JPH01302639A - Shadow mask for color cathode-ray tube - Google Patents

Abstract

PURPOSE:To eliminate the limitation on the hole diameter against the mechanical strength and improve resolution by stacking and sticking and fixing the first plate body and the second plate body so that multiple holes bored on them individually correspond to each other. CONSTITUTION:Long holes 12 and 22 are formed on the first and second plate bodies 11 and 21 by etching in advance, they are correctly stacked using these long holes 12 and 22 as a reference and welded and integrated via multiple welding points 31. The shape and precision of holes required for the operation of a color cathode-ray tube are determined by the long holes 22, the long holes 22 are provided on the sufficiently thin second plate body 21, thus there is no limitation on the ratio between the plate thickness and the hole diameter. The total strength of a shadow mask is determined by the sum of the plate thicknesses of the first and second plate bodies 11 and 21, particularly by the strength of the first plate body 11. Its strength has no relation with the size of holes required for the operation of the color cathode-ray tube, the mechanical performance of a large-sized color cathode-ray tube is secured, its resolution can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a shadow mask for a color cathode ray tube.

(Prior Art) A conventional shadow mask of this type will be explained based on FIGS. 5 to 8.

That is, 1 is the shadow mask body, and this shadow mask body! is made of pure iron or an alloy containing 2.7 Kel, and has a plurality of regularly arranged holes 2 for passing the electron beam.

These holes 2 were created by printing a resist pattern on both sides of a flat original plate using a photochemical method, and then etching both sides to form the hole 2 accurately in shape and size. Portion 3 is a portion that was not etched due to the application of resist at this time. Furthermore, the hole 2 has a front side taper part 4 whose diameter increases toward the front surface of the shadow mask main body l, and a rear side taper portion 5 whose diameter expands toward the rear surface of the shadow mask main body l, so that the color cathode ray tube is To prevent loss of screen contrast,
The opening on the front side of the shadow mask main body 1 of 7L2 is formed larger than the opening on the back side. The shadow mask main body 1 was suitably annealed, then curved in the direction of the back surface using a press, and then mounted on a color cathode ray tube.

The shape of the hole 2 may be oval or rectangular as shown in FIGS. 5 and 6, or circular as shown in FIGS. 7 and 8.

[Problem to be solved by the invention]

In recent years, as color cathode ray tubes have become larger and higher resolution is required, the virtual jγL of the shadow mask body l has been increased due to the demand for increased strength for the larger size, and the pitch of holes 2 has been decreased for higher resolution. In other words, it has become difficult to satisfy the demand for reducing the diameter of each hole 2 due to an increase in the number of holes 2. In other words, it has become difficult to incorporate a shadow mask into a color cathode ray tube and project a satisfactory screen. The holes 2 must be uniformly provided to a predetermined size over the entire surface of the shadow mask, but this becomes difficult as the thickness of the shadow mask main body 1 increases.

In general, the size of the holes 2 that can be evenly provided is as follows:
It is almost determined by the ratio to t, and if the hole diameter is d, this ratio is d/l=0.75 in the case of the elongated hole 2, and d/1. = about 0.90 is the limit.

In addition, the demand for high-resolution color cathode ray tubes with large screens has increased year by year, and in recent years, tubes with square diameters of 30 inches or more have been manufactured. By the way, for example, if the diagonal diameter is 35 inches, the plate 1'itt of the shadow mask body 1 must be at least 60°2 in order to be formed into a curved shape by the plate 1/s and maintain its shape. ■It is necessary to meet the above requirements. Therefore, the diameter d of the hole 2 of the glossy mask of a 35-inch color cathode ray tube is 0.
2 Xo, 75-〇, 15a+s, in case of circular hole, 0.
2Xo,90=about 0.18 mm or less, but there was a problem in that it was difficult to form such a hole 2 practically.

SUMMARY OF THE INVENTION An object of the present invention is to solve the two problems, and to provide a shadow mask for a color cathode ray tube that does not have a restriction on mechanical strength in terms of hole diameter.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention includes a first plate having a plurality of holes through which electron beams pass, and a second plate having a small opening area and having a plurality of holes corresponding to the holes in the first plate. In the present invention, the first plate and the second temporary body are overlapped and fixed with adhesive so that the holes of the first and second temporary bodies correspond to each other individually. The two plates are adhesively fixed so that these holes correspond to each other, and since the openings of the holes in the second temporary body are formed small, the holes have a small diameter and the first plate and the second plate have a small hole diameter. The strength is improved by increasing the plate thickness due to double construction with the plate body.

〔Example〕

An embodiment of the shadow mask of the present invention will be described below with reference to FIGS. 1 to 4.

