KR20020066280A - Shadow mask frame assembly for flat type CRT - Google Patents

Abstract

PURPOSE: A shadow mask assembly for a flat CRT is provided to prevent howling by forming a damper. CONSTITUTION: A shadow mask assembly for a flat CRT comprises a frame, and a flat shadow mask. The frame includes a first and a second support members(12) which are spaced from each other, and a first and a second elastic members which are connected to the first and the second support members. The flat shadow mask is fixed to the first and the second members and has slots. A contact damper(27) is mounted on the upper surface of the first and the second support members, and an end part of the damper is contacted to the lower surface of the shadow mask.

Description

Shadow mask frame assembly for flat type cathode ray tube

The present invention relates to a planar cathode ray tube, and more particularly, to a shadow mask frame assembly for a planar cathode ray tube having a contact damper to prevent the howing phenomenon caused by the vibration of the strip of the flat panel shadow mask.

The color cathode ray tube excites them by landing on the red, green, and blue phosphors of the fluorescent film formed on the screen surface of the panel through the electron beam passing through the shadow mask having a color screening function. An image is formed. In recent years, since the color cathode ray tube pursues the flattening of the screen surface, the shadow mask having the color screening function must also be flattened, and such a flat mask is deformed due to the domming phenomenon during operation of the cathode ray tube, which makes production difficult.

1 is a schematic perspective view of an example of a shadow mask frame assembly fabricated for use in the planar colored cathode ray tube.

Referring to the drawings, the shadow mask frame assembly is fixed to both ends of the first and second support members 11 and 12 and the first and second support members 11 and 12 installed in parallel to each other. Welding the frame 10 with the first and second elastic members 13 and 14 to maintain the distance between the members 11 and 12 and to provide elastic force, and to the upper part of the support members 11 and 12. It is provided with a shadow mask 20. The long side portion of the shadow mask 20 is welded to the support members 11 and 12 so that the tensile force by the elastic members 13 and 14 is applied to the shadow mask 20 through the support members 11 and 12. All.

As shown enlarged in circle A in FIG. 1, the shadow mask 20 has a plurality of strips 21 spaced at predetermined intervals to form slits 22 on the stripe, and the strips 21 are tied at predetermined intervals. Slits 22 are divided by being connected by bars 23.

The shadow mask frame assembly as described above is supported by the first and second support members 11 and 12 with the flat shadow mask 20 applied with a large tensile force, and the plurality of strips 21 are provided with the shadow mask 20 Since it is formed on), a howling phenomenon in which the strips 21 vibrate when an external force is applied may occur.

In more detail, in order to weld the flat shadow mask 20 to the frame 10, first, the first and second support members 11 and 12 are pressed on both sides and displaced in close proximity to each other. The first and second elastic members 13 and 14 are elastically deformed. Next, both ends of the flat shadow mask 20 are welded to the first and second support members, and then the pressing force applied to the first and second support members 11 and 12 is removed. By doing so, the shadow mask 20 is subjected to a tension, because the tension 21 keeps the strip 21 in tension in the shadow mask 20, even though the strips 21 are connected to each other with tie bars 23. Even if the external force is applied, the strip 21 is shaken. This phenomenon is exacerbated when the loudspeaker volume is increased, especially when applied to large televisions. If the strip 21 is shaken, the electron beam does not reach the fluorescent point of the screen surface accurately, and thus the image quality is deteriorated.

The present invention is to solve the above problems, it is an object of the present invention to provide a shadow mask frame assembly for a flat cathode ray tube can be prevented howling phenomenon.

It is another object of the present invention to provide a shadow mask frame assembly for a planar cathode ray tube provided with a contact damper to prevent howling.

1 is a schematic exploded perspective view showing a shadow mask frame assembly of a conventional planar cathode ray tube;

2 is a schematic exploded perspective view of a portion of a shadow mask frame assembly of a planar cathode ray tube according to the present invention;

FIG. 3 is a front view showing the shadow mask frame assembly of FIG. 2 as viewed in the A direction. FIG.

<Brief Description of Major Codes in Drawings>

11.12. Support member 13.14. Elastic member

20. Shadow Mask 21. Strip

22.Slot 23.Tie Bar

27. Contact damper

In order to achieve the above object, according to the present invention, the first and second support members spaced apart from each other and arranged in parallel, and the first and second elastic members each end is connected to the first and second support members A frame having; And a flat shadow mask fixed with respect to the first and second support members while being subjected to the tensile force due to the elastic force of the first and second elastic members, and having a slit through which the electron beam passes. The shadow mask frame assembly of claim 1, further comprising a contact damper disposed at an upper surface of the first and second support members, the contact damper having one end of which contacts the bottom surface of the shadow mask.

