JPS6036057B2 - How to make fluorescent surfaces for television picture tubes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a step of exposing a photoresist film formed on a face plate on the inner surface of a panel of a television picture tube to form a temporary pattern of phosphor or light-absorbing material. By controlling the amount to an appropriate value, a mask with different distances from the face plate for each layer, such as a cylindrical mask, is used to produce a temporary pattern with a uniform stripe width. Regarding the method.

Generally, the manufacturing process for the striped phosphor screen of a television picture tube, for example a black matrix television picture tube, involves forming a photoresist film on the face plate of a panel made of glass or the like by means such as a spin coating method. Ultraviolet light from a point or linear exposure light source such as a mercury lamp that is sensitive to light is irradiated onto the photoresist film through the transmission grooves of a mask having a striped pattern,
Portions of the photoresist coating attached to predetermined locations on the face plate on which phosphors will later be attached are exposed to light and cured.

Next, the non-exposed portions of the photoresist film are melted and removed, a striped temporary pattern is formed using the exposed portions of the photoresist film, and a light beam such as graphite is applied to the exposed portions of the photoresist film and the entire surface of the face plate. Apply absorbent material and dry. Then, the exposed portion of the photoresist film is melted and swollen with a stripping agent, and further,
A high-pressure water spray removes the exposed portion of the photoresist film as well as the light-absorbing material adhering to its upper surface, forming a striped pattern of light-absorbing film, ie, a black matrix, on the face plate. Thereafter, the same process as described above is repeated three times to attach green, blue, and red phosphors in stripes to the gaps between each light-absorbing coating, resulting in a striped phosphor screen. . Note that, contrary to the above, a black matrix may be formed after three types of phosphors are attached to the face plate in stripes, and the manufacturing process is the same as that described above. By the way, what is important in terms of the quality of television picture tubes is the uniformity of the stripe width of each light-absorbing film and each phosphor formed in a striped pattern on the face plate. The method is to expose a certain stripe apart, and for that purpose,
It is necessary to arrange the face plate and the mask so that the distance between them is constant, and conventionally, a shadow mask is used which is formed so that the distance between the face plate and the mask is constant.

However, since the panel of a television picture tube generally has a shape with a spherical curvature, creating a shadow mask with a spherical surface of the same curvature as the panel would result in distortion, and normally each panel and each shadow mask would be distorted. are paired, and 1
The drawback is that a single shadow mask cannot be shared by multiple panels. In the case of a cylindrical surface with a cylindrical curvature, a flat mask can be easily transformed into a cylindrical surface without distortion, and can be used in the same way as a shadow mask, but in reality, a panel with an accurate cylindrical surface can be used. cannot be considered due to its strength, and spherical panels are common. The present invention takes into consideration the above-mentioned conventional problems, and uses a mask in which the distance between the mask and the panel differs depending on the location, without using a shadow mask, and controls the exposure amount of the photoresist film to an appropriate value. This makes it possible to perform exposure with a constant stripe width.Next, this invention will be explained in detail with reference to the drawings showing one embodiment thereof.

FIG. 1 shows the arrangement of a spherical panel 1 and a mask 2. The shape of the mask 2 is such that a striped pattern of transmission grooves (not shown) is formed on a flat plate, and then a curvature is formed in a direction perpendicular to the transmission groove. Moreover, the cylindrical surface is curved so that the center of curvature is the same as the center of curvature of the spherical panel 2.

Figure A shows a sectional view taken in a direction parallel to the transmission grooves of the mask 2, and Figure B shows a sectional view taken in a direction perpendicular to the transmission grooves.The light source 3 is a point light source located at the center of curvature of the spherical panel. shall be. Therefore, as is clear from Figure a,
The distance between the face plate 1' of the spherical panel and the transmission groove of the mask is not constant. Next, Figure 2 shows mask 2.
It shows the luminous intensity distribution of the light spot that passed through the transmission groove 2' in the direction perpendicular to the stripe direction of the transmission groove 2', and the distance between the mask and the 4 sides of the photoresist coating formed on the face plate 1' of the panel 1. Let d be the width of the light source 3, W be the width of the light source 3, and let the distance between the mask and the light source 3 be 1.

When the photoresist coating 4 is exposed to light in this arrangement, the profile of the light intensity distribution on the photoresist coating 4 becomes trapezoidal, as shown by A. Next, the light intensity distribution will be explained with reference to FIG. 3, which is an enlarged view of profile A. Now, the width of the true shadow area where the light intensity is maximum is Dm
in, and if the width of the penumbra where the light intensity becomes zero is Dmax, then Dmjn:a+(a-W)d'1. ．． -. ．． -
(a) Dmax=a+(a+W)d'1...
・．．・It becomes {o}.

