JPS5848984B2 - Color ink print screen - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a screen for a color cathode ray tube equipped with electrodes for determining the electron beam arrival position, such as a shadow mask and an aperture grill.

In this type of color cathode ray tube, a fairly large portion (for example, about 80% of the total electron beam) is emitted from the electron gun.
%) collides with the shadow mask or aperture grille, which becomes quite hot and generates radiant heat.

However, since a metal back is formed on the phosphor layer, the radiant heat is reflected by the metal back and returned to the shadow mask or aperture grill, resulting in poor heat dissipation from the shadow mask or aperture grill. Therefore, thermal expansion accelerates deformation, which increases mislanding of the electron beam (resulting in color shift on the screen).

Therefore, a conventional practice has been to form a heat absorbing material layer on the metal back in an attempt to suppress the above-mentioned problems as much as possible.

As an example, a method has been proposed in which a heat absorption layer is formed by directly applying an aqueous suspension of carbon onto a metal back.

However, this method penetrates the phosphor layer through the gap in the metal back, increasing the brightness of the cathode ray tube by e.g.
It has the disadvantage that it decreases by as much as 0%.

Therefore, in order to solve this problem, we applied a water-based emulsion of acrylic resin on the metal back in advance to form a water-repellent film, and then coated a water-based carbon suspension on top of it to form a heat-absorbing layer. Conventionally, methods have been proposed to form .

However, this method has the disadvantage that the aqueous suspension of carbon is repelled by the water-repellent coating, making its application extremely difficult.

In view of these points, the present invention provides a color cathode ray that allows a heat absorbing material layer to be easily and reliably deposited on a metal back with a desired thickness, and that does not cause a decrease in brightness. This paper aims to propose a method for manufacturing pipe screens.

The present invention will now be described in detail with reference to FIG. 1, with reference to one embodiment thereof.

In FIG. 1, 1 is a panel (glass) of a color cathode ray tube (equipped with electrodes for determining the electron beam arrival position such as a shadow mask and aperture grill), on which a phosphor layer 2 is adhered. has been done.

This phosphor layer 2 consists of phosphors (delta arrangement dots or stripes) of three colors: red, green, and blue.

On this phosphor layer 2, aluminum or the like is deposited by vapor deposition.
A metal bag 3 is deposited.

In the present invention, a water-repellent polymer layer 4 is deposited on the metal bag 3, and a hydrophilic polymer layer 5 is deposited on the water-repellent polymer layer 4, or A heat absorbing material layer 6 is formed on the hydrophilic polymer layer 5.

After that, baking is performed.

The water-repellent polymer layer 4 is made of, for example, acrylic emulsion (trade name Primal C-72) on the metal bag 3.
1 part and 10 to 30 parts of water) (for example, by a spin coating method).

The hydrophilic polymer layer 5 is formed on the water-repellent polymer layer 4 by, for example, a polyvinyl alcohol aqueous solution (1 part of polyvinyl alcohol, 0.001 to 0.0 parts of ammonium dichromate).
．． This layer is formed by coating (eg, by spin coating) an aqueous solution consisting of 500 to 2,000 parts of water and 500 to 2000 parts of water and exposing it to light.

The heat absorbing material layer 6 is made of, for example, carbon suspension (trade name: Aquadakku) 1 on the hydrophilic polymer layer 5.
This layer is formed by applying (for example, by spin coating) an aqueous solution consisting of 1.5 parts and 5 to 20 parts of water.

Note that water, polyvinyl alcohol, and primal disappear after baking.

Next, a comparison of characteristics between a color cathode ray tube in which a heat absorbing material layer is formed on a metal back as in the above embodiment and a color cathode ray tube in which a heat absorbing material layer is not formed will be explained.

The color cathode ray tube used is a 22-inch tube, with an acceleration voltage of 27kV.
, and a cathode current of 1.2 mA.

Figure 2 shows the characteristic curve of the drift (C) of the landing position of the electron beam on the phosphor versus time (minutes), and Figure 3 shows the panel temperature (°C) versus time (minutes).
) shows the characteristic curve of change.

Curves 7 and 9 are for a color cathode ray tube without a heat absorbing material layer, and curves 8 and 10 are for a color cathode ray tube with a heat absorbing material layer.

From these figures 2 and 3, it can be seen that in the color cathode ray tube obtained according to the present invention, the heat absorbed by the heat absorbing material layer from the shadow mask or the aperture grill is transferred to the panel and is well radiated to the outside. (The temperature of the panel is higher than that without a heat-absorbing material layer.)
It can be seen that the drift of the landing position of the electron beam on the phosphor is much smaller than that in the case where no heat absorbing material layer is provided.

Furthermore, as the size of the cathode ray tube increases (the above-mentioned drift is larger for dog-shaped tubes), the panel (glass) 1 becomes thicker, so the heat capacity per unit area also increases, and therefore the heat dissipation effect of the heat absorbing material 6 increases. Therefore, the above-mentioned drift reduction effect becomes even more significant.

According to the present invention described above, the heat absorbing material layer can be easily and reliably deposited on the metal pack with a desired thickness.

Thus, according to the present invention, a color cathode ray tube with less color shift due to mislanding of the electron beam can be realized due to good heat dissipation of the electron beam position determining electrode such as a shadow mask or aperture grill without reducing brightness. Obtainable.

[Brief explanation of drawings]

Figure 1 is a sectional view for explaining the present invention, Figures 2 and 3 are
The figure is a curve diagram showing the characteristics of a color cathode ray tube obtained according to the present invention and a color cathode ray tube without a heat absorbing material layer. 1 is a panel, 2 is a fluorescent layer, 3 is a metal back, 4 is a water-repellent polymer layer, 5 is a hydrophilic polymer layer, and 6 is a heat-absorbing material layer.

Claims (1)

[Claims] 1. A water-repellent polymer layer is deposited on the metal back, a hydrophilic polymer layer is deposited on the water-repellent polymer layer, and a hydrophilic polymer layer is deposited on the hydrophilic polymer layer. A method for manufacturing a color cathode ray tube screen, characterized in that a heat absorbing material layer is deposited on the screen.