JPS5845777B2 - 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 phosphor surface for a color picture tube, and more particularly to a method for forming a black matrix type phosphor surface and an apparatus for forming the phosphor surface.

In general, a black matrix type phosphor surface consists of a light-absorbing film selectively formed to have a large number of spaces consisting of dead weights or stripes, and three types of dot-shaped films filled in the spaces. 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 the face 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 housing, and a large number of spaces is obtained.

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

In FIG. 1, a light-absorbing film is indicated by a thick dashed line, and a phosphor film is applied within the space 1 of this film.

In the phosphor film application step, the photosensitive phosphor film 3 is uniformly coated on the inner surface of the face panel 2 so as to cover the light-absorbing film.

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

Then, through the development process performed after this selective exposure process,
Since one kind of dot-like residue or stripe-like phosphor film is completed, the remaining two kinds 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 phosphor film portion with the same width as the space G will be obtained for the space G of the light-absorbing film. There is.

The light intensity level has changed. 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 amount level I
b indicates the middle between the two light intensity levels Ia and Io.

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 R4 and 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 to 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, and in this case, a photosensitive phosphor film is provided. The exposure light beam that has passed through the face panel 2 without being absorbed by the reflector plate 9 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 smearing and poor color mixing due to fogging.

However, the reflection exposure method shown in FIG. 4 causes unfavorable results 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 becomes reflected light r1 on the reflective surface of the reflector plate 9 and is deflected outward, resulting in poor color mixing.

The present invention has been made with the above-mentioned points in mind, and will now be described with reference to embodiments shown in the drawings.

The reflecting plate 10 shown in FIG. 5 includes a spherical lens body 12 made of high refractive index glass beads as shown in FIG. The face panel 2 has a structure in which a pair of reflecting mirrors consisting of a surface 11 is used as an element body, and a large number of these element bodies are arranged along the outer surface of the face panel 2.

The reflector pair refracts the incident light beam 11 by a lens body 12 as shown in FIG.

The light beam exiting the lens body 12 is reflected by the reflecting surface 11 located at the focal position F at the same angle as the incident angle of the incident light beam 11, returns to the lens body 12, and is refracted.

Therefore, the reflected light ray r1 takes a trajectory parallel to the incident light ray 11 and proceeds toward the face panel, becoming a supplementary light ray.

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

Incident light rays 11, 12, 13 and reflected light rays rllr2 + r3 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 reflecting mirror pair is changed.
This shows the relationship between the diameter of the lens body 12 and P,
The arrangement pitch of the spaces in the light-absorbing film is H1, and the maximum width of the spaces in the light-absorbing film is D.

In FIG. 8, when P>HD, the incident light ray 11 into the space G becomes a reflected light ray r1 at the opposite surface 11 of the pair of reflecting mirrors, which is not preferable because it enters the adjacent space R.

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, since the reflecting mirror pair is smaller than the light-absorbing film portion 13, the incident light rays 11, 12, 13 into the space G are
Even if .
Since the light enters the original space G, no defective color mixture occurs.

FIG. 11 shows the case of PH, and although it is inconvenient to install the reflecting mirror pair on the outer surface of the face panel in accordance with the arrangement pitch of the light-absorbing film portion, a good fluorescent surface can be obtained.

Therefore, in order to prevent the light beam transmitted through the space G where the light-absorbing film is located from entering a space other than the original space G after being reflected by the pair of reflecting mirrors, the diameter P of the lens body 12 must be adjusted to the space G where the light-absorbing film is located. It is necessary to set the width to be less than or equal to the width (H-D) of the light-absorbing film portions interposed between each other, or to a value equal to the arrangement pitch H of the space, and it is necessary to arrange a large number of reflecting mirror pairs that meet this condition. When a reflective mirror is installed on the outer surface of the face panel and the light rays emitted from the exposure light source and passed through the shadow mask are applied to the photosensitive phosphor film, the light rays from the face panel are not absorbed by the photosensitive phosphor film. The transmitted light beam is reflected by the pair of reflecting mirrors, and this reflected light accelerates the curing of the photosensitive phosphor film, forming a dot-shaped or striped phosphor film without fogging or chipping. This enables efficient formation.

Note that when the space of the light-absorbing film is rectangular or striped, the lens body can be made cylindrical instead of spherical, and a wavy reflective surface may be provided at the focal point of this lens body.

The reflector is installed on the outer surface of the face panel so that the length direction of the lens body is parallel to the length direction of the slot of the shadow mask.

In addition, the reflecting mirror pairs do not have to be arranged over the entire area of the reflecting plate, but can be arranged only in the peripheral area of the fluorescent surface or other areas which are particularly problematic due to the formation of the 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.
Figures 4 and 4 are block diagrams and explanatory diagrams for explaining a conventional method for forming a fluorescent surface, Figure 5 is a block diagram for explaining an embodiment of the present invention, and Figure 6 is a block diagram for explaining an embodiment of the present invention. FIG. 7 is a diagram for explaining the action of the reflecting mirror pair, and FIGS. 8 to 11 show the size and reflection action of the reflecting mirror pair. 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, 11... Reflection surface, 12
... Lens body, 13 ... Light absorbing film part.

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. A fluorescent light for a color picture tube, characterized in that the reflected light is refracted and reflected by a lens body and a wavy reflective surface installed at a focal point of the lens body, and the reflected light is guided to a photosensitive fluorescent film portion in the space. How to form surfaces. 2. A face panel having on its inner surface a selectively formed light-absorbing film and a photosensitive phosphor film coated uniformly over the film, and a face panel installed close to the inner surface of the face panel. a shadow mask, an exposure light source installed facing the inner surface of the shadow mask; and radiation emitted from the light source through the space of the shadow mask, the photosensitive phosphor film, the light-absorbing film, and the face panel. a lens body disposed on the outer surface of the face panel to refract the refracted light; and a wavy reflecting surface disposed at a focal position of the lens body to reflect the refracted light toward the space. A device for forming a fluorescent surface for a color picture tube, comprising: