KR200258242Y1 - Shadow mask with dual structure - Google Patents

Abstract

[Objective] When the shadow mask provided in the color cathode ray tube has a double structure, when the metal layer constituting the shadow mask acts on the color cathode ray tube, the thermal expansion coefficient difference adversely affects the counter metal layer, resulting in miss landing of the electron beam. This prevents the quality of the color cathode ray tube from deteriorating.

[Configuration] The shadow mask is formed by combining two metal layers having different thermal expansion coefficients with each other. In this case, the arrangement relationship of the metal layers allows the metal layers having large thermal expansion coefficients to be arranged toward the panel side of the color cathode ray tube.

Description

Shadow mask with double structure

[Industrial use]

The present invention relates to a shadow mask, and more particularly, to a shadow mark having a double structure that can improve the landing characteristics of the electron beam with good doming when the color cathode ray tube acts in the colored cathode ray tube.

[Prior art]

In general, a color cathode ray tube emits R, G, and B electron beams emitted from an electron gun through a shadow mask and lands on a corresponding phosphor on a fluorescent surface to realize a predetermined image.

At this time, each of the electron beam is achieved by the convergence in one pass hole among the electron beam pass holes provided in the shadow mask about 100,000, and then landing on the fluorescent surface.

In the color cathode ray tube, the shadow mask is formed as one assembly with the mask frame, and then the shadow mask is installed inside the panel constituting the bulb of the color cathode ray tube. As a material, aluminum Killed (A.K) is mainly used.

On the other hand, during the action of the color cathode ray tube, the transmittance of the electron beam emitted from the electron gun and passing through the electron beam passing hole of the shadow mask is approximately 20%.

That is, the remaining electron beams do not pass through the shadow mask and collide with each other and are lost as heat.

Accordingly, the shadow mask and the mask frame are so-called thermal drift, which is heated and thermally expanded by the electrons, thereby causing a domming phenomenon, which is more likely to occur at the center portion than at the periphery of the shadow mask.

As the shadow mask is domed, the position of the shadow mask changes, causing a change in the position of the electron beam through hole. As a result, in the conventional color cathode ray tube, the mis-landing of the electron beam due to the shadowing of the shadow mask causes the initial color purity deterioration. The result was generated.

Therefore, in order to prevent the color purity of the color cathode ray tube due to the shadowing of the shadow mask, a hook for providing the shadow mask with Invar, which is a low thermal expansion material, or connecting the shadow mask assembly to the inside of the panel. The situation is corrected by applying a bimetal to the spring.

On the other hand, the shadow mask domming suppression method conventionally made is to form the shadow mask without a single material, but to have a double structure formed by joining or overlapping two metal materials.

In other words, when the shadow mask has a double structure, when the two metal plates are domed, the coefficient of thermal expansion is different, so that the Invar mask reduces the amount of domming, and the A.K. mask serves as a structural support.

One of the techniques for such a double structure shadow mask is proposed in Korean Patent Laid-Open Publication No. 91-13408, and the shadow mask according to this technique is formed of two or more metal layers having different thermal expansion coefficients, The portion having the expansion ratio is formed so as to be positioned on the incident side of the electron beam, that is, positioned on the electron gun side.

[Problem to solve]

Therefore, in the shadow mask, as the metal layer having the high thermal expansion rate is positioned on the incident side of the electron beam, the metal layer having the low thermal expansion rate is bonded to the upper surface of the high thermal expansion rate metal layer and positioned to the panel side.

However, in the shadow mask having the above structure, the color cathode ray tube is operated, which may cause damage to the perforations of the shadow mask when the shadow mask is windowed by the electron beam.

This is the case where the high thermal expansion coefficient metal layer located on the back side of the low thermal expansion coefficient layer causes excessive expansion during the shadowing of the shadow mask. In this case, the low thermal expansion coefficient metal layer is twisted or even wrinkled by the high thermal expansion coefficient. The weak strength will be broken.

Therefore, the shadow mask of the double structure is deteriorated in the landing characteristics of the electron beam due to the above problems, and bears the burden of deteriorating the quality of the color cathode ray tube.

[Means to solve the problem]

Therefore, the present invention was devised to solve the above problems, and when it is domed by an electron beam, it achieves good do not damage other metal layers located on its upper surface, thereby improving the landing characteristics of the electron beam and improving the quality of the color cathode ray tube. The purpose is to provide a shadow mask having a dual structure that can improve the.

The present invention in order to realize the above object,

In the shadow mask provided inside the panel of the color cathode ray tube to allow the electron beam emitted from the electron gun to land on the phosphor of the fluorescent surface,

The shadow mask is provided by combining two metal layers having different thermal expansion coefficients, and provides a shadow mask having a double structure in which a metal layer having large thermal expansion coefficients is disposed on the panel side.

