KR100805183B1 - Method and apparatus for fabricating plasma display panel using the electrophotographic image forming method - Google Patents

Abstract

The present invention relates to a method of manufacturing a plasma display panel for forming a barrier rib and a conductive phosphor layer by using an electrophotographic laser beam printing method, wherein the barrier rib and a conductive phosphor layer on a thick glass substrate are subjected to an electrophotographic laser beam printing method. It is characterized by a simple work process, easy implementation of various patterns, and high resolution of the plasma display panel.

Plasma display, PDP, electrophotography, laser beam print, resin, static electricity, binder

Description

Pattern forming method of plasma display panel and apparatus for manufacturing pattern of plasma display panel {Method and apparatus for fabricating plasma display panel using the electrophotographic image forming method}

1 is a front perspective view showing the structure of a typical plasma display panel.

2 is a cross-sectional view showing the structure of a general plasma display panel.

3 is a process diagram illustrating a process of forming a pattern on a plasma display panel using a conventional screen printing method.

4 is a schematic view showing a pattern manufacturing apparatus of a plasma display panel according to the present invention;

5 is a block diagram illustrating a method of forming a pattern of a plasma display panel according to the present invention.

FIG. 6 is a process diagram illustrating a process of forming a partition and a phosphor pattern by using an electrophotographic laser beam printing method of a plasma display panel according to the present invention. FIG.

Explanation of symbols on the main parts of the drawings

1: lower plate 2: address electrode

3, 7: dielectric layer 4: phosphor layer                 

5: partition 6: dielectric protective layer

8: Sustain Electrode 8a: Transparent Electrode

8b: bus electrode 9: top plate

101: bulkhead paste stacked by screen printing

102: phosphor paste filled between partition walls

301: lower glass substrate 302: laser beam scanning unit

311: developing device 312: fixing unit

321: feed roller 322: transfer roller

323: photosensitive drum 324: backboard roller

331: Resin coated bulkhead powder or phosphor powder toner

501: bulkhead stacked by electrophotography

502: resin coated phosphor powder filled between bulkheads

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel, and more particularly, to a method for manufacturing a plasma display panel and an apparatus for manufacturing a plasma display panel.

In general, a plasma display panel (hereinafter referred to as a PDP) is a device that displays an image by generating light by exciting a fluorescent material or a special gas.

That is, the PDP applies a predetermined voltage to the electrode while the gas is charged between the two electrodes installed in the enclosed space so that a glow discharge occurs, and a predetermined pattern is generated by the ultraviolet rays generated during the glow discharge. To form an image by exciting the phosphor layer formed.

In the PDP, barrier ribs forming a discharge space are formed between upper and lower plates, and at least one pair of electrodes forming a kitchen discharge or an auxiliary discharge is formed in the discharge space depending on the type of the plasma display panel.

In particular, as the demand for multimedia displays increases, the development of the PDP is further advanced, and the technology for the AC / DC PDP, which has advantages in large screen and viewing angles, has made significant progress.

The core of this PDP technology is to realize vivid image quality, and to satisfy this problem, the technology of reducing the size of the red (R: red), green (G: green) and blue (B: blue) technologies and the exact location The technique of forming the is essential. In addition, simplification of the process is essential to secure price competitiveness.

A general PDP has a structure as shown in FIGS. 1 and 2. Referring to this, a general PDP is described as follows.

It consists of the upper board 9 which is a display surface of an image, and the lower board 1 located in parallel with this upper board 9 at predetermined distance.

At this time, the lower plate is arranged in a stripe form a plurality of barrier ribs 5 forming a discharge space, and a plurality of address electrodes formed in parallel with the barrier ribs on the rear glass substrate between each barrier rib to cause discharge (2) and a phosphor layer 4 formed on an address electrode in the discharge space formed by each of the partition walls and excited by ultraviolet rays during discharge of each cell to emit visible light.

Referring to the manufacturing process of the PDP having the above configuration in the prior art in detail as follows. First, the upper plate is completed by depositing an Indium Tin Oxide (ITO) electrode as the sustain electrode 8a on the front glass substrate 9 and depositing and etching the Cr / Cu / Cr electrode as the bus line 8b.

Thereafter, after applying the dielectric layer 7 to cover the sustain electrode by using a screen printing method, the dielectric protective layer 6 is formed by about 2 m.

On the other hand, the lower plate is formed on the rear glass substrate (1) by using a screen printing method to form a plurality of partition walls and a plurality of address electrodes (2) in a stripe shape and then to form a dielectric protective layer (3) about 2㎛ thick do.

The barrier rib 5 may be repeatedly formed by screen printing, or may be formed by a sand blast after forming a pattern using a photosensitive polymer.

As an example, the process of forming the partition wall and the phosphor layer stacked by the screen printing method will be described in detail with reference to the process example shown in FIG. 3.

