JP2000036269A - Conductive adhesive tape and cathode-ray tube using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the mutual current-carrying property of an explosion-proof band and a transparent conductive film and absorb electromagnetic waves generated from a deflection yoke by forming an adhesive conductive film layer containing a conductive material and an acrylic resin on one surface of an insulating film layer and thereby shielding the electromagnetic waves. SOLUTION: An insulating film layer 21 and an adhesive conductive film layer 22 are formed, the insulating film layer 21 is formed by including an extreme infrared- ray radiating substance such as bio-ceramics in a heat-resistant polyester resin, and the conductive material contained in the adhesive conductive film layer 22 is formed from graphite or conductive metal powder. If the conductive material is graphite, nickel is preferably also included as a conduction supporting material. Because it is difficult to form a low resistance film having a resistance value not more than several tens of Ω/cm2 in the case of graphite, a metal thin film layer 23 is formed between the adhesive conductive film layer 22 and the insulating film layer 21 in order to lower the resistance value further. A conductive adhesive tape composed of the insulating film layer 21, the adhesive conductive film layer 22 and the metal thin film layer 23 constitutes an electromagnetic wave absorbing means and can provide a sufficient electromagnetic wave shielding effect.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cathode ray tube, and more particularly, to a conductive adhesive tape for shielding electromagnetic waves and a cathode ray tube employing the same.

[0002]

2. Description of the Related Art In recent years, as it has been found that electromagnetic waves emitted from a cathode ray tube are very harmful to the human body, regulations on the electromagnetic waves are becoming stronger. Therefore, means for maximizing the electromagnetic wave shielding and antistatic effects at low cost is required.

[0003] The Swedish Congress, which is one of the representative organizations conducting electromagnetic wave regulation tests,
In order to comply with the electromagnetic wave regulation standard specified by Federation Of Professional Employees (TCO), the transparent conductive film applied on the screen surface of the cathode ray tube should satisfy the following characteristics.

The resistance of a transparent conductive film used as an antistatic film should be 10 ⁹ Ω / cm ² or less. The resistance of the conductive film used as the electromagnetic wave shielding film should be 10 ³ Ω / cm ² or less, the hardness should be 5H or more, and the transparency should be 95% or more.

[0005] Transparent conductive films satisfying such conditions are platinum, gold, and indium tin oxide (hereinafter referred to as IT).
O).

FIG. 1 shows an example of a cathode ray tube in which a transparent conductive film for shielding electromagnetic waves as described above is coated on a screen surface.

The cathode ray tube has a panel 13 having a screen surface 12 coated with a fluorescent film (not shown) on its inner surface, a funnel 14 sealed to the panel 13, and a neck portion of the funnel 14. It includes an electron gun 15 and a deflection yoke 16 mounted on the cone of the funnel 14. A transparent conductive film 17 is formed on the screen surface 12 using ITO having a resistance per unit area lower than 10 ³ Ω / cm ² . The transparent conductive film 17 is an explosion-proof band with a conductive tape 19 made of copper or aluminum.
It is connected so as to be energized with 11. An external conductive film 18 is applied to the outer surface of the funnel 14.

An electron gun for a cathode ray tube having such a configuration.
The electron beam emitted from 15 is deflected by the deflection yoke 16 and landed on the fluorescent film. The landed electron beam excites the phosphor. During the operation in this manner, the electromagnetic wave emitted from the deflection yoke 16 is blocked by the transparent conductive film 17 and the external conductive film 19, and emission to the outside of the cathode ray tube is suppressed.

In order to effectively shield electromagnetic waves, the transparent conductive film 17 applied to the screen surface 12 should have a resistance per unit area of less than 10 ³ Ω / cm ² . However, forming the transparent conductive film 17 from a material having the above-described resistance value, for example, ITO increases the manufacturing cost of the cathode ray tube.

