KR100418042B1 - A Safety Band of The Cathode-Ray-Tube - Google Patents

Abstract

The present invention relates to a color cathode ray tube, and in particular, in applying a reinforcement band to a lightweight panel structure, a color cathode ray tube implementing an optimal explosion-proof characteristic by setting the width and an installation position of the reinforcement band according to the weight of the panel. It is about.

According to the technical means of the present invention, when the shortest distance from the end of the skirt to the extension plane of the outer surface of the panel is OAH, and the diagonal length of the effective screen is USD, 0.19 <OAH / (USD / 2) <0.30 is satisfied. A color cathode ray tube comprising a panel having a predetermined curvature and a substantially flat outer surface, wherein the width of the reinforcing band is W, the following expression is satisfied.

The present invention can not only ensure the stability of the user by improving the explosion-proof characteristics of the panel, but also can increase the national competitiveness of the product by satisfying the quality standards of UL / CSA.

Description

Reinforcement band structure for cathode ray tube {A Safety Band of The Cathode-Ray-Tube}

The present invention relates to a color cathode ray tube, and in particular, in applying a reinforcement band to a lightweight panel structure, a color cathode ray tube implementing an optimal explosion-proof characteristic by setting the width and an installation position of the reinforcement band according to the weight of the panel. It is about.

In the conventional color cathode ray tube, as shown in FIG. 1, R, G, and B fluorescent films 6 are coated on the inner surface, and a panel 1 having explosion-proof means is fixed on the front surface thereof, A funnel (2) fused at the rear end, an electron gun (5) inserted into the neck (3) of the funnel and radiating an electron beam (4), and mounted at regular intervals inside the panel to allow a plurality of electron beams to pass through. A shadow mask (7) having holes formed therein; a frame (8) for holding and supporting the shadow mask so that the shadow mask is kept at a constant distance from the inner surface of the panel; and a deflection yoke (9) for deflecting the electron beam in a vertical direction; Is installed around the side of the panel consists of a reinforcement band 11 to prevent external impact.

The general panel is designed to have a predetermined curvature on both the inner surface and the outer surface. The curvature of the outer surface causes distortion of the image and severe reflection of external light, thereby increasing eye fatigue. In order to improve this, the inner surface has a certain curvature and the outer surface forms a flat panel structure so that the image of the plane can be realized to eliminate the distortion of the screen at the proper viewing distance and lower the eye fatigue.

However, in the related art, the shortest distance from the end of the skirt portion of the panel to the outside surface of the panel is designed to be the same for the manufacturing process of the panel having a flat curvature and the panel having a certain curvature, so that the deflection margin of the flat panel is excessively designed and the skirt length is There is a problem that is long.

In addition, the general flat cathode ray tube has a flat outer surface, but the inner surface has curvature, and the panel thickness of the corner portion is sharply thicker than that of the center portion, and the weight of the panel is increased by 10 to 15% compared to the conventional curved cathode ray tube. Due to the large wedge rate, excessive thermal stress generated in the furnace caused damage to the inside of the furnace or lowered the yield of the recycled product in the process of regenerating the bulb.

In order to solve the above problems, the weight of the panel is reduced and the overall length is reduced by shortening the center thickness (CFT) and the length of the skirt of the flat color cathode ray tube panel. That is, in a rectangular panel having an outer surface having a radius of curvature of 30000 mm or more, an inner surface having a constant curvature, and a skirt extending substantially perpendicular to the inner and outer surfaces, the diagonal length of the panel effective screen is USD, and the skirt end of the panel is provided. When the shortest distance from the surface of the panel to the extension plane of the panel is OAH, a lightweight panel structure satisfying 0.19 < OAH / (USD / 2) < 0.30 has been proposed.

