JPH10261363A - Coating method of inner conductive graphite film for cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating method of an inner conductive graphite film for a cathode-ray tube, for forming a conductive graphite coating film of such uniform thickness as not to cause thin and puddles of its graphite solution, its peeling and the falling-off its pieces, with the use of relatively simple equipment. SOLUTION: A coating method of an inner conductive graphite film for a cathode-ray tube coats the inner surface of a funnel part 11 with a neck part 12 welded thereto with an inner conductive graphite film with the use of coating tools. Concretely, the coating method forms an inner conductive graphite film for a cathode-ray tube, through a first process of charging any one of coating rollers 41 to 43 as the coating tools, typically the roller 41 in this case, with a graphite solution, a second process of bringing the roller 41 into contact with the inner surface of the funnel part 11 at a coating region, a third process of moving the roller 41 rotated along the coating region on the inner surface of the funnel part 11 to coat the region with a graphite film, and a fourth process of doing the first to third processes repeatedly to regions not yet to be coated on the inner surface of the funnel part 11 .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for coating an inner conductive graphite film of a cathode ray tube, and more particularly, to a method of manufacturing a cathode ray tube, in which a funnel portion having a neck portion welded to a funnel portion has a uniform thickness. The present invention relates to a method for coating a conductive graphite film inside a cathode ray tube, which applies a graphite conductive graphite film which does not cause any substantial separation.

[0002]

2. Description of the Related Art Generally, a process for manufacturing a cathode ray tube includes:
A step of applying a graphite liquid to the inner surface of the funnel portion to which the neck portion is welded, and applying a conductive graphite film for conductively connecting the anode button led out to the side surface of the funnel portion and the anode electrode of the electron gun housed in the neck portion. There is.

[0003] In this case, in a known cathode ray tube, when a graphite liquid is applied to the inner surface of the funnel and a conductive graphite film is formed, the gas absorption and emission are compared with the coating area near the panel on the inner surface of the funnel. A graphite liquid containing graphite with very low properties is applied, and the coating area near the neck of the inner surface of the funnel contains graphite, which has relatively high gas absorption and release but high strength of the coating film. It is common practice to apply the obtained graphite liquid to form conductive graphite films having different characteristics at two locations on the inner surface of the funnel portion.

By the way, the step of applying a graphite liquid to the inner surface of the funnel portion and depositing the conductive graphite film is performed by a kind of a closed type in which the applied region of the conductive graphite film to be deposited is surrounded by a glass bulb called the inner surface of the funnel portion. Since it is a special area where the inner surface of the funnel is almost funnel-shaped, it is difficult to apply a graphite liquid to form a conductive graphite film. An apparatus or a general-purpose conductive graphite film coating / forming method cannot be used as it is.

For this reason, conventionally, as a method of applying a graphite liquid to the inner surface of the funnel portion to form a conductive graphite film, a brush made of a sponge or the like is used, and the graphite liquid is sequentially applied to the application region of the inner surface of the funnel portion by the brush. Coating method using a brush (first coating method), and a spray method in which a graphite liquid is applied to a coating area on the inner surface of the funnel while spraying the graphite liquid from the spray apparatus in order using a spray device ( Second coating method), a flow coating method (third coating method) in which a graphite liquid is caused to flow along the coating area on the inner surface of the funnel portion, and the graphite liquid is applied to the coating area, and the like have been adopted.

[0006]

The first known coating method can easily cope with a case where a conductive graphite film is formed on a small amount of a cathode ray tube, and the like.
Although it has the advantage that the equipment cost of the conductive graphite film coating and forming device can be reduced, the formed conductive graphite coating film has a relatively large amount of blurred portions and pools, and a uniform thickness of conductive graphite coating. There is a problem that considerable skill is required when forming a film.

In the second known coating method, the equipment of the conductive graphite film coating and forming apparatus can be similarly simplified.
Although it has the advantage of being able to form a conductive graphite coating film having a uniform thickness, graphite is particularly suitable for frit seal surfaces that require confidentiality in order to maintain a vacuum state in a cathode ray tube. There is a problem that it is difficult to block the spray of the liquid and the efficiency of adhering the graphite liquid to the inner surface of the funnel portion is relatively low.

