JPS60119055A - Manufacture of color cathode-ray tube - Google Patents

Abstract

PURPOSE:To achieve improved uniformity, color purity and luminance by repeating the procedure consisting of forming resist layers on areas other than those which are to be coated with desired phosphor layers before applying a phosphor slurry prior to performing exposure over the entire outer surface of the panel. CONSTITUTION:A light-absorbing layer 3 of a given pattern is formed on the inner surface of a panel 2. Next, a PVA photosensitive liquid 11 is applied to the entire inner surface before drying is performed. Exposure is performed twice by using an aperture grill 6 as an opticsl mask at the point when an exposure light source is positioned facing a blue light source and at the point when the light source is positioned facing a red light source. Next, development is performed to form a resist layer 11' consisting of a hardened PVA photosensitive film. A reversing agent for the hardened PVA photosensitive film 11' is H2O2. Next, a green phosphor slurry 12G prepared by adding a green phosphor to a photosensitive agent which is not reversed by H2O2 is applied to the entire inner surface of the panel 2. After that, exposure 13 is performed on the entire outer surface of the panel 2 before development is performed. When the development is performed by immersing the panel 2 in the reversing agent H2O2, only a green phosphor stripe 14G remains. The same procedure as above is performed to form each of a blue phosphor stripe and a red phosphor stripe.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for manufacturing a color cathode ray tube, and in particular to the formation of a color phosphor screen thereof.

Background Art and Problems In color cathode ray tubes, uniformity, contrast, and brightness must be improved in order to obtain high quality. The state of the phosphor screen contributes to these indirect factors.

Tsutomu, the phosphor screen in a color cathode ray tube, especially the so-called black matrix type color phosphor screen in which a light absorption layer is formed between red, green, and blue phosphor stripes (or dots), is formed as follows. be done.

First, apply PVA photosensitive liquid to ih1 inside the cathode ray tube panel.
After drying, using an aperture grill (or shadow masking color selection electrode as an optical mask), it is exposed to ultraviolet light and developed to form a large number of stripes (
or dot-shaped) resist layer is formed. In this exposure process, exposure is performed three times with the exposure light source shifted to correspond to the red, green, and blue light source positions, respectively. Next, resist Tta
After drying, the resist layer and the carbon layer thereon are subjected to lift-off (so-called reverse development) to form a carbon layer in a predetermined pattern. After that, for example, a green phosphor slurry 2, in which a green phosphor is suspended in a solution of polyvinyl alcohol (PVA) containing a small amount of ammonium dichromate (ADC), is applied to the inner surface of the panel and exposed to light. It is exposed to light through the above optical mask and developed to form green phosphor stripes (or dots) in the so-called white areas between the predetermined carbon layers, and in the same manner, blue and red phosphor stripes are formed in other white areas, respectively. The desired color phosphor screen is obtained by sequentially forming phosphor stripes (or dots 1). Figures A and B show the stripe-type color phosphor screen (1) formed in this way. (2) is a cathode ray tube panel, (
3) has a carbon stripe, and (4R), (4G), and (4B) have a red phosphor stripe, a green phosphor stripe, and a blue phosphor stripe, respectively.

By the way, in this conventional phosphor screen formation method, the phosphor film is baked through an optical mask (color selection electrode), so there are problems such as half shadows, and the adhesion between the phosphor film and the inner surface of the panel. Due to power issues, it is thin and has beautiful edges.
Moreover, it was difficult to form a fluorescent film with good packing density. Further, due to the diffraction of light during exposure, phosphor stripes (or dots) may be formed in a certain area of the panel 1h1 in a misaligned manner. Furthermore, looking at the actual operating state, in the ideal operating state (as designed) shown in Figure 1A, the electron beam (5) passes through the aperture grill (6).
is correct and there is no problem if, for example, a green phosphor stripe (4G) is irradiated, but in actual operation with various errors taken into account, the mislanding of the electron beam (5) may cause the irradiation of, for example, a green phosphor stripe (4G) as shown in Figure 1B. 4G), when the adjacent red phosphor stripe (4R
) also emit light, and that light leaks out, causing color mixture. As a result, improvements in C uniformity and color purity were hindered. In the conventional phosphor screen forming method, it is particularly difficult to form a phosphor screen with minute pinches such as those for high-definition tubes.

