JPH03129635A - Exposure method for image screen of color picture tube - Google Patents

Abstract

PURPOSE:To enhance tolerance in forming a black matrix(BM) film and adhesive strength in forming a phosphor(PH) film and prevent both the films from deviating from the positions, by performing exposure at the time of forming the BM film keeping a greater distance between a light source and a shadow mask than at the time of forming the PH film. CONSTITUTION:An exposure unit having a diameter A of a light source larger than that in forming a phosphor(PH) film stripe 7 is exposed in forming a black matrix(BM) film stripe 6. Therefore, tolerance in forming the BM film strip 6 as well as adhesive strength of the PH film stripe 7 can be enhanced. Since the difference in thickness between a photoresist and a phosphor slurry is considerable, exposure is performed at the time of forming the BM film, keeping a greater distance between the light source and a shadow mask than at the time of forming the PH film in consideration of the difference, thereby preventing the PH film and the BM film from deviating from the positions.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for exposing a color picture tube video screen.

The exposure method for forming the fluorescent film, which is the image screen of a color picture tube, is a black matrix film (hereinafter referred to as 8
The method of forming the 8M film and the fluorescent film (hereinafter referred to as PHIl!!) under the same conditions eliminates the misalignment of the 8M film and the PH film, and also eliminates the need for extraction pressure. However, the thickness of the photoresist when forming the BM film is, for example, 0.6
The film thickness of the phosphor slurry during formation of the PH film is, for example, about 30 μm, whereas the photoresist film 71. In addition, the photoresist and phosphor slurry have different photosensitive characteristics, and the 8M film is smaller than the aperture of the shadow mask.In other words, in the case of a slot-shaped aperture, the width of the 8M film is the width of the slot cap. In the case of a smaller, circular aperture, the diameter of the BM protrusion is smaller than the circular diameter, and the PH film is larger than the shadow mask aperture due to film thickness.In other words, in the case of a slot-shaped aperture, the width of the PH film is smaller than the slot. In the case of circular apertures, the pH value of 111 is larger than the diameter of the circular aperture, so forming the pores under the same conditions increases the margin of BM film formation and increases the ) The adhesive strength (illuminance x time) of i-film formation is disadvantageous.

The present invention has been made against the above background, and is a color picture tube image screen that can improve the margin of bM film formation and the adhesion strength of PH film formation, as well as prevent misalignment of the 8M film and PH film. The purpose of this invention is to provide an exposure method.

Hereinafter, the present invention will be explained with reference to an illustrated embodiment.

As shown in Figure 1, the fluorescent surface formation of a color picture tube is
The photoresist or phosphor slurry 2 coated on the inner surface of the panel 1 is exposed to light in the slit pattern 5 of the openings formed in the shadow mask 4 using an exposure device using a mercury lamp as direct linear light ij, g3. , as shown in Figure 2, BMll! a stripe 6 and PH [forming stripe 7].

At this time, the minimum exposure range Dmax and minimum exposure range Dmin of the light spot 8 are the diameter of the light source 3 as A, the slit width of the slit pattern 5 as B, the distance from the light source 3 to the shadow mask 4 as P, and the distance from the shadow mask 4 as P. Letting Q be the distance to the inner surface of the panel 1, it is approximately geometrically expressed by the following equation.

Dmax=(B+A)XQ/)'+BDmin=(
B A) XQ/P+B This relationship is illustrated as shown in FIG.

Now, the width C of the BM film stripe 6 is formed to be smaller than the width of the electron beam, that is, smaller than the slit width B of the slit pattern 5, in order to improve the purity margin. To explain this with reference to FIG. 3, the light spot 9
Exposure should be made at Dmin. That is,
As the light source diameter A increases, Dmin decreases, which is advantageous for forming small BMI′lA stripes 6.

In order to form the PH film stripes 7, a sufficient amount of light is required because a thick phosphor slurry with an exhaustion of, for example, 30 μm is exposed to light. To explain this with reference to FIG. 3, increasing the exposure amount will result in exposure at Dmax. That is, although the width E of the PHrlA stripe 7 is larger than the slit width B of the slit pattern 5,
The maximum width is set to a width that does not protrude into adjacent PH film stripes 7. For this purpose, Dmax should be as small as possible,
The smaller the difference between Dmin and Dmax, the more advantageous it becomes.

To compensate for this, it is better to have a smaller light source diameter A.

