JPH0620596A - Manufacture of cathode ray tube - Google Patents

Abstract

PURPOSE:To provide the manufacture of a cathode ray tube capable of preventing carbon particles from adhering to a pin for mounting a color selection electrode. CONSTITUTION:A panel 1 is rotated at the speed of 5-15rpm in the condition that it is directed upwardly (revolution angle theta=10-15 degrees), and a slurry 4 is injected into the panel 1 from the upward direction. The panel is stopped at a predetermined position after aging, its corner is directed downward to let the carbon slurry 4 flow out and the slurry is collected. Then, the panel 1 is rotated at the speed of 60-180rpm in the condition that it is directed horizontally (revolution angle theta=100-120 deg.) so that the carbon slurry 4 is shaken off.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for manufacturing a cathode ray tube,
In particular, the present invention relates to a method for preventing carbon from adhering to a pin for mounting a color selection electrode provided in a panel when forming a light absorption film pattern of a so-called black matrix type color fluorescent screen.

[0002]

2. Description of the Related Art Generally, a fluorescent screen in a color cathode ray tube is a so-called black matrix type color in which a black pattern serving as a light absorbing film is formed between red, green and blue phosphor stripes (or dots). A phosphor screen is used. This black pattern is formed as follows in the process of forming the phosphor screen. That is, first, PVA (polyvinyl alcohol) is formed on the inner surface of the panel of the cathode ray tube.
After applying a photosensitive film such as PVP (polyvinylpyrrolidone) and drying it, stripe-shaped (or dot-shaped) resist is applied at positions corresponding to each color by exposing it to ultraviolet rays and developing it with water using the color selection electrode as an optical mask. Form the layers. Next, the carbon slurry is applied to the entire surface including the resist layer, dried, and then subjected to reversal development (that is, an inversion agent such as H ₂ O ₂ is injected to swell the resist layer, and then the resist layer is washed with water or the like together with the resist layer. By lifting off the carbon layer thereon, a carbon film having a predetermined pattern, that is, a black pattern (light absorbing film) is formed.

Conventionally, the following method has been used to apply carbon slurry to the inner surface of the panel of a cathode ray tube. That is, as shown in FIG. 3, this method uses the panel 10 rotating at the revolution angle θ = 100 to 120 °.
(FIG. 3A) Inject carbon slurry 12 from flood cap or spray nozzle 11 (sideways injection)
Or the carbon slurry 1 for the panel (FIG. 3B) rotating at the revolution angle θ = 140 to 160 °.
After injecting 2 (downward injection) and aging,
As shown in FIG. 3C, the panel 10 has a revolution angle θ = 180 °.
Is rotated at high speed to shake off the unnecessary carbon slurry 12 (shake downward).

[0004]

However, in such a conventional method, the inner surface of the panel 10 (the surface on the effective screen side) is used.
Is filled with the carbon slurry 12,
Since the carbon adheres to the pin 13 for mounting the color selection electrode, which originally does not need to be coated with carbon, the following problems occur. That is, since the carbon 12a thus attached to the pin 13 is scraped off by the spring 14 for mounting and removing the color selection electrode in the manufacturing process of the cathode ray tube (see FIG. 4), it becomes dust in the cathode ray tube and the pressure resistance is reduced. (Discharge, stray) was the cause of the failure. Therefore, the carbon 12a adhering to the pin 13 needs to be removed from the pin 13, but this requires manual or mechanical trimming, resulting in an increase in manufacturing equipment and a complicated process. Further, such trimming cannot completely remove the carbon 12a adhering to the pin 13, resulting in deterioration of the withstand voltage of the cathode ray tube.

The present invention has been made in view of the above problems of the conventional example, and an object of the present invention is to provide a method of manufacturing a cathode ray tube capable of preventing carbon from adhering to a pin for mounting a color selection electrode. It is in.

[0006]

According to the present invention, for example, as shown in FIG. 1, a panel 1 having a pin 2 for mounting a color selection electrode is rotated with its inner surface facing upward so that the carbon slurry 4 is applied to the inner surface of the panel 1. Then, the rotation of the panel 1 is stopped, the panel 1 is tilted to allow the carbon slurry 4 to flow out from the corner portion of the panel 1 so as to avoid the pin 2, and then the panel 1 is rotated. It has a step of shaking off the carbon slurry 4.

[0007]

In the present invention having such a structure, since the carbon slurry 4 is injected with the inner surface of the panel 1 facing upward, thereafter the compatibility with the lower layer is improved (aging).
Therefore, even if the panel 1 is rotated, the carbon slurry 4 is not applied to the pins 2. Further, after that, the rotation of the panel 1 is stopped and the carbon slurry 4 is caused to flow out from the corner portion of the panel 1 while avoiding the pin 2, so that the carbon slurry 4 is not applied to the pin 1 also in this step. Further, even in the step of shaking off the carbon slurry 4, the applied carbon slurry 4 hardly moves, so that the carbon slurry 4 is not applied to the pins 2.

[0008]

Embodiments of the method of manufacturing a cathode ray tube according to the present invention will be described below with reference to the drawings. In the following, the process of forming the phosphor screen will be described centering on the carbon slurry coating process of the present invention, and the description of other known processes will be omitted for convenience.