Furthermore, if Eo is the limit exposure amount of the photoresist film 4, which is the minimum exposure amount required for the photoresist film 4 to adhere and remain on the face plate 1' when the exposed photoresist film 4 is developed, then The stripe width of the temporary pattern formed by the film 4 is D as is clear from the figure. Then, the exposure amount of the true shadow area (
If E is the exposure amount when the mask 2 is removed (in general, a light control filter is used to maintain a constant value over the entire face plate 1' of the panel 1), then the temporary pattern of stripes formed by the photoresist film 4 is The width D is D:a+
(a+W-2WEo/E)d'1.・---It is expressed by the following formula.

In the above set, the mask 2 and the face plate 1'
If the distance d between the upper photoresist film 4 and the distance between the face plate 1' of the panel and the mask 2 is not constant as shown in FIG. Although it varies, it can be resolved by setting the exposure amount E of the photoresist film 4 to a certain condition. That is, a+W-2WEo/E=0...
...If the relational expression 9 holds, then the set becomes D=a, and even though the distance d is constant, the stripe width D of the temporary pattern formed by the photoresist film 4 is equal to the transmission groove 2' of the mask 2. is the same as the width a of the face plate 1'
A temporary pattern with the same stripe width D is obtained over the entire surface.

In order to establish the above-mentioned Japanese formula, the exposure amount E must be
E=2WEo/(a+W)...You can use it as a mouse.

That is, the exposure amount E of the photoresist film 4 may be set to 2W' (a+W) times the limit exposure amount Eo of the photoresist film 4. For example, the width a of the exposure amount 2' of the mask 2 is set to 0.
If the width W of the light source 3 is 1.0 ribs, then E=
By exposing the photoresist film 4 with an exposure amount E that is 1.74 times the limit exposure amount Eo, the amount becomes 0.75o.
A temporary pattern with a uniform stripe width of 15 willows can be obtained. Further, the limit exposure amount Eo of the photoresist film 4 can be easily determined experimentally, and will be a constant value if the type of photoresist film 4, the formation conditions, etc. are the same, and the light source 3 is the same. Once a temporary pattern with a uniform stripe width is formed using the photoresist film 4, a phosphor screen with three-color lines is formed by applying phosphor to the area from which the temporary pattern has been removed in the same process as described above. be done. Note that the light source 3 is not limited to a point light source, but a line light source parallel to the transmission groove 2' of the mask 2 can also achieve the same effect. Of course, similar effects can be obtained not only during formation but also during exposure of the photoresist film during the formation of a temporary pattern of phosphors.

As described above, according to the phosphor screen manufacturing method of the present invention, in the step of forming a photoresist film on the face plate of a panel and exposing the photoresist film to light from a light source through transmission grooves in a striped pattern of a mask, , when the width of the light source is W and the width of the transmission groove of the mask is a, the exposure amount of the photoresist film is increased by 2W/a+W times the limit exposure amount of the photoresist film, and the exposed or non-exposed portion of the photoresist film is By applying phosphor to the removed portion to create a striped phosphor screen, the photoresist film can be easily removed even when the photoresist film is exposed through the transmission groove of a mask where the distance between the mask and the face plate is not constant. By setting the exposure amount to an appropriate value, it is possible to expose a pattern with a uniform stripe width, and the stripe width of the phosphor formed on the exposed portion of the photoresist film or the portion where the non-exposed portion has been removed is made constant. In addition, one mask can be shared by many panels.

Furthermore, the invention can be applied to both spherical panels and cylindrical panels, and the present invention provides an inexpensive and high-quality method for producing a phosphor screen for a television picture tube.

[Brief explanation of drawings]

The drawings show an embodiment of the method for manufacturing a phosphor screen of a television picture tube according to the present invention, and FIG. 1 shows the arrangement of a panel and a mask, and FIG. , Figure b is a cross-sectional view cut perpendicular to the stripe direction of the transmission grooves of the mask, Figure 2 is an explanatory diagram of the profile of the light intensity distribution of the light spot in the direction perpendicular to the stripe direction of the transmission grooves of the mask, and Figure 3 The figure is an explanatory diagram of the exposure amount and the stripe width of the temporary pattern according to the profile of FIG. 2. 1... Panel, 1'... Face plate, 2...
...Mask, 2'... Transmission groove, 3...
Light source, 4... ...Photoresist coating. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. In the step of forming a photoresist film on the face plate of the panel and exposing the photoresist film to light from a light source through transmission grooves in a striped pattern of a mask, the width of the light source is W, and the transmission groove of the mask is When the width of the photoresist film is a, the exposure amount of the photoresist film is 2W/a with respect to the limit exposure amount of the photoresist film.
A method for manufacturing a phosphor screen for a television picture tube, characterized in that the photoresist film is multiplied by +W, and a phosphor is applied to the exposed portion or the non-exposed portion of the photoresist film to produce a striped phosphor screen.