In consideration of the above-described problems, it is possible to use ITO having a resistance per unit area of 10 ⁵ Ω / cm ² or less, or to use a waveform synchronized with the waveform of the voltage applied to the deflection yoke. The method of applying the reverse pulse voltage to the external conductive film is adopted. However, in the former case, a sufficient electromagnetic wave shielding effect cannot be obtained. In the latter case, it is necessary to provide another circuit for applying a reverse pulse voltage, and the reverse pulse voltage must be synchronized with the deflection yoke. There is difficulty.

A cathode ray tube for absorbing a part of an electromagnetic wave from a deflection yoke is disclosed in US Pat. No. 5,451,840 and US Pat. No. 5,635,79.
No. 3, U.S. Pat. No. 5,304,891.

In the disclosed cathode ray tube, a part of the external conductive film extends to the outer peripheral surface of the cone portion on which the deflection yoke is mounted, or a piece (pie) connected to the external conductive film of the funnel.
ce) extends to the cone where the deflection yoke is mounted, or the conductive film extends from the external conductive film to the cone where the deflection yoke is mounted and is bonded.

However, such a method has a problem that a manufacturing process thereof is complicated and an electric resistance of the conductive film is increased by an adhesive layer, so that a sufficient electromagnetic wave shielding effect cannot be obtained.

[0014]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has improved the mutual conduction between an explosion-proof band and a transparent conductive film so that electromagnetic waves generated from a deflection yoke can be absorbed. It is an object of the present invention to provide a conductive adhesive tape which can be used and a cathode ray tube employing the same.

[0015]

A conductive adhesive tape according to the present invention for achieving the above object includes an insulating film layer, and is formed on one surface of the insulating film layer and includes a conductive material and an acrylic resin. And an adhesive conductive film layer.

Here, a metal thin film layer may be further formed between the insulating film layer and the adhesive conductive film layer.

A cathode ray tube according to the present invention comprises a panel having a screen surface, a funnel sealed to the panel and having a cone and a neck, an electron gun mounted on the neck, and a panel mounted on the cone. Deflection yoke, an external conductive film applied to the outer peripheral surface of the funnel, a transparent conductive film applied to the screen surface, an explosion-proof band attached to the outer peripheral surface of the funnel, and electrically connected to the external conductive film. An insulating film layer, which is adhered to the cone portion and the neck portion, and an adhesive conductive film layer formed on one surface of the insulating film layer and made of a conductive material and an acrylic resin; and An electromagnetic wave absorbing means including an insulating film layer and a metal thin film layer interposed between the insulating film layer and the insulating film layer.

According to another embodiment of the present invention, a panel having a screen surface, a funnel sealed to the panel and having a cone and a neck, an electron gun mounted on the neck, The deflection yoke to be mounted, the external conductive film applied to the outer peripheral surface of the funnel, the transparent conductive film applied to the screen surface, the explosion-proof band mounted to the outer peripheral surface of the funnel, and the inner peripheral surface of the deflection yoke The insulating film layer is adhered, and is formed on one surface of the insulating film layer. The adhesive conductive film layer includes a conductive material and an acrylic resin, and is interposed between the adhesive conductive film layer and the insulating film layer, and is grounded. And an electromagnetic wave absorbing means including a metal thin film layer.

[0019]

Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

One embodiment of the conductive adhesive tape according to the present invention is shown in FIG.

As shown, the conductive adhesive tape is composed of an insulating film layer 21 made of a synthetic resin material, and an adhesive conductive film layer formed on one surface of the insulating film layer 21 and containing a conductive material and an acrylic resin.
22.

The insulating film layer 21 is formed by adding a far-infrared radiation material such as bioceramic to a heat-resistant polyester resin. The conductive material contained in the adhesive conductive film layer 22 is made of graphite or conductive metal powder. Here, when the conductive material is graphite, it is preferable that nickel as a conductive auxiliary material is further included. And several tens of Ω / c for graphite
Since it is difficult to form a low resistance film of m ² or less, a metal thin film layer 23 is formed between the adhesive conductive film layer 21 and the insulating film layer 22 to further reduce the resistance value. Desirably, the metal thin film layer 23 is made of aluminum. The thickness of the conductive film layer 21 is 30 to 40 μ
m, the thickness of the metal thin film layer 23 is preferably 25 to 30 μm.