However, since the inside of the cathode ray tube is vacuumed by the panel and the funnel, as shown in FIG. 2, the cathode tube is subjected to compressive or tensile stress to the inside and the outside of the cathode ray tube by atmospheric pressure. Since the side surface of the panel to which tensile stress is applied is structurally weak compared with other parts. Therefore, when an external impact is applied to the cathode ray tube in the state in which the compression and tensile pressure by vacuum are applied, a detonation phenomenon occurs in the panel or the funnel as shown in FIG. 3. The process of detonation is as follows.

First, when an impact is applied to any part of the cathode ray tube by the external impact source 10 as shown in FIG. 3A, a small crack is generated and proceeds in a conical form. That is, when the strength of the impacted site reaches its limit momentarily, a micro crack occurs in this site, and the impact energy is diffused throughout the cathode ray tube, and the crack progresses toward the skirt portion where the defect or stress of the cathode ray tube is concentrated. Will be. Therefore, the fine crack proceeds to the entire cathode ray tube as shown in Figure 3b, in particular, the tensile force is applied to the skirt portion, the crack is further expanded, thereby expanding the skirt portion. At this time, if a crack passes from the outside of the panel to the inside, the outside of the panel or the funnel is recessed as shown in FIG. 3C. That is, the crack expands as the skirt portion expands, and the panel and the funnel glass are recessed due to the internal and external pressure difference of the cathode ray tube. Kinetic energy is generated in the process of sinking the cathode ray tube inside, and each fragment is scattered to the outside unless stopped by a collision.

The detonation phenomenon makes the cathode ray tube inoperable and poses a safety threat to the user, so that the reinforcing band 11 is attached to prevent the detonation phenomenon. By attaching the reinforcing band to the side portion of the panel where the tensile stress is concentrated, it is possible to reinforce the rigidity to prevent the explosion.

Figure 4 compares the stress before and after the reinforcing band attached. When a shock is applied to the surface of the cathode ray tube, a tensile stress that expands the side portion is generated, but the tensile stress is suppressed by the rigidity of the reinforcing band, and the reinforcing band strongly compresses the side portion to prevent the crack from passing through the side portion and the surface portion. This will slow down the crack. In addition, the strain stress caused by fastening of the reinforcing band is applied to the vacuum strain so that the main stress direction of the surface portion is changed and the direction of cracking is changed to prevent the explosion.

However, in the above-mentioned lightweight panel structure, the fastening position of the reinforcing band is biased to the rear of the panel relative to the panel of the conventional flat cathode ray tube, so that the front part of the panel is vulnerable and the thickness of the panel is thinned by the weight reduction. Stress is concentrated in the cracks and cracks are likely to occur. In addition, in the lightweight panel structure, the center of the curved curved surface where the curvature changes rapidly becomes a diverging point of the compression effect, so the width and installation position of the reinforcing band should be set differently according to the size and weight of the panel.

Accordingly, the present invention provides a color cathode ray tube implementing optimal explosion-proof characteristics by setting the width and installation position of the reinforcement band according to the weight of the panel in applying the reinforcement band to the lightweight panel structure to solve the above problems. It aims to do it.

1 is a structural diagram of a general color cathode ray tube,

2 is a stress distribution diagram of a typical cathode ray tube,

3A to 3D are diagrams illustrating a contraction phenomenon of a cathode ray tube;

4 is a diagram showing the stress distribution before and after the reinforcing band attached;

5 is a schematic diagram of a general reinforcing band,

6 is a view showing a ball impact experiment of the panel,

7 is a graph showing the relationship between impact energy and impact effect;

8 is a diagram illustrating crack generation of panels.

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

1 panel 2 funnel 11 reinforcement band

According to the technical means of the present invention for achieving the above object, the shortest distance from the end of the skirt to the extension plane of the outer surface of the panel is called OAH, and when the diagonal length of the effective screen is USD, the panel is 0.19 <OAH / (USD / 2) a panel having a constant curvature on the inside and substantially flat on the outside, a funnel connected to the panel, an electron gun mounted on the neck of the funnel to emit an electron beam toward the phosphor screen, A shadow mask disposed at regular intervals with respect to the phosphor screen on the inner surface of the panel to serve as color screening, a frame for fixing and supporting the shadow mask, and a reinforcing band installed around the side surface of the panel to prevent external impact In the color cathode ray tube which

When the width of the reinforcing band is W, it is characterized by the following equation.