Purpose of the Invention In view of the above points, the present invention provides a method for manufacturing a color cathode ray tube that improves uniformity, single color purity, brightness, etc. in the formation of a phosphor screen, and makes it possible to form a high-definition color phosphor screen. It is something.

Summary of the Invention The present invention comprises a step of forming a light absorption layer in a predetermined pattern on the inner surface of a panel, and then forming a resist layer on a portion other than the portion to which the first color phosphor layer is coated; A process of applying a phosphor slurry made by mixing a first color phosphor into a photosensitizer that cannot be removed with a layer reversal agent, a process of exposing the entire panel to light from the outside surface and developing it, and a process using the above-mentioned reversal agent. and removing the phosphor in the other portions together with the resist layer to form a first color phosphor layer, and in the same manner ζ repeat the above steps to form at least a second color phosphor layer. This is a manufacturing method for color cathode ray tubes characterized by the following.

In this invention, each color phosphor layer is accurately formed, uniformity, nine color purity, brightness, etc. are improved, and it is possible to form a color phosphor layer with surface definition.

Embodiments]; Examples of the present invention will now be described with reference to the drawings.

In this example, the present invention is applied to a stripe-type color fluorescent device. First, as shown in Figure 3, a predetermined pattern of light absorption layer, that is, carbon stripe (3) is applied to the inner surface of the panel (2).
is deposited and formed in the same manner as described above.

That is, a PVA photosensitive liquid is applied to the inner surface of the panel, and after drying, an aperture grill (a color selection electrode with a large number of slit-shaped beam transmission holes arranged at a predetermined pitch) is used as an optical mask, and the light source position is set at each position. It is exposed to ultraviolet light three times at positions corresponding to red, green, and blue, and developed by washing with water to form a striped resist layer at positions corresponding to each color. Next, the entire surface including the resist layer is coated with carbon. After applying the slurry and drying, lift off the carbon layer on it together with the resist layer to form carbon stripes in a predetermined pattern (3).
form.

Next, as shown in Figure 3B, carbon stripe (3)
The entire inner surface of the panel, including polyvinyl alcohol (PVA) and ammonium dichromate (ADC), is coated with PV.
Apply photosensitive solution A (11) and dry.

Next, using the conventional exposure method as shown in Figure 3C,
Expose using the percha grill (6) as an optical mask. At this time, exposure is performed twice by shifting the exposure light source so as to correspond to the positions of the blue and red light sources, for example. Then, as shown in the third diagram, after processing, except for the part where the green phosphor stripe is to be formed, the other parts, that is, the part where the blue phosphor stripe and the red phosphor stripe are to be formed, are covered. Resist layer i.e. hardened PVA photoresist film (
11') is formed. This cured PVA photoresist film (11')
The reversal agent for is 11202.

Next, as shown in Section 3F, we use a photosensitizer that cannot be reversed (melted) with this H2O2, such as polyvinyl alcohol (PV).
Green phosphor slurry (1) made by mixing a green phosphor into a photosensitive liquid containing a stilbazolium group (S B K) in A)
2G) on the entire surface facing inward of the panel. Then, the entire surface of the panel (2) is exposed (13) from the outer surface.

Next, it is developed. As a result, ζ, the part corresponding to green (carbon stripe (4)
The first color green phosphor stripe (
14G) is formed. At this time, the cured PVA film (11
') is transparent, green phosphor (14G
') remains.

Next, the material in the state of 3F is immersed in reversal agent 11202 and developed. Due to this reversal development, only the cured PVA photosensitive film (11') decomposes due to the difference in reversal ability, and the cured PVA photosensitive film (11') decomposes due to the difference in reversal ability.
The green phosphor (14G') on the photoresist film (11')
) are removed. As a result, a green phosphor stripe (1
4G) remains. - Then harden the green phosphor stripes (14G). This hardening process involves washing the entire surface with a hardening agent such as boric acid, or
There are methods such as heating at 0°C.