As shown in FIG. 3, a far infrared ray emitting layer 24 may be formed between the metal thin film layer 23 and the insulating film layer 21 by a resin containing bioceramic. Layer 21 need not include a far-infrared emitting material.

FIG. 4 shows an example of a cathode ray tube using a conductive adhesive tape.

As shown, the cathode ray tube has a fluorescent film on the inner surface.
Panel (not shown) having screen surface 31 formed thereon
30 and a funnel 40 sealed to the panel 30 and having a cone 41 and a neck 42. An external conductive film 43 made of graphite is formed on the outer peripheral surface of the funnel 40, an electron gun 50 is mounted inside the neck portion 42, and the electron gun 50 is mounted on the cone portion 41.
A deflection yoke 60 for deflecting the electron beam emitted from the light source is provided.

An explosion-proof band 70 is provided at a sealing portion between the panel 30 and the funnel 40. The screen surface 31 has a resistance per unit area of more than 1 × 10 ⁵ Ω / cm ² and 1 × 10 ⁶ Ω
A transparent conductive film 80 smaller than or equal to / cm ² is formed. The transparent conductive film 80 may be formed of any transparent material having the above-described resistance value, but is preferably formed of ITO. The transparent conductive film 80 and the external conductive film 43 are
Are connected by a conductive connecting means so as to be able to conduct electricity.
As the conductive connecting means, a normal conductive adhesive tape or the conductive adhesive tape 20 described with reference to FIGS. 2 and 3 is used.

The funnel 40 is provided with electromagnetic wave absorbing means for absorbing electromagnetic waves generated from the deflection yoke 60. The electromagnetic wave absorbing means includes a conductive adhesive tape 20 ′ extending from the external conductive film 43 to the neck 41 through the cone 42 where the deflection yoke 60 is mounted. The conductive adhesive tape 20 'is preferably the same as that shown in FIGS. 2 and 3, but is not limited to this.

The conductive adhesive tape 20 ′ may be adhered straight from the outer conductive film 43 to the neck portion 41, or may be spirally or net-likely adhered. It is preferable that the conductive adhesive tape 20 ′ includes a far-infrared ray emitting layer, and the inner peripheral surface of the deflection yoke 60 is coated with a bioceramic layer of far-infrared ray emitting material.

When the cathode ray tube is driven, an electromagnetic wave is generated from the deflection yoke 60 and some parts, and the electron beam emitted from the electron gun 50 lands on the fluorescent film, so that the fluorescent film is coated on its inner surface. The outer surface of the screen 31 is charged with electrons. The electromagnetic waves thus generated and the electrons charged on the screen surface 31 are absorbed through the transparent conductive film 80 formed on the screen surface 31, and then the conductive adhesive tape is used.
It is released to the outside through 20 and the grounded explosion-proof band 70.

The electromagnetic wave emitted from the deflection yoke 60 is absorbed by the conductive adhesive tape 20 'located between the inner peripheral surface of the deflection yoke 60 and the outer peripheral surface of the neck portion 41, and the external conductive film 43 and the explosion-proof band Spilled through 70. Therefore, electromagnetic waves generated from the deflection yoke 45 or components of the cathode ray tube are prevented from being emitted to the front or rear of the cathode ray tube.

Another example of the electromagnetic wave absorbing means has a structure in which an insulating layer 63, a conductive layer 64 and an adhesive layer 65 are sequentially formed on the surface of a wire 62 forming a coil 61 of a deflection yoke as shown in FIG. Having. The conductive layer 64 is electrically grounded
(Not shown). In this case, the electromagnetic waves emitted from the deflection yoke flow out through the grounded conductive layer 64 to the outside.

