JPH0567432A - Manufacture of picture tube - Google Patents

Abstract

PURPOSE:To realize both functions of reduced luminous reflection and charge prevention relatively inexpensively by baking a first layer and a second layer which is obtained by rotary-applying a volatile solution containing silica besides drying, during frit welding or bulb evacuation. CONSTITUTION:Tin oxide and a volatile solution containing silica are rotary- applied on the outer surface of a face panel member 4 forming a glass bulb 3 and dried so as to form a first layer. Next, the volatile solution containing silica is rotary-applied on this first layer and dried so as to form a second layer which is a surface layer. Then, these first and second layers are baked on the member 4 during heating of the member 4 to frit-weld it to a funnel member 5 or heating of the bulb 3 to vacuum-evacuate the inside. Thereby, a luminous reflection rate in the outer surface of the member 4 is suppressed to low value so that a good luminous reflection reducing effect can be obtained, a charge preventive effect can be obtained, and a picture tube relatively inexpensive provided with these both functions and having a good optical characteristic can be obtained.

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 antistatic function and light reflection reducing function.

[0002]

2. Description of the Related Art When so-called external light from an indoor illumination lamp or the like is reflected on the outer surface of a face panel member of a picture tube glass bulb, it becomes difficult to see a reproduced image. Further, when static electricity is accumulated on the outer surface of the face panel member, not only is there a risk of electric shock, but dust is likely to adhere. Therefore,
The outer surface of the face panel member may be roughened chemically or mechanically to reduce light reflection, or a conductive thin film made of tin oxide or the like may be provided on the outer surface of the face panel member as an antistatic measure. It is generally done.

[0003]

However, when the above-mentioned light reflection reducing measures are taken, although a large number of fine irregularities formed on the outer surface of the face panel member diffusely reflect the outside light, the phosphor film Since the image light generated in 1 is also diffusedly reflected, not only the resolution is deteriorated but also the gloss feeling is lost. Also, when a conductive thin film is attached to the outer surface of the face panel member by a method such as spraying as an antistatic measure, an independent heating step is required for baking the conductive thin film, which increases man-hours and costs. It becomes high.

[0004]

According to the present invention, on a first layer obtained by spin-coating and drying a volatile solution containing tin oxide and silica on the outer surface of a face panel member forming a glass bulb. Then, a volatile solution containing silica is spin-coated and dried to obtain a second layer as a surface layer. Then, the first layer and the second layer are baked onto the face panel member during a heating period in which the face panel member is frit-welded to the funnel member or during a heating period in which the inside of the glass bulb is evacuated to a vacuum.

[0005]

With this structure, the interference effect of the composite film obtained by the above-mentioned baking can not only reduce the light reflectance on the outer surface of the face panel member to 1.5% or less, but also obtain the antistatic effect. be able to. Moreover, the first and second layers can be formed in a continuous process, and the baking is accomplished during frit welding or evacuation, so no separate heating step is required.
In addition, since a large number of minute irregularities are not formed on the outer surface of the face panel member, resolution is not deteriorated, and a picture tube having both optical reflection reduction function and antistatic function and good optical characteristics can be obtained at a relatively low cost. be able to.

[0006]

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 pre-exhaust treatment color picture tube 2 mounted on a turntable 1 is a 29-inch type, and its glass bulb 3 has a face panel member 4 and a funnel member 5. The stem 7 sealed to the neck portion 6 of the funnel member 5 has an exhaust pipe 8.
The face panel member 4 is welded to the funnel member 5 via the frit layer 9. However, the outer surface of the face panel member 4 in the illustrated state has been subjected to polishing treatment with a buff impregnated with an abrasive such as cerium oxide, and cleaning with deionized water and air blow for drying and dust removal. It is assumed that each of the processing has already been received. Reference numeral 10 is a coating booth, and 11 is a solution injection nozzle.

