JPS6047338A - Method of forming cathode-ray tube phosphor screen - Google Patents

Abstract

PURPOSE:To obtain a fully antireflective effect by forming a layer consisting of inorganic transparent material such as magnesium fluoride and calsium fluoride and low melting point glass powder on the inner surface of a panel and forming a phosphor screen on this layer. CONSTITUTION:After a layer in which low melting point glass is mixed in inorganic transparent material such as magnesium fluoride and calcium fluoride is formed on the inner surface of a panel, a black matrix phosphor screen or normal phosphor screen is formed. Consequently, the low melting point glass forces into a gap between the inorganic transparent material and a phosphor due to capillarity at the after-process baking or frit bake and the phosphor makes a fully optical contact to the inorganic transparent material. As a result, since the reflectivity of the interface between the phosphor screen and glass is reduced sharply as compared with the conventional reflectivity, a screen is easy to see and display quality is improved considerably.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention is directed to a method for forming a fluorescent surface of a cathode powder tube, which forms a favorable light surface with an anti-reflection effect on the inner surface of a panel.

[Background of the invention]

Conventionally, to form a fluorescent surface that has an anti-reflection effect,
Method ◇; has been proposed by etching the inner surface of the panel of a bipolar ray tube, but in either method, sufficient optical antireflection effect cannot be obtained because the optical contact with the phosphor, which is the light emitter, is not complete. There wasn't.

[Purpose of the invention]

The present invention has been made in order to eliminate these conventional drawbacks, and an object of the present invention is to provide a method for forming a fluorescent surface of an polar ray tube that can provide a sufficient light reflection prevention effect.

[Summary of the invention]

In order to achieve such an object, the present invention forms a layer of a transparent inorganic material such as magnesium fluoride or calcium fluoride mixed with low-melting glass on the inner surface of the panel, and then forms a normal fluorescent surface. It is. As a result, the low melting point glass enters the gap between the inorganic transparent material and the phosphor by capillary action during baking or frit baking in the subsequent process, and the phosphor and the inorganic transparent material come into complete optical contact.

[Embodiments of the invention]

Next, the present invention will be explained in detail by way of examples.

(Example 1) First, a photoresist having the following composition (% by weight) was applied to a thickness of 0.3 μm on the inner surface of a panel of a 14-inch Cassie cathode ray tube.

Polyvinyl Alcohol 15% Ammonium Chromate 0.075% Primal C-
420,075 Colloidal Silica 0025 Thiemal NCO, 001 Water Residual Next, after exposure for 30 seconds in the ultraviolet region with an intensity such that the inner panel illuminance is No. 10-, an IO second curved image with water at 25°C Then, in a wet state, a mixed powder having the following composition (% by weight) is dusted.

When 80 strips of magnesium fluoride (average particle size 1 μm) are formed, a mixed layer of magnesium fluoride and low melting point glass is formed with a thickness of about 1.5 mg/c and ti.

Next, this panel is subjected to a well-known black matrix forming process and a phosphor film forming process to form a black matrix phosphor surface.

When we measured the reflectance of Color Brown-Q produced using such a process with the glass interface between fluorescent surfaces, it was found that the reflectance of a normal color CRT that did not use the process of the above example was 8%, but it was 2%. Reduced to the head.

(Example 2) A photoresist having the following composition (Kyoma %) was coated to a thickness of 0.2 μm on the inner surface of the panel of a 4-inch color cathode ray tube.

Diazonium salt 3-line alginate propylene glycol ester 05 polyvinyl alcohol 0.07 thietelene glycol o7 g/l/Ronik L-920,002% Next, the illuminance inside the panel was 20W, and the light was strong enough to turn your back. The area to be adjusted to fσ to the extent that a green phosphor is formed is exposed through a shadow mask for 60 seconds, and then the following composition Hu
m%) of the mixed powder is applied to the area that has been viscosified by the j-4 light.

Green phosphor (average particle size lOμm) 9591! Calcium fluoride (average particle size Iμm) 4% low grade 11 point glass (X
V-average particle size 0.5 μm) 1% When this powder is applied,
Calcium fluoride and low melting point glass having a small average particle size are formed in many layers on the inner surface of the panel, and the phosphor having a large average particle size is distributed on each layer.

Approximately 2 kgAta for the inner surface of the panel in this condition
When sprayed with suppressed air, a pattern of green phosphor, calcium fluoride, and low-melting glass is formed at the exposed area. The light body confirms the above process.

Repeat for red phosphors. Next, the inner surface of the panel is similarly circled for 60 seconds without a shadow mask, and then a mixture of the composition (% by weight) of fire is applied and developed with air spray.

Barium ferrite (average particle size 8 μm) 95 Calcium tyfluoride (average particle size 1 μm) 4% #, melting point glass (average particle size 0.5 μm) 1% Barium ferrite is a black substance, so by this manufacturing method, A black matrix phosphor surface is completed in which a light-absorbing material surrounds a swath of phosphor pixels in three colors: green, blue, and red.

After that, the color brown manufactured through the normal process)
The reflectance at the interface between the fluorescent surface and the glass for g is g+++
As a result, a low value of 1.8% was obtained.

In this way, when transparent inorganic substances such as calcium heptafluoride and magnesium heptafluoride are mixed with low-melting glass into a phosphor or light-absorbing substance, they fill the gaps between the phosphors or light-absorbing substances and improve the appearance. By creating a capillary tube at the top, when the low melting point glass melts, the force that enters this gap is strengthened. Other examples of the transparent inorganic substance include silica dioxide and glass powder.

In the embodiment, a color cathode ray tube is used as a negative/ray tube, but it goes without saying that the present invention can also be applied to a monochrome cathode ray tube, display tube, etc.

〔Effect of the invention〕

As described above, according to the cathode ray tube fluorescent surface forming method according to the present invention, the reflectance between the fluorescent surface and the glass interface is significantly reduced compared to conventional methods, making it easier for art dealers to see and significantly improving display quality. do.

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Claims (1)

[Claims] A layer consisting of an inorganic transparent substance such as magnesium fluoride or calcium fluoride and a low contact point glass powder is formed on the inner surface of the panel, and a black matrix fluorescent surface or a fluorescent surface is formed on this layer. (Cathode capillary fluorescent surface formation method using il.