JPH0447649A - Cathode-ray tube - Google Patents

Abstract

PURPOSE:To improve workability and prevent generation of sputtering by forming a semispherical recessed part whose diameter is proportional to the thickness of a mask plate and whose depth is almost the half of the diameter in the outer periphery of a skirt part and a frame except a welded part by half-etching. CONSTITUTION:In the case that a plurality of semispherical dot-like recessed parts 3d are formed in a prescribed pitch by half-etching, in the outer periphery of a skirt part 3a of a shadow mask 3, the recessed parts are so set as to have proportional diameter A2 to the thickness (t) of a mask plate and the depth d2 almost the half of the diameter A2 and formed in a frame 5 except welded parts P, for example total 12 points consisting of 4 points of corner parts, each 2 parts of long and short lines. Consequently, the skirt part 3a is inserted into a frame 5 smoothly and the curvature of the mask is possible to be kept constant after insertion. Further, in the case of welding the outer periphery of the skirt part 3a and the inner periphery of the frame 5 by a welding electrode 9, adhesion strength of both at the points P becomes high and sputtering is prevented from being caused.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a cathode ray tube using a shadow mask, and more specifically, a cathode ray tube using a shadow mask, which is formed on the outer peripheral surface of the skirt portion of a banyado mask to improve fitting of the shadow mask into the frame. This relates to a half-etched structure.

[Conventional technology]

A color cathode ray tube using a shadow mask consists of a Harz funnel part (1) and a panel part (2), as shown in Figure 3.
) is formed separately, a shadow mask (3) and a magnetic shield (not shown) are built in, and then sealed with a seal (4) made of glass powder or the like. Above funnel part (
An internal conductive film for collecting secondary electrons is coated on the inner surface of panel section 1), and a fluorescent film (8) for emitting light in three primary colors is coated on the inner surface of panel section (2) (see Figure 4). has been done.

In addition, a shadow mask (3
), as shown in FIGS. 3 and 4, has a skirt portion (3a) fitted into a steel frame (5) and welded at a predetermined position to the inner peripheral surface of the frame. The frame (5) is fitted with a splinter (6) having a hole (6b) on its side surface (5a) and an end (6a), and a stud pin provided on the inner surface of the panel section (2). (7
) is mounted by fitting the hole (6b) and supporting it on the panel part (2).

Here, during operation, about 85% of the electron beam hits the shadow mask (3) and the temperature rises to about 80°C, so the temperature of the shadow mask (3) increases to about 80°C.
As shown in the figure, the mask surface is transformed into a mask (3b) by heating and expansion, and the same electron beam transmission hole (3c1) is shifted to (3C2). Then, the electron gun (9)
(See Figure 3), the electron beam (EB') that passes through the electron beam transmission hole (3c+) and is to be irradiated onto the corresponding phosphor dot (8a) of the fluorescent film is transmitted through the electron beam transmission hole (3c+).
3C2) and is also partially irradiated onto the adjacent phosphor dot (8b), causing color shift and so-called doming. In order to minimize this doming, a shadow mask (3
) is used. However, the Invar material has a large spring hack and has poor press formability, so the skirt part of the shadow mask (3) (
Although the curvature of the mask is kept constant by inserting 3a), it also has the disadvantage that the inserting operation is difficult. Therefore, as shown in FIG. 4, as a countermeasure, dot-shaped recesses (3b) are hollowed out into a hemispherical shape by half-etching on the outer peripheral surface of the skirt portion (3a) of the shadow mask (3).
are formed at a predetermined pitch, and the skirt portion (3a
) is made partially thinner so that it is easily deformed and the above-mentioned insertion and insertion work is facilitated.

[Problem to be solved by the invention]

By the way, as mentioned above, the shadow mask (3) has a plurality of dot-shaped recesses (3b) in its skirt portion (3a).
is formed to facilitate insertion into the frame (5). However, the diameter (AI) of the recess (3h)
and depth (d 1 ) are not set to specific values,
If they are too large, the strength of the skirt portion (3a) will be weakened, making the above-mentioned insertion operation easier, but it will be difficult to maintain a constant curvature of the mask. Conversely, the above diameter (A
l) and depth (dl) are too small, frame (5)
There was a problem that the shadow mask (3) would not fit when inserted inside.

