KR100232571B1 - Fixing process for manufacturing dry electrophotographical screen of crt - Google Patents

Abstract

The present invention provides a fixing process for the production of a dry electrophotographic screen of a cathode ray tube.

The fixing process is carried out by spraying a liquid electrostatic spray gun with a solvent in which 0.1-3% by weight of the polymer is dissolved.

As a result, the solvent in which the polymer is dissolved is sprayed by the liquid electrostatic spray gun to permeate the R, G, and B phosphor powder to dissolve the polymer of the photoconductive film, thereby forming the polymer film in the R, G, and B phosphor powders, It is possible to fix the R, G, and B phosphor powders.

Description

Fixing process for cathode-ray tube dry electrophotographic screen manufacturing

The present invention relates to a fixing process for manufacturing a dry electronic screen of a cathode ray tube, and more particularly, to a fixing process for manufacturing a dry electronic screen of a cathode ray tube, in which a liquid electrostatic spray gun is used to fix R, G, B phosphor powders developed by dry electrophotography in a short time To a fixing process for manufacturing a dry electrophotographic screen of a cathode ray tube.

In general, the cathode ray tube comprises a vacuum bulb divided into a panel 12, a funnel 13 and a neck 14 as shown in FIG. 1, And a shadow mask 16 mounted on a side wall of the panel 12. The shadow mask 16 is mounted on the side wall of the panel 12,

A fluorescent screen 20 is formed on the inner surface of the face plate 18 of the panel 12 so that the electron beams 19a and 19b emitted from the electron gun 11 are focused and accelerated by various lens systems, And is deflected to the deflection yoke 17 and passes through the aperture or slot 16a of the shadow mask 16 and is scanned onto the fluorescent screen 20. [

The fluorescent screen 20 is formed on the rear surface of the face plate 18. In the case of a color, as shown in FIG. 2, a plurality of stripe or dot-shaped phosphors R, G, B ) And a light absorbing material 21 such as a black coating between the respective phosphors. In addition, the back surface has the aluminum thin film layer 22 formed as a conductive film layer so that the fluorescent surface plays a role of increasing the luminance, preventing the ion damage of the fluorescent screen, and preventing the potential drop of the fluorescent screen. Although not shown, a resin such as a lacquer is applied between the fluorescent screen 20 and the photoconductive film layer 34 in order to increase the flatness and the reflectance of the aluminum thin film layer 22.

A conventional photolithographic wet process, in which such a fluorescent screen 20 is formed by applying and drying a suspension containing a fluorescent material such as a coloring light phosphor and a suspension containing a light absorbing material, The manufacturing process and manufacturing facilities are complicated and the manufacturing cost is high. In addition, there are various problems such as the consumption of a large amount of clean water, the generation of waste water, the emission of phosphorus, and the discharge of hexavalent chromium photoconductor. In recent years, an electrophotographical screen manufacturing method has been developed in which such a wet photolithography process is improved. In this photolithographic process, wet process still has the above-mentioned problems. According to the dry process, It has been resolved considerably.

As an example, a method of manufacturing a screen of a cathode ray tube according to the present invention will be described below.

3 (a) to 3 (e) schematically show each process according to the above-mentioned production method.

3A is a coating process in which a conductive film 132 and a photoconductive film 134 are formed on the inner surface of the face plate 18. The conductive film 132 may be formed of, for example, an aqueous solution of 1-50% by weight of Catfloc-c (trade name, product of Calgon) as a polyelectrolyte and 1-50% by weight of a 10% And then drying it. A new photopolymer coating solution containing a substance reactive with ultraviolet rays is applied thereon and dried. At least one of bis dimethyl phenyl diphenyl butatriene, trinitro-fluorenone (TNF), and ethyl anthraquinone (EAQ) may be used as the material that reacts with ultraviolet rays. The photoconductive coating solution was prepared by adding 0.01 to 10% by weight of bisdimethylphenyldiphenylbutyricene as a polymer binder and 1 to 30% by weight of polystyrene as a polymer binder in a balance amount of toluene or xylene (xylene).

