JPS6041819B2 - Method for manufacturing color picture tube fluorescent surface - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing a color picture tube fluorescent surface.

FIG. 1 is a schematic cross-sectional view of a color picture tube device.

Generally, in a color picture tube, three electron beams IA, IB, and IC emitted from an electron gun scan the screen by the deflection magnetic field of the deflection yoke 2, and pass through the aperture 3 of the shadow mask over the entire surface of the scanning screen. By impinging on each corresponding phosphor dot, desired light is emitted and a color image is formed. In this case, if the electron beam that has passed through the shadow mask aperture 3 hits the phosphor dot accurately, it will emit light in the desired color; In other words, when the mislanding error becomes large, adjacent phosphor dots also emit light, resulting in a decrease in color purity. Therefore, in the exposure process for forming phosphor dots, an optical correction plate is generally installed in the exposure system so that the final trajectory of the electron beam to the phosphor dots matches the exposure light beam that arranges the phosphor dots. is used for exposure. FIG. 2 shows an exposure optical system that arranges phosphor dots corresponding to the central electron beam IB. It is a correction curved surface that forms an exposure light beam locus 7B that matches the locus of incidence on the shadow mask aperture 3.
Generally, on the upper surface of this type of optical correction plate, there is a mark with respect to the tube axis such that the deflection center position advances from the deflection center position 4 near the center of the screen to the position 5 as the deflection angle increases. A radial correction curved surface that performs a substantially axially symmetrical correction is made, and an optical correction plate 8A used in an optical system corresponding to, for example, IA among the double-sided electron beams IA and IC includes:
In addition to the radial correction curved surface, a degrouping correction curved surface is formed on the lower surface of the lens so that the trajectory of the electron beams on both sides intersecting at the shadow mask aperture 3 matches the exposure light beam passing through the mask aperture. Now, in order to form a fluorescent surface using such an optical system, a photosensitive resin film is applied to the inner surface of the face plate panel of a color picture tube, and the spectrum is applied to the near-ultraviolet region emitted from the exposure source on the tube axis. The exposure light beam having a distribution is refracted by an optical correction plate 8B having a radial correction curved surface, and exposed with a light flux passing through a shadow mask aperture 3, and after development processing, a center dot corresponding to the center electron beam 1B is formed.

Next, as shown in FIG. 3, the light emitted from the light source 6A, which is placed eccentrically from the tube axis, has a radial correction and degrouping correction curved surface so as to correspond to each of the electron beams on both sides of the tube axis. The light is refracted by the optical corrector plate 8A, passes through the shadow mask aperture 3, and exposes the fluorescent surface, and through subsequent development processing, one of the side dots located on both sides is formed. At this time, the degrouping correction curved surface has the characteristic of correcting in the eccentric direction of the light source, so for exposure of the phosphor dot corresponding to the other electron beam 1C, the optical system should be placed at a position rotated 180 degrees. good. In this way, in order to arrange the phosphor dots corresponding to each of the double-sided electron beams 1A and 1C and the central electron beam 1B, the amount of optical correction is different. was necessary. In addition to this step of forming phosphor dots, as schematically shown in FIG.
A color picture tube filled with a so-called black matrix 10 and having a shadow mask aperture 3 having a diameter larger than that of the phosphor dots has extremely good image contrast and is commercially available as a black matrix type color picture tube. has been done.

Such a fluorescent surface is produced by applying a photosensitive resin film to the inner surface of the face plate before forming the fluorescent dots, and exposing it to light by an exposure optical system corresponding to the center dot 9B and both side dots 9A and 9C. Dots of the resin film are formed by a development process. Next, when a black light-absorbing material is applied to the inner surface of the face plate, the black light-absorbing material is layered on the dots of the resin film, but if the resin film dots are dissolved and removed using a solvent in the next step, the subsequent three colors Effective light-emitting regions, ie, black matrix holes, are formed at positions where phosphor dots are formed. Thereafter, a black matrix type phosphor surface is formed through a phosphor dot forming process.
This black matrix hole is filled with each phosphor and is irradiated with an electron beam and a beam spot larger than the diameter of the hole, causing the entire hole to emit light.
If the diameters of the holes filled with colored phosphors are not made the same, the amount of light emitted for each color will be different, resulting in color unevenness on the phosphor surface. It is desirable that the light source used to expose the photosensitive resin film be a point light source that emits near-ultraviolet light with high brightness.Usually, an ultra-high pressure mercury lamp is used as the light source, and an exposure source device using the same is generally used. The outline is shown in Fig. 5.

Here, the light emitted from the ultra-high pressure mercury lamp 11 is transmitted to the condensing lens 1
There is light 12 directly incident on the condenser lens 14 and light 13 reflected by the reflector 17 and incident on the condenser lens 14. , is repeatedly reflected and guided to the tip, and is emitted from the extremely small tip 15 of the condenser lens. Furthermore, a recently proposed method is to create a point light source by attaching an aperture cover to an ultra-high-pressure mercury lamp and rotating it, but in both cases, one ultra-high-pressure mercury lamp is used as an exposure light source. However, with this type of ultra-high pressure mercury lamp, the amount of light emitted by each mercury lamp changes from the initial stage to long-term use, and the emission spectrum changes depending on the condition of the discharge electrode. It is difficult to make the diameters of the three colors the same, and in reality, color unevenness occurs during fluorescent surface emission, which has been a drawback of this type of color picture tube. SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a fluorescent surface of a color picture tube that eliminates the drawbacks of the prior art, allows easy exposure, and is free from color unevenness.