Thereafter, the same steps (3F to 3G) are repeated to form blue phosphor stripes (14B) and red phosphor stripes (14R), and as shown in 3F, the desired color phosphor Obtain surface (15).

In this example, the first photosensitizer used in 3F and the second photosensitizer used in the phosphor slurry are a combination of a first photosensitizer made of PVA and ADC and a second photosensitizer made of PVA and SBK. was used, but other combinations such as PV
A and the first photosensitizer by ADC and polyvinylpyrrolidone (
A combination of ff12 photosensitizers with PVP) and azide photosensitizers can also be used. That is, in Kenpo, it is possible to create a color fluorescent screen by using two types of photosensitizers that have different reversal abilities.

In addition, when regenerating the fluorescent direction due to defects etc. after creating the fluorescent direction, use other reversing agents such as periodic acid, which is an oxidizing agent,
), it is possible to decompose a phosphor stripe using a photosensitive agent of PVA+SBK.

Moreover, although the over-layering method has been applied to the formation of a stripe-type color phosphor screen using an aperture grill, it is of course applicable to the formation of a dot-type color phosphor screen using a shadow mask.

Furthermore, in the top stripping process from 3rd F to 3rd drawing, a negative type photosensitive agent was used and exposed twice to form a resist layer (11') in the portions corresponding to ζ blue and red, but other than positive type It is also possible to form the resist I[(11') in the part corresponding to the helmet and red by exposing once at the position of the green light source using a photosensitive agent. In this case, since only one exposure is required, the manufacturing process can be simplified.

Effects of the Invention According to the present invention described above, when exposing the phosphor slurry, the edge of the light absorption layer is used as an optical mask to expose the entire surface from the outside of the panel, so that the adhesive strength to the inner surface of the panel is high and the phosphor slurry has a good packing density. Body stripes (or dots) can be formed. This can improve brightness.

Further, the edges of the phosphor stripes (or dots) can be made clean, and the desired thin phosphor stripes (or dots) can be formed. Furthermore, since the light absorption layer and the phosphor stripes (or dots) are formed by self-alignment, there is no need to worry about mutual misalignment. These lead to improvements in uniformity and color purity.

In addition, the amount of phosphor deposited on the light absorption layer is reduced, so the amount of phosphor used is reduced, and costs can be reduced.

Furthermore, phosphor stripes (or dots) for second and subsequent colors
In the preparation of the phosphor strips (or dots), the previously applied phosphor stripes (or dots) are covered with a reversible resist layer, so no color mixing occurs.

In addition, when looking at actual operating conditions, not only the ideal state shown in FIG. 2 but also various errors in FIG.

It is not affected by mislanding of the electron beam (5) caused by other factors. That is, even if there is a mis-landing, there is no problem as long as it is within the allowance in the light absorption layer (3), and the uniformity one color purity can be improved.

Therefore, the present invention is particularly suitable for use in forming finely pinched color phosphor screens in Western quality 111+ definition tubes.

[BRIEF DESCRIPTION OF THE DRAWINGS] Figures 1A and B are cross-sectional views showing an example of a conventional color phosphor screen in actual operation, and Figures 2A and B are sectional views of a color phosphor screen obtained by the present invention. An example of the dynamic state is not shown...The first view and Figures 3 A to 4 are W' of the manufacturing process of the color phosphor screen of the present invention.
It is a front view. (2) is the panel, (3) is the light absorption layer, (11') is the resist layer, (12G) is the green phosphor slurry, (141?
). (14G) and (14B) are red, green and blue phosphors. Figure 1A Figure 2A Figure 1B Figure 2B2 Figure 3

Claims (1)

[Claims] After forming a light absorption layer with a predetermined pattern on the inner surface of the panel,
A step of forming a resist layer on areas other than the area where the first color phosphor layer is applied, and mixing the first color phosphor into a photosensitizer that cannot be removed by the reversing agent of the resist layer. The process includes a step of applying a phosphor slurry, a step of exposing the entire panel from the outside surface to light and developing it, and a step of removing the phosphor in the other parts along with the resist layer using the reversing agent. 1. A method for manufacturing a color cathode ray tube, comprising forming a phosphor layer of a second color, and similarly forming a phosphor layer of at least a second color by repeating the above steps.