KR200171433Y1 - A phosphor fixed-quantity supplying system of developing device for manufacturing a dry-type electro-photographical screen of crt - Google Patents

Abstract

The present invention provides a phosphor quantitative supply system of a developing device for producing a dry electrophotographic screen of a cathode ray tube.

The phosphor quantitative supply system of the developing apparatus charges the inner surface of the panel 12 on which the volatile conductive film 132 and the photoconductive film 134 are formed with a predetermined electrostatic charge and supplies the shadow mask 16 with a charge latent image of a predetermined arrangement. After exposure through, a dry electrophotographic screen of a cathode ray tube for attaching phosphor powders charged at the discharge electrode 144a in the developing container 142 and sprayed by air pressure at the nozzle 144b in an arrangement structure of the latent charge image thereof. A phosphor supply apparatus for a developing process, comprising: a hopper 148 in which phosphor powder is stored; A load cell 151 supporting the hopper 148 to generate a weight signal according to the weight; By rotating the screw 149 of the tongue powder in the hopper 148 connected to the lower portion of the hopper 148 by the variable speed motor 150, the phosphor powder is transferred to the phosphor supply pipe 147 via the venturi tube 146. Feeding means (146, 149, 150) for feeding; And the controller for controlling the variable speed motor 150 of the feeding means (146, 149, 150) at a relatively low speed when the weight is large, and a relatively high speed when the weight is low, according to the weight signal of the load cell 151 ( 152).

Accordingly, the supply of the phosphor powder can be varied according to the weight of the phosphor powder remaining or newly added to the hopper 148 storing the phosphor powder in the developing step, thereby feeding the quantitative phosphor powder regardless of the pressure. There is an effect that the supply of the phosphor powder and the developing density can be made uniform.

Description

Phosphor Determination Supply System of Developing Device for Dry Electrophotographic Screen Manufacturing of Cathode Ray Tube

The present invention relates to a quantitative supply system of phosphors in a developing apparatus for manufacturing a dry electrophotographic screen of a cathode ray tube, and more particularly, from a hopper regardless of the pressure of phosphor powder in a hopper in a developing process of a dry electrophotographic screen manufacturing process. A fluorescent material quantitative supply system of a developing device for producing a dry electrophotographic screen of a cathode ray tube capable of uniformly supplying phosphor powder to a nozzle via a phosphor supply pipe.

In general, a cathode ray tube, as shown in FIG. 1, has a vacuum bulb divided into a panel 12, a funnel 13 and a net 14, and a neck 14 thereof. An electron gun 11 mounted therein and a shadow mask 16 mounted on the side wall of the panel 12 are provided.

A fluorescent surface 20 is formed on the inner surface of the face plate 18 of the panel 12, and the electron beams 19a and 19b emitted from the electron gun 11 are focused and accelerated by various lens systems, and the anode button 15 It is greatly accelerated by the high voltage applied through the deflection yoke (17) and deflected by the deflection yoke (17) and passed through the apertures or slits (16a) of the shadow mask (16) to the fluorescent surface (20).

The fluorescent surface 20 is formed on the back surface of the face plate 18. In the case of the color, as shown in FIG. 2, a plurality of stripe or dot-shaped phosphors R, G, and B in a constant arrangement structure are shown. ) And a light absorbing material such as a black coating between the respective phosphors. In addition, the rear surface of the aluminum thin film layer 22 is formed as a conductive film layer, which serves to increase the luminance of the fluorescent surface, to prevent ion damage of the fluorescent surface, and to prevent the potential drop of the fluorescent surface. In addition, in order to improve the top view and reflectance of the aluminum thin film layer 22, a resin film layer 22 'made of a resin such as lacquer is formed between the fluorescent surface 20 and the aluminum thin film layer 22, which is a conductive film layer. This resin film layer 22 'is combusted and volatilized for the life of the tube after formation of the aluminum thin film layer 22.

The conventional photolithographic wet process in which the fluorescent surface 20 is formed by applying and drying a suspension containing fluorescent particles such as a chromophoric phosphorus component or a suspension containing a light absorbing material is high quality. Not only does it not meet the requirements, but the manufacturing process and manufacturing equipment is complicated, the manufacturing cost is large, and also has a number of problems, such as the consumption of a large amount of correction water, wastewater generation, phosphorus emissions, hexavalent chromium photoreceptor discharge. Recently, an electrophotographic screen manufacturing method has been developed that improves the wet photolithography. In this electrophotographic manufacturing method, the wet still has the above-mentioned problems. It was considerably resolved.

A representative dry electrophotographic screen manufacturing method is disclosed in US Pat. No. 4,921,767 (patented May 1, 1990). However, in the patent, since the photoconductive film contains a dye which reacts with visible light, darkroom operation is inevitable, and energy consumption is considerable because it is caused by infrared heating in the fixing step.