According to another feature of the invention, the contact damper is in contact with the no air of the shadow mask.

According to another feature of the present invention, the contact damper is in contact with the shadow mask is formed in a curved surface.

According to another feature of the invention, the contact damper is disposed to approach and contact the center of the long side portion of the shadow mask, a pair is symmetrically installed on one support member.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a schematic perspective view of a shadow mask frame assembly for a planar cathode ray tube according to the present invention, with a portion cut away.

Referring to the drawings, the overall structure is similar to the conventional shadow mask frame assembly shown in FIG. 1, and since FIG. 2 shows only half of the shadow mask frame assembly, the first support member 11 is omitted. That is, the shadow mask frame assembly has both end portions fixed to both sides of the first and second support members 11 and 12 and the first and second support members 11 and 12 installed in parallel to each other, so that the support member 11 A frame 20 including first and second elastic members 13 and 14 to maintain an interval between the two and twelve members, and to provide an elastic force, and a shadow mask welded to an upper portion of the support members 11 and 12. 20 is provided. The long side portion of the shadow mask 20 is fixed to the support members 11 and 12, and the tensile force by the elastic members 13 and 14 is applied to the shadow mask 20 through the support members 11 and 12. Is applied.

According to a feature of the invention, a contact damper 27 is provided on the first support member 11 or the second support member 12. One end of the contact damper 27 contacts a part of the shadow mask 20, and the other end thereof is welded to the support member 12. The contact damper 27 is for damping the strip of the shadow mask 27 when it vibrates by a howling phenomenon. The contact damper 27 is welded inside the support member 12 having an L-shaped cross section. In the entire area of the shadow mask 27, the portion close to the support members 11 and 12 is a non-slit part 28, in which no slit is formed, and a contact damper 27 is provided with respect to the portion of the non-slip part 28. Contact does not interfere with the incidence of the electron beam on the fluorescent film.

FIG. 3 shows the view of FIG. 2 in the direction of arrow A. FIG.

Referring to the drawings, the contact damper 27 is in a state in which the body portion 27a and the weld portion 27c are bent to each other, and the head portion 27b in contact with the bottom surface of the shadow mask 20 is entirely curved. It is desirable to have a shape. That is, the head portion 27b having a curved shape comes into contact with the bottom surface of the shadow mask 20. In addition, if the main body portion 27a has a predetermined elasticity and an external force that causes the support members 11 and 12 and the shadow mask 20 to vibrate together is applied, the contact dampers 27 on the support members 11 and 12 are applied. ) Can also be vibrated with different frequencies to cancel the vibration of the shadow mask 20.

It is preferable that the head 27b of the contact damper 27 is in contact with the portion where the howling phenomenon is most severe. In practice, the tensile force is the strongest at both end portions of the support members 11 and 12 to which the respective ends of the elastic members 13 and 14 are welded, and the tensile force is weaker as the center of the support members 11 and 12 approaches. Become. Therefore, the shadow mask 20 also has the smallest howling phenomenon at both ends of the long side portion, which has the strongest tensile force, and the howling phenomenon is most severe as it approaches the central portion of the long side portion having the weakest tensile force. Therefore, it would be desirable for the head 27b of the contact damper 27 to be in close contact with the central portion of the long side of the shadow mask 20. In the example shown in the figure, it can be seen that two contact dampers 27 are symmetrically installed so as to be close to the central portion of the long side of the shadow mask 20.

The shadow mask assembly for a planar cathode ray tube according to the present invention includes a contact damper in contact with the shadow mask so that the shadow mask can be effectively damped when the shadow mask is affected by external force, thereby ensuring stable image quality.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary and will be understood by those skilled in the art that various modifications and embodiments may be made therefrom. Therefore, the present invention will be defined by the technical spirit of the appended claims the true technical protection scope of the present invention.

Claims (4)

A frame having first and second support members spaced apart from each other and arranged in parallel, and first and second elastic members having respective ends connected to the first and second support members; And a flat shadow mask fixed with respect to the first and second support members while being subjected to the tensile force due to the elastic force of the first and second elastic members, and having a slit through which the electron beam passes. To And a contact damper disposed at an upper surface of the first and second support members and having one end thereof in contact with a bottom surface of the shadow mask. 2. The shadow mask frame assembly of claim 1, wherein the contact damper contacts the non-perforations of the shadow mask. The shadow mask frame assembly of claim 1, wherein a surface of the contact damper contacting the shadow mask is formed in a curved surface. The shadow mask frame assembly of claim 1, wherein the contact damper is disposed to approach and contact the center of the long side portion of the shadow mask, and a pair is symmetrically installed on one support member.