First, the PVA (Po
Livinyl alcohol), PVP (polyvinyl pyrrolide)
(2) apply a photosensitive film and dry it, and then light the color selection electrode.
As a school mask, it is exposed to ultraviolet rays and developed with water etc.
Stripe (or dot) marks are placed at the positions corresponding to the colors.
Form a dist layer. Next, after the entire surface including the resist layer,
Apply the carbon slurry by the method described above, dry it, and then
Transfer development (ie H₂O ₂Inject a reversal agent such as
After swelling the resist layer, wash it with water etc. together with the resist layer.
Lift off the carbon layer on it)
Form a carbon film, that is, a black pattern (light absorption film)
It

Next, a method for applying the carbon slurry will be described. First, as shown in FIG. 1A, the panel 1 of the cathode ray tube is turned upward (revolution angle θ = 10 to 15 °) and rotated at a rotation speed of 5 to 15 rpm. As shown in FIG. 1B, the inner surface of the skirt portion 1a of the panel 1 is provided with pins 2 (2a to 2d) for mounting color selection electrodes at the center of each side. Then, using the injection nozzle 3, the carbon slurry 4 is injected from above the panel 1. In this case, the injection amount of the carbon slurry 4 is, for example, 50 to 500 ml for 5 to 10 seconds in the case of a cathode ray tube of 6 to 36 inches.
It is preferable that According to such an injection process, as shown in FIG.
As shown in A, the carbon slurry 4 is not applied to the pin 2.

Next, after aging for a predetermined time in order to improve the compatibility with the resist layer, the panel 1 is stopped at a fixed position, and the corner portion of the panel 1 is turned downward as shown in FIG. Pour 4 and collect this.
In this case, in the panel 1 having four pins 2 as shown in FIG.
It is preferable to incline the panel 1 so that the straight line connecting a and 2c forms an angle of 30 to 45 ° with respect to the horizontal line. However, the corner portion located below may be any corner portion. A panel with three pins (not shown)
In this case, it is preferable that the corner of the long side of the panel on the side where the pin is provided is downward. And, in this step as well, the carbon slurry 4 has the respective pins 2a-2.
It flows out from panel 1 without being applied to d.

Further, in order to adjust the thickness of the carbon slurry 4 applied to the inner surface of the panel 1, the panel 1 is rotated at a high speed (160 to 180 rpm) to shake off the carbon slurry 4. In this case, the panel 1 is oriented laterally (revolution angle θ = 100 to 120 °) as shown in FIG. 1C or downward (revolution angle θ = 180 °) as shown in FIG.
As a result, the carbon slurry 4 is shaken off from the corner portion without adhering the carbon slurry 4 to the pin 2. Then, after the shaking off step, a predetermined drying step is performed, and a black pattern is formed by the method described above.

After that, for example, a green phosphor slurry is applied, dried, exposed through a color selection electrode, and developed to form a green phosphor layer (a phosphor stripe or a phosphor) at a position between predetermined carbon films. Dots), and thereafter, similarly, a blue phosphor layer and a red phosphor layer are formed at positions between other predetermined carbon films, respectively. After that, an intermediate film is applied and formed, and a metal back layer of Al is formed to form a desired color phosphor screen.

As described above, according to the method of this embodiment, a black pattern can be formed without adhering carbon to the pins 2 for mounting the color selection electrodes, so that it is necessary to perform pin trimming in a later step. Therefore, the manufacturing equipment and manufacturing process can be simplified. Further, since carbon is not attached to the pin 2 at all, deterioration of breakdown voltage (discharge, stray) of the cathode ray tube due to carbon powder can be prevented.

The method of the present invention is not limited to the above-mentioned embodiment but can be applied to various cathode ray tubes.

[0016]

As described above, in the present invention, the carbon slurry is injected with the inner surface of the panel facing upward,
Form a black pattern, that is, a light-absorbing film without adhering carbon to the pins for mounting the color selection electrodes by allowing the carbon slurry to flow out from the corners of the panel so as to avoid the pins of the panel and then shaking off the carbon slurry. As a result, there is no need for pin trimming in the subsequent process, and the manufacturing equipment and manufacturing process can be simplified. Further, since no carbon is attached to the pins for mounting the color selection electrodes, it is possible to prevent deterioration of the breakdown voltage (discharge, stray) of the cathode ray tube due to the carbon powder.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a coating process of a carbon slurry according to this embodiment.

FIG. 2 is an explanatory view showing another example of the step of shaking off the carbon slurry in the example.

FIG. 3 is an explanatory diagram showing a conventional carbon slurry coating process.

FIG. 4 is an explanatory view showing a state in which carbon attached to a pin is scraped.

[Explanation of symbols]

 1 panel 2 pin 4 carbon slurry

Claims (1)

[Claims] 1. A panel having a pin for mounting a color selection electrode is rotated with the inner surface thereof facing upward to inject carbon slurry into the inner surface of the panel, and then the rotation of the panel is stopped.
A method of manufacturing a cathode ray tube, which comprises the steps of tilting the panel so as to avoid the pins so that the carbon slurry flows out from the corners of the panel, and then rotating the panel to shake off the carbon slurry.