KR100562859B1 - Frame of CRT - Google Patents

Abstract

The present invention relates to a frame for color cathode ray tubes. The frame for color cathode ray tube of the present invention includes a side wall portion to which a shadow mask is welded, a flange portion parallel to the mask panel so as to be connected to the side wall portion in a direction in which the electron beam is incident, and to connect a geomagnetic shielding device, and the flange portion In the frame for a color cathode ray tube comprising a bent portion formed to form a predetermined inclination angle at the end of the bent, the bent portion is formed in the frame corner side higher than the long side / short side.

According to the present invention, the frame structure prevents unnecessary electron beam reflection at the corners, increases the intensity of the frame, reduces vibration transmission to the shadow mask due to external impact, and improves color purity and luminance of the color cathode ray tube. It can be effective.

Collar, Cathode Ray Tube, Frame, Shadow Mask, Vibration, Color Purity

Description

Frame for color cathode ray tube {Frame of CRT}             

1 is a schematic view of a typical cathode ray tube.

FIG. 2 is a schematic diagram of a shadow mask mounted in the cathode ray tube shown in FIG.

3 shows a frame according to the prior art shown in FIG. 1,
(A) is a plan view, (b) is a side view, and (c) is a sectional view of each part of (a).

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4 is a schematic diagram of a spring mounted in a cathode ray tube;

FIG. 5 shows a fluorescent film in the cathode ray tube shown in FIG. 1, wherein (a) is a stripe type shape and (b) is a dot type shape.

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Figure 6 is a combination of mask frame structure according to the prior art.

7 is a state diagram of a halation occurrence according to the prior art.

Fig. 8A is a diagram of an unlanding state of an electron beam caused by mask vibration in a stripe and dot type fluorescent film.

9 is a cross-sectional view for each part of the frame in the frame for color cathode ray tubes according to the embodiment of the present invention.

10 is a cross-sectional view of the corner portion of the mask frame assembly according to the present invention.

*** Explanation of symbols for the main parts of the drawing ***

1 panel 3 electron beam

4: shadow mask 8: stud pin

9: spring 20: frame

20c: side wall 20d: bend

20e: flange

The present invention relates to a color cathode ray tube, and more particularly, to a frame for a color cathode ray tube, which is mounted while supporting a shadow mask and a magnetic shield on an inner surface of a cathode ray tube to form a structure.

In general, a cathode ray tube is a type of image display device that displays an image by emitting pixels, and is applied to television receivers and monitors widely used in homes, offices, and industrial sites. Screens are becoming larger.

In particular, in the color cathode ray tube, the electron beam emitted from the electron gun is deflected by the deflection means to the entire screen and passes at a constant speed, passes through the color-selective electrode, and then strikes the fluorescent surface to emit the desired phosphor.

The apparatus shown in Figs. 1 to 8 is described as an example of the color cathode ray tube according to the prior art.

The overall configuration of the color cathode ray tube is a panel (1) mounted on the front of the CRT as shown in Figure 1, and the red (R), green (G), blue (B) on the inner surface of the panel (1) It is combined with the rear surface of the panel 1 and the shadow mask 4 which has the color-selection function of the fluorescent film 2 to which fluorescent substance is apply | coated, the electron beam 3 incident to the fluorescent film 2, and the inside is made into a vacuum state. A retaining funnel 5, a tubular neck portion 5a that is retracted to the rear of the funnel 5, an electron gun 6 mounted inside the neck portion 5a and emitting an electron beam 3; A deflection yoke (7) surrounding the outer side of the funnel (5) and deflecting the electron beam (3), a frame (10) coupled by a stud pin (8) and a spring (9) formed on the inner surface of the panel (1); Inner shield 12 coupled to the rear end of frame 10 by a fixing spring 11 to shield the geomagnetic field so that the electron beam 3 deflected by the deflection yoke 7 is not affected by an external magnetic field. Is done.

Each part structure of the cathode ray tube having such a structure will be described in more detail.

First, as shown in FIG. 2, the shadow mask 4 has a top end portion 4a having a plurality of holes to perform color selection, a pair of long side skirt portions 4b extending from the top portion 4a, and a short side side. The side skirt portion 4c is formed, and the edge between each of the upper portion 4a and the skirt portions 4b and 4c and a bead 4d are inserted into each skirt portion to reinforce the strength of the shadow mask, and the shadow mask In order to improve the moldability, narrow and long skirt holes 4e are formed in each skirt portion, and corner holes 4f are also formed in the corners.

