JPH11233048A - Cathode ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ground a conductive film of a multilayer conductive film formed on an outer surface of an effective part of a panel by a low resistance connection. SOLUTION: In this cathode ray tube, a multilayer conductive film 20 in which at least a lower layer is made as a conductive film is provided on an outer surface of an effective part 1 of a panel 3, and the multilayer conductive film is electrically connected to an explosion proof band 5 mounted onto a skirt part. In this case, a conductive film 24 for connection containing a conductive particle with a bigger particle diameter than a film thickness of the multilayer conductive film is provided on the outer surface of the effective part of the panel 3, the conductive film for connection is electrically connected to the conductive film of the multilayer conductive film and the conductive film of the multilayer conductive film is connected to the explosion proof band through the conductive film for connection.

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 having a multilayer conductive film provided on an outer surface of an effective portion of a panel.

[0002]

2. Description of the Related Art Generally, a cathode ray tube is, as shown in FIG.
Panel 3 provided with skirt portion 2 around effective portion 1
And a funnel-shaped funnel 4 having a vacuum envelope, and an explosion-proof band 5 for preventing implosion of the vacuum envelope is attached to the skirt portion 2 of the panel 3. Further, a phosphor screen 6 is provided on the inner surface of the effective portion 1 of the panel 3. On the other hand, an electron gun 8 is provided in the neck 7 of the funnel 4. The electron beam 9 emitted from the electron gun 8 is deflected by a magnetic field generated by a deflection yoke 11 attached from the outside of the large-diameter portion 10 of the funnel 4 to the outside of the adjacent portion of the neck 7, and the phosphor screen 6 is deflected. Are formed in a structure for displaying an image by scanning.

[0003] In recent years, such a cathode ray tube has ergonomic factors such as legibility of display, prevention of electrification, and shielding of leaked electromagnetic waves with the increase in time for which a user faces the display device of OA equipment. Highly required.

Regarding the visibility of the display, there is a problem that the display is deteriorated due to reflection of external light on the inner and outer surfaces of the effective portion of the panel and the phosphor screen, and it is particularly necessary to reduce strong reflection on the outer surface of the effective portion. . As a solution, an antireflection film is provided on the outer surface of the effective portion to prevent reflection on the outer surface of the effective portion. As the anti-reflection film, recently, as shown in FIGS. 7 and 8, a multilayer anti-reflection film 15 of at least two layers 13 and 14 for suppressing reflection by an interference effect of light with little deterioration in resolution has become mainstream. .
In addition, due to the price and ease of production, the sol-gel method of applying and baking a solution obtained by adding a metal alkoxide to an alcohol solution of ethyl silicate and a solution obtained by adding and dispersing ultrafine particles by a spin coating method or a dipping method are generally used. It is formed with.

On the other hand, in a cathode ray tube in which a high voltage is applied to the phosphor screen, a potential is induced by the high voltage on the outer surface of the effective portion of the panel, and the screen is charged. This charging of the outer surface of the effective part gives discomfort when the human body approaches or comes into contact,
When severe, receive an electric shock.

[0006] Also, regarding the leakage electromagnetic wave, there is a problem that the leakage AC electric field emitted from the front surface of the cathode ray tube affects the human body, and it has already been regulated.

As means for preventing these charges and shielding the leaked AC electric field, one of the multilayer antireflection films 15 shown in FIG.
Layer, typically the lower layer 13, is formed of ITO (Indium T
A conductive film containing conductive ultrafine particles such as inOxide or SnO _{2 is used,} and the conductive film of this multilayer conductive film is electrically connected to the explosion-proof band 5 via a conductive tape 16 and grounded. .

[0008]

As described above, the display is degraded due to the reflection of external light on the outer surface of the effective portion of the panel, the outer surface of the effective portion is prevented from being charged, and the leakage AC electric field emitted to the front of the effective portion is shielded. For at least 2
There is a cathode ray tube provided with a multilayer antireflection film having a layer or a multilayer conductive film having a lower layer as a conductive film.

However, in order to form a multilayer conductive film and shield a leaked AC electric field, better conductivity is required than in the case where charging is prevented. It is necessary to reduce the resistance of the connection with the explosion-proof band for grounding.

That is, in general, a conductive film is formed as a lower layer of a multilayer conductive film, and an insulating film is formed on this conductive film. Therefore, the conductive film is connected to an explosion-proof band via a conductive tape and grounded. However, the connection resistance increases.
Therefore, the shielding effect is reduced, and the leakage AC electric field shielding effect is impaired.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide a cathode ray tube capable of grounding a conductive film of a multilayer conductive film formed on an outer surface of an effective portion of a panel by a low-resistance connection. With the goal.

