KR20020075498A - Shock-absorbing Body for A Shadow Mask - Google Patents

Abstract

PURPOSE: A shadow mask vibration absorbing structure is provided to prevent deterioration of color purity by effectively reducing the vibration energy transmitted to the shadow mask from an external source. CONSTITUTION: A shadow mask vibration absorbing structure comprises a shadow mask(3) having a plurality of fine holes for passage of electron beams; a frame(5) for supporting the shadow mask, and where a vibration energy is transmitted from an external source; and a skirt portion(20) having an end extended from an effective surface of the shadow mask and the other end coupled to the frame, wherein the skirt portion has a bent section formed between both ends of the skirt portion. Thus, the shadow mask vibration absorbing structure reduces the vibration energy transmitted to the frame by absorbing the vibration energy. The bent section of the skirt portion is shaped as a square C, and includes an outer part coupled to the frame, an inner part extended toward the shadow mask, and a lower end interposed between the outer part and the inner part.

Description

Shadow mask absorbing structure {Shock-absorbing Body for A Shadow Mask}

The present invention relates to a shadow mask anti-vibration structure of the cathode ray tube (or CRT), in particular, shadow mask vibration for effectively reducing the vibration energy transmitted to the shadow mask in the cathode ray tube due to external shock or sound waves, etc. It relates to a prevention structure.

1 is a cross-sectional view of a general structure of a cathode ray tube. As shown in FIG. 1, the cathode ray tube is formed in a panel 1 formed of glass having a predetermined thickness on the front surface, and integrally formed with the panel 1 at the rear of the panel 1 to form an outer appearance of the cathode ray tube, while forming the inside of the cathode ray tube. Color of the electron beam 12 incident on the fluorescent film 4, the funnel 2 for maintaining the vacuum state, the fluorescent film 4 coated with a fluorescent material of red / green / blue on the inner surface of the panel 1, and the fluorescent film 4. A shadow mask 3 having a function, a frame 5 on which the shadow mask 3 is welded and supported, a stud pin 7 and a spring 6 formed on an inner wall of the funnel 2 to support the mask frame assembly. ), Which is installed inside the neck 10 of the funnel, which is formed in a tubular shape at the rear end of the funnel 2, and the inner shield 8 and the neck 10 for blocking an external magnetic field. And an electron gun 9 or the like that emits the electron beam 12.

In view of the action, the various electron beams emitted by the electron gun 9 are irradiated to the respective positions of the fluorescent film 4 formed in a predetermined pattern through the micro holes of the shadow mask 3 while performing the constant velocity motion. An image is embodied on the screen by the phosphor element of each color being emitted by the illuminated spectral electron beam.

In such a cathode ray tube, a shadow mask is mentioned as one of the components that play a very important role. The shadow mask is positioned between the fluorescent film and the electron gun, and is mounted close to the fluorescent film. The microholes formed in the shadow mask are aligned with the phosphor element applied to the fluorescent film, and the electron beam is irradiated from the electron gun and converges in the shadow mask. After the electron beam passes through each of the microholes, they split off and reach a phosphor element of the corresponding color. The shadow mask 3 is generally made of a thin steel sheet of 0.10 mm to 0.25 mm thickness and has a plurality of fine holes. Looking at the structure of the microholes of the shadow mask 3, by oxidizing etching on the opposite side of the electron gun 9 to prevent secondary radiation from the shadow mask itself, it is formed as a conical microhole instead of a cylindrical shape. Since the conical microhole shows a blade-like ridge when viewed from the electron gun 9 side, the obliquely irradiated electron beam is not reflected from the inner surface of the microhole.

As such, the shadow mask requiring high precision is supported by a frame. The frame is secured to the funnel, allowing the shadow mask and the fluorescent film to be placed under proper registration. At this time, the matching should be maintained not only in the X and Y directions but also in the Z direction. By doing so, it is possible to prevent the electron beam from reaching the adjacent phosphor element, thereby maintaining the color purity of the display image. That is, the shadow mask must be exactly matched to a predetermined position.

However, when the cathode ray tube is operated, displacement occurs in the frame 5 due to vibration, external shock, thermal deformation, etc. of the speaker, and the displacement of the frame is transmitted to the shadow mask so that the shadow mask 3 is shaken. (Howling) phenomenon occurs. In this case, a phenomenon such that the electron beam passing through the microholes of the shadow mask is blocked by the shadow mask or only partially passes, the amount or position of the electron beam reaching the fluorescent film is changed. This phenomenon results in a problem of color purity deterioration.