The barrier rib paste is first formed on the lower panel covered with the address electrode 2 and the dielectric protective layer 3 by screen printing. The first film-formed paste undergoes a drying process and then forms a barrier paste again on it. This process is repeated several times to several tens to obtain a partition paste film 101 having a height of 50 to 500 µm. (Step A) The partition paste film forms a rigid partition wall 5 through a firing step (Step B). . Finally, the phosphor paste 102 is filled between the partition walls by the screen printing method (step C), and the phosphor layer 4 is formed by the firing step (step D).

The PDP device is completed by fusion and exhaust of the upper and lower plates made as described above using sealing glass, followed by injecting and sealing an inert gas at a predetermined pressure in each discharge space.

In the PDP device formed by the above process, when a voltage is applied to the sustain electrode and a voltage is applied to the address electrode, plasma discharge occurs in a space therebetween, and the generated ultraviolet rays excite the emission center of the phosphor layer. According to the visible light we will recognize the color.

The smallest unit that emits the desired light in the display panel completed by the above process is called a fire point. One flash point consists of three cells of red (R: Red), green (G: Green), and blue (B: Blue). The size and shape of the flash point is an important factor in determining image quality, and how small and how accurately to place a phosphor in a predetermined cell determines the resolution and quality of color.

However, in the conventional technology, the phosphor layer formed by the screen printing method has a low surface luminous efficiency because of its rough surface and low density, and it is difficult to narrow the distance between cells when using the screen printing method. do. In particular, the large display of 40 inches or more due to the deflection of the screen due to gravity, the mismatch between the center and the edge of the focus is severe, which is a great difficulty in increasing the resolution.

In order to solve this problem, the method disclosed in Japanese Patent Laid-Open No. Hei 7-121056 has been developed to solve the above problem, and the substrate is formed by charging, exposing and patterning an electrophotographic photosensitive member layer having an organic photoconductive layer, As a method of forming a pattern by removing the photoconductive layer, it is a method of achieving high pattern dimension accuracy and pattern position precision.

An object of the present invention is to provide a conductive phosphor and a method for manufacturing the same used in a PDP.

In addition, another object of the present invention is to provide a method for producing a PDP patterned directly on the back glass substrate by using an electrophotographic laser beam printing method after the phosphor powder is coated with a synthetic resin so as to attract the static electricity to form a toner. have.

In addition, another object of the present invention is to provide a PDP manufacturing apparatus capable of simultaneously simplifying the process, achieving a uniform surface, high density, and high image quality of the conductive phosphor layer.

Among the above objects, the conductive phosphor of the present invention for achieving the first object is coated with various types of resins.                     

The method for producing a conductive phosphor includes a powder treatment step of using the barrier powder and the phosphor powder in a resin coating process to use the toner for laser beam printing; Heating the barrier rib powder or the phosphor powder together with the resin to be mixed; Passing the liquid mixture between cold rollers to produce a resin film comprising a bulkhead powder or a phosphor powder in a solid state; And pulverizing the resin film finely using a grinder.

The pattern forming method of the present invention for achieving the second object comprises the steps of depositing and etching the Cr / Cu / Cr electrode on the glass substrate and forming the electrode by depositing a dielectric layer by screen printing method; A first lamination process of stacking barrier ribs and a conductive phosphor layer on the dielectric layer by using an electrophotographic laser beam printing method; Heating the glass substrate on which the barrier ribs and the conductive phosphor layer are stacked; Repeating the process from the first lamination process to the heating process to repeat lamination of the barrier rib and the conductive phosphor layer; When the repeating lamination to form a pattern of the desired shape includes the step of baking and removing the resin.

The PDP pattern manufacturing apparatus of the present invention for achieving the third object comprises a laser beam scanning unit for generating a laser beam; A photosensitive drum, the surface of which is exposed by a laser beam; A developer for supplying a resin-coated barrier powder or a phosphor powder to form an image on the photosensitive drum; A plurality of rollers for transferring, pressing, and discharging the lower glass substrate; And fixing means installed in front of the photosensitive drum to heat the lower glass substrate on which the image pattern is formed so that the image pattern is firmly attached to the glass surface.

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

The conductive phosphor of the present invention, which is used as a barrier rib and a fluorescent substance, must be processed to be electrostatically capable of being used in laser printing, and for this purpose, the powders are coated with a suitable resin.