[0012]

Means for Solving the Problems A vacuum envelope comprising a panel provided with a skirt portion around the effective portion and a funnel-shaped funnel is provided, and at least the lower layer is made of a conductive film on the outer surface of the effective portion. A multilayer conductive film is provided, and the multilayer conductive film is electrically connected to an explosion-proof band attached to a skirt portion, and emits an electron beam emitted from an electron gun disposed in a funnel neck to the outside of the funnel. In a cathode ray tube which scans a phosphor screen formed on the inner surface of the effective portion by deflecting by the attached deflection yoke, conductive particles having a particle size larger than the thickness of the multilayer conductive film are formed on the outer surface outside the effective portion of the panel. The connecting conductive film was provided, and the conductive film of the multilayer conductive film was electrically connected to the connecting conductive film, and the conductive film of the multilayer conductive film was connected to the explosion-proof band via the connecting conductive film.

[0013] The particle size of the conductive particles constituting the connection conductive film is 2,000 to 10,000 Å.

The multilayer conductive film was connected to an explosion-proof band via a conductive tape adhered to the connecting conductive film.

[0015]

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

FIG. 1 shows a cathode ray tube which is one embodiment of the present invention, and FIG. 2 shows a main part thereof. This cathode ray tube has a vacuum envelope composed of a glass panel 3 provided with a skirt 2 around a curved effective part 1 and a funnel-shaped glass funnel 4. A phosphor screen 6 is provided on the inner surface of the effective portion 1. On the outer surface of the effective portion 1, a multilayer conductive film 20 described later is provided. Further, the skirt portion 2 has an explosion-proof band 5 for preventing implosion of the vacuum envelope.
Is installed. On the other hand, an electron gun 8 is provided in the neck 7 of the funnel 4. And this electron gun 8
Of the electron beam 9 emitted from the large diameter portion 1 of the funnel 4
It is formed to have a structure in which an image is displayed by being deflected by the magnetic field generated by the deflection yoke 11 attached from the outside to the outside of the adjacent portion of the neck 7 and scanning the phosphor screen 6.

As shown in FIG. 3, the multilayer conductive film 20 is formed in a structure of two or more layers (two layers in the illustrated example), and a lower layer 21 made of a conductive film is provided directly on the outer surface of the effective portion 1. On this lower layer 21, an upper layer 22 made of an insulating film is provided.

Further, in this cathode ray tube, the panel 3
At least at one location on the outer surface outside the effective portion of
0 to 10000 angstroms and the multilayer conductive film 2
A connection conductive film 24 including conductive fine particles 23 having a particle size larger than 0 is provided, and is electrically connected to the lower conductive film 21. A conductive tape 25 is adhered to the connection conductive film 24, and is electrically connected to the explosion-proof band via the conductive tape 25.

The connection of such a cathode ray tube to the multilayer conductive film 20 and its explosion-proof band 5 is performed as follows.

As shown in FIG. 4, after manufacturing a cathode ray tube by a known method, the outer surface of the effective portion is cleaned. Next, as shown in FIG. 5 (a), at least one portion of the outer surface of the panel 3 outside the effective portion 1 includes ethyl containing conductive fine particles 23 having a particle size larger than the thickness of a multilayer conductive film to be formed thereafter. An alcohol solution of silicate is applied by a method such as brush coating or dipping, and is dried by hot air to form a conductive film 24 for connection.

As the conductive fine particles 23, ITO (Ind
By using ium tin oxide (SnO ₂ ) or SnO ₂ , the connecting conductive film 24 can be formed as a transparent conductive film. However, since the connecting conductive film 24 is formed outside the effective portion, it is opaque using opaque conductive particles such as Al. It may be a conductive film.

When the refractive index is n, the film thickness is d, the wavelength of light is λ, and λ = 550 nm, the multilayer conductive film is formed to a thickness satisfying nd = λ / 4. In the case of a multilayer conductive film having a layer structure, conductive fine particles 23 having a particle size of 2000 Å or more and a multilayer conductive film having a three-layer structure have a particle size of 3000 Å or more. However, when the particle size of the conductive fine particles 23 exceeds 10,000 angstroms,
Care must be taken because the film stress decreases the film strength.

