JPH07118261B2 - Method and apparatus for manufacturing antistatic cathode ray tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention is intended to prevent the discomfort to the human body due to the adhesion of fine dust in the air due to the charging of the outer surface of the face plate and the discharge phenomenon. The present invention relates to a method and an apparatus for manufacturing an antistatic treatment type cathode ray tube.

[Prior Art] With the recent increase in size of color cathode ray tubes and improvement in luminance performance and focusing performance, the voltage applied to the phosphor screen of the cathode ray tube, that is, the acceleration voltage of the electron beam has increased. For example, in the 21-inch class conventional color cathode ray tube, the high voltage applied to the phosphor screen was about 25 to 27 KV, but according to the recent 30-inch or more color cathode ray tube, the phosphor screen has 30 to 34 KV. High voltage is applied. for that reason,
Especially when the power of the TV set is turned on and off, the outer surface of the face plate part of the color cathode ray tube is charged up, and fine dust in the air adheres to the outer surface of the face plate part, making dirt more noticeable. As a result, it is a cause of deteriorating the luminance performance of the color cathode ray tube. In addition, there is a disadvantage that a discharge phenomenon occurs when a viewer approaches the outer surface of the face plate portion that has been charged up, and the viewer gives discomfort.

FIG. 6 is a graph showing changes in the surface potential of the face plate portion of the cathode ray tube, (L) in the figure is a curve of the surface potential when the power is ON, and (L1) is the power OFF. It is a change curve of the surface potential at the time.

In order to eliminate such a charge-up phenomenon on the outer surface of the face plate portion of the cathode ray tube, a smooth transparent conductive film is formed on the outer surface of the face plate portion of the cathode ray tube so that the charge escapes to the ground. Antistatic-treated cathode ray tubes have come into use in recent years.

FIG. 5 is a diagram for explaining the principle of antistatic treatment of the above-described antistatic-type cathode ray tube. In FIG. 5, (6) is a neck portion, which contains an electron gun (not shown).
(7) is a deflection yoke, (13) is a funnel portion, (4) is a face plate portion, (5) is a high voltage button, and the deflection yoke (7) is connected to a deflection power source through a lead wire (7a).
The electron gun is connected to the driving power source via the lead wire (6a), and the high voltage button (5) is connected to the high voltage power source via the lead wire (5a).

In the cathode ray tube having the above structure, an electron beam emitted from an electron gun built in the neck portion (6) is electromagnetically deflected from the outside of the cathode ray tube by a deflection yoke (7), and a face is passed through a high voltage button (5). -A high voltage is applied to the fluorescent surface provided on the inner surface of the plate portion (4). As a result, the electron beam is accelerated and the energy thereof excites and emits light on the phosphor screen to extract a light output. Due to the influence of the high voltage applied to the fluorescent surface on the inner surface of the face plate portion (4), the potential on the outer surface of the face plate portion (4) changes as described above, which causes adverse effects such as adhesion of dust. Occurs.

Therefore, as a measure to eliminate such adverse effects,
As shown in FIG. 5, a smooth transparent conductive film (11) is formed on the outer surface of the face plate portion (4), and the transparent conductive film (11) is grounded, so that the charge is always grounded. It was the antistatic cathode ray tube (3) that escaped to prevent charge-up.

By the way, in this antistatic cathode ray tube (3), in order to drop the transparent conductive film (11) formed on the outer surface of the face plate portion (4) to the ground, as shown in FIG. A conductive tape (12) connects the metal explosion-proof band (8) wound around the side wall of the face plate (4) and the transparent conductive film (11). As a result, since the metal explosion-proof band (8) is joined to the ground (10A) by the ground wire (10) hooked on the mounting ear (9), it is easy to drop the transparent conductive film (11) to the ground. Is possible.

Curves (M) and (M1) in FIG. 6 are power ON-OFF of the antistatic treatment cathode ray tube (3) in which a smooth transparent conductive film (11) is formed on the outer surface of the face plate portion (4). This figure shows changes in the electric potential of the outer surface of the face plate portion (4) at this time, and it can be seen from the figure that the charge-up is significantly smaller than in the conventional case.

Since the smooth transparent conductive film (11) formed on the surface of the face plate portion (4) is required to have a certain degree of hardness and adhesiveness, a silica (SiO ₂ ) based film is generally formed.

