JPS5850322B2 - 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, considering the same as above, the optical filter shown in FIG. 2 is symmetrical with respect to point 0, and has the highest transmittance at the center and decreases 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, the conventional optical filter has a light transmittance distribution as shown in FIG. 5, where the light transmittance is low in the center and increases as it spreads toward the periphery.

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. As mentioned above, the optical filter has the highest light transmittance in the center, is symmetrical only about one axis of the face plate, and has a high light transmittance distribution over the whole, at least about 80%. I can't get it.

The present invention solves these problems and provides a novel optical filter manufacturing apparatus capable of producing the above-mentioned novel optical filter with a desired light transmittance distribution. be.

The present invention will be explained below based on examples together with the drawings.

FIG. 6 is a structural perspective view showing an embodiment of the present invention,
Vapor deposition substrate 11 such as glass and heating wire 1 such as tungsten wire
A vapor deposition mask 13 is provided between the two.

The heating wire 12 is shown in the seventh enlarged side view and front view of its main part.
As shown in Figures a and b, a vapor-deposited metal 14 such as nickel, chromium, or inconel is welded onto the heating wire 12, and this serves as an evaporation source.

The shape of the heating wire 12, as shown in FIG. At first glance, it appears to be U-shaped.

The vapor deposited metal 14 is densest at the connecting part 122, as shown by the welding position marked with an x, and extends from the connecting part 122 to the connecting parts 123, 123', and then to the side parts 121, 121'.
The further the welding progresses, the more sparsely welded.

Further, the shape of the vapor deposition mask 13 is a tongue-like shape that suppresses the inside of the U-shape formed by the heating wire 12, as shown in FIG. 9, which is a plan view of the configuration diagram shown in FIG. It has the shape of

In this embodiment, a Dungesten wire with a diameter of 0.5 to 3 mm is used as the heating wire 12, and a diameter of 0.0 to 0.0 mm is used as the vapor-deposited metal 14.
Using an inconel with a length of 3 to 0.3 mm and a length of 1 to 10 cm, welding is performed densely at intervals of 1 to 2 crrL at the connecting part 122 and sparsely at intervals of 4 to 5 crrL at the side part 12L121'. Complete vapor deposition was performed in which the metal 14 was evaporated.

Note that the vapor deposition mask 13 was obtained by molding a stainless steel plate.

In complete vapor deposition, the light transmittance is closely related to the mass of the vapor-deposited metal 14, and if the mass is constant, the light transmittance is also constant.

The light transmittance distribution can be controlled by (1) the distance between the heating wire 12 serving as the evaporation source, the evaporation substrate 11, and the evaporation mask 13;
2) the position of the evaporation mask 13 and the heating wire 12 with respect to the center of the evaporation substrate 11; (3) the shape of the heating wire 12, especially the shape of the connecting portions 122, 123, 123'; (4) the shape of the evaporation mask 13; ) The vapor-deposited metal 14 is attached by adjusting its direction and position.

By the way, in order to manufacture a light source filter having the light transmittance distribution shown in FIGS. 2 and 4, after manufacturing the optical filter having the light transmittance distribution shown in FIGS. 1 and 3, By performing the same vapor deposition while rotating the deposition substrate 11 by 1800 degrees, the same light transmittance distribution can be obtained after rotating the deposition substrate 11 by 1800 degrees, and as a result, the concentric circular shape shown in FIGS. 2 and 4 is obtained. An optical filter with the highest light transmittance at the center can be obtained.

As explained above, in the optical filter manufacturing apparatus of the present invention, the shape of the heating wire is formed as two opposing side parts and a connecting part, and the vapor deposition mask is shaped to cover the inside of the shape of the heating wire. In addition, by forming the vapor-deposited metal densely at the joints and sparsely at the sides, on the vapor-deposited substrate, not much is vapor-deposited in the center, resulting in the highest light transmittance, and one axis of the face plate. , for example, symmetric only about the horizontal axis,
In addition, an optical filter with high overall transmittance can be obtained.

[Brief explanation of the drawing]

1 to 4 are light transmittance distribution characteristic diagrams of an optical filter already proposed by the present applicant, FIG. 5 is a light transmittance distribution characteristic diagram of a conventional optical filter, and FIG. 6 is a light transmittance distribution characteristic diagram of an optical filter of the present invention. 7a, b, and 8 are side views, front views, and plan views of the heating wire of the same embodiment. FIG. 9 is a plan view of the same embodiment. It is a diagram. 11... Vapor deposition substrate, 12... Heating wire,
13... Vapor deposition mask, 14... Vapor deposition metal, 121, 121'... Side part, 122, 1
23,123'...Connection part.

Claims (1)

[Claims] 1. A heating wire consisting of two opposing side portions and a connecting portion connecting the both side portions, a vapor deposition metal formed on the heating wire, and a vapor deposition substrate on which the vapor deposition metal is vapor deposited;
an evaporation mask provided between the heating wire and the evaporation substrate, the evaporation metal is formed more densely at the connecting portion than at the side portions of the heating wire, and the evaporation mask is provided between the heating wire and the evaporation substrate. 1. An optical filter manufacturing apparatus characterized in that the optical filter has a shape that covers the inside of a shape formed by both side portions and the connecting portion.