That is, the shadow mask shown in FIGS. 1 and 2 is composed of a first plate 11 and a second plate 21, which are made of metal plates containing pure iron or nickel. The first temporary body 11 has a sufficient thickness to maintain the strength of the shadow mask, and has a plurality of long holes 12 formed therein by etching for passing electric beams therethrough. Also, the second
In the plate body 21, a plurality of long holes 22 corresponding to the long holes 12 are bored by drilling and drilling through an electron beam.
It is molded from a thin enough material to allow the elongated hole 22 of a size necessary for the operation of the color cathode ray tube to be formed with sufficient precision.

By the way, in the case of a shadow mask used for a 35-inch cathode ray tube, for example, the thicknesses of the first plate 11 and the second plate 21, and t and 8 are, for example, 0.25 com and 0.0.
5-, and the holes i1 d and d2 are, for example, 0.2
5 kan and 0.15 ■. Furthermore, these elongated holes 12 and 22 have tapered portions 14.24 that expand in diameter toward the front and back surfaces of the first and second plate bodies 11.21, respectively, and the surfaces thereof are also similar to the elongated holes 2.
2 is formed smaller than the long hole 12. In addition, the first plate body 11 and the second plate body 21 are accurately overlapped so that the elongated holes 12 and 22 are individually in a predetermined positional relationship, and the effective portion 7 of the shadow mask body 6, which will be described later, is They are securely welded and integrated by electron beam or laser welding at a plurality of welding points 31 over the entire area.

In this case, in order for the first plate 11 and the second plate 21 to be overlapped accurately, the pattern of the resist layer applied to these plates 11° 21 needs to be accurate. However, for this purpose, it is better to use a method of printing the original drawing drawn by an automatic drawing device.

In addition, as shown in FIG. 3, the first and second temporary bodies 11.21 have an effective part 7 provided with the elongated holes 12 and 22, and around this effective part 7, for reinforcement and retention. A peripheral portion 8 is formed. A plurality of positioning holes 32 for positioning are provided in this peripheral portion 8, and the first and second plates 11 and 21 are accurately aligned using a jig having a guide rod or optical means. can be superimposed on

Therefore, according to the present invention, the first and second bodies 11°21
After forming elongated holes 12 and 22 by etching in advance, these elongated holes 12 and 22 were accurately overlapped and welded together at multiple welding points 31, which is necessary for the operation of the color cathode ray tube. The shape and accuracy of the hole are determined by the long hole 22, and since the long hole 22 is provided in the sufficiently thin second plate 21, the above-mentioned problem of limiting the ratio of plate thickness to hole diameter does not occur. . Further, the overall strength of the shadow mask is determined by the sum of the plate thicknesses of the first and second temporary bodies 11.21, and in particular by the strength of the first plate body 11. This makes the strength independent of the size of the holes necessary for the operation of color cathode ray tubes, and increases the number of holes to ensure mechanical performance and improve resolution for larger color cathode ray tubes, in other words, miniaturization of individual holes. I can do it.

In addition, the first Fi body 11 contains Fe-36N called amber.
A low thermal expansion alloy of i may be used, and pure iron or a copper-nickel alloy may be used for the second plate 21. In this case, the first temporary body 11 has a lower thermal expansion than the second plate 21. It is desirable that the i series number be small.

[Effects of the Invention] As explained above, according to the present invention, the first plate body and the second plate body are overlapped and fixed by adhesive so that the plurality of holes drilled therein correspond to each other individually. Since the shadow mask has a double structure, the strength of the shadow mask can be improved by increasing the plate thickness, and it can therefore be made larger. Furthermore, the number of holes can be increased by making the holes of the second temporary body smaller, which makes it possible to increase the size of the shadow mask. The above-mentioned problems can be solved by unique effects such as improved resolution.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the shadow mask of the present invention, in which FIG. 1 is a sectional view of the shadow mask main body, FIG. 2 is a plan view of essential parts of the shadow mask main body, and FIG. 4 is a plan view of the shadow mask, FIG. 4 is a sectional view of the shadow mask, and FIGS. 5 to 8 show conventional examples.
The figure is a plan view of the main part of the shadow mask main body having a long hole, FIG. 6 is a sectional view taken along the α-α line in FIG. β- in Figure 7
A cross-sectional view of the β plane. 6... Shadow mask body, 7... Effective part, 8...
- Peripheral part, 11... First temporary body, 12.22... Long hole, 14°24... Taper part, 21... Second plate body,
31... Welding point, 32... Hole. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Masuo Oiwa Figure 1 Figure 2 Figure 3 32: W Figure 4 W&C

Claims (1)

[Claims] a first plate having a plurality of holes through which the electron beam passes;
A second plate having a small opening area and a plurality of holes corresponding to the holes in the first plate is overlapped and bonded so that the holes in the first and second plates correspond to each other individually. A shadow mask for color cathode ray tubes that is fixed.