JPS5829567B2 - Ink Yokusen Kanno Seizouhouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a cathode ray tube, and in particular provides a method for manufacturing a cathode ray tube that is most suitable for application to color television picture tubes.

Conventionally, in this type of picture tube, phosphors of three colors are coated on the inner surface of the face plate in the form of dots or stripes, and a thin film layer of AII is formed on the phosphors.

This thin film layer serves to provide the phosphor screen with electrical conductivity and to increase the amount of light in front of the face plate by reflecting the light emitted from the phosphor screen toward the rear, that is, toward the electron gun, forward.

In addition, a shadow mask or aperture grill, which is a color selection electrode, is arranged behind the phosphor screen to regulate the landing position of the electron beam on the phosphor surface. The light is transmitted to the phosphor surface side, and the remaining approximately 80% is blocked.

Therefore, about 80% of the beam amount is involved in increasing the temperature of the color selection electrode.

Furthermore, as the temperature rises, heat radiation from the color selection electrodes occurs, and this radiation heat is concentrated on the nearest phosphor screen and most of it is reflected by the A/thin film layer on this phosphor screen.

This reflected heat reaches the color selection electrode again.
The temperature rise of the electrode is further promoted.

Generally, the color selection electrode thermally expands in proportion to the rise in temperature, deforming its original shape, which may result in mislanding of the electron beam.

In this case, since the A7 thin film layer has good heat reflection efficiency,
Most of the radiant heat from the color selection electrode is reflected and absorbed by the color selection electrode, which further increases the amount of deformation of the color selection electrode.

In order to correct such defects, in conventional television picture tubes, carbon paint is applied to the surface of the KL thin film layer of the phosphor screen, and the heat absorption effect of this carbon paint absorbs the radiant heat from the color selection electrode. (U.S. Pat. No. 3,703,401).

However, the carbon paint must be dissolved in a solvent such as water and then applied by spraying, and this coating process must be performed separately from the AA vapor deposition process on the phosphor surface, making the process cumbersome. It is also impossible to work continuously.

The present invention aims to correct the above-mentioned defects.It is an object of the present invention to solve the above-mentioned defects. While supplying a carbon compound, the conductive material is further deposited on the light emitting layer to form a second deposited layer, and the second deposited layer contains the conductive material and carbon from the carbon compound, respectively. The present invention relates to a method for manufacturing a cathode ray tube.

By this method, not only can heat absorption and light emission be performed well, but the process is extremely simple and continuous operation is possible.

The above-mentioned carbon compounds include linear hydrocarbons and derivatives thereof such as methane, ethane, and propane, cyclic hydrocarbons and derivatives thereof such as benzene and toluene, methanol,
Alcohols such as ethanol, and polymeric compounds such as polystyrene and polymethyl methacrylate may be used.

Next, an embodiment in which the present invention is applied to a method of manufacturing a color television picture tube will be described with reference to the drawings.

First, referring to FIG. 1, the configuration of a vapor deposition apparatus used in this embodiment will be explained.

This vapor deposition apparatus 1 is a conventionally known one, and has a vacuum container 2.
The inside is kept in a vacuum.

This vacuum container has a methane gas inlet 3 and a vacuum pump (
(not shown) are provided respectively.

Further, a tungsten filament 7 having electrodes 5 and 6 on both sides is arranged in the vacuum vessel 2.

Then, in the recess 8 of this filament, a vapor-deposited metal A
19 are accommodated.

Further, a face plate 10 of a picture tube is arranged opposite to this filament with its vapor deposition surface facing downward.

A mask 11 for preventing Al vapor deposition is arranged around this vapor deposition surface, so that vapor deposition is performed only on the phosphor screen, which will be described later.

Next, a method for manufacturing a picture tube using the vapor deposition apparatus configured as described above will be explained in the order of steps with reference to FIGS. 2A to 2C.