This shadow mask 4 is fixed by welding on the inside or outside of the frame side wall.

The frame 10 to which the shadow mask 4 is welded is composed of a long side portion 10a and a short side portion 10b as shown in FIG. 3, and a flange portion 10e to which the inner shield 12 is coupled. The side wall portion 10c extending from each long side portion and the short side portion and the elongated side portion 10c extend from the flange portion 10e to prevent the electron beam reflected by the collision of the electron beam on the opening side toward the fluorescent surface so as to be constant with the long side portion or the short side portion. It consists of the bending part 10d which has an angle.

The support spring 9 welded to the side wall portion 10c of the frame 10 to support the frame 10 inside the panel 1 is a welded portion 9a welded to the frame as shown in FIG. 4. And a coupling portion 9c having a coupling hole 9b coupled to the stud pin 8 formed on the inner surface of the panel, and a coupling portion 10d connecting the welding portion 9a to the coupling portion 9c.

In the fluorescent film 2 applied to the inner surface of the panel 1, as shown in FIG. 5, phosphors of R, G, and B colors form a stripe of (a) or a dot of (b), and a black matrix therebetween. (BM) 2a is formed.

Some of the electron beams 3 emitted from the electron gun 6 in the state configured as described above pass over the bent portion 10d of the frame 10 by overscanning and form an edge formed by the upper portion 4a of the shadow mask 4 and the skirt portion. Leads to At this time, the upper portion 4a forming the corner with the skirt portions 4b and 4c of the shadow mask 4 does not pass through the mask because there is a non-perforated portion 4g of about 10 to 20 mm. Therefore, unnecessary reflection of the electron beam does not occur.
However, as shown in FIG. 7, when the inner surface of the panel and the shadow mask become flatter, the electron beam 3 passing through the frame corner side has a long side skirt portion 4b and a short side skirt portion 4c of the shadow mask 4. Passing through the corner hole 4f near the encountering edge, it collides with the side wall portion 10d of the frame 10 and is reflected back to the fluorescent surface. This unnecessary reflection of the electron beam 3 degrades the color purity of the fluorescent surface.
That is, it emits a fluorescent surface that should not be emitted. This phenomenon is called "halation" and occurs mainly in the vicinity of the corner portion in the diagonal direction of the frame. In order to prevent such unnecessary reflection of the electron beam, the length L2 including the flange portion 10e at the corner portion of the frame 10 should be increased by “d” as shown in FIG. 7, but the length of the flange portion 10e should be increased. Increasing decreases the strength of the frame 10.
When external shocks or vibrations are applied to the cathode ray tube, the shocks or vibrations are sequentially transmitted to the spring 9 → the frame 10 → the shadow mask 4 through the stud pins 8 of the panel 1. When the vibration is transmitted to the shadow mask 4 and the shadow mask vibrates, the position of the mask is changed. Therefore, the impact position of the electron beam 3 reaching the fluorescent surface through the mask hole as shown in FIG. 8 is also changed. .
Therefore, the electron beam does not strike the center of the spreop or dot type phosphor formed on the inner surface of the panel correctly, causing mis landing in which the center is shifted. The vibration transmitted to the shadow mask by external shock or vibration is transmitted as the intensity of the frame is lower. As described above, if the length of the frame flange portion 10e is increased to prevent the reflection of the unnecessary electron beam, the strength of the frame is naturally lowered, and since the vibration transmitted to the shadow mask by external vibration cannot be effectively prevented, Mislanding is caused by vibration, and such mislanding causes a problem of lowering luminance and degrading color purity.

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The present invention has been made to solve the problems of the prior art as described above is to provide a frame for a color cathode ray tube that can reduce the transmission of vibration due to external impact to the shadow mask by improving the strength of the frame. .

In addition, at the same time for another object of the present invention to prevent unnecessary reflection of the electron beam at the corner of the frame to reduce the color purity of the color cathode ray tube.

