JPH11149889A - Cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable cathode-ray tube which is capable of preventing conductive film on an inner wall of a funnel from being flaked in a manufacturing process to seal an electron gun in a bulb. SOLUTION: This cathode-ray tube is equipped with a bulb 6 composed of a panel 2 with phosphor 1 on its inner surface and a funnel 5 with conductive film 4a on its inner wall, an electron gun 7 housed in a neck part 5a of the funnel 5 and a spring 10 which is provided on a final electrode 8 of the electron gun 7 and has a contact part 9 by which the conductive film 4a on the inner wall of the funnel 5 is brought into contact with the final electrode 8. The conductive film 4a contains ruthenium oxide and glass frit as main ingredients, and they are baked on the inner wall of the funnel 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode ray tube used for a television receiver, a computer display and the like.

[0002]

2. Description of the Related Art A conventional cathode ray tube comprises a panel having a phosphor on its inner surface and an inner wall for reducing electrical loss between a final electrode of an electron gun and a conductive film on the inner wall of a funnel and reducing a deflection magnetic field of a deflecting device. A valve connected to a funnel having a conductive film, an electron gun housed in the neck of the funnel, and contact means for electrically contacting the final electrode of the electron gun with the conductive film on the inner wall of the funnel. The conductive film is formed of a material containing at least graphite, titanium oxide and water glass.

[0003]

However, in such a cathode ray tube, the contact means is generally a spring provided on the final electrode of the electron gun. A spring provided on the electrode rubs the surface of the conductive film on the inner wall of the funnel, peels off the conductive film, causes poor electrical connection between the final electrode of the electron gun and the conductive film on the inner wall of the funnel, and peels off the conductive film. Insufficient sparking between the electrodes and peeling of the conductive film adhered to the phosphor on the inner surface of the panel, resulting in screen missing points and the like, and high quality could not be obtained.

The present invention has been made based on the above circumstances, and provides a highly reliable cathode ray tube which prevents the conductive film on the inner wall of a funnel from peeling off in a manufacturing process of sealing an electron gun in a bulb. Things.

[0005]

According to the present invention, there is provided a cathode ray tube comprising: a bulb comprising a panel having a phosphor on an inner surface and a funnel having a conductive film on an inner wall; an electron gun housed in a neck portion of the funnel; A spring provided on the final electrode of the electron gun and having a contact portion for electrically contacting the conductive film on the inner wall of the funnel and the final electrode, wherein the conductive film is made of ruthenium oxide (RuO ₃ )
And a glass frit as a main component, which is fired on the inner wall of the funnel.

With this configuration, the glass frit having ruthenium oxide adhered to the surface is welded together,
The glass frit also welds to the funnel inner wall.

[0007]

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

As shown in FIG. 1, a cathode ray tube according to a first embodiment of the present invention is used for a projection tube, and includes a panel 2 having a monochromatic phosphor 1 on an inner surface and a panel 2 on a panel inner wall 3. The first conductive film 4a and the second conductive film 4a connected to the first conductive film 4a.
6 comprising funnel 5 having conductive film 4b
An electron gun 7 for radiating an electron beam housed in the neck 5 a of the funnel 5; a first electrode 8 provided on the final electrode 8 of the electron gun 7;
A spring 10 having a contact portion 9 for electrically contacting the conductive film 4a with the final electrode 8 and a second portion of the inner wall of the cone portion 5b provided on the cone portion 5b of the funnel 5.
Conductive film 4b and first conductive film 4 on the inner wall of neck 5a
and an anode terminal 11 for applying a high voltage to the final electrode 8 of the electron gun 7 via a. At least the first conductive film 4a on the inner wall of the neck portion 5a contains ruthenium oxide (RuO ₃ ) and glass frit as main components, and is formed on the inner wall of the neck portion 5a of the funnel 5 at 400 ° C. to 470 ° C.
Fired at the firing temperature of The first conductive film 4a has a ruthenium oxide (RuO ₃ ) content of 15 to 60% by weight based on the total amount of ruthenium oxide (RuO ₃ ) and glass frit, and has a specific resistance of 0.1 to 60% by weight. Two
1.5 Ωcm. The second conductive film 4b is made of graphite,
Titanium oxide as main component, specific resistance 0.2-1.5Ω
cm. Note that the second conductive film 4b may be formed using the same material as the first conductive film 4a.