Accordingly, the present applicant solved the above problem by forming the photoconductive film into a photoconductive solution sensitive to ultraviolet rays.

As an example, the following describes the "method of manufacturing a cathode ray tube" filed by the present applicant.

3a to 3e schematically show each process according to the manufacturing method. 3A illustrates a coating process in which the conductive film 132 and the photoconductive film 134 are formed on the inner surface of the face plate 18. The conductive film 132 is a polyelectrolyte, for example, which is a conventional solution of 1-50% by weight of Catfloc-c and 1-50% by weight of 10% PVA solution (water remaining) manufactured by Calgon. It is formed by application and drying by a method. A new photoconductive coating solution containing a substance reacting with ultraviolet rays is applied thereon and dried. One example of a material that reacts to ultraviolet radiation is as a donor 0.01 to 1% by weight of bis dimethyl phenyl diphenyl butatriene (bis-1,4-dimethyl phenyl (-1,4-diphenyl (butatriene))) or 0.01 to 2% by weight of at least one of tetraphenyl ethylene and at least one of trinitro-fluorenone (TNF) and ethyl anthrquinone (EAQ) each as an acceptor 1% by weight was used by dissolving 1 to 30% by weight of polystyrene (PS) as a polymer binder in toluene or xylene, which is the remaining amount. In addition to the polystyrene as the polymer binder (poly (α-methylstyrene: PAMS), polymethyl methacrylate (PMMA) and polystyrene-oxazoline copolymer (polystryrene-oxazoline copolymer: PS-) OX) and the like can be used.

3b schematically shows a charging process. A DC voltage of + 1K volts or less, preferably +700 volts or more was applied to charge the corona discharge device. Since the photoconductive film 134 reacts with ultraviolet rays having a wavelength of at least 450 nm or less, darkroom work is unnecessary.

3C schematically shows an exposure process, in which ultraviolet light having a short wavelength and straightness from the ultraviolet light source 138 passes through the ultraviolet transmission lens 140 and enters the shadow mask 16 at a desired angle of incidence. The photoconductive film 134 is exposed in a desired arrangement through an aperture or a slit 16a hole of the shadow mask 16 having an arrangement of. At this time, the conductive film 132 is earthed, and the charge of the exposed portion is discharged through the conductive film 132. The 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 a dark room.

3d schematically shows a developing process. Conventionally, in this development step, the carrier beads and the phosphor particles or the light absorbing material particles are mixed to charge static electricity by friction, but according to the inventors' design, the fine powder, such as the powder of the phosphor powder or the light absorbing material, by air pressure From the hopper 148 through the venturi tube 146 through the discharge electrode 144a, such as a corona discharge device and the nozzle 144b, the fine powder is charged and the exposed portion of the photoconductive film 134 and the non-exposure. Attach to either part. The polarity of the static electricity charged by the fine electrode by the discharge electrode 144a is determined by whether the fine powder is attached to the exposed portion or the unexposed boron powder in the exposure process. In other words, the fine powder is charged to -charge when attached to the non-exposed portion that is positively charged, and the fine powder is charged to + charge when attached to the exposed portion where the charge is released. The charged fine powder injected into the developing container 142 is strongly attached to the surface of the photoconductive film 134 in a desired arrangement by the action of electrical attraction and repulsive force.

Figure 3e schematically illustrates a fixing process using a liquid electrostatic spray gun. In this step, petroleum-based xylene, toluene, TCE, methyl isobutyl ketone (MIBK) are formed on the surface of the photoconductive film 134 in which the desired fine powder (s) are attached in a desired arrangement in the developing step. By spraying a solvent such as), at least the polymer contained in the photoconductive film 134 is dissolved, and the micropowder (s) attached by the action of electric force by the adhesive force of the dissolved polymer are fixed. In this fixing step, a vapor swelling method may be used in which solvent vapors such as acetone and methyl isobutyl ketone are contacted to fix the developed fine powder.

The above-described processes are repeated for three kinds of phosphors for the production of the color cathode ray tube. In addition, the light absorbing material of the black matrix may be formed as described above before or after the attachment of the three phosphors.

After the phosphor and the light absorbing material are formed, the lacquer film is formed by the conventional method in the lacquer process, and the aluminum thin film is formed by the conventional method in the anodizing process, and then, is introduced into the baking process in the air. By heating and drying at 425 ° C. for about 30 minutes, volatile components such as the conductive film 132, the photoconductive film 134, and a solvent present in each phosphor and lacquer are removed, and the light absorbing material 21 and each phosphor R, A fluorescent surface 20 is obtained in which G and B are formed as in FIG.

