KR920006234B1 - Color crt without innershield - Google Patents

Abstract

The colour cathode ray tube (CRT) not having inner shield has high permeability conductive layer coated on the inner and outer surface of funnel. The conductive layer comprising 10-87 wt.% Fe, 11-89 wt.% Ni, and 0.38-0.58 wt.% Mn is formed by thermal evaporation method. The high resistance material having a titanium oxide (TiO2) is deposited at the region not having the conductive layer for transmitting the high voltage genrated from anode to electron gun via a high resistance material.

Description

Color cathode ray tube without inner shield

1 is a partial cutaway side view of a conventional color cathode ray tube.

2 is an enlarged view of a portion A of FIG.

3 is a cross-sectional view of one embodiment of the present invention.

4 is an enlarged view of part B of FIG.

5 is an enlarged view of part C of FIG.

6 is a cross-sectional view of another embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

10a, 10b, 10c: cathode ray tube 12: panel

3: electron gun 14: retainer (of electron gun)

16: Inner Shield 17: Anodized Cup

18a: embedded graphite film 18b, 18c: metal coating film

19: exterior graphite film R1, R2: high resistance film

The present invention relates to a color cathode ray tube without an inner shield, and more particularly, to a color cathode ray tube improved to have a sufficient geomagnetic shielding effect without an inner shield used as a geomagnetic shielding means.

Generally, the color cathode ray tube 10a includes a panel 12, a panel 11, an electron gun 13, an inner shield 16, a frame 20, a shadow mask 21, and the like, as shown in FIG. Graphite conductive films 18a and 19 are formed on the inner side and the outer side of the panel 12, so that a capacitor having a predetermined capacitance is formed. ) Is structurally formed.

The embedded graphite film 18a is electrically connected to the enowood cup 17 to which a high voltage from the outside is applied, as shown in FIG. It serves as a conductor that conducts the high voltage from 17) to the electron gun 13 through the retainer 14 of the electron gun. An inner shield 16 is coupled to the frame 20 to protect the electron beam from the geomagnetism. The inner shield 16 is installed to surround the deflection region of the electron beam. When the inner shield is moved to an area where geomagnetic intensity is different from color television vision sets or computer monitors in which all performance is adjusted under the standard geomagnetism at the time of manufacture, the image quality is deteriorated by geomagnetism of a different intensity. For this reason, if the product is manufactured in an area with almost the same geomagnetic strength and then used in the same area, the inner shield is unnecessary.

However, since it is unpredictable where the product will be moved to and used after it is manufactured, it is possible to use it in a wide range of areas, including areas with different geomagnetism strengths, if possible, without any need for performance tuning. Inner shields are currently used in all color cathode ray tubes except for a few products.

The inner shield manufactured by this necessity has a structure as described above. In the case of Toshiba, Japan, as disclosed in Japanese Utility Model Publication No. 57-25495, the inner shield size is minimized while the amount of the inner shield is minimized. The inner shield is divided into two parts within a certain standard for economical setting, and the one disclosed in Japanese Utility Model Laid-Open No. 63-20044 restricts the standard, especially the height. As such, the inner shield should be developed in a variety of difficult structures that combine economic feasibility and feasibility to be employed in the color-brown tube, which increases the cost of the product and requires a separate assembly process for assembling it.

On the other hand, a problem other than the above-mentioned problem is the contamination of the cathode ray tube by the built-in graphite film. A part of the built-in graphite film is peeled off from the inner surface of the panel and attached to the shadow mask or the electron gun, so that the hole blocking phenomenon of the shadow mask or It causes the arc phenomenon in the hall.

Accordingly, the present inventors have attempted to develop a cathode ray tube having a new structure that can improve the problems caused by the above-described inner shield and the built-in graphite.

The inner shield is used to prevent abnormal deflection of the electron beam by the external geomagnetic field by enclosing the final deflection section where the electron beam is very sensitive to external influences, so the material has a coerciveforce and permeability above a certain value. Must have If the coercive force and permeability are lower than the reference value, the abnormal deflection of the electron beam cannot be prevented, and thus the electron beam is landed on another part of the screen through an abnormal trajectory, thus causing problems such as deterioration of color purity.

In addition, the embedded graphite film acts as a condenser together with the outer graphite film formed on the outer surface of the panel, and also serves as a conductive agent for transferring the high voltage applied from the outer surface of the panel to the screen and the shadow mask-frame assembly on the anode and the inner surface of the electron gun. Will be

Therefore, in order to form a coating film instead of the built-in graphite film on the inner surface of the panel and to remove the inner shield, the material of the coating film should have a certain level of conductivity, coercivity, and permeability.

An object of the present invention is to provide an improved color cathode ray tube that can enjoy the geomagnetic shielding effect without the inner shield, eliminating the problems caused by the graphite residue in the tube by removing the built-in graphite.

In order to achieve the above object, the inner shield-free color cathode ray tube of the present invention has a panel and a panel outer panel, an interior of an electron gun, a shadow mask-frame assembly, and an inner and outer circumferential surface of the panel. In the color cathode ray tube in which a conductive film is formed,

The conductive film is 10-87wt% Fe,

11-89 wt% Ni and

0.38-0.58% Mn

It is characterized by consisting of an alloy body as the main material.

The alloy layer of the present invention has sufficient coercive force and permeability required for the inner shield within the range of the composition as described above, and is also made of metal, so it is naturally conductive. If the composition range is out of the above range, the coercive force and permeability are sharply lowered due to the correlation between alloy metals, so that the geomagnetic shielding effect is also significantly reduced, and thus, it cannot serve as a substitute for the inner shield.

