JPH06139950A - Aperture grill mask for cathode-ray tube - Google Patents

Abstract

PURPOSE:To reduce the twist of an extreme end tape section around the extension direction of an extreme end slit, even when a mask is laid on a frame under high tension. CONSTITUTION:Regarding the extreme tape section 17a of a mask 12, the side end 17b thereof opposite to an extreme end slit 16a has a curved form, so that the breadth of the section 17a becomes not uniform but larger at a center than at both ends in the extension direction of the slit 16a. As a result, the section 17a in the extension direction of the slit 16a becomes less twisted, and the breadth of the slit 16a is not reduced, thereby ensuring proper color screening.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mask which constitutes an aperture grill which is a color selection mechanism in a color cathode ray tube.

[0002]

2. Description of the Related Art FIG. 4 shows an aperture grill as a color selection mechanism in a color cathode ray tube. The aperture grill 11 includes a mask 12, a frame 13,
A spring 14 for supporting the aperture grill 11 on the panel of the cathode ray tube, a holder 15 and the like are included.

FIG. 5 shows a main part of the mask 12.
The mask 12 is provided with a slit 16 for transmitting an electron beam and a tape portion 17 between these slits 16 on the effective screen. Edge slit 1
The outermost tape portion 17 having a linear and uniform width is provided on the outer side of 6a.
a are adjacent to each other, and a slit 18 for trimming or the like is provided outside thereof. The mask 12 is initially provided with a peripheral portion 12a.

To manufacture the aperture grille 11 shown in FIG. 4, the frame 13 is cleaned and then the holder 15 is attached to the frame 13 as shown in the flow chart of FIG. Then, pressure is applied to the frame 13 so that the frames 13 at the portions where the mask 12 is welded are brought close to each other, and the mask 12 is welded to the frame 13 in this state.

Thereafter, the pressure applied to the frame 13 is released and the mask 12 is stretched over the frame 13 with high tension.
This is to reduce color misregistration caused by thermal expansion of the mask 12 during operation of the cathode ray tube. And
Trimming of the peripheral portion 12a is performed by cutting the portion of the mask 12 protruding from the frame 13. Further, the mask 12 is blackened, and the spring 14
Install the.

However, when the mask 12 is stretched on the frame 13 with a high tension as described above, a high stress is distributed toward the outside of the x-axis as shown in FIG.
A rotational moment is generated about the axis toward the inside of the mask 12. As a result, the outermost tape portion 17a was twisted inward, and the width of the outermost slit 16a was narrower than a predetermined width, so that good color selection could not be performed. Therefore,
Conventionally, as shown in FIG. 8, an extra or dummy slit 19 is provided in the outermost tape portion 17a.

The extra slit 19 is provided with an extra slit 19 which is narrower than the ordinary slit 16.
The above-mentioned stress after the mask 12 is stretched on the frame 13 is absorbed by the slit 19, and the slit 19 is deformed to eliminate its actual width. Also,
The dummy slit 19 is also provided with an extra slit 19 having a normal width in order to absorb the above-mentioned stress. However, before forming the fluorescent screen, the slit 19 is covered with a stainless ribbon or the like to remove the fluorescent screen. Is not exposed.

[0008]

However, it is not easy to form the extra slit 19 which is narrower than the ordinary slit 16. For this reason, if the extra slit 19 is not deformed as desired and its actual width is eliminated, an extra slit is created on the phosphor screen. Further, it is not easy to cover only one extra dummy slit 19, and the number of steps and the number of parts for that purpose are increased. Therefore, with the conventional mask for aperture grilles of cathode ray tubes, it has been impossible to perform good color selection with a simple structure or the like.

[0009]

According to the aperture grill mask 12 of the cathode ray tube of claim 1, the width of the outermost tape portion 17a adjacent to the outermost side of the outermost slit 16a of the aperture grill mask 12 is: The most end slit 16a
Is wider at the central portion than at both ends in the extending direction of.

In the aperture grill mask 12 for a cathode ray tube according to the second aspect, the end tape portion 1 adjacent to the outer side of the end slit 16a of the aperture grill mask 12 is provided.
The thickness of the cross section of 7b in the direction orthogonal to the extending direction of the outermost slit 16a is thinner on the side opposite to the outermost slit 16a than on the side of the outermost slit 16a.

[0011]

According to the mask 12 for the aperture grille of the cathode ray tube of claim 1, even when the mask 12 is stretched over the frame 13 with a high tension, the distribution of the stress generated in the endmost tape portion 17a of the mask 12 is gentle. . Therefore, the mask 12
The twist of the end tape part 17a around the extension direction of the end slit 16a is small, and the width of the end slit 16a does not become narrow.