As shown in FIGS. 2 to 4, the spring 10 is formed of a metal plate 10a made of a stainless material having the same diameter as the outer diameter of the final electrode 8, and the outer surface of the metal plate 10a is A plurality of elastic arms 1 provided at right angles
0b and a contact portion 9 at the free end of the elastic arm portion 10b. The spring 10 is disposed so as to cover the final electrode 8 and is fixed to the final electrode 8 by welding.

The firing temperature of the first conductive film 4a is 47
If the temperature exceeds 0 ° C., the neck 5 a of the funnel 5 is deformed,
When the electron gun 7 is inserted into the neck portion 5a, the center position of the electron gun 7 is displaced, and the cone portion 5b and the neck portion 5 are displaced.
a, a deflecting device (not shown) cannot be provided at a predetermined position on the outer circumference of
If the temperature is lower than 0 ° C., there is a problem that the first conductive film 4a is easily baked because the first conductive film 4a is not sufficiently baked. And 400 ° C
When the first conductive film 4a having the above-described components and resistance conditions was formed at a firing temperature of about 470 ° C, the film surface hardness was Hv (0.5) 300 to 500 in terms of Vickers hardness.

Next, the operation and effect of the embodiment of the present invention will be described. In the cathode ray tube according to the first embodiment of the present invention, when the first conductive film 4a contains ruthenium oxide (RuO ₃ ) and glass frit as main components and is fired on the inner wall of the neck portion 5a, fine ruthenium oxide is formed on the surface. The attached glass frit is welded to each other, and the glass frit is also welded to the inner wall of the neck portion 5a. As a result, the peeling of the first conductive film 4a from the inner wall of the neck portion 5a can be reduced, and the surface hardness of the first conductive film 4a becomes as high as glass hardness. Even if the contact portion 9 of 10 rubs the surface of the first conductive film 4a on the inner wall of the neck portion 5a, the first conductive film 4a
Can be reduced. Therefore, a poor electrical connection between the final electrode 8 and the first conductive film 4a on the panel inner wall 3, a spark failure between the electrodes due to the peeling foreign material of the first conductive film 4a, and a peeling foreign material of the first conductive film 4a are generated. It is possible to reduce defects such as screen missing points caused by adhering to the phosphor 1 on the inner surface of the panel 2, and to provide a highly reliable cathode ray tube.

The elastic arm 10b of the spring 10
Are provided in a direction perpendicular to the surface of the metal plate 10a (in the pipe axis direction) from the outer periphery of the metal plate 10a, so that the elastic arm portion 10 is provided.
The elastic force can be finely adjusted by the arm length b. As a result, when the electron gun is inserted into the neck portion 5a of the funnel 5, the damage of the first conductive film 4a on the panel inner wall 3 due to the pressing force of the contact portion 9 of the elastic arm portion 10b is reduced, and the first conductive material is reduced. Spark failure between the electrodes due to the peeling foreign matter of the film 4a can be reduced.

Note that the first embodiment of the present invention is the first embodiment.
In this case, the conductive film 4a contains ruthenium oxide (RuO ₃ ) and glass frit as main components, and the main components contain lead oxide (PbO) and boron oxide (B ₂ O ₃ ).
It may be fired on the inner wall of the neck 5a. The content of ruthenium oxide (RuO ₃ ) is set to 15 to 60% by weight based on the total amount of other components such as glass frit, lead oxide (PbO), and boron oxide (B ₂ O ₃ ). I have.
In this case, the specific resistance of the first conductive film 4a is set to 0.2 to 1.
The specific resistance value enables stable electrical connection with the contact portion 9 of the spring 10 and also reduces the loss of the deflecting magnetic field of the deflecting device.

(Example) Next, an example in which the effect of the present invention has been confirmed will be described.

The cathode ray tube of the present invention having the structure shown in FIGS. 1 and 2 uses a unipotential electron gun 7 for a φ29.1 mm neck shown in FIG. 1 and a second conductive film made of graphite and titanium oxide. 4b is set to 0.65 Ωcm, the first conductive film 4a is mainly composed of ruthenium oxide (RuO ₃ ) and glass frit, and ruthenium oxide (Ru
O ₃ ) content of 50% by weight (specific resistance 0.5Ωcm)
Then, the first conductive film 4a and the second conductive film 4b are formed on the inner wall of the funnel 5 at a firing temperature of 400 ° C. and 470 ° C.

