KR100421908B1 - Method for establishing compression point in mask frame assembly of CRT - Google Patents

Abstract

The present invention relates to a compression position setting method for applying tension of a mask frame assembly for a cathode ray tube, to minimize the howling phenomenon by setting the compression point of the frame to optimize the tension distribution applied to the shadow mask. It is.

To this end, the present invention, in the mask frame assembly of the cathode ray tube comprising a shadow mask for color screening and a frame to which the shadow mask is applied tension is fixed, the length of the long side of the frame is L, (L / 2) × 0.38 ≤ X1 ≤ (L / 2) × 0.52 and (L / 2) × 0.80 when the distance from the center of each of the compression points P1 and P2 on both sides is X1, X2. A compression position setting method for applying tension of a mask frame assembly for a cathode ray tube, characterized in that each compression point of the frame is set to satisfy ≤ X2 ≤ (L / 2) x 0.98.

Description

Method for establishing compression point in mask frame assembly of CRT for tension application of mask frame assembly for cathode ray tube

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mask frame assembly of a cathode ray tube, and more particularly to a cathode ray tube for minimizing howling by setting a compression point of a main frame to optimize a tension distribution applied to a shadow mask of a mask frame. A compression position setting method for applying tension of a mask frame assembly.

In general, the cathode ray tube is the main component of the image is implemented in a video display device such as a television receiver or a computer monitor, the cathode ray tube and the panel (1) as a whole, as shown in Figure 1 of the accompanying drawings and It consists of a funnel (2) installed on the rear of the panel (1).

In addition, the interior of the panel 1 and the funnel 2 is partitioned by a fluorescent surface 3 that serves as a predetermined light emission and a neck of the funnel 2 to emit light of the fluorescent surface 3. An electron gun 8 which emits an electron beam 11 to make it appear, a shadow mask 4 for selecting a color to emit light of the predetermined fluorescent surface 3, and a tension applied to the shadow mask 4. The frame assembly 5 is installed.

In addition, a deflection yoke 8 is provided outside the neck portion of the funnel 2 to deflect the electron beam 11 emitted from an electron gun (not shown) up and down and to the left and right. A magnet 9 of 2, 4, 6 poles is provided to correct its trajectory so as to strike a predetermined phosphor to prevent poor color purity.

In addition, since such a cathode ray tube is made of high vacuum, it may be easily deflated due to an external impact. In order to prevent this, the reinforcing band 10 is mounted along the outer surface of the skirt of the panel 1. As a result, the stress of the cathode ray tube in a high vacuum state is dispersed to secure impact resistance.

On the other hand, the frame assembly 5 is composed of a main frame (5a) and a subframe (5b), the shadow mask 4 is installed on the main frame (5a) in a state where the tension is applied in the vertical direction after the main welding The spring 6 coupled to the side of the frame 5a and the subframe 5b is installed inside the panel by being coupled to the stud pins 1a provided on the inner surface of the panel 1, and as described above, the shadow mask 4 is attached to the shadow mask 4. The application of tension up and down is to cope with howling, which is a phenomenon that the mask is shaken by increasing the natural frequency of the mask.

Typically, applying the tension to the shadow mask (4) is made by compressing the main frame (5a) to a constant load, in this state by welding the mask (4) and then release the compression force applied to the main frame (5a) At this time, the tension distribution applied to the mainframe 5a depends on the compression position applied to the mainframe, and as the tension distribution forms a smooth U-shaped curve (see FIG. 6), the shadow mask 4 vibrates howling ( Howling) can be appropriately responded to.

However, as the size of the cathode ray tube gradually increases, the length of the mask becomes longer, and thus, the natural frequency decreases, causing the shadow mask 4 to vibrate violently even in the low frequency band of the speaker of the television chassis.

In addition, in order to have a tension distribution corresponding to various frequency bands with respect to an external excitation circle, it is important to set a compression point for compressing the mainframe. When the compression is performed at a conventional compression point, the tension in the center of the center and the corner of the mainframe The distribution has a non-smooth U-shaped tension distribution having an inflection point, and the vibration range is widened such that the mask vibrates violently with respect to the external excitation circle of the frequency band in the region near the inflection point.

Accordingly, the present invention has been made to solve the above problems, the cathode ray tube mask that can minimize the howling phenomenon by setting the compression point on the main frame to optimize the tension distribution applied to the shadow mask of the mask frame assembly It is an object of the present invention to provide a compression position setting method for tension application of a frame assembly.

1 is a view showing a part cut to show the structure of a typical cathode ray tube

FIG. 2 is a cross-sectional view illustrating main parts of a mask frame assembly structure of the cathode ray tube of FIG. 1. FIG.

3 is a perspective view of a mask frame assembly showing a first embodiment of a method for setting a mask frame compression position according to the present invention;

Figure 4 is a perspective view of a mask frame assembly showing a second embodiment of the method for setting the mask frame compression position of the present invention;

5 is a perspective view of a mask frame assembly showing a third embodiment of the method for setting a mask frame compression position according to the present invention;

Figure 6 is a graph showing the tension distribution appearing on the mask frame when a compressive force is applied to the mask frame assembly by the mask frame compression position setting method of the present invention

Explanation of Reference Symbols in Major Parts of Drawings

4-Shadow Mask 5-Frame Assembly

5a-mainframe 5b-subframe

C-Mainframe Center P0, P1, P2, P3-Compression Point

X1, X2, X3-distance from mainframe center to each compression point

In order to achieve the above object, the present invention, in the mask frame assembly of the cathode ray tube comprising a shadow mask for color screening and the shadow mask is applied tension is fixed, the length of the long side of the frame Is L, and the distance from the center of the frame to each compression point P1, P2 on both sides is X1, X2, where (L / 2) x 0.38? X1? (L / 2) x 0.52 and ( A compression position setting method for applying tension of a mask frame assembly for a cathode ray tube, characterized in that each compression point of the frame is set to satisfy L / 2) × 0.80 ≦ X2 ≦ (L / 2) × 0.98.

