JPS5843853B2 - Keikomenrokohouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a phosphor screen exposure method suitable for application to exposure processing when forming a phosphor screen of a color cathode ray tube by a photographic printing method.

The color phosphor screen of a color cathode ray tube uses a phosphor slurry applied to the inner surface of the face plate using an electrode for determining the electron beam arrival position, such as a shadow mask or an aperture reel, as an optical mask, which is mounted opposite to the inner surface of the face plate of the cathode ray tube. , are created using the so-called photo printing method, which optically prints using light replaced by electron beams of each color.

That is, as shown in FIG. 1, a phosphor slurry 2 mixed with a photosensitive binder is applied to the inner surface of a face plate 1 of a cathode ray tube.
At the same time, an electrode for determining the electron beam arrival position, for example, an aperture grill 4 having a large number of slits 3 is attached to a predetermined position, a light source 5 is arranged at a position corresponding to the deflection center point of the electron beam, and the light source A correction lens 6 and a light amount correction filter 7 are arranged between the lens 5 and the aperture grill 4.

In this case, the phosphors of each color formed are in the form of stripes parallel to the slits 3 of the aperture grille 4.

In this case, the light amount correction filter 7 is
It is used to correct the difference in the amount of transmitted light between the center and the periphery of the inner surface of the spray plate and expose it to a uniform stripe width over the entire screen. A metal vapor deposited film such as A1 is formed thinner from the center toward the periphery, and the Wako transmittance increases from the center toward the periphery.

However, in the light amount correction filter 7 having such a configuration, it is difficult to control the thickness of each part of the metal vapor deposited film, and the manufacturing efficiency is low, as well as the reproducibility is poor.

To improve this point, as shown in FIG. 2, a large number of striped light shielding parts 9 extending in one direction at a predetermined pitch P are arranged on a transparent substrate 8 by vapor deposition, printing, etc. to shield light. A pattern consisting of a portion 9 and a light transmitting portion 10 is formed, and the area ratio of the light shielding portion 9 and the light transmitting portion 10 is changed according to the amount of light to be corrected to obtain a desired light transmittance distribution. A correction filter 11 is proposed.

However, when exposing and printing a phosphor screen with such a light amount correction filter 11 fixed at a predetermined position, although the filter as a whole exhibits a uniform light transmittance distribution, some parts are affected by the light shielding part 9. In this case, good exposure printing may not be possible.

That is, as shown in FIG. 3A, the filter 11 is
When the filter 11 is installed so that it is parallel to the linear light source 5 and the slit 3 of the aperture grill 4, the filter 11
The light intensity distribution on the inner surface of the face plate through
The light transmitting portion 10 of the filter 11 becomes like the curve I in Figure B.
The light passing through the striped phosphor 12 effectively acts on the exposure and printing of the striped phosphor 12, but the light is blocked in the part corresponding to the light shielding part 9, and sufficient exposure and printing is not performed, and the striped phosphor 1
There is a fear that part 2 (shaded area) is missing.

Further, as shown in FIG. 4A, the filter 11 is
When the light source 5 is installed at right angles to the linear light source 5 and the slit 3 of the aperture grill 4, in addition to the unevenness of the geometric light intensity distribution, if the space between the light shielding parts 9 is considered as a slit, there will be an effect of interference. The light intensity distribution on the inner surface of the face plate after passing through the filter 11 is shown by the curve ■ in Fig. 4B.
For this reason, as shown in Figure 4C, the areas exposed and printed with sufficient light become thicker, and the areas exposed and printed with insufficient light become thinner, resulting in a fluorescent stripe of uniform width as a whole. Body 12 is difficult to obtain.

Although not shown, when the light amount correction filter 11 is used to form, for example, a dot-shaped phosphor screen for a glossy mask, the same situation as shown in FIGS. 3A and 3B occurs, and good exposure and printing cannot be achieved.

In view of the above-mentioned points, the present invention uses a light amount correction filter having a desired transmittance distribution by changing the area ratio of the striped light shielding part and the light transmitting part as shown in FIG. An object of the present invention is to provide a phosphor screen exposure method that enables good exposure and printing when performing exposure and printing.

Hereinafter, the phosphor screen exposure method according to the present invention will be explained in detail using FIG. 5 and subsequent figures.

In the present invention, as shown in FIG. 5, a predetermined phosphor slurry 2 mixed with a photosensitive binder is coated on the inner surface of the face plate 1 of a cathode ray tube, and an electrode for determining the electron beam arrival position is formed with, for example, a large number of slits. 3, a light source 5, a correction lens 6, and a light amount correction filter, that is, a striped light shielding part 9 and a light transmitting part 1 as shown in FIG.
After changing the area ratio of 0 and arranging the light quantity correction filter 11 having a desired light transmittance distribution at a predetermined position, the filter 11 is moved in the direction intersecting with the extension direction of the stripes within the plane thereof.
That is, exposure and printing is performed while vibrating in a direction that allows the right angle direction.

Here, to further describe the filter 11, the second
As shown in the figure, the light shielding portions 9 are formed in a pattern in which the stripe width d gradually varies from the center to the end in the extending direction of the stripes. According to this pattern, the light shielding portions 9 are The width of each part of the light transmitting part 10 sandwiched between the light shielding parts 9 (corresponding to each staircase part with different stripe widths of the light shielding part 9) a, b, and c is calculated as X + 'J + Z , or if the length of each part a+b+c is 11 + 12+ 13, then each part a+b
The light transmittance T at +c is the area ratio of the light transmitting part 10 and the light shielding part 9, and is expressed as follows.