FIG. 6 shows still another example of the electromagnetic wave absorbing means. Referring to the drawing, the conductive adhesive tape 20 "described above is attached to the inner surface of the deflection yoke 60, and the attached conductive adhesive tape 20" is grounded. When the cathode ray tube is driven, the electromagnetic wave generated from the deflection yoke 60 is absorbed by the grounded conductive adhesive tape 20 ".

<Experimental example> In the cathode ray tube of the present invention used in the experiment, the conductive adhesive tape according to the present invention (see 20 in FIG. 4)
Then, the explosion-proof band and the transparent conductive film were connected, and a conductive adhesive tape (see 20 'in FIG. 4) was extended and adhered from the external conductive film to the neck portion through the cone portion as an electromagnetic wave absorbing means. In contrast, in the cathode ray tube of the comparative example, the explosion-proof band and the transparent conductive film were connected using the conventional conductive tape. Electromagnetic waves emitted from the screen surface while changing the resistance per unit area of the transparent conductive film applied on the screen surface of the cathode ray tube to 1 × 10 ⁴ Ω / cm ^{2 to} 9 × 10 ⁹ Ω / cm ² Was measured, and the results are shown in FIG.

As shown in FIG. 7, in the case of the comparative example, the resistance value of the transparent conductive film was 1 × 10 ⁴ Ω / cm ² and 1 × 10 ⁹ Ω / cm ² , and the emission amount of the electromagnetic wave was 0.4 V / m 2. And 1.9 V / m. And in the case of the present invention, the resistance is 1 × 10 ⁴ Ω / cm ² and 1 × 10 ⁹ Ω / cm ² and the amount of generated electromagnetic waves is 0.1 V / m and 1.23 V / m, respectively. It was found to be significantly smaller.

Accordingly, in the example of the present invention, when the resistance of the transparent conductive film is 1 × 10 ⁶ Ω / cm ² or less, the TCO electromagnetic wave regulation standard (FIG.
Electromagnetic waves can be shielded below (broken line shown in FIG. 7).

[0036]

As described above, since the electromagnetic wave generated from the deflection yoke 60 is absorbed by the electromagnetic wave absorbing means, the transparent conductive film 80 applied to the screen surface 31 has a relatively low resistance value per unit area. high transparency material, for example, the resistance value per unit area electromagnetic shielding effect can be obtained sufficiently be formed from 1 × 10 ⁶ Ω / cm ² less than or equal ITO greater than 1 × 10 ⁵ Ω / cm ² . Therefore, since a material having a high resistance value per unit area can be used as the transparent conductive film, the production cost can be reduced.

In the various embodiments of the present invention, the far-infrared ray emitting layer 24 is formed on each of the conductive tapes 20, 20 'and 20 ", or the far-infrared ray emitting material is mixed in the insulating film layer 21. Only the far infrared rays harmless to the human body are emitted from the far infrared emitting layer 24 or the insulating film layer 21 by the heat generated by driving the cathode ray tube.

[Brief description of the drawings]

FIG. 1 is a perspective view of a conventional cathode ray tube.

FIG. 2 is a perspective view showing a conductive adhesive tape according to the present invention.

FIG. 3 is a cross-sectional view of the conductive adhesive tape according to the present invention.

FIG. 4 is a perspective view of a cathode ray tube according to one embodiment of the present invention.

FIG. 5 is a partially enlarged perspective view showing another example of the electromagnetic wave absorbing means according to the present invention.

FIG. 6 is a perspective view of a cathode ray tube according to another embodiment of the present invention.

FIG. 7 is a graph showing the amounts of electromagnetic waves emitted from the conventional cathode ray tube and the cathode ray tube according to the present invention.

