JP3159487B2 - Picture tube manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a picture tube having both functions of preventing static electricity and reducing light reflection.

[0002]

2. Description of the Related Art If so-called external light from an indoor lamp or the like is specularly reflected on the outer surface of a face panel of a picture tube glass bulb, a reproduced image is difficult to see. In addition, when static electricity accumulates on the outer surface of the face panel, not only the risk of electric shock is generated, but also dust tends to adhere. Therefore, the outer surface of the face panel may be chemically or mechanically roughened to prevent specular reflection, or a conductive thin film made of tin oxide or the like may be provided on the outer surface of the face panel as an antistatic measure. Generally done.

[0003]

However, when the above-described light reflection reducing measure is taken, although a large number of fine irregularities generated on the outer surface of the face panel cause the external light to be irregularly reflected, the fluorescent film is not sufficient. Since the generated image light is also irregularly reflected,
Not only does resolution drop, but glossiness is also lost. When the reflection and antistatic thin film is applied to the outer surface of the face panel by spraying or the like at the final stage of the picture tube production, the thin film is heated to about 200 ° C.
In addition, there is a risk that gas in the tube is generated during the heating step of baking at a temperature of, and that the emission is deteriorated, and that it is difficult to provide sufficient adhesive strength to the thin film.

[0004]

According to the present invention, a first layer is obtained by spin-coating and drying a volatile solution containing tin oxide and silica on the outer surface of a glass face panel in a single state. A step of spin-coating and drying a volatile solution containing silica on the first layer to obtain a second layer as a surface layer, and heating the face panel to form the first layer and the second layer Baking on the face panel.

[0005]

With this structure, not only the light reflectance on the outer surface of the face panel can be reduced to 1.5% or less, but also the antistatic effect can be obtained by the interference effect of the composite film obtained by the printing. Can be. In addition, the problems of generation of gas in the tube and deterioration of emission are eliminated, and furthermore, in addition to increasing the adhesive strength of the thin film, there is no generation of a large number of fine irregularities on the outer surface of the face panel, so that resolution is not reduced, A picture tube having both optical reflection reduction and antistatic functions and good optical characteristics can be obtained.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in the drawings.

As shown in FIG. 1, a glass face panel 2 mounted on a turntable 1 is of a 17-inch type, and its outer surface is polished by a buff impregnated with an abrasive such as cerium oxide. In addition to treatment, it is assumed that cleaning with deionized water and air blow for drying and dust removal have already been performed. Reference numeral 3 denotes a coating booth, and 4 denotes a solution injection nozzle.

The turntable 1 can rotate around a shaft 1a. While rotating the face panel 2 at a rotation speed of about 100 rpm together with the turntable 1, a volatile solution containing tin oxide and silica is dropped onto a central portion on the outer surface of the face panel 2 through the solution injection nozzle 4. The outer surface of the face panel 2 in this state is maintained at a temperature of about 40 ° C. The solution supplied on the outer surface by the dripping over about 30 seconds spreads from the center to the periphery. Thus, a uniform coating film is formed by spin coating, that is, spin coating. At this point, the dripping is stopped, and the rotation speed is reduced to about 50 rpm, which is almost half. The coating is dried by this rotation for about 80 seconds, and the outer surface temperature of the face panel 2 during this drying is maintained at about 50 ° C. by a surface heater, an infrared lamp, or the like. This is because it is convenient to prevent mixing with the second layer described later. The volatile solution used was obtained by charging about 1.5% by weight of SiO ₂ and SnO ₂ into an alcoholic solvent.

Thus, as shown in FIG. 2, the first layer 5 having a thickness of about 1,000 A is formed on the outer surface of the face panel 2. Next, the second layer 5 for imparting a low reflection function is formed.
Layer 6 is formed on the surface of first layer 5. As a material of the second layer 6, a material having about 1% by weight of only SiO ₂ in an alcoholic solvent is used, and a film having a uniform thickness of about 1,000 A is formed by the same spin coating and drying treatment as described above. I do. The application conditions are the same as the application conditions in the formation of the first layer 5, but the temperature in the final drying process is set to 60 to 80 ° C. including the meaning of temporary baking.

The face panel 2 taken out of the turntable 1 is heated at 400 to 450 ° C. for about 20 minutes. As a result, the first layer 5 and the second layer 6 are
Is baked on the surface of the surface and has a smooth surface with conductivity.
An interference film having a layer structure is obtained. The thickness of this interference film is about 2,
000 A to reduce the reflection of daylight outside light from indoor lighting fluorescent lamps and the like. The electric resistance value at 20 mm intervals on the surface of this film is 1,0 at an applied voltage of 500 V DC.
00 MΩ to 3,000 MΩ, which sufficiently fulfills the antistatic function. The interference film is electrically connected to a reinforcing metal band (not shown) attached to the outer peripheral surface of the face panel 2 so as to go around the surface, and the band is connected to a ground line of the set. .

[0011]

Since the present invention is configured as described above,
The light reflectance on the outer surface of the face panel can be suppressed to a low value, so that not only a good light reflection reducing effect can be obtained, but also an antistatic effect can be obtained. In addition, since a thin film is formed on the outer surface of the face panel in a single state, a conventional product in which the antistatic thin film attached to the finished ball by spraying or the like is baked at a temperature of about 200 ° C. was observed. The problems of gas generation and emission deterioration in pipes are completely eliminated. Further, regarding the adhesive strength of the thin film, since the baking can be performed at such a high temperature that the face panel is not deformed, a higher adhesive strength can be obtained as compared with a conventional product.

[Brief description of the drawings]

FIG. 1 is a side view showing a relationship between a face panel formed with a film by a manufacturing method of the present invention and a manufacturing apparatus.

FIG. 2 is a side sectional view showing a relationship between a face panel and a film formed by a method according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 turntable 2 face panel 4 nozzle for solution injection 5 first layer 6 second layer

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor, Tomoaki Toda 1006, Kazuma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (56) References JP-A-2-247957 (JP, A) -91650 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01J 9/20

Claims (1)

(57) [Claims] 1. A step of spin-coating and drying a volatile solution containing tin oxide and silica on the outer surface of a glass face panel in a single state to obtain a first layer; A step of spin-coating and drying a volatile solution containing silica to obtain a second layer as a surface layer, and a step of heating the face panel to bake the first and second layers on the face panel. A method for manufacturing a picture tube, comprising: