ultrasonic transducer and the hammer ring, and is intermittent from the magnetic field generation coil. A method for removing harmful substances from a cathode ray tube, characterized in that an alternating magnetic field is generated.