The rotary table 1 can rotate about the shaft 1a. While rotating the pre-exhaust treatment color picture tube 2 together with the turntable 1 at a rotation speed of about 100 rpm, a volatile solution containing tin oxide and silica is passed through the solution injection nozzle 11 to the central portion on the outer surface of the face panel member 4. Drop it. The outer surface of the face panel member 4 in this state is maintained at a temperature of about 40 ° C. The solution provided on the outer surface by the dripping for about 30 seconds spreads from the central portion to the peripheral portion. Thus, since a uniform coating film is formed by spin coating, that is, spin coating, the dropping is stopped at this point and the rotation speed is reduced to about 50 rpm, which is about half. The coating film is dried by this rotation for about 80 seconds, and the outer surface temperature of the face panel member 4 during the drying is kept at about 50 ° C. by a surface heater, an infrared lamp or the like. this is,
This is because it is convenient to prevent mixing with the second layer described later. The volatile solution used is Si in an alcohol solvent.
It was obtained by adding about 1.5% by weight of fine powder of O ₂ and SnO ₂ .

Thus, as shown in FIG. 2, the first layer 12 having a thickness of about 1,000 A is formed on the outer surface of the face panel member 4.
Next, the second layer 13 for imparting the low reflection function is formed on the surface of the first layer 12. As the material for the second layer 13, a material prepared by adding only about 1% by weight of fine powder of SiO ₂ into an alcohol solvent is used, and about 1,000 A is obtained by the same spin coating and drying treatment as described above.
To form a film of uniform thickness. The coating conditions are the same as the coating conditions for forming the first layer 12, but the temperature in the final stage of the drying treatment is 60 to 80 ° C., including the meaning of calcination.
Set to.

The pre-exhaust treatment picture tube 2 taken out from the rotary table 1 is transferred to a conventional exhaust process, where the exhaust treatment is carried out. The picture tube 2 having the exhaust pipe 8 connected to the vacuum pump is heated in the exhaust furnace to discharge the stored gas, but the face panel member 4 becomes a high temperature of about 380 ° C. during this process. For this reason, the first layer 12 and the second layer 13 are baked on the surface of the face panel member 4, and an interference film having a two-layer structure having a conductive and smooth surface is obtained. The thickness of this interference film is about 2,000 A, and reduces reflection of daylight white external light from a fluorescent lamp for indoor lighting. The electric resistance value at 20 mm intervals on the surface of this film is the applied voltage DC50.
It becomes 1,000 MΩ to 3,000 MΩ at 0 V, and this value 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 member 4 so as to circulate the surface, and the band is connected to the ground line of the set. It

In the above-mentioned embodiment, the baking treatment of the first layer and the second layer is performed during the exhaust step, but it may be performed during the frit welding step. In this case, the first layer and the second layer are provided on the surface of the face panel member 4 before frit welding, but the face panel member 4 is heated to about 450 ° C. during the frit welding process, which is better. A baking effect can be obtained.

As described above, when the heat treatment for baking the thin film is carried out at the same time during the exhaust process or the frit welding process by using the exhaust furnace or the frit welding furnace, it is not necessary to prepare a heating furnace dedicated to the baking. Further, the problems of gas generation in pipes and emission deterioration found in conventional products in which an antistatic thin film attached to a finished sphere by a method such as spraying is baked at a temperature of about 200 ° C. are completely solved.

[0013]

Since the present invention is constructed as described above,
Not only can the light reflectance on the outer surface of the face panel member be suppressed to a low value and a good light reflection reduction effect can be obtained, but also an antistatic effect can be obtained. In addition, since it does not require a heating process dedicated to film baking and does not cause fine irregularities on the outer surface of the face panel member, a picture tube with both optical reflection reduction and antistatic functions with good optical characteristics is compared. It can be obtained at a very low cost. Also, the adhesive strength of the coating film is improved.

[Brief description of drawings]

FIG. 1 is a side view showing a relationship between a pre-exhaust treatment picture tube formed by a manufacturing method of the present invention and a manufacturing apparatus.

FIG. 2 is a side sectional view showing a relationship between a film and a face panel member of a pre-exhaust treatment picture tube formed by a manufacturing method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 rotary table 2 color picture tube before exhaust treatment 3 glass valve 4 face panel member 5 funnel member 9 frit layer 11 solution injection nozzle 12 first layer 13 second layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hito Enda 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electronics Industrial Co., Ltd.

Claims (1)

[Claims] 1. A volatile solution containing silica is applied onto a first layer obtained by spin-coating and drying a volatile solution containing tin oxide and silica on the outer surface of a face panel member forming a glass bulb. Spin coating and dry to obtain a second layer which is a surface layer, and during the heating period for frit welding the face panel member to the funnel member or during the heating period for evacuating the glass bulb to vacuum, A method of manufacturing a picture tube, comprising baking the second layer on the face panel member.