As shown in FIG. 2A, the inner surface of the face plate 10,
That is, on the surface of the electron beam landing side, which will be described later, there are phosphor dots 12 for green, blue, and red light emission.
G, 12B, and 12R are formed, respectively, and a conductive intermediate film layer (not shown) is formed on the surface of these phosphor dots.

These phosphor dots may be formed by conventionally known methods.

With this face plate 10 placed in the vacuum container 2 described above, gas is sucked into the vacuum container to
While maintaining the degree of vacuum at mmHg, the fryment 7 is heated to a temperature equal to or higher than the Al evaporation temperature.

As a result, kl 9 is a phosphor dora t-12G. 12B, 1
As shown in FIG. 2B, the A1 layer 13 is deposited on the 2R surface.
000 to 4000A, for example, approximately 3000A.

When the A7 layer 13 is formed to such a thickness, CH4 gas is introduced into the vacuum container 2 from the gas inlet 3 of the container.

At this time, it is preferable to maintain the pressure inside the vacuum container 2 at 10 to 10 mmHg.
The temperature can be kept at room temperature.

As a result, the surface of the A7 layer has a thickness of 10 mm as shown in Figure 2C.
00A to several, for example, black AA-C of about 3000A
Layer 14 is deposited.

This A7-C layer 14 is a fine AA whose surface is coated with C.
Consists of particles or molecular clusters.

That is, by depositing Al in an atmosphere of CH4 gas, while the A1 particle is flying, the CH4 attached around this human particle is thermally decomposed and carbonized, and the C produced by this carbonization converts the M particle. This is considered to be because the A1 particles are deposited on the A1 layer 13 in a carbonized form as if by coating.

In this case, if the degree of vacuum in the vacuum container 2 is too low or the temperature of the vapor deposition source Kl 9 is low, particles tend to adhere to each other and become larger, resulting in a particle size difference. Al-C is deposited.

The adhesion strength of C on the A1 particles in this Al-C is so weak that it is not of practical use.

Next, the heat absorption effect of the face plate 10 manufactured in this manner will be explained.

That is, from the Al-C layer 14 of the face plate 10, about 20
A 125W infrared lamp (not shown) is placed opposite the crIL, and the infrared rays emitted by this infrared lamp are
The layer 14 is irradiated to form the face plate 10 by this irradiation.
That is, the relationship between the heating time and temperature of the Al-C layer 14 is measured.

As a result, a result as shown by the broken line a shown in FIG. 3 was obtained.

According to this figure, it is understood that when the kl-C layer 14 is formed, the heat absorption effect of this layer is very good.

In other words, the broken line is an AI as described above! This is the result when the -C layer is not formed. In this case, the temperature of the face plate 10 is not much different from the initial temperature, and it can be seen that the heat absorption effect is significantly inferior to that with the A7-C layer 14. I understand.

Furthermore, if the amount of CH4 introduced is small or the degree of vacuum is too high, the content of CH4 in the AlClC layer will be low and the degree of blackening of this layer will be undesirable.

Note that FIG. 4 schematically shows a television picture tube 15 in which a face plate 10 having an AA-C layer 14 is incorporated.

The face plate 10 is a funnel portion 16 of a glass outer tube.
The aperture grill 17, which is sealed to the end of the face plate 10 and attached to the inner circumferential surface of the face plate 10, is also incorporated into the glass outer tube at the same time.

Also, only the cathode 18 is shown on this glass outer tube for the sake of simplicity, and the electron beam 1 from this cathode is
9 is accelerated and deflected so that it can land on the phosphor screen through the opening 20 or slit of the anno-cha grill 17.

When this state is shown in an enlarged view in FIG. 5, the electron beam 19 passing through the opening 20 of the aperture grille 17 reaches the Al--C layer 14 of the face plate 10 at a certain angle.

However, about 80 yen of the electron beam is blocked.

However, as described above, since the heat absorption effect of this Al-C layer is extremely good, the amount of radiant heat rays 20 of this aperture grille reflected from the Al-C layer 14 to the aperture grille 17 side is significantly reduced.

