KR20010015499A - Material of spring to Tri-metal for color braun tube - Google Patents

Abstract

PURPOSE: A trimetal spring material for a color braun tube that supports a shadow mask and compensates deflection of the shadow mask originated from differential thermal expansion is provided to suppress mis-landing of electron beam by adopting trimetal materials having a low coefficient of thermal expansion and also modifying a spring mechanism according to the shadow mask. CONSTITUTION: The trimetal spring material consists of an Fe-Ni invar alloy plate in the middle of the trimetal spring plate, and two STS 304H stainless steel plates at both sides of the Fe-Ni invar alloy plate. The Fe-Ni invar alloy plate having 1.165 to 1.234n/m in thickness and 20.85 to 21.15n/m in width comprises 0.02wt.% or less of C, 0.25wt.% or less of Si, 0.2 to 0.4wt.% of Mn, 0.007wt.% or less of P, 0.002wt.% or less of S, 35.5 to 36.5wt.% of Ni, and a balance of Fe. The STS 304H stainless steel plate having 1.165 to 1.235n/m in thickness and 11.85 to 12.15n/m in width comprises 0.12wt.% or less of C, 1.0wt.% or less of Si, 2.0wt.% or less of Mn, 0.03wt.% or less of P, 0.03wt.% or less of S, 8.0 to 10.5wt.% of Ni, 17.0 to 19.0wt.% of Cr, and a balance of Fe.

Description

Trimetal spring material for color-brown tubes {Material of spring to Tri-metal for color braun tube}

The present invention relates to a trimetal spring material for a color brown tube, and more specifically, a 29 "NS type color for serving as a support for supporting a support frame to a panel and compensating for thermal expansion of a shadow mask due to collision of an electron beam during operation of a CRT. It relates to a trimetal spring material for CRT.

First, explaining the structure of the color-brown tube and the role of the spring in the color-brown tube, Figure 1 is a cross-sectional view showing a general color-brown tube, Figure 2 a, b, c shows a state diagram of the use of the spring.

The CRT consists of a rectangular panel 1 and a funnel 3 in which the neck portion 3a into which the electron gun 2 is sealed is integrally formed.

The panel 1 has a tube axis passing through the center thereof, and phosphors of three colors emitting blue, green, and red light are coated on the inner surface of the panel 1 to form a fluorescent surface 4, and in the vicinity of the fluorescent surface, there are a myriad of holes 5a. The shadow mask 5 is formed to serve as color screening of the electron beam. The shadow mask is welded and supported by the rectangular support frame 6.

The support frame 6 is fitted to the stud pin 8 fixed to the inner surface of the panel 1 by a plurality of springs 12 to maintain the suspended state to the panel (1).

The spring 12 is formed between the hole 5a formed in the shadow mask and the fluorescent surface 4 of the screen when the shadow mask 5 and the support frame 6 are heated and expanded due to the collision of the electron beam according to the operation of the CRT. The role of preventing discoloration (color distortion) caused by relative displacement and preventing shock from being transmitted to the shadow mask (5) even when an impact is applied during the operation of the CRT can be prevented from deteriorating color purity. Play a role.

Springs and shadow masks in a CRT having such a structure are generally Invar, in which the support frame 6 is iron (Fe), and the shadow mask (5) is made of aluminum-kilted steel (AK) or Fe-Ni alloy. In order to reduce the compensation amount of the landing error of the electron beam 11 due to thermal expansion of the shadow mask 5, the material of the spring 12 is also Fe-Ni alloy such as shadow mask, Invar or aluminum. Kilda steel (AK) is used.

However, this Invar alloy is an alloy whose Ni content is 36% (the remainder is Fe), and its thermal expansion coefficient is very small at 1.2X10 ^-6 / ℃ or less at room temperature, so it is sensitive to thermal effects. As it is an alloy that contains a lot of expensive Ni, which is frequently used for the head support, the lead alloy of the lead frame, etc., the manufacturing cost of the spring material is increased, causing the cost of manufacturing the color-brown tube to be a problem. When used as a material, although the price is cheaper than the Inba alloy, there is a problem that the coefficient of thermal expansion is high.

The present invention has been made to solve such a problem in the prior art using a low cost and relatively low coefficient of thermal expansion of trimetal material instead of expensive invar alloy or aluminum-kilted steel with high coefficient of thermal expansion and according to the shape of the shadow mask. The purpose of the present invention is to improve the structure of the spring and improve the mis-landing phenomenon of the electron beam due to thermal expansion of the shadow mask during the operation of the CRT.

According to an aspect of the present invention for achieving the above object, a plate of stainless steel STS 304H, iron-nickel alloy Inbar, and stainless steel 304H are arranged side by side and the contact cross section is a known continuous electron beam welding method. It is a technical problem to form a single spring plate by welding with the welding method shown in the method of manufacturing trimetal for color brown tube filed in the patent 95-1120 of January 24, 1995.