According to the aperture grill mask 12 for a cathode ray tube of claim 2, even when the mask 12 is stretched over the frame 13 with a high tension, the mask 12 is placed on the side of the end slit 16a of the end tape portion 17a. The generated stress is small and the stress distribution is gentle. Therefore, the end tape portion 17a is less twisted around the extending direction of the end slit 16a of the mask 12, and the width of the end slit 16a is not narrowed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The first to third embodiments of the present invention will be described below with reference to FIGS. The components corresponding to those of the first and second conventional examples shown in FIGS. 5 and 8 are designated by the same reference numerals.

FIG. 1 shows a first embodiment. In the first embodiment, the width of the endmost tape portion 17a adjacent to the outermost side of the endmost slit 16a of the mask 12 is not uniform, and is more centered than both end portions in the extending direction of the endmost slit 16a. End tape portion 17a so that it becomes wider
Side edge 17b on the side opposite to the endmost slit 16a
Is curved. Further, the slit 18 provided further outside the outermost tape portion 17a and used for trimming or the like is also curved along the side edge 17b of the outermost tape portion 17a.

Except for the above points, this first embodiment has substantially the same structure as the first conventional example shown in FIG. In the first embodiment as described above, even if the mask 12 is stretched on the frame 13 with a high tension as shown in FIG. 7, the distribution of the stress generated in the outermost tape portion 17a is gentle. Therefore, the rotational moment generated around the z-axis toward the inside of the mask 12 is small, and the innermost end tape portion 17 is inward.
Little twist of a. Therefore, the width of the outermost slit 16a does not become narrow, and good color selection can be performed.

FIG. 2 shows a second embodiment. This second embodiment is substantially the same as the first embodiment shown in FIG. 1 except that the slit 18 has a plano-convex lens shape rather than a curved shape along the side edge 17b of the outermost tape portion 17a. Has the same configuration. Even in such a second embodiment, the first
The same effect as that of the embodiment can be obtained.

FIG. 3 shows a third embodiment. In the third embodiment, as shown in FIG.
The endmost tape portion 17 in the direction perpendicular to the extending direction of a
5A except that the thickness of the cross section of a is not uniform as in the first conventional example shown in FIG. 5B and is thin on the side opposite to the endmost slit 16a. It has substantially the same configuration as the conventional example.

In the third embodiment as described above, even if the mask 12 is stretched over the frame 13 with a high tension as shown in FIG.
The stress generated in the endmost slit 16a side of the endmost tape portion 17a, that is, in the thickest section of the endmost tape portion 17a is small, the stress distribution is gentle, and the same effect as the first embodiment is obtained. Can play.

[0019]

In the mask for the aperture grille of the cathode ray tube according to the present invention, the mask is stretched over the frame with a high tension even though the structure is simple without the need for extra slits, steps or parts. However, since the twist of the end tape portion around the extension direction of the end slit of this mask is small and the width of the end slit is not narrowed, good color selection can be performed.

[Brief description of drawings]

FIG. 1 is a plan view of an essential part of a first embodiment of the present invention.

FIG. 2 is a plan view of an essential part of a second embodiment of the present invention.

FIG. 3 shows an essential part of a third embodiment of the present invention,
(A) is a top view, (b) is an expanded side sectional view in the position which follows the BB line of (a).

FIG. 4 is a perspective view of an aperture grill to which the invention of the present application can be applied.

FIG. 5 shows a main part of a first conventional example of the invention of the present application,
(A) is a top view, (b) is an expanded side sectional view in the position which follows the BB line of (a).

FIG. 6 is a flowchart showing manufacturing steps of an aperture grill.

FIG. 7 is a perspective view of a main part of an aperture grill.

FIG. 8 is a plan view of a main part of a second conventional example of the invention of the present application.

[Explanation of symbols]

 12 Mask 16a Edge slit 17a Edge tape part

Claims (2)

[Claims] 1. The width of the outermost tape portion adjacent to the outermost side of the outermost slit of the aperture grill mask is wider in the central portion than in both end portions in the extending direction of the outermost slit. Mask for aperture grille of cathode ray tube. 2. The thickness of the cross section of the outermost tape portion adjacent to the outermost slit of the aperture grill mask in a direction perpendicular to the extending direction of the outermost slit,
A mask for an aperture grill of a cathode ray tube, which is thinner on the side opposite to the end slit than on the end slit side.