The third (b) schematically shows the charging step. A DC voltage of + 1K volts or less, preferably +700 volts or more was applied to the corona discharge device. Since the photoconductive film 134 reacts with ultraviolet rays having a wavelength of 450 nm or less, dark room operation is unnecessary.

3 (c) schematically shows the exposure process. Ultraviolet rays having a short wavelength and a directivity from the ultraviolet light source 138 pass through the ultraviolet transmitting lens 140 and enter the shadow mask 16 at a desired incident angle. And passes through the aperture or slit 16a of the shadow mast 16 having the desired arrangement to expose the photoconductive film 134 in a desired array. At this time, the conductive film 132 is grounded, and the electric charge of the exposed portion is discharged through the conductive film 132. Then, the electric charge in the non-exposed portion remains in the photoconductive film 134 as it is. Since this exposure process uses the ultraviolet light source 138, it is not necessary to work in the dark room.

FIG. 3 (d) schematically shows the developing process. Conventionally, in this developing process, the carrier beads and the phosphor particles or the light absorbing material particles are mixed to charge the static electricity caused by the friction. However, according to the invention of the present applicant, the fine powder such as the powder of the phosphor or the light- The fine powder is charged by passing the discharge electrode 144a and the nozzle 144b such as a corona discharge device through the venturi pipe 146 from the hopper 148 and discharging the exposed portion of the photoconductive film 134 and the non- Or < / RTI > The polarity of the static electricity charged to the fine powder by the discharge electrode 144a is determined according to which portion of the exposed portion and the non-exposed portion in the above-described exposure process the fine powder is to be attached. That is, when the positive charge is attached to the non-exposed portion, the fine powder is charged with - charge, and when the positive charge is adhered to the exposed portion where the charge is discharged, the fine powder is charged with positive charge. The charged fine powder injected into the developing container 142 is strongly adhered to the surface of the anticorrosion film 134 in a desired arrangement by the action of electric attraction and repulsive force.

3 (e) schematically shows a fixing process according to the applicant's invention using a vapor swelling method. In this step, the solvent vapor such as acetol or methyl isobutyl ketone is brought into contact with the surface of the photoconductive film 134 to which the desired fine powder (s) are adhered in a desired arrangement in the above-described developing process, 134, and fixes the attached fine powder (s) by the action of an electric force by the adhesive force of the dissolved polymer.

The above-described fixing process using the Vapor Swelling method described above is applied to the surface of the photoconductive film having the R, G, B phosphor powder attached thereto by using acetone, methyl Since the solvent vapor such as isobutyl ketone must be used, the polymer contained in the photoconductive layer 134 is dissolved after a considerable time, and the fine powder (s) adhered by the action of the electric force is fixed by the adhesive force of the dissolved polymer This process also takes a lot of time, and there is a problem that the adhesive strength is not good.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a method of manufacturing a dry electrophotographic screen, in which the R, G, and B phosphor powders adhered to the surface of a photovoltaic The purpose of the tube is to provide a fixing process for the manufacture of dry electrophotographic screens.

1 is a schematic plan view of a partial cross-section of a color cathode ray tube;

FIG. 2 is a partially enlarged cross-sectional view showing the screen configuration of the cathode ray tube of FIG. 1; FIG.

FIG. 3 is a schematic view for explaining a method of manufacturing a dry electrophotographic screen. FIG.