Therefore, when forming the BMl 1% stripe 6, by performing exposure with an exposure device equipped with a larger light source diameter A than when forming the formed film stripe 7, the margin for forming the BM film stripe 6 is improved, and the margin for forming the PH film stripe 7 is improved. Improves adhesive strength. In addition, since there is a considerable difference in the thickness of the photoresist film and the film thickness of the phosphor slurry, the distance between the light source and the shadow mask should be adjusted in consideration of the thickness of the photoresist and the phosphor slurry.
By making the dimensions different during film formation, misalignment of the PH film and the 8M film can be prevented. That is, as shown in Figure 4, a
When the photoresist film 2a is exposed from the point light source 3 through the slit pattern 5 of the aperture of the shadow mask 4, A is obtained.
The point is exposed to light, and an 8M film centered on this point A is formed. On the other hand, if the phosphor film 2b is exposed from point a, which is the same as the exposure of the 8M film, due to the difference in film thickness, the exposure will be centered on point A1, and a PH film will be formed centered on point A1, and the 8M film and PH film will be exposed at point A1. A positional shift occurs by the distance. Therefore, the light source 3 at point b, which is closer to the shadow mask 4 than point a, is configured to expose the fluorescent film 2b to point 0 whose center coincides with point A.
By performing this step, it is possible to prevent misalignment between the BMM and the PH film. For example, the light source diameter A is 1.5++aφ when forming BM film stripe 6, and 0.
9m+φ, respectively, and the distance P from the light source 3 to the shadow mask 4 is BMl! i! When the stripe 6 was formed 0.3 m larger than the PH film stripe 7 to correct the exposure position shift, satisfactory results were obtained. Here, BM film stripe 6 due to the difference in light source diameter
The exposure position deviation between the PH film strip 7 and the PH film strip 7 can be dealt with by changing the distance #IP as described above, but it can also be dealt with by changing the thickness of the correction lens and the glass plate (not shown). . In addition, to prevent positional deviation, the light source diameter is 8.
M membrane and PH1i! i! may be the same.

By changing the distance between the light source and the shadow mask in this way, BM film stripe 6 and PH film stripe 7 can be formed.
Although the quality of formation can be improved, when forming a striped fluorescent surface, a slit pattern 5 as shown in FIG.
The bridge portion 9 in the longitudinal direction may be deleted. In order to erase this bridge part 9, if the pitch of the bridge part 9 is F and the length of the linear light source 3 is α, then 12=(P+
Q)/Q-? A linear light source 3 with a length of ' is required.

However, if the length Q of the linear light source 3 is the same when the BM film stripe 6 is formed and when the PH film stripe 7 is formed, the effective surface of the PH film stripe 7 becomes longer than the BH film stripe 6. Since it is formed small in the direction, a non-light emitting part occurs at the end in the longitudinal direction, which becomes a drawback of the fluorescent surface. This means that from the light source length Q during exposure of 8M film stripe 6, the light source length during exposure of PH film stripe 7 is
For example, by increasing the length by 3 to 4 wm, the non-light emitting part could be removed. Further, this problem can be dealt with by increasing the moving distance of the light source without changing the length Q of the light source during vfJjIg light.

In the above embodiments, a stripe type color picture tube has been described, but the present invention can also be applied to forming a fluorescent surface of a dot type color picture tube.

As is clear from the above explanation, according to the method of the present invention,
The latitude for forming the 8M film is improved, the adhesive strength of PHPtA is improved, and misalignment of both films can be prevented.

[Brief explanation of the drawing]

The figures show an example of the method according to the present invention, Fig. 1 is an IM diagram of the straight-edge method, Fig. 2 is a plan view of the stripe type tip, and Fig. 3 is an explanation showing the exposure intensity. Figure, 4th
The figure is a principle explanatory diagram for explaining the position of the light source and the axis point,
FIG. 5 is a principle explanatory diagram showing the length of the edge line light source for erasing the bridge portion of the shadow mask. 1... Panel, 2... Photoresist or phosphor slurry 3... Linear light source, 4... Shadow mask, 5... Slit pattern, 6... BMIi stripe type... PH1l! 4-strike diagram diagram diagram diagram diagram diagram

Claims (1)

[Claims] 1. A color picture tube video screen in which the photoresist and phosphor slurry coated on the inner surface of the panel are exposed to light from a light source through the apertures of a shadow mask to form a black matrix film and a phosphor film using an exposure device, respectively. An exposure method for a color picture tube video screen, characterized in that when forming the black matrix film, the distance between the light source and the shadow mask is made larger than when forming the fluorescent film.