Hereinafter, preferred embodiments of the method for setting a compression position of a mask frame according to the present invention will be described in detail with reference to the accompanying drawings. The same cathode ray tube components as in the prior art are denoted with the same reference numerals as in the prior art, and a detailed description thereof is omitted. Let's do it.

Figure 3 shows the frame structure of the cathode ray tube to which the compression position setting method of the present invention is applied.

Normally, in order to obtain a U-shaped tension distribution curve in a shadow mask, compression is performed at three compression points of the frame, but in this case, it is not possible to control the tension distribution in the middle region other than the center and the corner, and thus the four or more points of the frame. It is preferable to compress the frame by setting a compression point at.

Accordingly, in the present invention, the main frame 5a of the frame assembly in the initial unit state is compressed to a constant load, and the tension applied to the shadow mask 4 by applying a compressive load at four designated compression points of the main frame 5a. To optimize the distribution.

Here, the compression point of the main frame 5a is set as follows.

First, when the length of the main frame 5a is L, and the distances of the first compression point P1 and the second compression point P2 on both sides from the center C of the main frame 5a are X1 and X2, respectively. The position range of the compression point is determined so as to satisfy (L / 2) × 0.38 ≦ X1 ≦ (L / 2) × 0.52 and (L / 2) × 0.80 ≦ X2 ≦ (L / 2) × 0.98.

The compression points P1 and P2 are preferably formed at positions symmetrical with respect to the frame center C, respectively. These compression points are the result obtained by experiment.

The second compression point P2 of the compression points is near the weld between the mainframe 5a and the subframe 5b. Compressing near this weld is the point where the stiffness of the frame assembly is the greatest and is desired at the corner. This is to obtain a U-shaped tension distribution curve. Preferably, a compression point of 98% from the frame center can obtain the largest corner tension distribution.

When the compression point of a frame is set at a point outside the above-mentioned range, the inflection point at which the frequency value closer to the corner portion is smaller or equal to the frequency value closer to the center portion than the frequency value closer to the center portion in the frequency value of two near measuring points during compression It has a tension distribution, which causes the vibration range in which the mask vibrates with respect to an external vibration excitation source in the frequency band.

Meanwhile, in order to design the tension distribution of the shadow mask 4 by compressing the main frame 5a at five compression points, the four compression points P1 and P2 set in the first embodiment as shown in FIG. In addition, the compression point (P0) is additionally set in the mainframe center (C).

In this case, as compared with the case of designing the tension distribution using only four compression points, it is possible to directly control the tension value of the center part, and thus the tension distribution can be more easily applied to the shadow mask 4 as the design value.

5 shows an embodiment in which six compression points are set on the main frame 5a to apply a compression load. In this embodiment, two compression points are set at the same point as described in FIG. Compression point P3 is set at a distance of X3 from mainframe center C, where the third compression point P3 is in a range that satisfies (L / 2) × 0.66 ≦ X3 ≦ (L / 2) × 0.80. Is set.

Also in this case, it is preferable that compression points on both sides of the main frame center C are set to be symmetrical.

According to this embodiment, a third compression point P3 is present between the first compression point P1 and the second compression point P2, so that a variable capable of controlling the tension distribution is more than the case of four or five compression points. This increases the tension distribution between the center and the corners, making it easier to apply them as designed.

FIG. 6 is a graph showing the tension distribution of the shadow mask 4 when the compression load is applied at the compression points P1 and P2 set by the first embodiment of the present invention as described above, and the tension distribution curve has no inflection point. It can be seen that it forms a smooth U-shape.

As described above, according to the present invention, even if the size of the cathode ray tube changes, it is possible to set a compression point that can apply the optimal tension distribution to the shadow mask in response to the change in size, so It is possible to minimize the vibration range, thereby preventing the shaking of the screen of the screen.

Claims (5)

In a mask frame assembly of a cathode ray tube comprising a shadow mask for screening and a frame to which the shadow mask is tensioned and fixed, When the length of the long side of the frame is L and the distance from the center of the frame to each of the compression points P1 and P2 on both sides is X1 and X2, (L / 2) × 0.38 ≦ X1 ≦ (L / 2) × 0.52, and (L / 2) × 0.80 ≤ X2 ≤ (L / 2) × 0.98 Compression position setting method for applying the tension of the mask frame assembly for cathode ray tube, characterized in that for setting each compression point of the frame so as to satisfy. The method of claim 1, wherein a compression point is additionally designated to the frame center. The method of claim 1, wherein when setting an additional compression point P3 in the frame, the distance X3 from the frame center to the compression point P3 is And (L / 2) × 0.66 ≦ X3 ≦ (L / 2) × 0.80. A compression position setting method for applying tension in a mask frame assembly for a cathode ray tube. The method according to claim 1, wherein the compression points (P1, P2) of the frame are symmetrically set about a frame center. 4. The method according to claim 3, wherein the compression points (P1, P2, P3) of the frame are set at positions symmetrical with respect to the frame center, respectively.