DESCRIPTION OF THE REFERENCE NUMERALS

10: cathode ray tube (CRT) 11: electron gun

12: panel 13: funnel

14: neck 15: anode button

16: Shadow mast 17: Deflection yoke

18: panel face plates 19, 19a, 19b: electron beam

20: fluorescent screen (screen) 21: light absorbing material

22: Racker film 23: Aluminum thin film layer

36: corona discharge device 132: conductive film

134: photoelectric conversion film 138: light source

140: Lens 142: Developing container

144a: discharge electrode 144b: nozzle

In order to achieve the above object, the present invention provides a method of forming a volatile electroconductive film on a volatile conductive film coated on an inner surface of a panel, charging the electroconductive film with uniform static electricity, And the first phosphor charged by the discharge electrode is attached to and developed on the exposed portion of the phosphor. The second and third phosphors are also subjected to the charging step, the exposure step and the developing step And at least one of a petroleum-based xylene, toluene, TCE, methyl isobutyl ketone (MIBK), and the like, in a fixing process for manufacturing a dry electrophotographic screen of a cathode ray tube, Of 0.1 to 3% by weight of the polymer is dissolved in the solvent, and the R, G, B phosphor powder is sprayed with a liquid electrostatic spray gun.

In particular, the polymer may be readily volatilized in the baking process by having pyrolytic properties such as polymethylmethacrylate (PMMA), poly alpha-methylstyrene, and the like.

Hereinafter, embodiments of the present invention will be described in detail.

According to the present invention, unlike the prior art, 0.1-3 wt% of a polymer is dissolved in at least one solvent such as petroleum xylene, toluene, TCE, methyl isobutyl ketone (MIBK) And sprayed onto the R, G, B phosphor powder.

The polymer preferably has pyrolytic properties such as polymethylmethacrylate (PMMA), poly alpha-methylstyrene, and the like.

The method for manufacturing a dry electrophotographic screen of a cathode ray tube to which the present invention is applied is characterized in that a volatile conductive film and a volatile electroconductive film are spin-coated on the inner surface of a panel as described in FIGS. 3 (a) through 3 . The photoconductive film is charged uniformly and electrostatically using a corona discharge device. The photoconductive film is then passed through a shadow mask as a light source to selectively expose the exposed photoconductive film corresponding to the position to be developed. The phosphor powder of R, G, B is adhered and developed. Thereafter, the fixing process according to the present invention is performed.

As described above, when the polymer is dissolved and sprayed in an amount of 0.1-3% by weight, not only the penetration into each of the R, G, and B phosphor powders is excellent, but also the affinity with the polymers contained in the photoconductive film is improved, , Thus showing strong adhesive force.

In addition, a thin polymer film was formed on the R, G, and B phosphor powders, and was more firmly adhered. When the polymers having good thermal decomposition properties were dissolved, they were readily volatilized and easily volatilized in the baking process.

According to the structure and operation of the fixing process for manufacturing a dry electrophotographic screen of a cathode ray tube according to the present invention, the solvent in which the polymer is dissolved is sprayed with a liquid electrostatic spray gun, so that the solvent penetrates the R, G, B phosphor powder in a short time The polymer of the R, G, and B phosphors is dissolved while the polymer of the R, G, and B phosphors are dissolved. Thus, the R, G, and B phosphor powders can be more effectively adhered to each other.

While the present invention has been described in connection with certain exemplary embodiments thereof, it will be apparent to those skilled in the art that various modifications and variations are possible in light of the above teachings.

Claims (2)

A volatile photoconductive film is formed on the inner surface of the panel and a uniform static charge is charged on the photoconductive film, and the photoconductive film is selectively exposed through a shadow mask as a light source, The second phosphor material and the third phosphor material are repeatedly subjected to the charging step, the exposure step and the step of forming the same in a desired arrangement, and then the cathode material (0.1-3 wt%) of a polymer is added to at least one solvent such as petroleum xylene, toluene, TCE, methyl isobutyl ketone (MIBK) in a fixing process for the production of a dry electrophotographic screen And dissolving the R, G, B phosphor powder in a liquid electrostatic spray gun to spray the R, G, B phosphor powder onto a liquid electrostatic spray gun. The process according to claim 1, wherein the polymer has pyrolytic properties such as polymethylmethacrylate (PMMA), poly alpha-methylstyrene, etc. The fixing process for the manufacture of a dry electrophotographic screen.