For comparison, the material of the first conductive film 4a was changed to graphite, titanium oxide and water glass, and the first conductive film 4a having a specific resistance of 0.2 Ωcm was placed on the inner wall of the funnel 5. The second conductive film 4b made of graphite and titanium oxide was also formed on the inner wall of the funnel 5 at normal temperature, and a comparative cathode ray tube having the same other specifications as above was manufactured.

Then, the degree of peeling of the conductive film and the hardness of the film surface were examined. As a method for measuring the degree of peeling of the conductive film, the cathode ray tube before sealing the electron gun is, as shown in FIG.
Is installed on the lower side, and the electron gun 7 is positioned at a predetermined position in the neck portion 5a.
Was attached and detached twice, the first conductive film 4a was rubbed by the contact portion 9 of the spring 10, and the number of foreign substances that peeled off as fine pieces was evaluated. Also, the first conductive film 4a
The method of measuring the film surface hardness of JIS Z 2244
Evaluation was based on Vickers hardness according to the rules of 1961.

In the cathode ray tube of the present invention, at a firing temperature of 400.degree. C. and a firing temperature of 470.degree. C., the degree of peeling of the conductive film is 0 and the film surface hardness is about 300 (Hv (0.5)).
(0.5) was about 500. On the other hand, the cathode ray tube for comparison has a peeling degree of the conductive film of about 8 and a film surface hardness of Hv.
(0.5) was about 40. Therefore, in the cathode ray tube of the present invention, the degree of peeling of the conductive film was reduced and the film surface hardness was 7.5 times or more higher than that of the comparative cathode ray tube.

In the above embodiment, the diameter is 29.1 mm.
A projection tube having a unipotential electron gun for a neck has been described. However, the present invention is not limited to this, and a projection tube or a color cathode ray tube having a φ36.5 mm diameter unipotential electron gun for a neck and an electromagnetic focusing electron gun is used. In this case, the same effect can be obtained.

[0020]

As described above, according to the present invention, the conductive film on the inner wall of the funnel contains ruthenium oxide (RuO ₃ ) and glass frit as the main components, and is fired on the inner wall of the funnel. A highly reliable cathode ray tube capable of preventing peeling of the conductive film on the inner wall of the funnel and reducing defective electrical connection, spark failure, and color unevenness in a manufacturing process for sealing.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a cathode ray tube according to a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a neck portion of the cathode ray tube.

FIG. 3 is a plan view showing a spring of the cathode ray tube.

FIG. 4 is a front view of the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Phosphor 2 Panel 3 Panel inner wall 4a 1st conductive film (conductive film) 5 Funnel 5a Neck part 6 Valve 7 Electron gun 8 Final electrode 9 Contact part 10 Spring

Claims (5)

[Claims] 1. A valve comprising a panel having a phosphor on an inner surface and a funnel having a conductive film on an inner wall, an electron gun housed in a neck portion of the funnel, and a final electrode of the electron gun, wherein the funnel is provided. A spring having a contact portion for electrically contacting the conductive film on the inner wall and the final electrode, wherein the conductive film is mainly composed of ruthenium oxide (RuO ₃ ) and glass frit, and is formed on the inner wall of the funnel. A cathode ray tube characterized by being fired. 2. The method according to claim 1, wherein the conductive film is made of ruthenium oxide (RuO ₃ ).
And a glass frit, a cathode ray tube according to claim 1, characterized in that containing lead oxide (PbO) and boron oxide (B ₂ O _3). 3. The conductive film is made of ruthenium oxide (RuO ₃ ).
Is 15 to 60 with respect to the total amount including other components.
3. The method according to claim 1, wherein the weight is% by weight.
A cathode ray tube as described. 4. The sintering temperature of the conductive film is from 400 ° C. to 470.
The cathode ray tube according to any one of claims 1 to 3, wherein the temperature is ° C. 5. The cathode ray tube according to claim 1, wherein the film surface hardness of the conductive film is Hv (0.5) of 300 to 500 in Vickers hardness.