JPS5845776B2 - Method and apparatus for forming a fluorescent surface for color picture tubes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a fluorescent surface for a color picture tube, particularly a black matrix type fluorescent surface, and an apparatus for forming the same.

In general, a black matrix type fluorescent surface includes a light-absorbing film selectively formed to have a large number of spaces consisting of perforations or stripes, and three types of dot-shaped or striped holes filled in the spaces. It consists of a striped phosphor film and is formed by the procedure described below.

That is, first, a photosensitive resin liquid made of polyvinyl alcohol and dichromate is uniformly applied to the inner surface of a rough ace panel to form a photosensitive resin film thereon.

Next, a shadow mask is mounted inside the face panel, and an exposure light source installed at a position that is to be the center of deflection of the three electron beams is turned on.

By turning on the light source at three deflection center positions, the photosensitive resin film is selectively exposed, and the film portions at the exposed points are cured.

Next, when a water development treatment is performed, only the hardened resin film portion remains on the inner surface of the face panel, so a graphite film is then uniformly applied and formed on the resin film.

Then, when hydrogen peroxide is applied to swell the resin film below the graphite film, and development treatment with water is performed again, the resin film and the graphite film portion located directly above it are removed. A light-absorbing film with a black matrix, a glass, and a large number of spaces is obtained.

Next, three types of phosphor films emitting red, blue, and green light are attached within the space of this light-absorbing film.

In FIG. 1, a light-absorbing film is shown as a thick dashed line and a phosphor film is attached within the space 1 of this film.

In the phosphor film application step, the phosphor film 3 is uniformly coated on the inner surface of the face panel 2 without any trenches so that the phosphor film 3 covers the light-absorbing film.

Then, the shadow mask 4 is attached to a predetermined position, and the light emitted from the exposure light source 5 is applied to the photosensitive phosphor film 3 through the correction lens 6 button and the shadow mask 4.

Then, through the development process performed after this selective exposure process,
Since one type of dot-shaped or stripe-shaped phosphor film is completed, the remaining two types of phosphor films are applied in the same manner as described above.

The illuminance distribution on the photosensitive phosphor film 3 during the selective exposure process is as shown by the curve 7 in FIG.

Since a reciprocity law holds between illuminance and exposure, the exposure distribution can be discussed in terms of illuminance distribution.

The light intensity level Ia in FIG. 2 means that if the development process is performed based on this level, a dot-shaped phosphor film portion with the same width as the space G will be obtained for the space G of the light-absorbing film. are doing.

The light intensity level Ic means that if the development process is performed based on this, a phosphor film portion with a width that touches the adjacent space R1 or B will be obtained for the space G, and the light intensity level I
b indicates the middle of the two light intensity levels Ia and Ic.

Therefore, in order to obtain a good phosphor film, it is necessary to keep the zA level within the range.

On the other hand, in order to increase the brightness of the phosphor surface, it is necessary to increase the space of the light-absorbing film as much as possible to increase the effective light-emitting area of the phosphor film.

Since the phosphor film usually overlaps a part of the light-absorbing film, when the width of the light-absorbing film part is reduced from Ml to M2, the phosphor film in part a overlaps with the adjacent space R1 or B. It may stick out.

Furthermore, the phosphor film in some parts may be chipped.

Therefore, when the width is set to M2, it is necessary to compress the level range ZA into the level range ZB, and in this case, manufacturing accuracy becomes very strict.

As a measure to eliminate this drawback, it is conceivable to supplement the light from the outside and change the illuminance distribution to the one shown by curve 8 in FIG. 2.

In the configuration shown in FIG. 3, in addition to the conventional exposure light source 5, an auxiliary light source 5' is installed on the outer surface of the face panel 2.

In another example shown in FIG. 4, an omnidirectional reflector 9 having a reflective surface along the outer surface of the panel is installed on the outer surface of the face panel 2. The exposure light beam that has passed through the face panel 2 without being absorbed by the body membrane 3 is reflected toward the phosphor film 3 side by the reflective surface of the reflector plate 9 and becomes a supplementary light beam.

However, in the auxiliary light source method shown in FIG.
Since the light uniformly illuminates the face panel 2, not only the portion of the phosphor film in a predetermined space of the light-absorbing film but also the portion of the phosphor film in an adjacent space is exposed. This results in poor color mixing due to fogging.

Further, in the reflection exposure method shown in FIG. 4, it refers to an unfavorable result in areas other than the central area C1 of the face panel 2.

That is, in the central region C1, the light rays that have passed through the space G and have been reflected by the reflective surface of the reflector plate 9 are reflected back to the original space G, but in the peripheral regions C2 and C3, the light rays 11 that have passed through the space G The light becomes reflected light r1 on the reflective surface of the reflector plate 90 and is deflected outward, resulting in poor color mixing.

The present invention has been made with the above-mentioned points in mind,
Next, the present invention will be explained along with embodiments shown in the drawings.

The reflector 10 shown in FIG. 5 includes an elongated reflector body 10' having a reflecting surface having a rectangular cross section as shown in FIG. The structure is such that a large number of them are arranged in parallel so that they are arranged in succession.