Color cathode ray tube frame of the present invention for achieving the above object is parallel to the mask panel so that the shadow mask is welded and coupled to the side wall portion in the direction in which the electron beam is incident and the geomagnetic shielding device is coupled In the frame for a color cathode ray tube comprising a flange portion and a bent portion formed to form a predetermined inclination angle at the end of the flange portion, the bent portion is characterized in that the height is formed higher than the long side / short side at the frame corner side .
According to this feature, the bent portion has the same inclination angle at the frame corner side and the long / short side.
According to such a feature, the bent portion is formed 1.5 times higher in height than the long / short side at the frame corner side.
According to this feature, the flange portion has a length shorter than the long / short side at the frame corner side.

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

In addition, in the drawing used for description, about the component same as the prior art except frame, the same code | symbol is attached | subjected, and the overlapping description may be abbreviate | omitted.

9 is a cross-sectional view of the frame for each part according to an embodiment of the present invention, Figure 10 is a view showing the anti-halation state in the corner portion by the frame of the present invention.

The frame 20 according to the present embodiment, which includes the side wall portion 20c, the flange portion 20e, and the bent portion 20d, has a length L2 'including the flange portion at the corner side shown by the CC' cross section. However, the height h1 'of the corner-side bent portion 20d' is represented by a cross section A-A 'and B-B' in order to prevent unnecessary reflection of the electron beam impinging on the side wall portion 20c of the frame. It was designed to be higher than the short side bent portion 20d.

In addition, the length L1 ′ of the flange portion 20e is shorter than the conventional length L1 so that the bent portion of the frame 20 maintains a constant inclination angle at the corner side. In other words, by increasing the height of the bent portion 20d 'without increasing the length of the flange portion 20e, not only reflection of unnecessary electron beams but also a decrease in the strength of the frame 20 prevents the external impact applied to the cathode ray tube. It is possible to effectively prevent or reduce vibration transmission.

FIG. 10 shows the anti-halation state of the frame according to the present invention. In order to improve the strength of the frame 20, the height of the corner bent portion 20d 'is 1.5 of the height of the bent portion 20d on the long / short side. More than twice are preferable. If the length of the frame flange portion 20e is reduced to less than 1.5 times, the shadow mask 4 may not exhibit a great effect on the transmission of vibration due to external impact.

On the other hand, unlike the comparative example, that is, in the conventional frame structure, luminance and color purity deterioration have occurred due to vibrations to the shadow mask and the halation caused by the electron beam colliding with the frame at the corner and reflected to the fluorescent surface. It can be seen that it is possible to effectively prevent the occurrence of halation on the corner side and to improve the strength of the frame, thereby reducing the mislanding of the electron beam due to vibration transmission.

As a result, according to the present invention, it is possible to improve the decrease in luminance and color purity of the color cathode ray tube due to the electron beam reflection at the frame corner side and the electron beam mislanding at the fluorescent surface.

And while specific embodiments of the present invention have been described and illustrated above, it is obvious that the frame structure of the present invention may be variously modified and implemented by those skilled in the art.

Such modified embodiments should not be individually understood from the technical spirit or the prospect of the present invention, and such modified embodiments should fall within the appended claims of the present invention.

As described above, the frame structure of the present invention prevents unnecessary electron beam reflection at corners, and increases the intensity of the frame to reduce vibration transfer to the shadow mask due to external impact, thereby improving color purity and luminance of the color cathode ray tube. It can be effective.

Claims (4)

A side wall portion to which a shadow mask is welded, a flange portion connected to the side wall portion in the direction in which the electron beam is incident, parallel to the mask panel so that a geomagnetic shielding device is coupled, and a predetermined inclination angle formed at an end of the flange portion. In the frame for a color cathode ray tube which is comprised including the bending part to become, The bent portion is a color cathode ray tube frame, characterized in that the height is formed higher than the long side / short side at the frame corner side. The method of claim 1, The bent portion is a frame for color cathode ray tube, characterized in that the inclination angle is the same on the frame corner side and long / short side. The method of claim 1, The bent portion is a color cathode ray tube frame, characterized in that the height is formed 1.5 times higher than the long side / short side at the frame corner side. The method of claim 1, The flange portion is a frame for color cathode ray tube, characterized in that the length is formed shorter than the long / short side at the frame corner side.

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