Various techniques have been disclosed to solve this problem. First, as shown in FIG. 2A, a vibration absorbing agent 26, which is a material having a larger damping ratio than a metal part used in a cathode ray tube, is disposed between the skirt portion 20 of the shadow mask and the welding point 22 of the frame 5. By adhering, the vibration absorber 26 absorbs the vibration energy transmitted to the shadow mask 3, thereby reducing the shaking phenomenon of the shadow mask due to vibration. The vibration absorber used here is a high molecular compound, a ceramic, or the like.

In another prior art, as shown in Fig. 2B, a support piece 28 having a double bent portion is inserted between the frame and the skirt portion, and one end of the bent support piece 28 is the skirt portion 20. ) And the other end is welded to the inner wall side of the frame 5 to support the side end of the shadow mask 3 to reduce the shaking phenomenon of the shadow mask.

In the case of the vibration absorbent among the above-described conventional techniques, the polymer compound or ceramic used as the vibration absorber is cured by heat or the damping ratio decreases with time, so that the desired vibration absorption effect after a predetermined time has elapsed. A problem arises that cannot be obtained. In addition, when welding the shadow mask and the frame, a process of attaching the vibration absorber is further required.

On the other hand, in the case of using the support piece bent in the middle of the double, the use of a part called the support piece, which is not easy in the manufacturing process, such as welding must be made with each of the skirt portion and the frame of the shadow mask. There is a problem.

Accordingly, an object of the present invention is to provide a vibration absorbing structure capable of maximizing the shadow mask vibration absorbing effect.

Another object of the present invention is to provide a vibration absorbing structure having a simpler structure by eliminating the complexity of the vibration absorbing structure in the prior art, thereby simplifying the vibration absorbing structure process of the shadow mask in the manufacturing process of the cathode ray tube. In this way, the yield reduction due to defects that may occur in the shadow mask manufacturing process is greatly reduced.

1 is a cross-sectional view of a typical cathode ray tube,

Figure 2A is a cross-sectional view of the anti-vibration structure using a vibration absorber in the prior art,

Figure 2B is a cross-sectional view of the anti-vibration structure inserting the support piece bent between the frame and the skirt portion of the prior art,

3A is a cross-sectional view of a shadow mask vibration absorbing structure in which a bent portion having a U shape is formed in a skirt portion according to the present invention;

3B is an exploded view of the shadow mask skirt portion having a notch formed on the outer portion thereof;

3C is an exploded view of the shadow mask skirt portion in which the notches in the outer portion extend to the inner portion;

4A to 4D are cross-sectional schematic views of a shadow mask skirt portion in which various shapes of embossing are formed in the bend portion, and

5 and 6 are skirt section views showing examples of the skirt portion shape of the shadow mask.

* Description of the symbols for the main parts of the drawings *

3: shadow mask 5: frame

20: skirt portion 22: welded portion

30: through

The shadow mask vibration absorbing structure according to the present invention forms a bent portion in the skirt portion of the shadow mask to block the vibration energy transmitted from the outside to the shadow mask.

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

3A is a schematic cross-sectional view of a shadow mask vibration absorbing structure in which a bent portion having a U-shape is formed in a skirt portion of the shadow mask. As shown in Fig. 3A, the skirt portion 20, which is an ineffective portion of the shadow mask, has a c-shaped bent portion (a bent portion consisting of a, b and c). The U-shaped skirt portion 20 is an outer portion (c) directly welded to the frame (5), a lower end portion (b) of a predetermined length that can be appropriately adjusted according to the elastic modulus of the skirt portion material, and the effective surface of the shadow mask It consists of an inner part (a) directly connected to.

3B is an exploded view of the shadow mask skirt portion in which a notch is formed on the outer portion. As shown in Fig. 3B, the outer portion (c) of the skirt portion is formed with a plurality of semicircular recessed notches at the end to better absorb vibration or tension, and the shape of the notch is a semicircle in addition to the semicircular recessed type. It can be made in various shapes and sizes such as protrusions, U-shapes, and triangles. Some of the outer portions where the notches are not formed are directly welded to the frame by spot welding or the like. In addition, a through hole 30 for welding the outer portion of the skirt portion and the frame may be formed at the inner portion a of the skirt portion corresponding to the portion welded to the frame among the outer portion c of the skirt portion 20. The shape and size of the through hole can be various shapes and sizes depending on the ease of welding. 3B shows a circular through hole as an example of such a through hole.

FIG. 3C is an exploded view of the shadow mask skirt portion showing a form in which a part of the notch formed in the outer portion c extends to the lower end portion b and the inner portion a of the skirt portion. In general, the notch formed on the outer side (c) of the skirt portion may be formed in various forms in a range that does not hinder the welding of the skirt portion and the frame in order to enhance absorption of vibration or tension. Therefore, the notch of the outer portion (c) may be formed to extend to the inner portion (a) of the skirt portion.

