JPH07105853A - Manufacture of cathode-ray tube - Google Patents

Abstract

PURPOSE:To provide sufficient withstand voltage characteristic by applying an impulse high voltage between electrodes of an electron gun prior to getter treatment to perform a withstand voltage treatment. CONSTITUTION:A bulb in which an electron gun is sealed is exhausted while heating, and a cathode is decomposed in the latter stage of the exhausting to form an oxide cathode. Thereafter, an explosion-proof band is installed to the outer circumference of the panel of the exhausted bulb. An impulse high voltage obtained front an induction coil is applied between prescribed electrodes of the electron gun to perform a withstand voltage treatment. A getter member arranged in the bulb subjected to the withstand voltage treatment is heated by high frequency induction heating from the outside of the bulb to perform a getter treatment for scattering a getter. Further, cathode aging and heat-run are thereafter carried out. Since the getter material is never adhered to the electrodes at the withstand voltage treatment, thus, sufficient withstand voltage characteristic can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a cathode ray tube such as a color picture tube, and more particularly to a method for manufacturing a cathode ray tube in which a getter member is arranged in a bulb.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 3, a color picture tube has a bulb composed of a panel 1 and a funnel-shaped funnel 2 integrally joined to the panel 1, and an inner surface of the panel 1 has three colors. A phosphor screen 3 made of a phosphor layer is formed, and a shadow mask 4 is arranged inside the phosphor screen 3 so as to face the phosphor screen 3. On the other hand, in the neck 5 of the funnel 2, an electron gun 7 that emits the three electron beams 6 is arranged. Further, an anode terminal 9 is provided on the large-diameter portion 8 of the funnel 2, and a conductive film 10 is provided from the inner surface of the large-diameter portion 8 of the funnel 2 to the inner surface adjacent to the neck 5. Further, an explosion-proof band 11 is attached to the outer periphery of the panel 1 of the envelope.

Then, the three electron beams 6 emitted from the electron gun 7 are deflected by the magnetic field generated by the deflection yoke 12 mounted on the outer side of the funnel 2 to horizontally and vertically scan the phosphor screen 3. , A structure for displaying a color image. In addition, 13 is a getter member described later.

Conventionally, such a color picture tube is manufactured as follows.

That is, as shown in FIG. 4, a phosphor screen is formed on the inner surface of the panel. On the other hand, the inner conductive film is formed by coating from the inner surface of the large-diameter portion of the funnel to the inner surface of the adjacent portion of the neck. Then, a shadow mask is attached to the inside of the panel on which the phosphor screen is formed, and the panel on which the shadow mask is attached and the funnel on which the internal conductive film is applied and formed are integrally sealed (joined).
Next, a preassembled electron gun is sealed in the neck of the valve obtained by this sealing. Then, the sealed valve of this electron gun is evacuated. After that, an explosion-proof band is attached to the outer periphery of the panel of this exhausted valve (banding).

Next, regarding the bulb equipped with the explosion-proof band, the getter member attached to the shadow mask or the electron gun and arranged inside the bulb is heated from outside the bulb by high-frequency induction heating or the like to obtain the inside of the getter member. The getter material such as Ba contained in is scattered to increase the degree of vacuum in the valve (getter process). After that, it is manufactured by performing cathode aging, a withstand voltage treatment for increasing withstand voltage characteristics by applying a high voltage between the electrodes of the electron gun, and a heat run.

When a color picture tube is manufactured by the above method, the getter material scattered by the getter treatment adheres to the electrodes of the electron gun, and then a high voltage is applied between the electrodes of the electron gun to perform a withstand voltage treatment. However, the getter material attached to this electrode is not removed, and desired withstand voltage characteristics cannot be obtained.

For this reason, conventionally, the getter material is prevented from being adhered to the electrode of the electron gun by taking measures such as providing a barrier in the container filled with the getter material.

[0009]

As described above, in the conventional color picture tube, the withdrawn valve is subjected to the withstand voltage process after the getter process is performed.
When the withstand voltage process is performed after the getter process,
The getter material scattered by the getter treatment adheres to the electrodes of the electron gun, and thereafter, even when a high voltage is applied between the electrodes of the electron gun to perform withstand voltage treatment, the getter material adhered to the electrodes is not removed, The desired withstand voltage characteristics cannot be obtained. Therefore, conventionally, the getter material is prevented from being adhered to the electrode of the electron gun by devising a barrier or the like in the container filled with the getter material. However, providing a barrier to the getter material container in this way increases the cost.

The present invention has been made in view of the above problems, and an object of the present invention is to obtain a method of manufacturing a cathode ray tube which can obtain desired withstand voltage characteristics without providing a barrier or the like on the getter member.

[0011]

Various in-tube members including an electron gun and a getter member are arranged in a cathode ray tube valve, the inside of the cathode ray tube valve in which this in-tube member is arranged is exhausted, and then the getter member is heated. In a cathode ray tube manufacturing method that performs a getter process to scatter the getter and a withstand voltage process that applies a high voltage between the electrodes of the electron gun to obtain a predetermined withstand voltage characteristic, before performing the getter process, between the electrodes of the electron gun. Impulse high voltage was applied to perform withstand voltage treatment.

