JPS5850321B2 - Optical filter manufacturing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for manufacturing an optical filter, and more particularly to an apparatus for manufacturing an optical filter for exposure correction used when forming a luminescent screen for a color picture tube.

In forming the luminescent screen of an in-line color picture tube with three deflection centers on a straight line perpendicular to the tube axis,
The exposure light sources are sequentially arranged at three points on the above-mentioned straight line.

Therefore, the amount of exposure given to any given area on the photosensitive film attached to the inner surface of the face panel differs depending on each of the three light sources, and this non-uniformity results in the By varying the occupied area ratio of the color phosphors,
This causes uneven coloring in the image played on the screen.

In order to eliminate such drawbacks, the present applicant has proposed to install two types of optical filters between the light source and the shadow mask during exposure processing, in order to properly distribute the exposure amount. We have already proposed that it be installed in conjunction with the optical filter.

The optical filter proposed by the present applicant has an equal transmittance distribution as shown in FIG. 1 or 2.

The optical filter having the equal transmittance distribution shown in FIG.
Considering the axis, the transmittance gradually decreases in the positive direction of the X-axis symmetrically with respect to the X-axis, and increases at the center.

Further, the optical filter shown in FIG. 2 is considered in the same way as above, and is symmetrical with respect to point O, with the transmittance being highest at the center and decreasing toward the periphery.

FIGS. 3 and 4 show the light transmittance distributions of the above two types of optical filters along the X axis.

By the way, in the conventional optical filter, the light transmittance distribution is low in the central part and increases as it spreads to the peripheral part.

Therefore, conventional equipment for manufacturing optical filters has a structure in which more metal is deposited in the center of the deposition substrate than in the periphery. However, it is not possible to obtain a novel optical filter in which the light transmittance is highest in the center and the transmittance decreases evenly as it spreads to the periphery, as described above.

Therefore, the present applicant proposed a manufacturing apparatus having the configuration shown in FIG. 5, and thereby achieved an optical filter having the light transmittance distribution shown in FIGS. 2 and 4.

This manufacturing apparatus is an apparatus in which a vapor deposition mask 13 is installed between a vapor deposition substrate 11 and a heating wire 12, and the heating wire 12 has two opposing side portions 121 and a connecting portion 122 that connects them. The vapor deposited metal 14 to be welded to the heating wire 12 is densely deposited at the connecting portion 122 and becomes sparse as it advances toward the side portion 121, and the vapor deposition mask 13 is welded to the heating wire 12. It is designed to cover the inside of the shape formed by.

To create an optical filter having the transmittance distribution shown in FIGS. 2 and 4, first place a heating wire 12 at a predetermined position.
After installing the vapor deposition mask 13 and performing complete vapor deposition,
Next, the heating wire 12 and vapor deposition mask 13 are rotated 1800 revolutions and set up to perform complete vapor deposition again.

However, even with such a manufacturing apparatus, the following problems still remain.

(1) During the first and second evaporation, the degree of vacuum, the evaporated metal 14
It is necessary to completely match the amount of heating wire 12, the energization conditions of the heating wire 12, etc., and it is difficult to adjust these.

(2) Complete evaporation is performed, so once the first evaporation is completed,
The evaporation source must be replaced, its position set, and vacuum drawn again, which is time-consuming.

- Therefore, the present invention was made in view of the above problems, and by specifying the shape of the vapor deposition mask and the installation position of the mask and heating wire, the transmittance is high in the central part.
An object of the present invention is to provide a novel optical filter manufacturing apparatus that can easily manufacture a novel optical filter whose transmittance decreases uniformly as it spreads toward the periphery without any troublesome adjustments.

The present invention will be described below along with examples using the drawings.

FIG. 6 is a perspective view showing an embodiment of the present invention.

A vapor deposition mask 23 is installed between a transparent vapor deposition substrate 21 serving as an optical filter and a heating wire 22 serving as an evaporation source, and a predetermined opening 24 is formed in the vapor deposition mask 23-. .

In the figure, the center 0 of the vapor deposition substrate 21 is not on a straight line with the center o3 of the heating wire 22, and the center o5 of the vapor deposition substrate 21 is not on a straight line.
located at the end of the

Furthermore, the opening 24 of the vapor deposition mask 23 is located on the center o5 of the heating wire 22.

To be precise, the center o5 of the heating wire 22 and the vapor deposition mask 23
The center om of the opening 24 is the part where the transmittance of the optical filter is lowest, that is, in the case of an optical filter having the transmittance distribution shown in FIG. 2, the transmittance decreases as it spreads outward. It is located outward from the effective diameter of the

Moreover, the installation direction of the linear heating wire 22 is
It coincides with the x-x' axis direction.