Conventionally, as a method for forming the silica-based smooth transparent conductive film (11), an alcohol solution of Si (silicon) alkoxide having a —OH group, a —OR group or the like as a functional group is used as a face plate portion of a cathode ray tube. A method has been employed in which the outer surface of (4) is uniformly and evenly coated on the outer surface by a spin coating method and dried, and then baked at a temperature of 80 to 200 ° C. In addition, in the coating process by the spin coating method or the like, which has been adopted in view of manufacturing efficiency and easiness of handling of the cathode ray tube, the metal explosion-proof band (8) is attached to the side wall portion of the face plate portion (4) of the cathode ray tube. ) Was done after the explosion-proof treatment was completed.

FIG. 4 is a view showing a conventional method for manufacturing an antistatic cathode ray tube and its apparatus, showing a method for applying a coating solution by a spin coating method. First, an explosion proof treatment by a metal explosion proof band (8) is performed. Finished and face plate part (4)
The cathode ray tube whose outer surface has been cleaned is supported by the support base (18) of the spin coating machine (14) in the funnel portion (13), and the hole of the mounting ear (9) is fixed by the support (17). Set with the face plate (4) facing up. Next, in such a setting state, a relatively low speed (for example, 40-60
While rotating the cathode ray tube at (rpm), a certain amount of the coating liquid (19) is injected onto the outer surface of the face plate portion (4) from an injection nozzle (16) arranged above the face plate portion (4). . After the injected coating liquid (19) has spread to the entire outer surface of the face plate portion (4) to some extent,
The spin coater (14) is rotated at a high speed (for example, 100 to 150 rpm) to rotate the cathode ray tube, thereby uniformizing and stabilizing the coating film.

When the coating liquid is applied by the spin coating method as described above, the coating liquid that is shaken off and scattered by the rotation of the cathode ray tube is received by the coating liquid receiving member (15).

[Problems to be Solved by the Invention] The conventional method and apparatus for manufacturing an antistatic-type cathode ray tube as described above have the following two problems.

The first problem is that unevenness (hereinafter referred to as corner unevenness) is caused in the pair of diagonal portions of the face plate portion (4) due to the nonuniformity of the film thickness. That is, the cathode ray tube is rotated at a high speed in order to make the coating film non-uniform and stable,
When rotated at such a high speed, as shown in FIG. 2, the rectangular face plate portion (4) agitates the air inside the circular coating liquid receiving member (15), and Since the degree of air disturbance is different between the long side and the short side of the face plate portion (4), in the case of the rotation direction shown by the arrow in FIG. 2, the upper left and right sides of the face plate portion (4) Corner unevenness (22) is generated in the lower diagonal part due to non-uniformity of the film thickness. Such corner unevenness (2
2) was inevitable by adjusting the rotation speed of the cathode ray tube and adjusting the viscosity of the coating liquid.

The second problem is that the droplets of the coating liquid that have been shaken off by high-speed rotation collide with the bottom wall surface (15A) of the coating liquid receiving member (15) from the same oblique direction as the rotation direction of the cathode ray tube. The rebound and the rebounded droplets adhere to the funnel portion (13) of the cathode ray tube, especially near the high pressure button (5), which causes a high pressure leak or the like.

The present invention has been made in order to solve the above-mentioned problems, in which the cathode ray tube is rotated at a high speed to make the coating film non-uniform and stable, but the occurrence of corner unevenness and droplets It is an object of the present invention to provide a method of manufacturing an antistatic treatment type cathode ray tube and an apparatus therefor capable of obtaining a high quality antistatic treatment type cathode ray tube without bouncing.

[Means for Solving the Problems] A method of manufacturing an antistatic-type cathode ray tube according to claim 1 of the present invention comprises a step of supporting the cathode ray tube on a spin coating machine with an outer surface of a face plate portion facing upward. ,
From a step of injecting a coating liquid containing a conductive substance as a main component on the outer surface of the face plate portion, and then rotating the cathode ray tube at a high speed by the spin coating machine to apply the coating liquid to the face plate portion. In the method for producing an antistatic treatment type cathode ray tube, the coating liquid having a wall surface facing the outer periphery of the cathode ray tube is disposed at a distance from the cathode ray tube at the time of applying the coating liquid so as to surround the outer periphery thereof. The receiving member is rotated at a high speed in synchronization with the cathode ray tube.

A method of manufacturing an antistatic-type cathode ray tube according to claim 2 of the present invention is a spin coating machine provided with a support portion for supporting the cathode ray tube with the outer surface of the face plate portion facing upward, A coating liquid receiving member disposed so as to surround the plate portion at a distance from the outer periphery of the face portion and having a wall surface facing the outer periphery of the face plate portion, and fixing the coating liquid receiving member to the spin coating machine. It is characterized by being connected.