Further, the third known coating method can form a conductive graphite coating film having a uniform thickness, and can obtain a cathode ray tube having a relatively high quality with respect to the conductive graphite coating film. There is a problem that the adhesion efficiency of the graphite liquid to the inner surface of the funnel portion is low, and it is difficult to appropriately cope with the case where two types of conductive graphite coating films having different characteristics are formed on the inner surface of the funnel portion.

The present invention has been made to solve these problems. It is an object of the present invention to use relatively simple equipment, to prevent the graphite liquid from being blurred or accumulated, to prevent the peeling of the film and the falling of the film fragments, An object of the present invention is to provide a method for coating a conductive graphite coating inside a cathode ray tube, which can form a conductive graphite coating film having a uniform thickness.

[0010]

In order to achieve the above object, the present invention provides a method for coating a conductive graphite film on a cathode ray tube, wherein a coating roller is used as a coating tool and a graphite liquid is filled in the coating roller. The second step of contacting the application roller filled with the graphite liquid with the application area on the inner surface of the funnel section, and moving the applied roller while rotating along the application area on the inner surface of the funnel section to apply the graphite film on the application area Means for applying a conductive graphite coating film on the inner surface of the funnel portion to which the neck portion has been welded, through a third step, a fourth step of sequentially performing the first to third steps on the non-application region on the inner surface of the funnel portion. Is provided.

[0011] According to the above means, the coating roller filled with the graphite liquid is brought into contact with the coating area on the inner surface of the funnel portion by using the coating roller as the coating tool, and the coating roller is rotated along the coating area on the inner surface of the funnel portion while rotating the coating roller. Since it is moved and the graphite film is applied to the application area, the occurrence of blurring and pooling is remarkably reduced as compared with the case where a brush is used for the application device as before, and the conductive graphite coating film with a uniform film thickness Can be formed, and it is only necessary to use simple coating equipment.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION In the embodiment of the present invention, a method for coating an interior conductive graphite film of a cathode ray tube is to apply an interior conductive graphite film using an application tool to an inner surface of a funnel portion to which a neck portion is welded. Then, using an application roller for the application device, first, a first step of filling the application roller with graphite liquid, then a second step of contacting the application roller filled with graphite liquid with the application area on the inner surface of the funnel portion, A third step of applying the graphite film to the application area by rotating the contacting application roller along the application area on the inner surface of the funnel while rotating the application roller; The interior conductive graphite film is applied to the inner surface of the funnel through a fourth step of sequentially executing the steps from the third step to the third step.

In one preferred embodiment of the present invention, the moving speed of the application roller in the third step is selected to be 2 to 50 cm / sec.

In another preferred embodiment of the present invention, the application roller has an effective width of 50 to 100 mm.

According to these embodiments of the present invention, a general-purpose application roller is used as an application device, and the application roller filled with the graphite liquid is brought into contact with the application region on the inner surface of the funnel portion, and the contacted application roller Is rotated and moved along the coating area on the inner surface of the funnel part, so that the coating area is coated with a graphite film.
Uniform film with less blurring and pooling compared to using a brush as an applicator, and with no partial peeling of the film or partial falling of film fragments It is possible to form a thick conductive graphite coating film, and furthermore, it is possible to form a conductive graphite coating film by using a simple configuration of coating equipment.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic structural view showing a state in which a method for applying an inner conductive graphite film of a cathode ray tube according to the present invention is performed.

[0018] In FIG. 1, 1 is a glass bulb, 1 ₁ funnel, 1 ₂ a neck portion, 2 is a glass bulb holder, 3 is conductive graphite film coating apparatus, 3 ₁ the control unit, 4 ₁ first the application roller, 4 ₂ and the second coating roller 4 ₃ the third coating roller, 5 ₁ a first rotary drive shaft, 5 ₂ and the second rotary drive shaft, 5 ₃ third rotary drive axis, graphite-liquid tank 6, 6 ₁ impregnation roller 7 wringer, 7 ₁ is squeezing rollers.