Furthermore, the deposition substrate 21 is rotating around the z-z' axis.

Next, it will be explained that the transmittance distribution shown in FIG. 2 can be obtained with the above configuration.

FIG. 7 is an xz plane sectional view of the device shown in FIG. 6.

In the figure, the size of the opening 24 of the evaporation mask 23, the length of the heating wire 22, and each element are adjusted so that the maximum diameter 25 of the penumbra of the evaporation source is located near the center 0 of the evaporation substrate 21. The distance between them is determined.

Therefore, as is clear from the figure, the thickness of the deposited film on the deposition substrate 21 is the thickest near the os-0m line,
From there, it gradually becomes thinner toward the center, and the center becomes 0.
It becomes almost zero in the vicinity, resulting in the film thickness distribution shown in the figure.

As a result, the transmittance is shown in Figure 1. The distribution will be as shown in Figure 3.

However, since the deposition substrate 21 is actually rotating, FIG.

An optical filter having a concentric uniform transmittance distribution with the highest transmittance at the center as shown in FIG. 4 can be obtained.

By the way, the opening 24 of the evaporation mask 23 does not need to be symmetrical with respect to the center om, and the outward direction with respect to the center 0 of the evaporation substrate 21 does not play an important role in the film thickness distribution. As shown in the figure, it may be asymmetrical with respect to the center om, or it may be only the shaded portion.

Furthermore, the heating wire 22 serving as an evaporation source is shown in a side view as shown in FIG.
The one shown in the figure is used.

That is, a thin wire (0.03 to 0.3 m speed) 25 of vapor-deposited metal such as nickel, chromium, Inconel, etc. is attached to a heating wire 22 made of a tungsten wire with a diameter of 0.3 to 3 mm.
is wound with a pitch of 4.

In addition, the same vapor-deposited metal can also be welded at predetermined intervals.

26 is an electrode for passing a current through the heating wire 22, and 27 is a slit plate that determines the length of the evaporation source.

Furthermore, in this embodiment, the deposition substrate 21 is rotated, and its configuration is shown in FIG.

In the figure, a vapor deposition substrate 21, a vapor deposition mask 23, and a heating wire 22 are installed inside a vacuum container 28, and rotation given by a motor 30 is transmitted to the vapor deposition substrate 21 by a gear 29.

Note that the transmittance distribution can be adjusted using the opening 2 of the vapor deposition mask 23.
4, the length of the vapor deposition metal 25 and the length of the slit 27), the spacing between each element, or the horizontal arrangement.
A plurality of filters 7 can be used, and several filters can be obtained by installing the vapor-deposited metal once.

As is clear from the above description, according to the present invention, the evaporation substrate is rotated and the evaporation mask is configured to extend from the center of the evaporation substrate in one direction to cover the evaporation substrate. The substrate is not deposited at all in the center, and the amount of vapor deposited increases uniformly as it spreads to the periphery. Therefore, an optical filter is obtained in which the transmittance distribution is highest in the center and gradually decreases concentrically in the periphery.

Furthermore, since the manufacturing process can be carried out in one step, each mechanism can be easily adjusted only once, and the time required to manufacture one optical filter can be greatly reduced.

Therefore, according to the present invention, it is possible to save materials and improve work efficiency.

[Brief explanation of the drawing]

1 to 4 are light transmittance distribution characteristic diagrams of an optical filter already proposed by the applicant, FIG. 5 is a perspective view of the configuration of an optical filter manufacturing apparatus already proposed by the applicant, and FIG. 7th
10 are schematic configuration diagrams and side views showing one embodiment of the optical filter manufacturing apparatus of the present invention, and FIGS. 8 and 9 are configuration diagrams of essential parts of the same embodiment. 21... Vapor deposition substrate, 22... Heating wire,
23... Vapor deposition mask, 24... Opening, 25... Vapor deposited metal, 26... Electrode,
27... Slit plate, 28... Vacuum container, 29... Gear, 30... Motor.

Claims (1)

[Claims] 1. An optical filter manufacturing apparatus in which a vapor deposition mask is installed between a vapor deposition substrate and a heating wire, wherein the vapor deposition substrate is rotated about an axis perpendicular to the substrate, and the vapor deposition mask is rotated about an axis perpendicular to the substrate. is installed to cover the vapor deposition substrate in one direction from the center of the substrate, and the heating wire is provided with a vapor deposition metal to be vapor deposited on the vapor deposition substrate. .