JPS5843854B2 - Fluorescent surface exposure equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color phosphor screen of a color cathode ray tube, and particularly to a phosphor screen exposure apparatus for forming a color phosphor screen consisting of a large number of phosphor stripes by optical printing.

The striped color phosphor screen of a color cathode ray tube is a photosensitive phosphor film coated on the inner surface of the face plate by attaching a color selection electrode having a large number of slits to the face plate of the cathode ray tube, and using this as an optical mask. They are created by exposing and baking a phosphor slurry mixed with a photosensitive binder using light replaced by electron beams of each color.

In this case, the color selection electrode is formed so that the slit width becomes smaller toward the periphery in order to avoid mislanding of the beam at the periphery, so this color selection electrode was used as an optical mask. In this case, the amount of exposure at the periphery is insufficient.

Therefore, a light intensity correction filter is usually used that suppresses the light transmittance in the center and increases the light transmittance in the periphery, so that the stripe width is uniform in each part of the phosphor screen during exposure. .

However, conventional light intensity correction filters use chromium Cr deposited on a glass plate with a constant concentration distribution, but this is difficult to fabricate and has poor reproducibility.
Exposure printing on the phosphor screen cannot be performed accurately.

In view of the above points, the present invention uses a light intensity correction filter that is easy to manufacture and has good reproducibility, and combines this with a linear light source to expose and print a striped phosphor screen with high precision. It provides equipment.

The present invention will be explained in detail below.

First, the light amount correction filter used in the present invention will be described using FIGS. 3 to 6.

As shown in FIG. 3, this light amount correction filter 1 has a large number of striped light shielding parts 3 extending in one direction on a transparent substrate, for example, a glass substrate 2 (a pattern consisting of light shielding parts 3 and light transmitting parts 4). is formed, and the area ratio of the light shielding part 3 and the light transmitting part 4 is changed according to the amount of light to be corrected to obtain a desired light transmission blockage distribution.

The light shielding portion 3 may be formed in a pattern such that the stripe width d gradually changes stepwise from the center to the end in the extending direction of the stripe, as shown in FIG. 3, for example.

According to this pattern, the pinch between the light shielding parts 3 is p, and each part of the light transmitting part 4 sandwiched between the light shielding parts 3 (the part corresponding to each step part where the stripe width of the light shielding part 3 is different) is a, b, c. The width of each part is X + 'l + Z and each part a p b y
When the lengths of c are 11+12+13, the light transmittance T at each part a r b + c is expressed as the area ratio of the light transmitting part 4 and the light shielding part 3.

Therefore, the striped light shielding part 3 is formed by extending the stripe width d in the X direction so that the stripe width d at the center is set as a dog, and the stripe width d gradually decreases in steps toward the ends. If a large number of them are arranged with a predetermined pinch in the Y direction,
An optical filter can be obtained in which the light transmittance at the center is small and the light transmittance increases toward the periphery.

Note that the change in light transmittance in the Y direction can be determined by changing the pitch P gradually toward the periphery when using light shielding parts 3 of the same shape, or by changing the light shielding parts 3 when the pitch P is constant.
This can be obtained by making the width dK of each part smaller toward the periphery.

The transmittance at each point of the filter can be approximately calculated from the width of the phosphor stripe after exposure and phenomenon.

FIG. 4 shows an example of the light transmission weight distribution of the filter 1, where the transmittance is expressed in 10% intervals.

The numerical value indicates the transmittance. Note that the contour interval representing the transmittance can be made even smaller.

That is, for example, if the step-shaped light shielding part 3 is shaped so that the steps at the upper edge and the steps at the lower edge are shifted by approximately % as shown in FIG. 5, the transmittance contour line spacing will be as shown in FIG. % of the case, and a more accurate filter can be obtained.

Furthermore, the light shielding part 3 can also have a pattern in which the stripe width d connects and gradually becomes smaller from the center toward the ends, as shown in FIG. is obtained.

In this case, since one side of the light shielding part is linear, manufacturing is easy.

Also, the pitch P of the light shielding part of the filter varies slightly depending on the position where the filter is placed in the exposure device, but it is up to 3 m.
It is preferable that the width be as narrow as possible.

If the pitch P of the light-shielding portions becomes too coarse, the light from the light source projected onto the phosphor screen becomes a bright line, causing slanting that deteriorates the edges of the exposed and printed phosphor stripes.

This filter can be easily produced by a vapor deposition method, a printing method, or the like.

For example, in the case of the vapor deposition method, first, an original drawing of a pattern consisting of a light-shielding part 3 and a light-transmitting part 4 is enlarged using an automatic drafting device, and then reduced to the desired size with a camera and photographed to create a master pattern (photograph). Obtain a dry plate).

Next, a metal such as chrome or aluminum is vapor-deposited on a transparent glass substrate, and then the metal vapor-deposited layer is etched away using a photo-etching technique using a master pattern to obtain the desired filter.

Of course, the master pattern itself can be used as a desired filter.

Further, to form the light shielding portion 3, an ink in which carbon powder is dispersed in a binder can be used.

Alternatively, it is possible to use a phosphor slurry mixed with a dye or pigment binder that blocks the sensitive wavelength range (450 μm or less) and allows longer wavelength light to pass therethrough.

These can be used for printing methods, etc.

The phosphor screen exposure apparatus according to the present invention uses the light amount correction filter 1 having the above-described configuration, and will be described next with reference to FIGS. 1 and 2.

