JPH0218917Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a coating device for cathode ray tubes, and particularly relates to an improvement in the coating brush.

[Technical background of the invention and its problems] In a funnel having a neck part constituting a part of the envelope of a cathode ray tube, for example a color picture tube, from the funnel to the neck part there is an internal conductive material mainly composed of, for example, graphite. A film is formed. This internal conductive film is obtained by applying Doug solution and then drying it. The formation of this internal conductive film is carried out by two coating steps: Funnel Dag 1 and Neck Dag 2, as shown in FIG.

Of these, for Netsukudag 2, the Netsukudaku coating area on the inner surface from the funnel to the neck part is coated with the Dag liquid uniformly, dried, a panel is sealed to the large diameter open end of the funnel, and then an electron gun is placed inside the neck part. In the cathode ray tube formed by sealing the electron gun and sealing the electron gun inside the neck part, it is applied more densely than the funnel dag 1 application process in order to contact the valve spacer that establishes conduction between the electron gun and the anode button. Therefore, it is usually applied manually or with a brush.

Next, an example of a coating brush used in a conventional cathode ray tube coating device is shown in Figures 5 and 6.
This will be explained using figures.

That is, the applicator brush 10 has a substantially circular outer shape,
It consists of a gear-shaped sponge 11 with a notch 14 extending from the center to the periphery, and a supply pipe 17 that also serves as a rotating shaft is provided in the center.
After the dag liquid is allowed to seep into the coating brush 10 through the hole 18 provided at a position corresponding to the sponge 11, the net dag is applied while rotating the supply pipe 17 about its axis.

However, since the sponge 11 of the coating brush 10 is compressed at the position where the diameter of the funnel neck is small, when the coating brush 11 returns while rotating, there is a difference in the coating thickness of the daug liquid and it becomes thinner. In many cases, a uniform film was not formed, such as unevenness in the internal conductive film after drying. Therefore, during the formation of a cathode ray tube, the contact area with the valve spacer attached to the electron gun sealed in the neck part is rubbed and the internal conductive film peels off, and the particles of this peeled dag fall down to the electron gun. If it adheres to the surface, problems such as poor withstand voltage and stray emission may occur.

Utility Application No. 55-95601 (Utility Model Application No. 59-956) filed by the same applicant as the present invention as a coating brush for use in a netsukudag coating device for cathode ray tubes to solve this problem.
19855 Publication), a coating method as shown in FIGS. 7 to 9 has been proposed.

That is, the coating brush 20 is formed by stacking three thick polyurethane disc-shaped bodies 21, 22, and 23 with their centers aligned, and the upper disc-shaped body 23 is folded into a portion C in FIG. It applies liquid, and its outer diameter is smaller than the lower disc-shaped body 21 and 5 to 15% larger than the inner diameter D of the netskudag application part (portions a, b, and c in Fig. 9). The lower disk-shaped body 2 has a diameter.
1 is for applying Doug liquid to part a in Fig. 9, the outer diameter of which is determined by the coating diameter D ₁ of the funnel widening part, and is formed to a size that is, for example, 150 to 200% of the diameter of the neck part. Further, the middle layer disk-shaped body 22 is formed so that the dag liquid is applied to the part b. The disk-like bodies 21, 22, and 23 are each provided with a plurality of notches 24 toward the center, and a diagonal cut 25 is provided on the upper side of the circumferential green facing the funnel side. As a whole, the envelope surface of the outer periphery is formed in a shape that approximately corresponds to the Neck Dug application area.

Sponges 21 and 2 of the supply pipe 27 that also serves as the rotation axis
It is the same as in the conventional case that the dag liquid is allowed to seep through the holes 28 provided at positions corresponding to 2 and 23.

However, with this coating brush 20, the disc-shaped body 21,
Since 22 and 23 are made of one type of porous material (for example, cell range 26 to 43 cells/25 mm), they cannot respond to variations in Doug liquid or changes in temperature.
The conductive film is likely to be formed with uneven coating or puddles due to dirt clogging or lack of dirt. Therefore, there is a problem that the emission and breakdown voltage quality of the cathode ray tube deteriorates, such as variations in the distribution of electrical resistance values of the conductive film.

[Purpose of the invention] The present invention has been made in view of the problems of the conventional and prior applications mentioned above, and is a method for applying netskudag to cathode ray tubes, which is equipped with a coating brush capable of applying extremely high-quality netskudag. The purpose is to provide equipment.

[Summary of the invention] That is, the present invention arranges a funnel having a neck portion, which constitutes a part of the envelope of a cathode ray tube, with its large diameter open end facing downward, and coats the inner surface from the funnel to the neck portion. A coating brush soaked with daug liquid supplied from a tank through a supply pipe that also serves as a rotating shaft is raised along the axis of the neck part from the direction of the large-diameter open end, and the neck dag is applied by rotation application. In a cathode ray tube NETSUKUDAG coating device designed as described above, the coating is performed using a plurality of gears that are stacked in a shape that roughly corresponds to the shape of the NETSUKUDAG application area, and whose cell range increases from the upper layer to the lower layer. A dag liquid dropping jig is provided at the top opening of a supply pipe which also serves as a rotating shaft passing through the center of a plurality of gear-shaped sponges. This is a cathode ray tube coating device characterized in that the liquid is gradually soaked from the gear-shaped sponge in the uppermost layer to the gear-shaped sponge in the lower layer.