As the resin, known fixing resins can be used. Specifically, polyesters obtained by polycondensation reaction of an alcohol component and a carboxylic acid component, methyl polyacrylate, ethyl polyacrylate, butyl polyacrylate, poly Acrylic ester polymers such as 2-ethylhexyl acrylate, lauryl polyacrylate, polymethyl methyl methacrylate, polybutyl methacrylate, hexyl polymethacrylate, 2-ethylhexyl polymethacrylate, lauryl polymethacrylate, etc. Methacrylic acid ester polymers, copolymers of acrylic esters and methacrylic esters, copolymers of styrene monomers and acrylic esters or methacrylic esters, polyvinyl acetate, polypropionate vinyl, polyvinyl acetate, polyethylene and polypropylene Ethylene-based polymers and copolymers thereof, styrene butadiene Styrene copolymers such as polymers, styrene isoprene copolymers, styrene maleic acid copolymers, polyvinyl ethers, polyvinyl ketones, polyesters, polyamides, polyurethanes, rubber-like species, epoxy resins, polyvinyl butyral rosin, modified Rosin, a phenol resin, etc. can be used individually or in mixture.

The alcohol component is ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, cyclohexane dimethanol, xylene glycol, bisphenol A, bisphenol A ethylene oxide, bisphenol A propylene oxide Or dihydric alcohols or alcohol derivatives such as sorbitol and glycerin, alone or in combination.

And the carboxylic acid component is a divalent or higher carboxylic acid such as maleic acid, fumal, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, trimellitic acid, cyclopentane dicarboxylic acid, succinic anhydride, trimellitic anhydride and maleic anhydride. , Carboxylic acid derivatives, carboxylic acid anhydrides, etc. may be used alone or in combination.

Such a method for producing a conductive phosphor may include a powder treatment step of mixing the partition powder or the phosphor powder with the resin as described above in the mixing step; Mixing the partition wall or phosphor powder by heating at a temperature of 80-250 ° C. at which the resin is dissolved; Passing the heated liquid mixture between cold rollers to form a thin plate, and then lowering the temperature to produce a brittle resin film containing partition walls or phosphor powder; And pulverizing the resin film to a size of 0.1-50 μm using a general mechanical pulverizer or an air jet mill, to obtain a conductive phosphor powder coated with a resin.

The method for producing a conductive phosphor is also applicable to the production of barrier rib powder coated with a resin.

In the PDP pattern forming method using the conductive phosphor thus obtained, the partition powder and the phosphor powder toner are patterned on the back glass substrate by using a laser beam printing method.

Here, the laser beam printer prints a predetermined image on the PDP panel through a series of electrophotographic processes such as charging, exposing, developing, transferring, fixing and discharging.                     

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 4 schematically shows a laser beam printing method apparatus used in the present invention.

As shown in FIG. 4, a laser scanning unit (LSU) 302 generates a laser beam by driving a laser diode based on a video signal for a pattern of a lower plate transmitted from a video interface unit. .

The photosensitive drum 323 is rotatably installed at the center of the case, and the surface thereof is exposed by the laser beam scanned by the laser beam scanning unit during the rotation.

The developing device 311 is disposed adjacent to the photosensitive drum 323, the inside of which is filled with resin coated partition powder or phosphor powder 331 and the partition wall powder or phosphor powder resin coated with the exposed photosensitive drum 323. 331 is supplied to form an image on the photosensitive drum 323.

On the other hand, the supply roller 321 is installed in the lower portion of the developing device 311 to transfer the lower glass substrate 301.

And the pressure roller 322 is installed on the lower portion of the photosensitive drum 323 to press the lower glass substrate 301 supplied by the supply roller 321 by the resin coating barrier powder or phosphor powder on the lower glass substrate 301 The pattern of the formed image is formed.

The fixing unit 312 installed in front of the photosensitive drum 323 heats the lower glass substrate 301 on which the image pattern is formed so that the image pattern firmly adheres to the glass surface.                     

The backplate roller 324 provided in front of the fixing means discharges the glass substrate on which the pattern is formed to the outside of the case.

The apparatus for manufacturing a PDP of the present invention configured as described above has the following effects.

The laser beam scanning unit 302 generates a laser beam by driving a laser diode based on the video signal for the pattern of the lower plate transmitted from the video interface unit.

This laser beam exposes the surface of the rotating photosensitive drum 323.

At the same time, the barrier rib powder or the phosphor powder 331 coated by the developer 311 is supplied to the photosensitive drum 323 to form an image on the surface of the photosensitive drum 323.

When the lower glass substrate 301 is supplied to the photosensitive drum 323 through the supply roller 321, the surface of the lower glass substrate 301 passes between the photosensitive drum 323 and the pressure roller 322. A pattern of an image formed of the coating barrier powder or the phosphor powder is formed on the surface of the photosensitive drum 323.

The image pattern formed on the lower glass substrate 301 is heated by the fixing unit 312 and firmly adheres to the glass surface.

The lower glass substrate on which the pattern is formed is discharged to the outside of the case via the backing roller 324.

Through the above process, the glass substrate on which the primary pattern is completed is again fed to the supply roller 321 to stack the pattern through the above process.

At this time, the lamination of the pattern is performed to the desired height by the algorithm shown in FIG.