For reference, such a spring material forms a spring in the form as shown in FIG. 4, and this spring serves to fix the shadow mask to the panel as shown in FIGS. 2a, b, and c and serves as a compensator according to thermal expansion of the shadow mask. The mechanism that Spring acts as a calibrator is as follows.

1) Mask DOMING step

Only about 20% of the electron beam emitted from the electron gun collides with the phosphor-coated screen of the screen, and the rest of the electron beam collides with the shadow mask or the supporting frame to lose kinetic energy.

At this time, the frictional heat generated by the collision of the electron beam thermally expands the shadow mask, thereby causing a dominant phenomenon in which the mask curved portion swells in the screen direction, and the electron beam passing through the mask is moved toward the screen center by the displacement of the mask.

2) FRAME thermal expansion stage

The shadow mask, which has a relatively large number of electron beam collisions, has a low thermal capacity, thermally expands first, and then a dominant phenomenon occurs. Then, the shadow mask, which causes the dominant phenomenon, expands to the periphery of the screen as the support frame thermally expands in the peripheral direction of the screen.

The expansion of the mask causes the landing of the electron beam moving in the center direction of the screen to move in the peripheral direction again.

3) the displacement and stabilization stage of the spring

As the frame expands and the shadow mask expands in the circumferential direction, the spring welded to the frame also heats up, causing the bimetal action to lift the MASK ASS'Y toward the screen, while the landing of the electron beam gradually moves in the circumferential direction. Over time, it is a stable phase that balances incident energy and emitted energy and no further thermal displacement or landing changes occur.

4) Correction effect of spring

5) Spring compensation amount setting

The thermal displacement correction amount setting of the spring can be expressed as the following equation.

1 is a cross-sectional view showing a typical color-brown tube

2, a, b, c is a partial longitudinal cross-sectional view illustrating the use state of the spring in the CRT

Figure 3 a, b is a perspective view of the TRI-Metal integrally formed of the Invar alloy and STS 304H alloy

Figure 4 is a type of spring molded from bimetal or trimetal material

<Description of the symbols for the main parts of the drawings>

1 panel 3 funnel

5: shadow mask 6: support frame

12: spring

Hereinafter, the present invention will be described in detail with reference to FIG. 3.

3A and 3B show metals of STS 304H and Ni 36% containing Inva alloys having different chemical composition and mechanical properties, as shown in Tables 2 and 3, which are made of one metal strip using a continuous electron beam welding method. It can be seen that the standard of the trimetal is determined as shown in Table 1 according to the type of the product of the color CRT.

TABLE 1

Trimetal standard material standard unit according to the product type of color CRT

Note 1: The thickness of the material is 1.2m / m.

Note 2: Tolerance of material thickness is ± 0.035m / m.

Note 3: Tolerance of width is ± 0.15m / m.

TABLE 2

TABLE 3

This 29 "NS type trimetal spring material has very good bending constant and weld point tensile strength as shown in Table 4, so there is no significant difference in quality from springs using only Invar or aluminum-kilted steel (AK). In addition, there is an advantage in minimizing the loss of the Inba alloy, a low-expansion material in the center of the spring molding.

In addition, the reason for limiting the width and thickness of STS 304H and 36% Ni Invar alloy is that the standard of the trimetal is defined according to the color-brown tube specification.

TABLE 4

As described above, the present invention is to replace the spring material for the color-brown tube with aluminum alloy steel or expensive invar alloy to replace the Invar and STS 304H dissimilar metal by integrating with the so-called TRI-Metal without using an expensive material The manufacturing cost of the spring is saved without reducing the performance of the spring, thereby reducing the cost of the color brown tube.

Claims (1)

The thickness of the plate is 1.165 ~ 1.235m / m, the width is 20.85 ~ 21.15m / m, and the chemical composition is 0.0 0.0% or less of C, 0.25% or less of Si, 0.2 ~ 0.4% or less of Pn, 0.007% or less of P, S 0.002 Less than or equal to 3% by weight, 35.5 to 36.5% by weight of Ni, and the balance of Fe-Ni invar alloy sheet, which is Fe, has a thickness of 1.165 to 1.235 m / m, a width of 11.85 to 12.15 m / m, and a chemical composition of C 0.12 STS 304H stainless steel sheet with% or less, Si 1.0% or less, Mn 2.0% or less, P 0.03% or less, S 0.03% or less, Ni 8.0 to 10.5% by weight, Cr 17.0 to 19.0% by weight, and the balance is Fe The trimetal spring material for color brown tube of 29 "NS type which respectively arranges and abuts the surface to contact each other and integrates using a known continuous electron beam welding method.