[0019] Then, the glass bulb 1 is obtained by welding the elongated cylindrical neck portion 1 ₂ to the small diameter opening side of the funnel portion 1 ₁ of the substantially funnel-shaped glass bulb holder 2, the neck portion 1 ₂ holding large diameter opening side of the funnel portion 1 ₁ of the glass bulb 1 is arranged opposite to the conductive graphite film applicator 3. Conductive graphite film coating apparatus 3 includes a control unit 3 _1, attached to the first rotational end of the drive shaft 5 ₁ movable in any direction within a predetermined range, the rotation of the first rotary drive shaft 5 ₁ First coating roller 4 having the largest diameter which rotates with the rotation
₁ and, likewise attached to the second rotary drive shaft 5 _{and second} end movable in any direction within a predetermined range, the larger diameter to the next rotating with the rotation of the second rotary drive shaft 5 ₂ a second coating roller 4 _2, likewise mounted in any direction in the third end of the rotary drive shaft 5 ₃ that can be moved within a predetermined range, rotating with the rotation of the third rotary drive shaft 5 ₃ consist third coating roller 4 ₃ which the smallest diameter of the.
Graphite liquid tank 6, inside, with a graphite liquid is filled, rotatable impregnating roller ₆₁ is arranged, restrictor 7
Includes a squeezing rollers 7 _1.

In the above configuration, the conductive graphite coating film according to the present embodiment is applied through the following steps.

First, the neck 1 _{2 is connected} to the funnel 1 ₁
The glass bulb 1 welded to the neck is inserted into the holding part of the glass bulb holder _{2 with} the neck ₁₂ side of the glass bulb 1.
Is held by the glass bulb holder 2.

Next, the controller 3 _{1 of the} conductive graphite film coating device 3
The control of the first to third rotary drive shaft 5 ₁ to 5
One rotating drive shaft either in the _3, for example, to drive the first rotary drive shaft 5 _1, drawer glass bulb 1 side first coating roller 4 ₁ of a conductive graphite film coating apparatus 3,
It is moved onto the graphite liquid tank 6.

[0023] Next, the control of the control unit 3 _1, first
Of the application roller 4 ₁ in a state in contact with the impregnation roller 6 _1, first coating roller 4 ₁ is rotated via the first rotary drive shaft 5 _1, first by contact rotation between impregnation rollers 6 ₁ to the coating roller 4 ₁ is impregnated with graphite solution.

[0024] Subsequently, the control of the control unit 3 _1, first
After moving on to the application roller 4 ₁ wringer 7, the first coating roller 4 ₁ rotating in the squeezing rollers 7 ₁ contact at a predetermined pressure, is impregnated into the first coating roller 4 ₁ Remove excess graphite liquid.

[0025] Next, the control of the control unit 3 _1, first
Moving the application roller 4 ₁ to the application point of the predetermined graphite liquid glass funnel portion 1 ₁ inner surface of the valve 1 remains in a state of being rotated, is brought into contact with a portion of the coating portion.

[0026] Subsequently, the control of the control unit 3 _1, the first
In a state in which the application roller 4 ₁ is rotated and contacted, it is moved along the coating portion of the funnel portion 1 ₁ inner surface to form a conductive graphite coating film on the coated portion.

[0027] At this time, the funnel portion 1 ₁ in the coating portion of the graphite liquid of the inner surface, a large first coating roller diameter 4 ₁
Than was used, if there is a coating portion as difficult formation of a uniform film thickness of the conductive graphite coating film, the control of the control unit 3 _1, the first coating roller 4 ₁ conductive graphite film coating device pulled back 3 side, one of the rotary drive shaft or in the second and third rotary drive shaft 5 ₂ to 5 _3, for example, third
Of the rotary drive shaft 5 ₃ drives the third application roller 4 ₃
Is drawn out from the conductive graphite film coating device 3 toward the glass bulb 1 and moved onto the graphite liquid tank 6.

Next, as in the previous case, the control unit 3 ₁
The control of, the third state of the coating roller 4 ₃ is brought into contact with the impregnating roller 6 _1, by rotating the first coating roller 4 ₃ via the third rotating shaft 5 _3, and impregnation rollers 6 ₁ the contact rotating impregnated graphite solution to the third application roller 4 _3.