4A to 4D show examples of various types of embossing shapes formed on the bent portion of the shadow mask skirt portion. Fig. 4A is a cross sectional schematic view of the skirt portion in which the protrusions are formed in a circular embossing shape at the lower end of the skirt portion. Here, the embossed form may be formed in various shapes such as circular embossing downward, triangular embossing upward and downward, as shown in FIGS. 4B to 4D.

Fig. 5 is a cross-sectional view of the skirt section having a bent portion in which the outer section of the skirt section is bent at 30 degrees with respect to the inner section of the skirt section without the lower section of the skirt section. Here, as for the angle | cornered angle | corner, 5 degrees-45 degrees are preferable as an acute angle.

6 is a cross-sectional view of the skirt portion having a bent portion in which the lower end portion of the skirt portion is bent into a smooth shape in the shape of a bent.

On the other hand, in addition to the skirt portion shown in Figures 3A, 5 and 6 can be made in various forms of skirt portion.

As described above, referring to the action of the skirt having various types of bent portions, the vibration energy transmitted to the frame by external impact or speaker vibration is first absorbed by the outer portion (c) of the skirt portion in which notches of various sizes and shapes are formed (bottom portion). And the lower end portion and the inner side portion also absorb vibration energy when extending to the inner portion), and then most of the vibration energy transmitted by the bent lower portion b is absorbed. In particular, the absorption effect of the vibration energy is enhanced by the embossing of the circular or triangular shape formed in the lower end of the skirt portion.

On the other hand, the welding part of an outer part can be correctly determined through the through-hole 30 formed in the inner part a of a skirt part, and welding of an outer part and a frame becomes easy.

According to the skirt portion having the above-described bent portion, the vibration energy transmitted from the outside to the shadow mask by various forms of embossing formed on the outer portion (the lower portion and the inner portion when the notch is extended) and the bent lower portion and the lower portion. And the like can be effectively absorbed, so that the color purity deterioration of the image due to the displacement of the shadow mask can be greatly reduced. In addition, it contributes to reducing the displacement of the shadow mask according to the thermal deformation of the shadow mask.

In addition, since the bent portion is formed in the skirt portion forming process of the shadow mask, no additional structure for the shadow mask vibration prevention is required. This not only means that the structure for absorbing vibration is simplified, but also the coupling between the shadow and the frame is made only once in the manufacturing process of the cathode ray tube. Yield reduction can be greatly reduced.

While the invention has been shown and described with respect to certain preferred embodiments thereof, the invention is not limited to these embodiments, and has been claimed by those of ordinary skill in the art to which the invention pertains. It includes all variants of various forms that can be implemented without departing from the technical idea.

Claims (8)

In the vibration absorbing structure of the cathode ray tube for absorbing vibration energy from the outside, A shadow mask having a plurality of micro holes through which an electron beam passes; A frame for transmitting vibration energy from the outside and supporting the shadow mask; And One end extending from the effective surface of the shadow mask and the other end coupled to the frame and including a skirt having a bent portion between the one end and the other end, The shadow mask vibration absorption structure, characterized in that to absorb the vibration energy transmitted to the frame from the outside to reduce the vibration energy transmitted to the shadow mask. The method of claim 1, The bent portion of the skirt portion has a U-shape, and has an outer portion coupled to the frame, an inner portion extending to the shadow mask, and a lower portion having a predetermined length between the outer portion and the inner portion according to the material of the skirt portion. Shadow mask vibration absorbing structure. The method of claim 2, The lower end portion of the bent portion of the skirt portion includes an embossing having a predetermined shape, the shadow mask vibration absorption structure, characterized in that to enhance the absorption of vibration energy of the lower end portion. The method of claim 1, The bent portion of the skirt portion has a ⊂ shape, and has an outer portion coupled to the frame, an inner portion extending to the shadow mask, and a circular lower end portion having a predetermined length between the outer portion and the inner portion depending on the material of the skirt portion. Shadow mask vibration absorption structure. The method of claim 1, The bending portion of the skirt portion comprises a shadow mask vibration absorption structure comprising an inner portion extending to the shadow mask, the outer portion bent at an acute angle from the inner portion. The method of claim 5, The acute angle is a shadow mask vibration absorbing structure, characterized in that 5 ° to 45 °. The method according to any one of claims 2 to 6, The outer portion of the shadow mask vibration absorbing structure, characterized in that to enhance the absorption of vibration energy transmitted by forming a notch. The method of claim 7, wherein The notch is a shadow mask vibration absorbing structure, characterized in that formed extending to the inner side.