3. The apparatus for producing an antistatic-type cathode ray tube according to claim 2, wherein the coating liquid receiving member is a circular shape surrounding the outer periphery of the face plate portion and has a U-shaped cross section, and the coating liquid receiving member has a radial direction. It is preferable to provide a plurality of disturbance preventing partition plates extending along the ridge.

Further, in the apparatus for producing an antistatic-treatment type cathode ray tube according to claim 2, the coating liquid receiving member has a substantially rectangular shape surrounding the outer periphery of the face plate portion, and a corner portion of an outer wall surface of the coating liquid receiving member is formed. It is preferable to form a curved surface.

[Operation] According to the inventions of claims 1 and 2, after the coating liquid is injected into the outer surface of the face plate portion, the cathode coating tube is rotated at a high speed by a spin coating machine so that the coating liquid is applied to the face plate portion. At the same time as forming a uniform coating film on the outer surface of the cathode ray tube, at the time of high-speed rotation of the cathode ray tube, the coating liquid receiving member arranged so as to surround the outer periphery of the cathode ray tube at a distance from the cathode ray tube rotates integrally in synchronization. The air in the coating liquid receiving member also circulates together with the cathode ray tube, and the air is hardly agitated by the rectangular face plate portion. Hence,
It is possible to suppress the occurrence of corner irregularity due to the non-uniformity of the film thickness in the diagonal portion of the face plate portion. Also, as the cathode ray tube rotates, the droplets that are shaken off toward the outside collide with the bottom wall surface of the coating liquid receiving member almost vertically and are retained on the bottom wall surface by the centrifugal force. The occurrence of bad situations due to rebound can also be suppressed.

In particular, when the coating solution receiving member has a circular shape surrounding the outer periphery of the face plate portion of the cathode ray tube, by providing a plurality of disturbance preventing partition plates extending in the radial direction thereof, the coating solution at the time of high speed rotation is provided. The disturbance of the air in the receiving member can be prevented more effectively, and the quality of the antistatic treatment can be further improved.

Further, as the coating liquid receiving member, a substantially rectangular member that surrounds the outer periphery of the face plate portion of the cathode ray tube is used, and when the corner portion of the outer wall surface is formed into a curved surface, the coating liquid at high speed rotation is used. The air in the liquid receiving member is not disturbed at all, and the splash of the liquid droplet can be further reduced.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic front view showing an apparatus for producing an antistatic treatment type cathode ray tube according to an embodiment of the present invention and a production method using the apparatus, showing a method for applying a coating liquid by a spin coating method. The difference from the conventional example shown in FIG. 4 is the point described below.

That is, the coating liquid receiving member (15) arranged so as to surround the outer periphery of the cathode ray tube supported by the spin coating machine (14) was integrally fixedly connected to the spin coating machine (14) through the arm (20). It is a thing.

With the above configuration, the coating liquid receiving member (15) rotates integrally with the cathode ray tube at a high speed as the spin coating machine (14) is driven and rotated. As a result, the air in the coating liquid receiving member (15) also rotates together with the cathode ray tube at the time of high-speed rotation for unevenness and stabilization of the coating film, so that the rectangular face plate portion (4)
As a result, the air in the coating liquid receiving member (15) is not disturbed, the film thickness at the diagonal portions of the face plate portion (4) is made uniform, and corner unevenness hardly occurs.

Also, with the above high-speed rotation, the liquid droplets shaken outward reach the bottom wall surface (15a) of the coating liquid receiving member (15), but the coating liquid receiving member (15) is rotating at high speed. , Will stay on the bottom wall surface (15a) due to centrifugal force,
There is no rebound to the cathode ray tube side. Therefore, it is possible to suppress the occurrence of trouble such as high-pressure leak caused by the splashed liquid droplets adhering to the vicinity of the high-pressure button (5) of the funnel portion (13).

As the coating liquid receiving member (15), a circular member as shown in FIG. 2 or a rectangular member substantially similar to the face plate portion (4) as shown in FIG. 3 is used. .

When a circular coating liquid receiving member (15) as shown in FIG. 2 is used, a plurality of disturbance preventing partition plates (2) extending in the radial direction at substantially equal intervals in the circumferential direction are provided. By providing it, the disturbance of the air in the coating liquid receiving member (15) can be prevented more effectively.