The reflector body 10' has one reflecting surface 1 as shown in FIG.
1 is reflected toward the other reflective surface 12, which is perpendicular to the reflective surface 11, so that the reflected light ray r1 reflected from the reflective surface 12 passes through a trajectory parallel to the incident light ray 11 and reaches the face panel side. Proceed to and become a supplementary ray.

FIGS. 8 to 11 show the space G of the light-absorbing film.

Incident light rays 11, 12, 13 and reflected light rays r1 r r2 when the widths of R and B and the width of the light-absorbing film portion 13 between the spaces are constant and the size of the reflector body is changed.
+r3, where the opening width of the reflector body is P1, the arrangement pitch of the space of the light absorbing film is H1, and the maximum width of the space of the light absorbing film is D.

FIG. 8 shows the case where P>HD, and the incident light ray 13 into the space G becomes a reflected light ray r3 on the reflective surface of the reflector body,
There is no problem because it is absorbed by the light-absorbing film portion 13, but the incident light ray 11 becomes a reflected light ray r1 and is reflected in the adjacent space R.
This is not a good thing because it will be incident on the

Figure 9 shows the case where P=H-D, and Figure 10 shows the case where P<H-
This is the case of D.

In these cases, the width of the opening of the reflector element is not wider than the width of the light-absorbing film portion 13, so that the incident light rays 11, 12, 13, etc., into the space G are The reflected light rays r11 r2 t r3... on the reflective surface of the reflector body.
. . . and enters the original space G, so no defective color mixture occurs.

Figure 11 shows the case of P2H, and although it is inconvenient to install the reflector body on the outer surface of the face panel in accordance with the arrangement pitch of the light-absorbing film part, a good fluorescent surface is obtained. is obtained.

Therefore, in order to prevent the light rays that have passed through the space G where the light-absorbing film is located from entering spaces other than the original space G after being reflected by the reflector, the opening width P of the reflector body must be adjusted to It is necessary to make the width of the light absorbing film portion interposed between the spaces (H-D) or less, or equal to the arrangement pitch H of the spaces, and a reflector element that satisfies this condition is When a large number of continuously arranged reflectors are installed on the outer surface of the face panel as shown in FIG. 6, and the light rays emitted from the exposure light source and passed through the shadow mask are applied to the photosensitive phosphor film, the photosensitive phosphor film is exposed. The light that passes through the face panel without being absorbed by the light film is reflected by the reflector, and this reflected light accelerates the curing of the photosensitive phosphor film, resulting in dots without fogging or chipping. It becomes possible to efficiently form a phosphor film in the form of a shape or a stripe shape.

Note that such a reflector is installed on the outer surface of the face panel so that its vertical lines are parallel to the longitudinal axis of the shadow mask slits, but the reflector body extends over the entire area of the reflector. They do not need to be arranged, and can be arranged only in the fluorescent peripheral region or other regions that are particularly problematic for forming a fluorescent surface.

[Brief explanation of drawings]

Figure 1 is a block diagram for explaining the conventional method of forming a fluorescent surface, Figure 2 is a diagram showing the illuminance distribution on a photosensitive phosphor film, and Figure 3 is a diagram showing the illuminance distribution on a photosensitive phosphor film.
4 and 4 are respectively a block diagram and an explanatory diagram for explaining a conventional fluorescent surface forming method, FIG. 5 is a block diagram for explaining an embodiment of the present invention, and FIG. 6 is a block diagram for explaining an embodiment of the present invention. An enlarged perspective view showing an example of the reflector body of the reflector used, FIG. 7 is a diagram for explaining the reflection action of the reflector body, and FIGS. 8 to 11 show the size of the reflector body. FIG. 1... Space of light-absorbing film, 2... Face panel, 3... Photosensitive phosphor film, 4...
... Shadow mask, 5 ... Exposure light source, 1
0... Reflection plate, 10'... Reflection plate element, 11, 12... Reflection surface, 13... Light absorbing film portion.

Claims (1)

[Claims] 1. After selectively forming a light-absorbing film on the inner surface of the face panel, a photosensitive phosphor film is uniformly applied to cover the light-absorbing film, and is applied through a shadow mask. When selectively exposing the photosensitive phosphor film to light, the light transmitted through the photosensitive phosphor film, the space of the light-absorbing film, and the face panel is placed on the outer surface of the face panel. The light is reflected on one side of a large number of reflector bodies,
A method for forming a phosphor surface for a color picture tube, characterized in that the reflected light is guided to a photosensitive phosphor film portion within the space. 2. A face panel having on its inner surface a selectively formed light-absorbing film and a photosensitive phosphor film coated over the film; and a face panel installed in close proximity to the inner surface of the face panel. a shadow mask; a fluorescent light source disposed facing the inner surface of the shadow mask; and a fluorescent light source emitted from the light source that causes spatial rotation of the shadow mask, the photosensitive phosphor film, and the light-absorbing film, and the face. A firefly for a color picture tube, characterized in that it comprises a number of reflector bodies each having a reflective surface having a rectangular cross section and installed on the outer surface of the face panel in order to reflect the light that has passed through the panel into the space. Light surface forming device.