Next, ITO on the outer surface of the effective portion 1 of the panel 3
An alcohol solution of ethyl silicate, in which conductive fine particles such as SnO ₂ or SnO ₂ are dispersed, is applied to a predetermined thickness by a spin coating method or the like, and is dried with hot air to form a multilayer conductive film as shown in FIG. The lower layer 21 is formed. Then, on the lower layer 21, an alcohol solution of ethyl silicate or MgF ₂
5 is applied to a predetermined thickness by a spin coating method or the like, and is dried with hot air.
As shown in (c), the upper layer 22 is formed. Next, the lower layer 21, the upper layer 22, and the connection conductive film 24 formed on the outer surface of the effective portion of the panel 3 and the outer surface of the outer portion of the effective portion 20
Baking at a temperature of 0 ° C. or higher increases the film strength.

Thereafter, one end of the conductive tape is bonded to the conductive film 24 for connection, and the other end of the conductive tape is bonded to the explosion-proof band.

As described above, the conductive fine particles 23 having a particle size of 2000 to 10000 angstroms and a particle size larger than the thickness of the multilayer conductive film 20 are formed on the outer surface outside the effective portion 1 of the panel 3.
Is provided, the connection conductive film 24 is provided.
Can be formed so that the conductive fine particles 23 have an uneven surface protruding therefrom and are not covered by the upper layer 22 made of the insulating film of the multilayer conductive film 20. On the other hand, the connection between the lower layer 21 of the multilayer conductive film 20 and the connection conductive film 24 and the connection between the connection conductive film 24 and the conductive tape 25 can be reduced in resistance.

Therefore, with the above configuration, the conductive film of the multilayer conductive film 20 can be connected to the explosion-proof band 5 with a low resistance and grounded, and the reflection of external light on the outer surface of the effective portion 1 of the panel 3 can be achieved. It is possible to provide a cathode ray tube which effectively shields a leaked AC electric field emitted to the front surface of the effective surface, as well as preventing display deterioration and electrification due to interference.

[0027]

As described above, on the outer surface outside the effective portion of the panel, the connection conductive film including the conductive fine particles having a larger particle diameter than the thickness of the multilayer conductive film formed on the outer surface of the effective portion of the panel is provided. The connection between the lower layer of the multilayer conductive film and the connection conductive film and the connection between the connection conductive film and the conductive tape adhered to the connection conductive film can be connected to a low resistance and grounded, respectively. In addition to deterioration of display due to reflection of external light on the outer surface of the effective portion of the panel and electrification, in particular, a cathode ray tube that effectively shields a leaked AC electric field emitted to the front surface of the effective surface can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a cathode ray tube according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a main part thereof.

FIG. 3 is a view showing a connection structure between a multilayer conductive film and a conductive tape on an outer surface of an effective portion of the panel of the cathode ray tube.

FIG. 4 is a flowchart showing a method for forming the multilayer conductive film and the connection conductive film.

5 (a) to 5 (c) are views for explaining main forming steps of the multilayer conductive film and the connecting conductive film, respectively.

FIG. 6 is a diagram showing a configuration of a conventional cathode ray tube.

FIG. 7 is a diagram showing a configuration of a main part thereof.

FIG. 8 is a diagram showing a connection structure between a multilayer conductive film and a conductive tape on an outer surface of an effective portion of the conventional cathode ray tube panel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Effective part 2 ... Skirt part 3 ... Panel 4 ... Funnel 5 ... Explosion-proof band 6 ... Phosphor screen 8 ... Electron gun 9 ... Electron beam 11 ... Deflection yoke 20 ... Multilayer conductive film 21 ... Lower layer 22 ... Upper layer 23 ... Conductive particles 24: conductive film for connection 25: conductive tape

Claims (3)

[Claims] 1. A multi-layered conductive film having at least a lower layer as a conductive film on an outer surface of the effective portion, comprising a panel provided with a skirt portion around the effective portion and a funnel-shaped funnel. The multi-layer conductive film is electrically connected to an explosion-proof band mounted on the skirt portion, and an electron beam emitted from an electron gun disposed in the neck of the funnel is mounted on the outside of the funnel. A cathode ray tube that scans the phosphor screen formed on the inner surface of the effective portion by being deflected by the deflection yoke, wherein conductive particles having a particle size larger than the thickness of the multilayer conductive film are formed on the outer surface outside the effective portion of the panel. Is provided, and the conductive film for connection is electrically connected to the conductive film of the multilayer conductive film, and the conductive film of the multilayer conductive film is connected to the explosion-proof barrier via the conductive film for connection. Cathode ray tube, characterized in that connected to the de. 2. The cathode ray tube according to claim 1, wherein the conductive particles constituting the conductive film for connection have a particle size of 2,000 to 10,000 Å. 3. The cathode ray tube according to claim 1, wherein the multilayer conductive film is connected to the explosion-proof band via a conductive tape adhered to the connecting conductive film.