EXAMPLE

Hereinafter, preferred embodiments of the present invention will be described in detail to help understanding of the present invention.

1 is a cross-sectional view showing a color cathode ray tube to which a shadow mask according to the present invention is applied, which is similar to a conventional color cathode ray tube from the electron gun 3 installed in the neck portion 1 of the color cathode ray tube. The electron beam is emitted so that these electron beams pass through the holes of the shadow mask 7 provided inside the panel 5 to be landed on the fluorescent film 9 formed on the inner surface of the panel 5, thereby realizing a predetermined image.

In the above, the shadow mask 7 through which the R, G, B electron beams pass through one hole is formed in a converging manner with the mask frame 11 to be installed inside the panel 5. After being made, the spring 13 attached to the mask frame 11 is connected to the stud pin 15 mounted on the inner circumferential surface of the panel 5.

The shadow mask 7 has a double structure formed of two metal layers instead of a single structure formed of only one metal layer according to the present invention.

That is, the shadow mask 7 is formed by combining two metal layers having different thermal expansion coefficients.

At this time, the two metal layers are arranged so that the metal layer 7a having a high thermal expansion rule is disposed toward the panel 5 and the metal layer 7b having a low coefficient of thermal expansion is disposed on the electron gun 3 side. Has

Accordingly, in the present embodiment, the high thermal expansion coefficient metal layer 7a is formed of AK, and the low thermal expansion coefficient metal layer 7b is formed of Invar steel to provide the shadow mask 7 having the double structure as described above. Will be constructed.

Meanwhile, in the above, both metal layers 7a and 7b are formed with the same curvature, and the size of the hole 70a formed in the metal layer 7a of the high thermal expansion coefficient is large in relation to the size of the hole formed in the hole. It becomes larger than the size of the hole 70b of the low thermal expansion coefficient metal layer 7b.

Moreover, in the thickness relationship, it is preferable that the metal layer 7a of a high thermal expansion coefficient becomes thicker than the thickness of the metal layer 7b of a low thermal expansion coefficient.

As such, the shadow mask 7 has the low thermal expansion rate metal layer 7b as a main body, and the high thermal expansion rate metal layer 7a as the support of the low thermal window rate metal layer 7b. It consists of.

Therefore, when the shadow mask 7 has the structure as described above, the shadow mask 7 has a conventional double structure even when the shadow mask 7 is thermally expanded by the electron beam emitted from the electron gun 3 when the color cathode ray tube is acting. The shadow mask can be domed without wrinkles or breakage of the shadow mask.

That is, in the shadow mask 7, the low thermal expansion coefficient metal layer 7b is disposed as the electron gun 3, thereby preferentially thermally expanding the electron beam emitted from the electron gun 3, wherein the low thermal expansion coefficient metal layer 7b Since the thermal expansion coefficient is smaller than the thermal expansion coefficient of the high thermal expansion coefficient metal layer 7b, excessive thermal expansion can be prevented compared with the high thermal expansion coefficient metal layer 7a.

Therefore, the low thermal expansion rate metal layer 7b may be prevented from being warped and wrinkled during thermal expansion, as well as being affected by the high thermal expansion rate metal layer 7a while being wrinkled, thereby further preventing it from being damaged.

In this way, the shadow mask 7 passes the electron beam through the hole portions 70a and 70b while making the shadowing by the electron beam satisfactorily at the time of the action of the color cathode ray tube. Landing on the phosphor.

1 is a cross-sectional view showing a color cathode ray tube to which a shadow mask according to the present invention is applied.

Explanation of symbols on the main parts of the drawings

5: panel 7: shadow mask 7a, 7b: metal layer

As described above, the shadow mask having a double structure according to the present invention can reduce the cost by using a low-expansion invar material having a thin thickness, and also by changing the arrangement relationship of the metal layer constituting the structure by a conventional electron beam It is possible to achieve a good domming.

Therefore, the color cathode ray tube to which the present invention is applied can have an advantage in improving the quality of the color cathode ray tube according to the electron beam landing characteristics by reducing the mis-landing rate of the electron beam with good doming of the shadow mask.

Claims (1)

In a shadow mask provided inside the panel of the color cathode ray tube to allow the electron beam emitted by the electron gun to land on the phosphor of the phosphor surface formed on the inner surface of the panel, The shadow mask 7 is composed of two metal layers 7a and 7b having different thermal expansion rates, but the metal layer 7a having a high thermal expansion rate is disposed toward the panel 5 and the metal layer 7b having a low thermal expansion rate is the electron gun. The double structure, which is disposed toward the side (3), of course, has a hole portion 70a formed in the perforated portion of the high thermal expansion rate metal layer 7a larger than the hole portion 70b formed in the low thermal expansion of the metal layer 7b. Shadow mask having.