When the phosphor powder is injected from the hopper 148 to the nozzle 144b via the venturi tube 146 as in the developing process of FIG. 3d, the phosphor particles are charged to the phosphor particles by the discharge electrode 144a to charge the phosphor powder. A methyl methacrylate primary film and a polyacrylamide secondary film are formed. However, in the process, as in the developing process of FIG. 3D, the phosphor powder is supplied from the hopper 148 to the phosphor supply pipe 147 by the pressure of air through the venturi tube 146, and thus, in the hopper 148 Since the phosphor powder is reduced, the pressure of the phosphor powder acting on the venturi tube 146 also changes, so that the amount of the phosphor powder supplied is changed despite the constant air pressure, resulting in uneven development density.

Accordingly, the present invention has been made to solve the above-mentioned problems, and in the developing process of a dry-printed screen manufacturing process, regardless of the pressure of the phosphor powder in the hopper, the phosphor powder may be constantly supplied to the nozzle through the phosphor supply pipe from the hopper. An object of the present invention is to provide a system for quantitatively supplying phosphor of a developing device for manufacturing a dry electrophotographic screen of a cathode ray tube.

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

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

3A to 3E are schematic views for explaining a dry electrophotographic screen manufacturing method.

Figure 4 is a cross-sectional view showing the configuration of the phosphor quantitative supply system of the developing apparatus according to an embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

10 cathode ray tube (CRT) 11 electron gun

12: panel 13: funnel

14 neck 15 anode button

16: shadow mask 17: deflection yoke

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

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

22: aluminum thin film layer 36: charging device

132: conductive film 134: photoconductive film

138: light source 140: lens

142: developing container 144a: discharge electrode

144b: Nozzle 146: Venturi tube

147: phosphor supply pipe 148: hopper

150: variable speed motor 151: load cell

152: controller 153: replenishment tank

154: on-off valve

In order to achieve the above object, the present invention is to charge the inner surface of the panel on which the volatile conductive film and the photoconductive film are formed under a predetermined electrostatic charge, and expose the charge latent image of a predetermined arrangement through a shadow mask, and then charge the discharge electrode in the developing container. A phosphor supplying apparatus for a dry electrophotographic screen developing process of a cathode ray tube for attaching a phosphor powder sprayed by air pressure at a nozzle into an array of latent charge images thereof, comprising: a hopper in which phosphor powder is stored; A load cell supporting the hopper to generate a weight signal according to the weight; A feeding means connected to a lower portion of the hopper to feed the phosphor powder in the hopper by rotating the screw by a variable speed motor to feed the phosphor powder to the phosphor supply pipe through the venturi tube; And a controller for controlling the variable speed motor of the feeding means at a relatively low speed when the weight is large, and at a relatively high speed when the weight is low according to the weight signal of the load cell. Provided is a phosphor quantitative supply system of a developing device for screen production.

In this case, the venturi tube is hermetically inserted into the phosphor supply pipe so that the hopper moves up and down with respect to the load cell, thereby ensuring the action of the load cell, or double the hopper and interposing the load cell between the inner and outer hoppers.

A replenishment tank having an on / off valve may be installed at the top of the hopper, in which case the on / off valve of the replenishment tank is controlled by the controller by the lowest weight signal of the load cell to maintain the phosphor powder at the lowest level of the hopper. Can be.

Hereinafter, with reference to the drawings will be described a preferred embodiment of the present invention.

4 is a diagram illustrating a phosphor quantitative supply system of a developing apparatus according to an embodiment of the present invention in which phosphor powder is supplemented to a hopper 148.

In FIG. 4, the fluorescent substance supply system of the developing apparatus includes a hopper 148, a load cell 151, feeding means 146, 149, 150, and a controller 152, and further includes a supplement tank 153 thereon. have.

Phosphor powder is stored inside the hopper 148 and the load cell 151 is configured to support the hopper 148 to generate a weight signal according to the weight.

The feeding means 146, 149, 150 are connected to the lower portion of the hopper 148 to rotate the phosphor powder in the hopper 148 by the variable speed motor 150 to rotate the screw 149 through the venturi tube 146. It is configured to supply to the phosphor supply pipe 147, the controller 152 drives the variable speed motor 150 at a relatively low speed when the weight is heavy in accordance with the weight signal of the load cell 151, when the weight is light Control to drive the variable speed motor 150 of the feeding means (146, 149, 150) at a relatively high speed. The variable speed motor 150 may be, for example, a pulse motor. In this case, a desired speed change can be obtained by converting the output of the load cell 151 into an appropriate digital value in the controller 152 and outputting the corresponding pulse number in the controller 152.

In addition, when the replenishment tank 153 having the on-off valve 154 is installed on the upper portion of the hopper 148, by the lowest weight signal of the load cell 151 to maintain the phosphor powder of the lowest level of the hopper 148 The closing valve 154 of the replenishment tank 153 may be configured to be controlled by the controller 152.