In more detail, by using a computer to operate the laser beam scanning unit to form an image pattern on the lower glass substrate as in the above-described operation, the glass substrate is completed, the primary pattern is fed back into the feed roller 321 Thus, another pattern is stacked on the primary pattern. At this time, the lamination process is analyzed by using a digital camera as a video signal, and the lamination is continuously performed until it reaches a predetermined height. The lamination is performed to a predetermined height so that the lower glass substrate is finished at a temperature of 200 to 900 ° C. To control.

As described above, the process of stacking the patterns by the electrophotographic laser beam printing method will be described in detail with reference to FIG. 6.

First, the lower glass substrate is completed by depositing and etching a Cr / Cu / Cr electrode as the address line 2 on the glass substrate 1 and forming the dielectric layer 3 by screen printing.

In the first lamination process, the barrier rib and the conductive phosphor layer are stacked on the lower glass substrate prepared by the above method using an electrophotographic laser beam printing method.

After printing the layer, a heating step is performed to induce densification of the resin layer so that the next layer is printed cleanly on the surface thereof.

In the repeated lamination step (step G and step H), the steps from the first lamination step to the heating step are repeated several times to several tens, whereby the partition wall and the conductive phosphor layer are laminated at a height of 10 to 500 µm.

In the resin removal step, when a pattern having a desired shape is formed on the lower glass substrate, the resin is baked at a temperature of 350-600 ° C. to remove the resin.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes can be made in the art without departing from the technical spirit of the present invention. It will be clear to those of ordinary knowledge.

As described above, according to the present invention, by using an electrophotographic laser beam printing method to form the barrier ribs and the conductive phosphor layers, the difficulty of the barrier ribs and the conductive phosphor layer forming process is reduced, and the barrier ribs and the conductive phosphor layers are replaced. There is an effect that can be uniformly applied to the desired position, and thereby has the effect of improving the performance of the PDP.

Claims (6)

delete delete Depositing and etching a Cr / Cu / Cr electrode on the glass substrate and forming a dielectric layer by screen printing to form an electrode; A first lamination process of stacking barrier ribs and a conductive phosphor layer on the dielectric layer by using an electrophotographic laser beam printing method; Heating the glass substrate on which the barrier ribs and the conductive phosphor layer are stacked; Repeating the process from the first lamination process to the heating process to repeatedly stack the partition walls and the conductive phosphors; Forming a pattern of a plasma display panel comprising the step of firing and removing the resin when the pattern of the desired shape by repeating the lamination. The method of claim 3, wherein The pattern forming method of the plasma display panel in the step of repeating lamination, the pattern is repeated by taking a picture with a camera while checking the stacking height of the partition and the conductive phosphor layer. A laser beam scanning unit for generating a laser beam by driving a laser diode based on a video signal of a pattern of a lower plate transmitted from the video interface unit; A photosensitive drum rotatably installed in the center of the case, the surface of which is exposed by a laser beam scanned by the laser beam scanning unit during rotation; A developer disposed adjacent to the photosensitive drum, filled with resin coated partition powder or phosphor powder therein, and supplying the resin coated partition powder or phosphor powder to the exposed photosensitive drum to form an image on the photosensitive drum. ; A plurality of rollers for transferring or pressing the lower glass substrate to form an image pattern of barrier rib powder or phosphor powder on the lower glass substrate or to discharge the lower glass substrate on which the image pattern is formed; And And a fixing unit installed in front of the photosensitive drum to heat the lower glass substrate on which the image pattern is formed so that the image pattern is firmly attached to the glass surface. The method of claim 3, wherein the conductive phosphor layer is polyester which can be obtained by polycondensation reaction of an alcohol component and a carboxylic acid component; Acrylic ester polymers selected from the group consisting of methyl polyacrylate, ethyl polyacrylate, butyl polyacrylate, 2-ethyl hexyl polyacrylate, and lauryl polyacrylate; Methacrylic acid ester polymers selected from the group consisting of poly methyl methacrylate, butyl poly methacrylate, hexyl poly methacrylate, 2-ethyl hexyl polymethacrylate, and lauryl polymethacrylate; Copolymers of acrylic esters with methacrylic acid esters; Copolymers of styrene monomers with acrylic or methacrylic esters; Ethylene-based polymers and copolymers thereof selected from the group consisting of polyvinyl acetate, polyvinyl propionate, polyvinyl butyrate, polyethylene and polypropylene; Styrene-based copolymers selected from the group consisting of styrene butadiene copolymers, styrene isoprene copolymers, and styrene maleic acid copolymers; Polyvinyl ethers; Polyvinyl ketones; Polyamides; Polyurethane; Rubber; Epoxy resins; Polyvinyl butyral rosin; Denatured rosin; And a resin prepared by mixing one or more selected from the group consisting of phenolic resins.

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