Also, a shadow mask (3) is placed on the inner peripheral surface of the frame (5).
When welding the skirt part (3a), a recess (
If 3b)- is present, there is a problem that adhesion is reduced and spatter is generated, which adversely affects product characteristics.

[Means to solve the problem]

The present invention provides a cathode ray tube in which a scar part of a shadow mask made of an invar material is fitted and welded into a shadow mask mounting frame housed in a panel part.
On the outer circumferential surface of the shadow mask skirt part, a plurality of dot-shaped recesses are formed by half-etching into a hemispherical shape, the diameter of which is proportional to the thickness of the 7th board, and the depth of which is approximately half the diameter, with a predetermined pinch. It is characterized in that it is formed excluding the welded part with.

[Effect]

According to the above technical means, a plurality of dot-shaped recesses of predetermined dimensions are formed by half-etching on the outer peripheral surface of the shadow mask skirt portion at a predetermined pitch, excluding the welded portion with the frame, and the The skirt portion can be smoothly inserted and inserted, and the adhesion between the inner circumferential surface of the frame and the outer circumferential surface of the skirt portion at the welding site is good.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2. The same reference numerals as in FIG. 4 indicate the same parts, and the explanation thereof will be omitted. The difference is that when a plurality of hemispherical dot-shaped recesses (3d) are formed with a predetermined pinch on the outer peripheral surface of the skirt portion (3a) of the shadow mask (3) by half etching, the diameter (A2) is Mask plate thickness (1
) (A2 = kT, is a constant determined by the dot pitch), the depth (d2) is set to be approximately half of the diameter (A2), and the welding area (P ), for example, they are formed at 12 locations, excluding 4 locations at the corners and 2 locations each on the long and short sides.

According to the above configuration, the skirt portion (3a) can be smoothly inserted into the frame (5), and the curvature of the mask can be kept constant after being inserted. Furthermore, welding electrode (9)
The outer peripheral surface of part of Scar I (3a) and frame (5)
When welding the inner circumferential surface of the material to the inner peripheral surface of the material, the adhesion between the two is improved at that portion (P), and generation of spatter can be prevented. According to the measurement, at t-0, 15m(7), A2 = 200
±5 pmXd2 =90tt m (k =1.3
3xlO-3).

〔Effect of the invention〕

According to the present invention, in a color cathode ray tube in which the skirt portion of a shadow mask is fitted and attached to its mounting frame, the outer circumferential surface of the skirt portion is half-etched to form a hemispherical shape whose diameter is proportional to the mask plate thickness; Multiple dot-shaped recesses with a depth of approximately half the diameter are formed at a predetermined pitch.
And with Freno? Since the skirt part is formed excluding the contact area, it is easier to fit the skirt part into the frame, improving workability, and improving the adhesion between the outer circumferential surface of the skirt part and the inner circumferential surface of the frame. Spatter generation is eliminated and product properties are improved.

[Brief explanation of drawings]

FIG. 1 is a sectional side view of a main part showing an embodiment of a cathode ray tube according to the present invention, FIG. 2 is a partial plan view of a shadow mask according to the present invention, and FIGS. 3 and 4 are a side view of a conventional cathode ray tube. FIG. 5 is a cross-sectional view showing a specific example and a partially enlarged view thereof, and FIG. 5 is a partial side cross-sectional view of a shadow mask and a panel portion showing doming. (2) - Panel part, (3) (3a) - Part of mechanism 1, (3d) (5) - Frame, (P) Shadow mask, recess, welding part. Patent applicant Kansai NEC Corporation＼

Claims (1)

[Claims] (1) In a cathode ray tube in which a shadow mask made of invar material is fitted into a mounting frame housed in a panel part and is fixed to the frame by welding at its skirt part, the skirt part has a diameter on the outer peripheral surface excluding the welded part with the frame. 1. A cathode ray tube characterized in that a hemispherical recess is formed by half-etching so that the depth is proportional to the plate thickness and the depth is approximately half the diameter.