Meanwhile, in order to ensure the action of the load cell 151, the venturi tube 146 is airtight through the sealing member 147 ′ in the phosphor supply pipe 147 so that the hopper 148 moves up and down with respect to the load cell 151. Although not shown in the drawing, the hopper 148 may be doubled and the load cell 151 may be interposed therebetween so that a weight signal according to the weight change of the phosphor in the hopper 148 may be generated.

Also, as in FIG. 4, a mixer 148 'may be provided. In this case, the mixer 148 'prevents the aggregation or solidification of the phosphor in the hopper 148 and facilitates the smooth supply of the phosphor.

The operation of the phosphor quantitative supply system of the developing apparatus according to the embodiment of the present invention configured as described above is as follows.

Referring to FIGS. 3A to 3E, the shadow mask 16 is charged with a predetermined electrostatic charge by charging the inner surface of the panel 12 on which the volatile conductive film 132 and the photoconductive film 134 are formed with a predetermined electrostatic charge. After exposing through, and then loaded onto the developing container 142, the dry phosphor powder is supplied from the hopper 148 to the discharge electrode 144a at a constant flow rate through the venturi tube 146 and the phosphor supply tube 147, The discharge electrode 144a is charged with positive charge and sprayed to the panel 12 disposed upward through the nozzle 144b.

In this way, when the weight signal from the load cell 151 changes as the phosphor powder in the hopper 148 is reduced, the variable speed motor 150 is configured to gradually rotate at high speed in the controller 152.

On the other hand, when the amount of the phosphor powder in the hopper 148 is less than the predetermined level, to open the on-off valve 154 by the controller 152 to replenish the phosphor powder into the hopper 148 to replenish a certain amount of phosphor. When the maximum weight signal from the load cell 151 is input, the replenishment is completed by closing the open / close valve 154 by the controller 152. Such replenishment is preferably carried out at the time of unloading of the panel 12 which does not supply the phosphor, for the quantitative supply of the phosphor.

In this way, the speed of the feeding means 146, 149, 150 is varied by the controller 152 according to the storage amount of the phosphor powder in the hopper 48, that is, the pressure, and the amount of the phosphor supplied to the phosphor supply pipe 147 is determined. Irrespective of the amount of phosphor in the hopper 148, it can be supplied in a quantitative manner.

As described above, according to the configuration and operation of the phosphor quantitative supply system of the developing apparatus for manufacturing a dry electrophotographic screen of a cathode ray tube according to an embodiment of the present invention, the load cell 151 for sensing the amount of phosphor stored in the hopper 48 And the speed of the transfer screw 149 by the controller 152 according to the storage amount, the pressure can be changed to be able to uniformly supply the phosphor to the phosphor supply pipe 147, thereby making it possible to make the development density uniform. .

While preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes will be possible to those skilled in the art from the description of the claims.

Claims (3)

After the inner surface of the panel 12 on which the volatile conductive film 132 and the photoconductive film 134 are formed is charged with a predetermined electrostatic charge and exposed through the shadow mask 16 as a charge latent image having a predetermined arrangement, the developing container 142. In the phosphor supply apparatus of the developing apparatus for manufacturing a dry electrophotographic screen of a cathode ray tube for attaching a phosphor powder charged at an inner discharge electrode 144a and sprayed by air pressure at a nozzle 144b in an arrangement of its latent images: A hopper 148 in which phosphor powder is stored; A load cell 151 supporting the hopper 148 to generate a weight signal according to the weight; The phosphor powder in the hopper 148 connected to the lower portion of the hopper 148 is rotated by the variable speed motor 159 to rotate the screw 149 to feed the phosphor powder through the venturi tube 146 to the phosphor supply pipe 147. Feeding means (146, 149, 150); And In accordance with the weight signal of the load cell 151 includes a controller 152 for controlling the variable speed motor 150 of the feeding means 146, 149, 150 at a relatively low speed when the weight is large, at a relatively high speed when the weight is low Phosphor quantitative supply system of a developing device for producing a dry electrophotographic screen of a cathode ray tube. The minimum weight of the load cell 151 according to claim 1, wherein a replenishment tank 153 having an opening / closing valve 154 is installed at an upper portion of the hopper 148 to maintain a phosphor powder of the lowest level of the hopper 148. The opening and closing valve 154 of the replenishment tank 153 is controlled by the controller 152 by a signal, the quantitative phosphor supply system of a developing device for producing a dry electrophotographic screen of a cathode ray tube. The dry type cathode tube according to claim 1 or 2, wherein the venturi tube 146 is hermetically inserted into the phosphor supply tube 147 so that the hopper 148 moves up and down with respect to the load cell 151. Phosphor quantitative supply system of developing device for electrophotographic screen production.