Therefore, the stripe-shaped light shielding part 9t is formed by extending the central stripe width d in the X direction so that the stripe width dt gradually decreases stepwise toward the ends.
Width dt of each part of the light shielding part 9 with a constant pitch P in the Y direction
By arranging a large number of filters such that the light transmittance decreases toward the periphery, a light amount correction filter can be obtained in which the light transmittance at the center is small and the light transmittance increases toward the periphery.

The pitch P of the light shielding part 9 differs slightly depending on the position where the filter of the exposure device is placed, but it is preferably 3 studs at most and as narrow as possible.

In addition to the pattern shown in FIG. 2, the pattern of the light-shielding portion 9 may be one not shown, such as a stairway on the upper edge and a stairway on the lower edge of the step-shaped light-shielding portion in FIG. 2. It may be a pattern, or it may be a pattern in which the stripe width d continuously becomes smaller from the center toward the ends.

On the other hand, the vibration of the filter 11 occurs regardless of whether the filter 11 is arranged so that its light-shielding portion 9 is parallel to the linear light source 5 and the slit 3 of the aperture grill 4, or at right angles. In order to make the shadow or interference pattern uniform due to the striped light shielding part 9, the vibration is in the range of 1 pitch to 4 pinches as a reference pitch Pk of the light shielding part 9. It is possible to vibrate with the width.

In addition, when the amplitude is 4 pinches or more, the filter 11
Errors occur in the light transmittance distribution due to

Here, when the filter 11 is vibrated with uniform motion, ■
The amplitude of the pitch or a pinch of an integer multiple thereof may be sufficient, but in reality it is difficult to move the filter 11 at a constant velocity by mechanical means. For example, as shown in the velocity distribution curve 13 in FIG. The speed at the switching time t8 from the outbound route to the return route or from the return route to the outbound route is the uniform motion period t.
Therefore, the light intensity cannot be made uniform.

FIG. 7 shows this state. Curve 14 is the light amount distribution when the filter 11 is not vibrated, and curve 15 is the light amount distribution when the filter 11 is vibrated with an amplitude of 1 pinch. When vibrating with an amplitude of 1 pinch as described above, the amount of light is averaged compared to when not vibrating, but when comparing the portion corresponding to the light shielding portion 11 with the other portions, it is not equalized.

Considering this point, in order to make the light amount distribution more uniform, it is necessary to set the pitch such that the light shielding part 9 is at least a pinch and the light shielding part 9 is at an intermediate position between the original light shielding parts 9, for example, <1 as shown in FIG. .5
All you have to do is vibrate with the pitch of a pitcher.

In this way, compared to the light intensity distribution curve 14 when not vibrating, the light intensity distribution when vibrating with an amplitude of 1.5 pitches is as shown by the curve 16, and the light intensity between the part corresponding to the light shielding part and the other parts is uniform. be converted into

Also, when looking at the vibration of the filter 11, from Figure 6, if the width is the time of uniform movement, the time of the changeover period of the round trip is tS, and the time of one exposure is tB, one movement in one direction is Then 1m+2t, 2tB, tm/2n for n reciprocating movements
-tm+2tS, and the ratio of ts/1m does not change whether it is one movement or n times of reciprocating movement.

Therefore, the frequency of the filter 11 can be set to one round trip/second, but considering the case where exposure and printing are performed three times as in a color cathode ray tube, and the time for each exposure and printing is different, it is possible to set the frequency to one round trip/second. It is possible to choose.

In addition, in a color cathode ray tube, the exposure time is different for each color phosphor of red, green, and blue, so in this case, the vibration of the filter 11 should be determined according to the one with the shortest exposure time. For example, uniform exposure can be achieved even for other objects with long exposure times.

As described above, according to the present invention, a special light amount correction filter 11 is provided with a large number of striped light shielding parts and light transmitting parts, and the area ratio of the stripes is changed to obtain a desired light transmission blockage distribution. When performing exposure printing on the phosphor screen of a cathode ray tube using the filter 11, the filter 11 is vibrated with a predetermined amplitude in the direction intersecting the stripes.
It is possible to avoid unevenness in the light quantity distribution due to shadows or interference patterns caused by the light shielding part 9, and to perform good exposure and printing.

Note that although the aperture grill was used in the upper part to expose and print a striped phosphor screen, it goes without saying that it can also be applied to the exposure and print of a dot-like phosphor screen using a shadow mask.

[Brief explanation of the drawing]

Fig. 1 is a schematic layout of the exposure and printing process for the phosphor screen of a color cathode ray tube used to explain the present invention, Fig. 2 is a plan view of the main parts of the light intensity correction filter applied to the present invention, and Fig. 3 A and B are an exposure state diagram and its light amount distribution diagram provided for the present invention, respectively, and FIGS. 4A, B, and C are other exposure state diagrams, their light amount distribution diagram, and a plan view of the exposed portion, respectively, provided for explanation of the present invention. ,
FIG. 5 is a line layout diagram showing an example of the phosphor screen exposure method according to the present invention, FIG. 6 is a diagram showing the speed state during reciprocating motion of the filter used for explaining the present invention, and FIGS. 7 and 8 are light quantity distribution diagrams obtained by the present invention, respectively. 1 is a face plate, 21 is a phosphor slurry 3 is a slit, 4 is an aperture grill, 5 is a light source, 6 is a correction lens, and 11 is a light amount correction filter.

Claims (1)

[Claims] 1 A light amount correction filter having a desired light transmittance distribution by changing the area ratio of a striped light shielding part and a light transmitting part is vibrated within the plane of the filter in a direction intersecting with the extension direction of the stripes to generate fluorescence. A fluorescent screen exposure method characterized in that a surface is exposed to light.