[Embodiment of the Invention] Next, an embodiment of the cathode ray tube coating apparatus of the present invention will be described with reference to FIGS. 1 to 3.

First, the coating brush 30 will be explained with reference to FIGS. 1 and 2.

That is, the applicator brush 30 is formed by stacking three thick disk-shaped bodies 31, 32, and 33 made of polyurethane, for example, with their centers aligned, and is adapted to apply the dag liquid to the area where the dag is applied. , a plurality of cuts 34 are provided in each of the disc-like bodies 32, 32, 33 toward the center, and a diagonal cut 35 is made on the upper side of the periphery facing the funnel side.
The coating brush 30 as a whole has an envelope surface on its outer periphery formed in a shape that substantially corresponds to the coating portion. Furthermore, as the material for the disc-shaped bodies 31, 32, and 33, for example, polyester-based polyurethane foam is used. 32 is 26 to 43, and disk-shaped body 33 is 44 to 54, so that the cell range increases from the upper layer to the lower layer, that is, it is easy for the Doug liquid to penetrate.

The supply pipe 37, which also serves as a rotating shaft, passes through the three disk-shaped bodies 31, 32, and 33, and a guide body 38 is provided at the opening 37a. A Doug liquid dropping jig 39 is fixed to the uppermost layer of the body 33 so as to have an appropriate gap between the uppermost layers, and the Doug liquid is passed through the supply pipe 37 and inside the Doug liquid dropping jig 39 as shown by the arrow. The liquid is dripped onto the disc-shaped body 33, and further penetrates into the disc-shaped body 33 and the disc-shaped bodies 32 and 31 in turn.

Next, a cathode ray tube coating apparatus using this coating brush 30 will be explained with reference to FIG.

That is, a mounting table 41 for the funnel 40 having a neck portion is connected to a cylinder 42 that moves up and down by a control switch, and above the mounting table 41 there is a stopper 4 for placing the funnel 40 in a predetermined position.
3, 44, and 45 are attached. On the other hand, the coating brush 30 inserted into the funnel 40 is connected to the Doug liquid tank 47 through a pipe 48, and the support base 4
9, and this support is connected to a cam 50 so as to move up and down.

In order to apply the dag solution to the net dag application area using such a device, a funnel 40 is placed on the mounting table 41.
Place the cylinder 42 with its large-diameter open end facing down.
Move the mounting table 41 to raise the funnel 4.
0 hits the stopper 43 and further rises until the stopper 44 hits the stopper 45 and stops. A fixed amount of Doug liquid from the Doug liquid tank 47 is sent to the coating brush, and is transferred to the support base 49 by the rotation of the cam 50.
moves up and down, and the coating brush 30 attached to this support stand 49 is inserted into the net-dag application section, and the daug solution soaked into the coating brush 30 is applied to the net-dag application section.

[Effects of the invention] According to the invention, variations in the concentration and composition of the Doug liquid in the conventional and prior applications, insufficient penetration of the Doug liquid into porous materials,
Problems such as uneven coating, reduction in Doug adhesive strength due to accumulation of Doug solution, variation in electrical resistance of the conductive film, and scattering of Doug solution can all be resolved, and the emission and voltage resistance quality of cathode ray tubes can be improved. improves.

[Brief explanation of the drawing]

1 to 3 are views showing one embodiment of the present invention, in which FIG. 1 is a perspective view of the main parts of the coating brush, and FIG.
The figure is a sectional view of the coating brush, Figure 3 is an explanatory diagram of the Netsukudag coating device, Fig. 4 is an explanatory sectional view showing the funnel dag and the application part of the Netsukudag, and Figures 5 and 6 are the conventional coating brush. FIG. 5 is a perspective view, FIG. 6 is a sectional view, FIGS. 7 and 8 are views showing the coating brush of the earlier application, and FIG. 7 is a perspective view,
FIG. 8 is a sectional view, and FIG. 9 is an explanatory view showing the application range of the coating brush. 10,20,30...Applying brush, 11...Sponge, 14,24,34...Notch, 17,2
7, 37... Supply pipe, 18, 28... Hole, 2
1, 22, 23, 31, 32, 33... Disk-like body, 25, 35... Cutting, 40... Funnel, 41... Mounting table, 43, 44, 45... Stopper, 47... Doug liquid tank.

Claims (1)

[Scope of utility model registration request] A funnel having a neck part constituting a part of the envelope of the cathode ray tube is arranged with the large-diameter open end facing downward, and the neck part is supplied from a tank to the neck dag application part on the inner surface from the funnel to the neck part. A cathode ray tube in which a coating brush impregnated with a liquid through a supply pipe that also serves as a rotating shaft is raised from the direction of the large-diameter open end along the axis of the neck portion, and the coating brush is applied by rotational coating. In the NETSUKUDAG applicator of 2009, the coating is applied from a plurality of gear-shaped sponges that are stacked so that the shape approximately corresponds to the shape of the NETSUKUDAG application area, and the cell range increases from the upper layer to the lower layer. At the same time, a liquid dripping jig is provided at the top opening of the supply pipe that also serves as a rotating shaft passing through the center of the plurality of gear-shaped sponges,
A network dag coating device for a cathode ray tube, characterized in that the dag liquid from the dag liquid dropping jig is made to gradually soak into the gear-shaped sponge in the lower layer from the gear-shaped sponge in the uppermost layer.