[0012]

As described above, when the withstand voltage treatment is performed by applying the impulse high voltage between the electrodes of the electron gun before the getter treatment, the getter material is attached to the electrodes of the electron gun at the time of the withstand voltage treatment. Since the transition of the anode material to the cathode due to the withstand voltage treatment is relatively close to the cathode, it does not produce as large protrusions as the conventional manufacturing method in which the withstand voltage treatment is performed after the getter treatment, and the getter material scatters. Even if there is no barrier for controlling the direction, sufficient withstand voltage characteristics can be obtained unless the getter material is extremely deposited on the electrodes of the electron gun.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described based on embodiments with reference to the drawings.

FIG. 1 shows a method of manufacturing a color picture tube which is one of the embodiments. First, a shadow mask is detachably attached to the inner surface of the panel at a predetermined interval to assemble a panel-mask assembly, and on the inner surface of the panel of the panel-mask assembly,
By using a shadow mask as a photo mask by a photo printing method, a phosphor screen including a three-color phosphor layer that emits blue, green, and red is formed. On the other hand, the internal conductive film is formed by coating from the inner surface of the large-diameter portion of the funnel to the inner surface of the adjacent portion of the neck. Then, a shadow mask is mounted on the panel on which the phosphor screen is formed, and the panel on which the shadow mask is mounted and the funnel on which the internal conductive film is formed are put into a heating furnace and sealed by frit glass. Next, a preassembled electron gun is sealed in the neck of the bulb obtained by this sealing.

In this case, the getter member attached to the shadow mask is attached to the shadow mask before sealing, and the getter member attached to the electron gun is attached to the electron gun and sealed together with the electron gun. Each is arranged at a predetermined position.

Then, the electron gun is evacuated while heating the sealed valve, and the cathode is decomposed into an oxide cathode in the latter stage of the evacuation. After that, an explosion-proof band is attached to the outer periphery of the panel of this exhausted valve (banding).

Next, with respect to the valve equipped with the explosion-proof band, an impulse high voltage obtained from an induction coil or the like is applied between predetermined electrodes of the electron gun to perform withstand voltage treatment. After that, the getter member disposed inside the valve subjected to this withstand voltage treatment is heated by high-frequency induction heating from outside the valve to perform a getter treatment for scattering the getter. After that, cathode aging, heat run, etc. are performed.

By the way, if the thus exhausted valve is first subjected to withstand voltage treatment and then subjected to getter treatment, the getter material is not adhered to the electrode of the electron gun at the time of withstand voltage treatment. Therefore, the transition of the anode material to the cathode due to the withstand voltage treatment adheres relatively well to the cathode, and the protrusions do not become as large as those of the conventional manufacturing method in which the withstand voltage treatment is performed after the getter treatment, and the scattering direction of the getter material is controlled. Even if there is no such barrier, sufficient withstand voltage characteristics can be obtained unless the getter material is extremely deposited on the electrodes of the electron gun.

In the above embodiment, the manufacturing method in which the getter treatment is performed after the withstand voltage treatment has been described. However, as shown in FIG. 2, after the withstand voltage treatment, cathode aging is performed, and then the getter treatment is performed. However, the same effect can be obtained.

Although the method of manufacturing a color picture tube has been described in the above embodiment, the same effects can be obtained by applying the present invention to a cathode ray tube other than the color picture tube.

[0021]

In the method of manufacturing a cathode ray tube, when the withstand voltage treatment is performed by applying the impulse high voltage between the electrodes of the electron gun before the getter treatment, the getter is applied to the electrodes of the electron gun at the time of the withstand voltage treatment. Because the material is not applied,
The transition of the anode material to the cathode due to the withstand voltage treatment adheres relatively well to the cathode and does not form a projection as large as that of the conventional manufacturing method in which the withstand voltage treatment is performed after the getter treatment, and is a barrier that controls the scattering direction of the getter material. Even if the getter material is not adhered to the electrode of the electron gun, the sufficient withstand voltage characteristic can be obtained.

[Brief description of drawings]

FIG. 1 is a flowchart showing a method of manufacturing a color picture tube which is an embodiment of the present invention.

FIG. 2 is a flowchart showing another method for manufacturing a color picture tube.

FIG. 3 is a diagram showing a configuration of a color picture tube.

FIG. 4 is a flow chart showing a conventional method of manufacturing a color picture tube.

Claims (1)

[Claims] 1. A cathode ray tube valve is provided with various electron tube inner members including an electron gun and a getter member, the cathode ray tube valve in which the tube inner member is disposed is exhausted, and then the getter member is heated to scatter the getter. Getter processing,
In a method of manufacturing a cathode ray tube that performs a withstand voltage process by applying a high voltage between electrodes of the electron gun to obtain a predetermined withstand voltage characteristic, an impulse high voltage is applied between the electrodes of the electron gun before the getter process is performed. A method of manufacturing a cathode ray tube, which comprises applying a withstand voltage treatment.