[0029] Then, the control unit 3 by the _first control, the third
After moving on to the application roller 4 ₃ wringer 7, a third coating roller 4 ₃ rotating in the squeezing rollers 7 ₁ contact at a predetermined pressure, is impregnated into the third coating roller 4 ₃ Remove excess graphite liquid.

[0030] By Subsequently, the control of the control unit 3 _1, 3
Move to the coating position of the coating roller 4 ₃ predetermined graphite liquid remains of the glass bulb 1 funnel portion 1 ₁ inner surface of while rotating the, into contact with the portion of the coating portion.

[0031] Then, the control unit 3 by the _first control, the third
The application roller 4 ₃ while rotating and contacting, is moved along the predetermined coating positions of the funnel portion 1 ₁ inner surface,
A conductive graphite coating film is formed at the coating location.

[0032] Hereinafter, in the coating portion of the graphite solution of the funnel portion 1 ₁ inner surface, than using the first coating roller 4 ₁ and the third application roller 4 ₃ small diameter large diameter,
When formation of a uniform film thickness of the conductive graphite coating film had remained coated portion such as hard, the control of the control unit 3 _1, 3
A coating roller 4 ₃ pullback conductive graphite film coating apparatus 3, by driving the second rotary drive shaft 5 _2, the remaining second coating roller 4 ₂ from conductive graphite film applicator 3 in the glass bulb 1 side drawer, through the same circumstances as in the above, to form a conductive graphite coating film remaining coating portion of the funnel portion 1 ₁ inner surface.

Here, the first to third application rollers 4 ₁
To 4 ₃ either the application roller in, for example, the first
Of when the application roller 4 to form ₁ a conductive graphite coating film using, first only it was performed coating of graphite solution, if such is not possible to apply the whole of the predetermined coating area, the control of the control unit 3 _1, the after coating a portion of application region, the first coating roller 4 ₁ is impregnated with graphite solution to the first coating roller 4 ₁ again returned to the graphite-liquid tank 6 side, coating graphite solution is carried out for the remaining coated area using the first coating roller 4 ₁ impregnated with this graphite solution.

The application of the graphite liquid to the remaining application area using the _first application roller 41 is not necessarily performed only once, but may be performed twice as appropriate according to the state of the remaining application area. The above may be performed separately.
In addition, not limited to the case of applying the graphite liquid using a first coating roller 4 _1, at all if the second coating roller 4, _second or third coating roller 4 ₃ using coated graphite solution Is the same.

Furthermore, two types having different properties of graphite graphite solution, when applied to two application areas with different funnel portion 1 ₁ inner surface, for example, of one type in the first coating roller 4 ₁ graphite was impregnated with, was applied to one application area of the funnel portion 1 ₁ inner surface, then, for example, the third application roller 4 ₃ impregnated with other types of graphite solution, the funnel portion 1 ₁ inner surface other of What is necessary is just to apply to the application area.

By the way, in the practice of the interior conductive graphite film coating method such a cathode ray tube, the moving speed at the time of a graphite liquid coating according to the first to third coating roller 4 ₁ to 4 _3, 2 to the range of 50 cm / sec It is preferable to select so that That is, the moving speed at the time of a graphite liquid coating according to the first to third coating roller 4 ₁ to 4 _3, 2 cm / se
If less than c, conductive graphite film productivity is deteriorated at the time of application, on the contrary, if more than 50 cm / sec, during application of the graphite solution, the first to third coating roller 4 ₁ to 4 ₃ slip It becomes easier and, as with normal brushing,
Blur or reservoir to the formed conductive graphite film become occurs simultaneously, the first to third coating roller 4 ₁ to 4 ₃
The graphite droplets are scattered with the rotation of.

Further, the viscosity of the graphite solution to be applied by the first to third coating roller 4 ₁ to 4 _3, approximately 30mP
It is preferable to set to a · s. That is, when the viscosity of the graphite solution is less than 30 mPa · s, a conductive graphite layer formed is liable to be thin in order to avoid this, 4 ₁ to relatively large graphite solution first to third application roller 4 ₃ If so impregnate the, easily sag graphite solution, conversely, becomes more than 30 mPa · s, the first time a graphite liquid coating
In addition, the rotation of the third coating rollers 4 _{1 to} 4 ₃ may not be performed smoothly, or the formed conductive graphite film may be too thick.