As a result, the degree of temperature rise in the aperture grill 17 is reduced, and the amount of drift due to heat, that is, the amount of thermal deformation is significantly reduced.

To explain this with reference to FIG. 6, this figure shows a schematic view of the aperture grille 17 from the front, but even if heat ray reflection by the A7-C layer 14 is taken into account, it is still different from the conventional one. It can be seen that the amount of drift of the aperture grille has been significantly reduced.

That is, compared to the conventional aperture grill, the amount of drift of the metal strips 21 of the aperture grill 17 in this embodiment is, for example, 50φ, -51 mm, at the four corners thereof.
-30 points and -37 points also decreased.

In this case, the voltage applied to the A1 layer 13 on the face plate 10 is 24.2 KV, and the cathode current is 1.1 m
A, measurements were taken at 18° C., and an 18-inch picture tube with a 114° deflection was used.

As described above, in this embodiment, the Al-C layer can be formed while performing Al vapor deposition on the phosphor screen of the face plate 10, so the operation is extremely simple, and the N The advantage is that it can be done.

Further, the heat absorption effect of the Al--C layer 14 is very good, and it is possible to minimize changes in the original shape due to thermal expansion of the aperture grille 17, thereby greatly reducing mislanding of the electron beam.

Although the present invention has been described above based on one embodiment, it will be understood that further modifications can be made based on the technical idea of the present invention.

For example, metals other than AA may be used as the deposited metal.

Further, the thickness of the Al-C layer 14 may be increased to a considerable extent.

As described above, the present invention introduces a carbon compound while vapor-depositing a conductive material on the phosphor screen of a cathode ray panel. Therefore, C from this carbon compound is transferred onto the first vapor-deposited layer made of the conductive material. A second vapor-deposited layer that can be vapor-deposited and has a good heat absorption effect can be formed on the phosphor screen, thereby reducing the reflection of radiant heat from the color-selecting electrodes and reducing the amount of thermal drift of the color-selecting electrodes. Beam mislanding can be greatly reduced.

Furthermore, since the first vapor deposited layer is formed, the light emitted from the rear of the cathode ray tube can be reflected to the front of the cathode ray tube, thereby improving the light emitting effect.

In addition to these advantages, since the second vapor deposition layer can be formed while forming the first vapor deposition layer, there is no need to apply carbon paint in a separate process as in the past, making the process extremely simple. This significantly improves work efficiency.

Furthermore, it becomes possible to perform two steps consecutively.

[Brief explanation of drawings]

The drawings show an embodiment in which the present invention is applied to a method for manufacturing a color television picture tube, in which FIG. 1 is a schematic cross-sectional view of a vapor deposition apparatus, and FIGS. 2A to 2C are cross-sectional views showing the vapor deposition process. Figure 3 is a line diagram showing the heat absorption effect of the AA-C layer, Figure 4 is a schematic diagram of the face plate assembled into the picture tube, Figure 5 is a partial enlarged view of Figure 4, FIG. 6 is a schematic front view showing the amount of thermal drift of the aperture grill. In addition, in the symbols used in the drawings, 1 is a vapor deposition device, 2 is a vacuum container, 3 is a gas inlet, 4 is an exhaust port, 7 is a filament, 9 is AA, 10 is a face plate, 12
G, 12B, 12R are phosphor dots, 13 is A7 layer, 1
4 is an AA-C layer, 15 is a picture tube, 17 is an aperture grill, 18 is a cathode, 19 is an electron beam, and 20 is a heat ray.

Claims (1)

[Claims] 1. A conductive material is vapor-deposited on the luminescent layer formed on the inner surface of the cathode ray tube panel to form a first vapor-deposited layer, and then a gaseous carbon compound is supplied and the above-described gaseous carbon compound is heated in an atmosphere of the gaseous carbon compound. The conductive material is further deposited on the first deposited layer to form a second deposited layer, and the second deposited layer contains the conductive material and carbon produced by decomposition of the carbon compound, respectively. A method for manufacturing a cathode ray tube.