FIG. 1 schematically shows the exposure apparatus of the present invention.
1 shows a face plate of a cathode ray tube whose inner surface is coated with a photosensitive fluorescent film 9, which is placed and fixed on a support base 6 of the apparatus.

Reference numeral 7 designates an optical mask disposed opposite to the inner surface of the face plate 5, that is, an optical mask capable of exposing the photosensitive fluorescent film 9 to light in a stripe pattern, and 8 represents a linear light source for exposure.

The light amount correction filter 1 is inserted between the linear light source 8 and the optical mask 7.

Although not shown, a lens for optical path correction is further arranged between the linear light source 8 and the optical mask 7.

As the optical mask 7, for example, as shown in FIGS. 2 and 7, a mask formed by supporting a large number of band-shaped metal bodies 7a at a predetermined pitch on a required frame and forming a large number of parallel slits 7b can be used. can.

In the present invention, as shown in FIG. 2, the linear light source 8 is arranged so that its longitudinal direction is parallel to the extending direction of the grooves 1-7b of the optical mask 7, or in a state close to that, and the amount of light is controlled. The correction filter 1 is connected to its striped light shielding portion 3.
are arranged so that they intersect with the linear light source 8.

In this case, it is desirable that the striped light shielding portion 3 and the linear light source 8 be arranged orthogonally, but they may intersect at an angle that is deviated from orthogonal.

Here, when the linear light source 8 and the striped light shielding part 3 intersect, the light from the light source 8 is blocked by the striped light shielding part 3, that is, the shadow of the striped light shielding part 3 of the filter 1 becomes photosensitive. Although the projected filter shadow is projected onto the phosphor screen 9, by setting the length of the linear light source 8 to a certain condition, the shadow of the projected filter is canceled out on the surface of the optical mask 7. The influence of the projection of the striped light-shielding portion of the filter 1 during exposure is eliminated.

The conditions for the linear light source 8 in this case are selected as follows, for example, when the linear light source 8 and the striped light shielding part 3 are arranged orthogonally.

That is, as shown in FIG. 11, the length of the linear light source 8 is S,
Distance fm from linear light source 8 to filter 1, filter 1
If the pitch of the striped light shielding parts 3 is Pl, and the distance from the filter 1 to the optical mask 7 is e, then the length S of the linear light source 8 is as follows.

Further, as shown in FIG. 12, when the linear light source 8 and the striped light blocking portion 3 of the filter 1 are arranged at a certain angle θ, the conditions for the linear light source 8 are selected as follows.

That is, the pinch of the striped light shielding part 3 with respect to the light source 8 is P.
′, (however, θ<90° or 0>θ>−90'),
Even if the filter 1 is oscillated along the longitudinal direction of the linear light source 8, the influence of the shadow of the filter 1 can be eliminated.

In addition to the optical mask 7, which supports the strip-shaped metal body shown in FIG. 7 and has a large number of continuous slits in one direction, the optical mask 7 may also include, for example, the strip-shaped metal body shown in FIG. 1 as shown in FIG. A mask 12 is made of a thin metal plate 10 with a plurality of rows and stages of slint-like through holes 11 so as to have a structure in which adjacent parts of the mask 12 are partially connected, or as shown in FIGS. 9 and 10. For the circular type, a mask 14 or 15 having through holes 13 of a rectangular or similar shape, which are adjacent to each other and arranged linearly in one direction, can be used.

The optical masks of FIGS. 7 and 8 can use actual color selection electrodes.

According to the above-mentioned configuration, since the light quantity correction filter 1 having a large number of striped light shielding parts 3 and configured to obtain a desired transmittance distribution by the area ratio of the light shielding parts 3 and the light transmitting parts 4 is used, it is possible to accurately adjust the light quantity. In addition, a linear light source 8 is used as the exposure light source, and the linear light source 8 is arranged parallel to the liner 1-7b of the optical mask 7, and the filter 1 is connected to the striped light-shielding portion 3. Since the light source 8 is arranged to intersect with the linear light source 8, the exposure distribution on the photosensitive fluorescent film 9 becomes uniform, and stripe exposure can be performed with high precision.

Furthermore, since exposure can be performed using the linear light source 8 as a so-called direct light source, the amount of exposure light increases, and an improvement in exposure efficiency can also be expected.

Additionally, when choosing the length of the linear light source 8 to meet the above conditions, cancel the shadow of the filter 1 without shaking the filter 1,
Good stripe exposure is possible.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the exposure apparatus of the present invention, FIG. 2 is a perspective view of the main parts thereof, FIG. 3 is a plan view showing an example of a light amount correction filter used in the present invention, and FIG. 5 and 6 are plan views showing other examples of the light amount correction filter, and FIGS. 7 to 10 are plan views of main parts showing examples of optical masks that can be used in the present invention. 11 and 12 are diagrams for explaining the conditions of the linear light source, respectively. 1 is a light amount correction filter, 3 is a striped light shielding part, 5 is
is a face plate, 7 is an optical mask, 8 is a linear light source,
9 is a photosensitive fluorescent film.

Claims (1)

[Claims] 1. An optical mask for stripe exposure and a linear light source are arranged opposite to the inner surface of the face plate, and between the linear light source and the optical mask, a large number of striped light shielding parts are provided so that the light shielding parts and the light A light amount correction filter is inserted based on the area ratio of the transmitting portion, and the light amount correction filter is arranged so that its striped light shielding portion intersects with the linear light source, and the photosensitive fluorescent film on the inner surface of the face plate is formed into a striped shape. A phosphor screen exposure device that exposes and prints a phosphor screen.