Further, the first to third application rollers 4 ₁
The roller width of 4 to ₃ is the _{first on the} inner surface of the funnel 11.
It is preferable that the width is selected so that the third to third application rollers 4 _{1 to} 4 ₃ come into uniform contact. The width is usually in the range of 20 to 200 mm, depending on the shape of the cathode ray tube for forming the conductive graphite film. The preferred example is 50
The distance may be in the range of 100 to 100 mm.

In addition, the first to third application rollers 4
The material of ₁ to 4 _3, those of sponge material or a material which Ruishi it is preferable. In particular, as the coating roller for coating the conductive graphite film in the neck portion 1 ₂ side of the funnel portion 1 _1, a diameter of the diameter neck 1 ₂ 1
It is preferable to use one having about / 3.

In the above embodiment, the conductive graphite film coating device 3 is composed of the first to third three coating rollers 4 _{1 to} 4.
₃ and the first to have been described by way of example in which a third of the three rotary drive shaft 5 ₁ to 5 _3, conductive graphite film applicator 3 according to the present invention, first to third 3 The present invention is not limited to the case of having the four application rollers 4 _{1 to} 4 ₃ and the first to third three rotation drive shafts 5 _{1 to} 5 ₃ , the one having four application rollers and four rotation drive shafts, Or 5
A roller having at least five application rollers and at least five rotation drive shafts may be used.

In the above embodiment, the first to third three application rollers 4
₁ to 4 ₃ are led to the application area of the welded funnel inner surface of the neck portion disposed in one place, the first to third three coating roller 4 ₁ to sequentially graphite film by 4 ₃ Although an example in which the coating is performed has been described, the conductive graphite film coating apparatus 3 according to the present invention is not limited to the apparatus that performs such an operation, and the funnel portion having the neck portion welded to the predetermined transport path. Are transported and stopped in sequence along a common conductive graphite film coating device 3 at each stop.
May be operated so as to apply the graphite film to the application region by one or a plurality of application rollers derived from the above.

[0042]

As described above, according to the present invention, an application roller is used as an application device, and an application roller filled with graphite liquid is brought into contact with the application area on the inner surface of the funnel where the neck portion is welded. While rotating the applied roller, it is moved along the application area on the inner surface of the funnel part, so that the graphite area is applied to the application area, as in the past,
Compared to the case where a brush is used as an applicator, there is significantly less occurrence of blurring and pooling, and the film has a uniform film thickness without partial peeling or partial film falling. There is an effect that a conductive graphite coating film can be formed, and a conductive graphite coating film can be formed thereon by using a coating device having a simple configuration.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a state in which a method for applying a conductive graphite film inside a cathode ray tube according to the present invention is performed.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Glass valve 1 ₁ Funnel part 1 ₂ Neck part 2 Glass valve holder 3 Conductive graphite film coating device 3 ₁ Control part 4 ₁ First coating roller 4 ₂ Second coating roller 4 ₃ Third coating roller 5 ₁ First 1 rotary drive shaft 5 ₂ second rotary drive shaft 5 ₃ third rotary drive shaft 6 graphite liquid tank 6 ₁ impregnated roller 7 squeezer 7 ₁ squeeze roller

Claims (3)

[Claims] 1. A method for coating an interior conductive graphite film of a cathode ray tube, wherein an interior conductive film is applied to an inner surface of a funnel portion to which a neck portion is welded by using an application device. A method for coating the interior conductive graphite film of the cathode ray tube, wherein the interior conductive film is applied to the inner surface of the funnel portion through: a first step of filling the application roller with a graphite liquid; The second step of contacting the filled application roller with the application area on the inner surface of the funnel portion, and then moving the applied roller along the application region on the inner surface of the funnel portion while rotating the applied roller.
A third step of applying a graphite film to the application area, and subsequently, to a non-application area on the inner surface of the funnel portion,
A fourth step of sequentially executing the first to third steps. 2. The method according to claim 1, wherein in the third step, the moving speed of the coating roller is selected to be 2 to 50 cm / sec. 3. The coating roller has a length of 50 to 100 m.
2. An effective width of m.
The method for coating a conductive graphite film on the inside of a cathode ray tube according to the above item.