In addition, in the conductive film of the present invention, a high-resistance material may be appropriately resisted in the alloy of the high permeability metal element as described above. As the high-resistance material, titanium oxide (TiO ₂ ) is preferable.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

[First Embodiment]

As shown in FIG. 3, a metal coating film 18b is formed on the inner surface of the panel 12 of the cathode ray tube 10b, and the metal coating film 18b is made of an alloy of high permeability metal as follows.

Iron (Fe)... … … … … … … … … … … … … … … … … … … … … … … … 10 ~ 87wt%

Nickel (Ni)... … … … … … … … … … … … … … … … … … … … … … … 11 ~ 89wt%

Manganese (Mn). … … … … … … … … … … … … … … … … … … … … 0.38 ~ 0.58wt%

The above alloy is preferably vacuum deposited on the inner surface of the panel, and as a heating heater for vapor deposition, a borite heater including boron (B) as a main material is preferable, and in some cases, a high frequency induction heating method may be applied. have. At this time, the deposition range should be such that the electron beam excluding the neck portion of the panel in which the electron gun 13 is embedded can sufficiently wrap the periphery of the fun fragrance region. At this time, the metal coating film should not be formed on the exposed portion of the panel 12 and the area around it, as shown in FIG. 4. Instead, a separate high resistance layer R1 is provided. The metal coating film 18b and the anode cup 17 must be electrically connected to each other, and the contact portion of the electron gun retainer 14 positioned near the deck portion and a part of the surrounding area thereof are shown in FIG. As described above, the high resistance layer R2 is formed so that the metal coating layer 18b and the electron gun 13 are electrically connected through the high resistance layer R2. However, the high resistance layer (R1) (R2) may be selectively formed in only one portion according to the resistance value.

Example 2

A high resistance material is included in the metal alloy of Example 1 so that the metal coating film 18c has a high resistance value. At this time, the high-resistance material may be titanium oxide (TiO ₂ ), the cathode ray tube (10c) has a structure as shown in FIG. That is, the metal coating film is formed in the entire area of the panel 12 so that the anode cup and the electron gun are directly connected through the metal coating film 18c. At this time, the content of the titanium oxide (TiO ₂ ) should be limited to such that the resistance value from the anode cup to the electron gun can be a set value. In general, the anode current is about 150-220 mA so that the voltage applied thereto is And can be easily set through the required current.

According to the above embodiment, the degree of deflection of the electron beam by the geomagnetic field was evaluated by evaluating whether or not the conductive film obtained by depositing the metal alloy on the inner surface of the panel has a geomagnetic shielding effect which is a function of the conventional inner shield.

The following table shows the abnormal deflection of the electron beam by the external geomagnetic field in the final deflection section of the cathode ray tube of the present invention without the inner shield and the cathode ray tube having the conventional inner shield. The figure shows the beam displacement measured in μm, measured in one quadrant of the four quadrants of the panel.

[table]

As can be seen from the above table, the abnormal deflection of the electron beam in the cathode shield tube without inner shield of the present invention having an inner conductive film made of a metal alloy of a certain composition was smaller than or equal to that of a cathode ray tube having a conventional inner shield. Can be. In the case of the cathode ray tube 2, the deflection of the electron beam was higher than that in the ordinary cathode ray tube, but it was not a problem.

As described above, the cathode ray tube of the present invention has the same geomagnetic shielding effect as that of the conventional inner shield type cathode ray tube, and is easy to manufacture because the inner shield is not or most of the conventional embedded graphite film is removed, and thus, The problem caused by this is improved. On the other hand, because of the glossiness of the metal coating film, the image quality was deteriorated by scattering of the electron beam, but it was not visible.

Therefore, according to the present invention, the inner shield, which belongs to a relatively large part in the color-brown tube, is removed, thereby increasing productivity due to reduction of product cost and shortening of the manufacturing process. Furthermore, since the built-in graphite film becomes unnecessary and is formed only in a very narrow area, the deterioration of the product due to the graphite residue and the pollution of the factory due to the graphite dust are greatly reduced.

Claims (4)

In a color cathode ray tube having a panel and a panel, an interior of an electron gun, a shadow mask-frame assembly, and a conductive film formed on the inner and outer circumferential surfaces of the panel, The conductive film is 10 to 87wt% Fe, 11 to 89 wt% of Ni, 0.38 to 0.58 wt% of Mn A color cathode ray tube without inner shield, characterized by an alloy consisting of an alloy of the main material. The method according to claim 1, wherein the conductive film comprises a contact portion of the electron gun retainer of the panel and a portion of the surrounding portion of the panel, or an exposed portion of the enowood cup and a portion of the surrounding portion thereof, or a portion of the connection of the electron gun retainer and the portion of the surrounding portion of the electron gun retainer. It is formed only on the part except the exposed part and a part of the surrounding area, and a separate high resistance material is applied to the lacking part so that a high voltage from the anode cup is conducted to the electron gun via the high resistance material. Color cathode ray tube without inner shield. In a color cathode ray tube having a panel and a panel, an interior of an electron gun, a shadow mask-frame assembly, and a conductive film formed on an inner circumferential surface of the panel, The conductive film is 10 to 87wt% Fe, 11 to 89 wt% of Ni, 0.38 to 0.58 wt% of Mn A color cathode ray tube without inner shield, comprising an alloy and a high resistance material as its main material. The color cathode ray tube without inner shield according to claim 3, wherein the high resistance material is made of titanium oxide (TiO ₂ ).

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