Therefore, in the present invention, the axial direction of the ultra-high-pressure mercury lamp is aligned with the inline 3 electron array direction, and an exposure device is used in which three slit-like openings are arranged at equal intervals so as to be perpendicular to the axis of the mercury lamp. Create a light surface.

In this way, exposure can be performed at one time, thereby preventing color unevenness. First, regarding the present invention, we will discuss the case of manufacturing a mirror picture tube device with a reduced deflection angle and electron gun diameter in order to save deflection power, such as is used in a small portable television receiver, for example. explain.
For a mirror picture tube with a small deflection angle and a small electron gun diameter, degrouping correction is very small and is not practically necessary, and only radial correction may be performed. Therefore, the same three colors of optical correction plates can be used for forming the phosphor dots and black matrix holes corresponding to each electron beam. Therefore, as a light source for exposing the photosensitive resin film forming the black matrix hole, the tube axis of an ultra-high pressure mercury lamp 18 as shown in FIG. By using an exposure device equipped with a light source equipped with a light-shielding cover 19 having three slit-like openings, the photosensitive resin film forming the black matrix hole where the three-color phosphor is to be formed can be exposed to three colors at the same time. I can do it. Therefore, the diameter of each hole is the same, which was a drawback of conventional phosphor dots.
There is no color unevenness caused by the difference in the amount of light emitted by the trio. Furthermore, when exposing a photosensitive resin film, only one exposure device was required compared to the conventional three.
The equipment cost can be reduced to 113, and the optical systems of the three exposure devices are relatively misaligned, so the phosphor dots and
There are many advantages, such as eliminating defects such as abnormal arrangement of trios and improving product yield. The above is a case where degrouping correction is not necessary due to the small deflection angle and electron gun diameter.
As shown in Figure 2 of No. 8, even if negative degrouping correction is required in which the phosphor dots are grouped in a state opposite to degrouping, if a light source such as the one shown below is used, No optical degrouping correction surface is required, and simultaneous exposure of a trio of dots is possible when forming holes in the black matrix.

As shown in FIGS. 7 and 8, the light source is a slit-like aperture 22 with a straight line in the center, and slit-like apertures 23 and 24 located on both sides are curved concavely with respect to the center straight line. to do. These three slit-like openings 22, 23, 2
4 and the axis of the ultra-high-pressure mercury lamp 18 are perpendicular to the axis of the ultra-high-pressure mercury lamp 18.If exposure is performed using an exposure source with a light-shielding cover 25 that includes degrouping correction, the shadow mask aperture position 26 at the center of the screen and a point on the horizontal axis will correspond. The three exposure rays that intersect at the shadow mask opening position 27 are located at points 28 and 29 on the horizontal center line of the light-shielding cover, including degrouping correction.
, 30, and the interval is constant L, but at the shadow mask opening position 31 corresponding to the point in the vertical direction of the screen, the seventh
, passes through three points 28'', 29'', and 3'' in FIG. 8, and the interval therebetween becomes L+ΔL and increases by ΔL. That is, as the distance between the light sources increases, the distance between the beams of light that cross through the mask apertures and reach the face plate panel 32 increases proportionally, so that the grouping of exposed phosphor dots is eliminated. Conversely, if the phosphor dots are degrouped vertically above and below the screen, the center line of the slit-like openings located on the left and right sides of the light-shielding cover will be If the curve is convex, the apparent distance between the light sources at the point in the vertical direction of the screen will be smaller than that at the center, and therefore redegrouping in which the distance between the exposed dots 1 and the exposed dots is small will be eliminated. In addition, when increasing the privacy margin by gradually decreasing the black matrix hole diameter from the center of the screen to the top and bottom of the screen compared to the beam spot diameter, the slit-like aperture is made from the center to the end as shown by the chain line in Figure 8. If the width of the slit is gradually narrowed toward the top of the screen, the amount of light at the top and bottom of the screen will decrease accordingly, and the diameter of the exposed dot will become smaller. If more complex degrouping correction is required, a single mercury lamp can be used to perform switching exposure by providing a slit opening in the exposure source corresponding to each phosphor dot and a switching mechanism for the optical correction plate. Since a dot trio of holes in the black matrix can be formed after exposure, the holes have the same diameter and no color unevenness occurs when the fluorescent surface is emitted.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view to explain the principle of a shadow mask color picture tube, Figure 2 is a cross-sectional view showing the optical system that exposes dots corresponding to the central beam, and Figure 3 is one of the beams on both sides. 4 is a perspective view illustrating black matrix type fluorescent surface emission, and FIG. 5 is a sectional view of a conventional exposure source. FIG. 6 is a perspective view showing the relationship between an exposure source and phosphor dots used in the present invention, and FIG. 7 is a perspective view of an exposure source including degrouping correction used in the present invention, a shadow mask, and a face plate panel. , FIG. 8 is a plan view of a light shielding cover including degrouping correction used in the present invention. 1... Electron beam, 3... Shadow mask aperture, 18... Ultra-high pressure mercury lamp, 19... Light blocking cover, 25... Light blocking cover including degrouping correction.

Claims (1)

[Claims] 1. Align the axis of the ultra-high-pressure mercury lamp with the three electron beam array directions of the in-line electron gun, and pass through the straight central slit-shaped aperture arranged orthogonally to the axis of the mercury lamp and the curved left and right slit-shaped apertures. A method for manufacturing a color picture tube phosphor screen characterized by exposing it to light.