In addition, a rectangular coating liquid receiving member (1
When 5) is used, the air in the coating liquid receiving member (15) is not disturbed at all. Particularly, in the case of the rectangular coating liquid receiving member (15), by forming the corner portion (15a) of the side wall surface into a curved surface, the splash of the liquid droplet can be further reduced.

Since other configurations and operations other than the above are the same as those of the conventional example shown in FIG. 4, the same reference numerals are given and the description thereof is omitted.

In the above examples, the case where the coating liquid (19) is applied to the cathode ray tube which has been subjected to the explosion-proof treatment with the metal band (8) by the spin coating method to form a film is described. Alternatively, the same effect as that of the above-described embodiment can be obtained even when applied to a case of applying a film by spin coating to a single component of only the face plate portion (4) of the cathode ray tube to form a film.

[Advantages of the Invention] As described above, according to the first and second aspects of the invention, the coating solution receiving member is used as the cathode ray tube when the coating solution is shaken off by high-speed rotation for uniformization and stabilization of the coating film. Since it is rotated at a high speed in synchronism with the above, the disturbance of the air in the coating liquid receiving member is reduced, and it is possible to sufficiently suppress the occurrence of film thickness unevenness at the corners. Further, the rebound of the liquid droplets shaken off by the high speed rotation can be extremely reduced. Therefore, it is possible to produce a high quality antistatic cathode ray tube without causing troubles such as high-pressure leak.

According to a third aspect of the present invention, a circular coating liquid receiving member having a U-shaped cross-section surrounding the outer periphery of the face plate portion of the cathode ray tube is used. 5. A plurality of disturbance preventing partition plates extending vertically are provided, or as in claim 4, a substantially rectangular coating liquid receiving member that surrounds the outer periphery of the face plate portion of the cathode ray tube is used, and the corner portion of the outer wall surface thereof is used. In the case of forming a curved surface, the effect of preventing air turbulence during high-speed rotation and the effect of preventing splashing of droplets are more effectively performed, and a higher-quality antistatic cathode ray tube can be obtained. .

[Brief description of drawings]

FIG. 1 is a schematic front view showing a method of applying an antistatic treatment type cathode ray tube and an apparatus therefor according to an embodiment of the present invention, and FIG. 2 and FIG. 3 are spin coating methods. FIG. 4 is a plan view of the machine, FIG. 4 is a schematic front view showing a method of applying a coating liquid by a conventional spin coating method, and FIG.
FIG. 6 is a side view showing the antistatic principle of the antistatic cathode ray tube, and FIG. 6 is a graph showing changes in the surface potential of the face plate portion of the cathode ray tube. (4) …… face plate part, (5) …… high pressure button, (11) …… transparent conductive film, (13) …… funnel part,
(14) …… Spin coating machine, (15) …… Coating liquid receiving member, (19) …… Coating liquid. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (4)

[Claims] 1. A step of supporting a cathode ray tube on a spin coating machine with the outer surface of the face plate portion facing upward, and after injecting a coating liquid containing a conductive substance as a main component on the outer surface of the face plate portion. , The spin coating machine is used to rotate the cathode ray tube at a high speed,
In a method for producing an antistatic-type cathode ray tube comprising a step of applying the coating liquid to a plate portion, at the time of applying the coating liquid, the cathode ray tube is arranged so as to surround the outer periphery thereof at a distance from the cathode ray tube. A method for producing an antistatic-type cathode ray tube, characterized in that a coating liquid receiving member having a wall surface facing the outer circumference of the tube is rotated at a high speed in synchronization with the cathode ray tube. 2. A spin coating machine provided with a support portion for supporting a cathode ray tube with the outer surface of the face plate portion facing upward, and a spin coating machine arranged so as to surround the face plate portion at a distance from the outer periphery thereof. , Face above
An apparatus for producing an antistatic treatment type cathode ray tube, comprising: a coating liquid receiving member having a wall surface facing the outer periphery of a plate portion, wherein the coating liquid receiving member is fixedly connected to the spin coating machine. 3. A plurality of disturbance-preventing partition plates extending in the radial direction on the coating liquid receiving member in a circular shape surrounding the outer periphery of the face plate portion and having a U-shaped cross section. 3. The method according to claim 2, wherein
Manufacturing equipment for antistatic cathode ray tubes. 4. The coating liquid receiving member is formed into a substantially rectangular shape surrounding the outer periphery of the face plate portion, and the corner portion of the outer wall surface of the coating liquid receiving member is formed into a curved surface. Antistatic treatment type cathode ray tube manufacturing equipment.