[Explanation of symbols]

 21 Insulating film layer 22 Adhesive conductive film layer 23 Metal thin film layer

 ──────────────────────────────────────────────────続 き Continued on the front page (31) Priority claim number 99-2885 (32) Priority date January 28, 1999 (Jan. 28, 1999) (33) Priority claim country South Korea (KR) (31) Priority claim number 99-3508 (32) Priority date February 3, 1999 (1999.2.3) (33) Priority claim country South Korea (KR) (72) Inventor Park Zhen You Korea Kanai, Busan, Korea 388-1, Namsan-dong, Jung-gu International Green Apartment 1503

Claims (18)

[Claims] 1. An insulating film layer comprising: an insulating film layer; and an adhesive conductive film layer formed and formed on one surface of the insulating film layer and containing a conductive material and an acrylic resin, and shields electromagnetic waves. Conductive adhesive tape. 2. The conductive adhesive tape according to claim 1, wherein the conductive material is graphite. 3. The conductive adhesive tape according to claim 2, wherein said conductive material further contains nickel. 4. The adhesive tape according to claim 1, wherein a metal thin film layer is formed between said insulating film layer and said adhesive conductive film layer. 5. The adhesive tape according to claim 4, wherein a far-infrared emitting layer is formed between the insulating film layer and the metal thin film layer. 6. The conductive adhesive tape according to claim 1, wherein a far-infrared radiating substance is mixed in the insulating film layer. 7. A panel having a screen surface, a funnel sealed to the panel and having a cone and a neck, an electron gun mounted on the neck, and a deflection yoke mounted on the cone. An external conductive film applied to an outer peripheral surface of the funnel; a transparent conductive film applied to the screen surface; an explosion-proof band attached to an outer peripheral surface of the funnel; and electrically connected to the external conductive film. An insulating film layer adhered to the cone portion and the neck portion, an insulating film layer, an adhesive conductive film layer formed on one surface of the insulating film layer and containing a conductive material and an acrylic resin, and the conductive film layer and the insulating film. An electromagnetic wave absorbing means including a metal thin film layer interposed between the cathode ray tube and the film layer. 8. The cathode ray tube according to claim 7, wherein said conductive material is graphite. 9. The cathode ray tube according to claim 8, wherein said conductive material further contains nickel. 10. The cathode ray tube according to claim 7, wherein a far-infrared ray emitting material is mixed in said insulating film layer. 11. A far-infrared emitting layer is formed between said insulating film layer and said metal thin film layer.
A cathode ray tube according to claim 1. 12. The cathode ray tube according to claim 7, wherein the explosion-proof band and the transparent conductive film are electrically connected by a conductive tape. 13. The method according to claim 7, wherein the transparent conductive film is made of a transparent material having a resistance per unit area of 1 × 10 ⁵ Ω / cm ^{2 to} 1 × 10 ⁶ Ω / cm ^2. Cathode ray tube. 14. A far infrared ray emitting layer is formed between said insulating film layer and said metal thin film layer.
A cathode ray tube according to claim 1. 15. A panel having a screen surface, a funnel sealed to the panel and having a cone and a neck, an electron gun mounted on the neck, and a deflection yoke mounted on the cone. An external conductive film applied to an outer peripheral surface of the funnel; a transparent conductive film applied to the screen surface; an explosion-proof band attached to an outer peripheral surface of the funnel; and an inner conductive surface of the deflection yoke. An insulating film layer, an adhesive conductive film layer formed on one surface of the insulating film layer and containing a conductive material and an acrylic resin, and between the conductive film layer and the insulating film layer. A cathode ray tube having an electromagnetic wave absorbing means including a metal thin film layer interposed and grounded. 16. The cathode ray tube according to claim 15, wherein said conductive material is graphite. 17. The cathode ray tube according to claim 16, wherein said conductive material further comprises nickel. 18. The cathode ray tube according to claim 15, wherein the explosion-proof band and the transparent conductive film are electrically connected by a conductive tape.