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

In general, the tightening tension F of the reinforcing band can be obtained from the formula F = σ x T x W, where σ is the yield strength, T is the thickness of the reinforcing band, and W is the width of the reinforcing band. Since σ is about 29 to 34 kgf / f and T is a fixed value of 2 to 3 mm, F can be determined by W. Accordingly, the present invention seeks to provide a reinforcing band that conforms to the lightweight panel structure by adjusting the width W of the reinforcing band.

In each country, however, inspection agencies and safety standards are mandated for cathode ray tubes, and representative agencies include UL (USA), CSA (Canada), BSI (UK), VDE (Germany), JQA (Japan), SACI (China). ). The safety standard is for the case of applying a large impact that can occur in the home to the cathode ray tube as shown in the graph of Figure 7, in particular, UL and CSA define the greatest impact energy that can occur in the home as a golf club It is demanding to secure stability. Therefore, passing the safety standards of each country, especially UL and CSA, is very important not only for the stability of cathode ray tube but also for international competitiveness.

Therefore, through the experiment based on the above contents it is to optimize the dimensions of the reinforcing band for each panel.

In the present invention, the lightweight panel to which the reinforcing band is to be applied is structurally weak compared to a general panel having an outer surface almost flat and an inner surface having a constant curvature, both inner and outer surfaces having curvature. Table 1 and Table 2 compare the characteristics of general and lightweight panels. That is, thermal deformation can easily occur due to thermal expansion of the thickness ratio of the corner portion to the center of the panel to about 1.3, and the maximum stress during vacuum and reinforcement is large.

TABLE 1

Common panel Lightweight panel Maximum stress increase After F / S 51.40 MPa 62.40 MPa 21.31 MPa After exhaust process 63.20 MPa 69.50 MPa 9.91 MPa

TABLE 2

Common panel Lightweight panel Maximum stress increase vacuum 79.11㎏f / ㎣ 88.78㎏f / ㎣ 11.02㎏f / ㎣ Reinforcement 59.41㎏f / ㎣ 79.69㎏f / ㎣ 33.28㎏f / ㎣

FIG. 6 shows a panel ball impact test apparatus, in which a ball 12 having a predetermined weight is dropped on a panel surface while the height is changed while the panel is fixed to measure the strength of the panel. The experiment can measure the actual strength of the panel itself. Experimental results show that the general panel of 19kV is destroyed at energy of 7.35J and higher, and the 19kW panel is destroyed at energy of 5.79J and higher. The experimental results show that the strength of the panel is determined by the shape strength rather than the thickness.

In the present invention, after fastening the reinforcing band to the 19〃 flat lightweight panel with OAH / (USD / 2) = 0.29, the panel ball impact experiment was conducted while adjusting the width of the reinforcing band and the results are shown in Table 3.

TABLE 3

Band width [mm] Tightening Tension [㎏f] The degree of damage due to cracking [dog] 0% 25% 50% 75% 100% (complete damage) 34 1621 10 2 2 One 0 32 1513 12 One 2 0 0 30 1394 7 3 2 3 0 28 1277 5 2 5 2 One

As shown in Table 3, when the band width is 28 mm or more, the explosion-proof characteristics satisfying UL and CSA standards are shown. Particularly, when 28 mm, the crack progression of the panel surface satisfies the specification, but the funnel crack progresses somewhat. In the case of 30 mm and 34 mm, both the panel surface and the funnel crack propagation are suitable. In addition, at 32 mm, the crack on the panel surface continues and stops the funnel crack progression, causing rotational cracks. The shape of the crack is shown in FIG.

Therefore, it is desirable that the optimum width of the reinforcing band applied to the flat lightweight panel with OAH / (USD / 2) = 0.29 is about 30 to 34 mm. In addition, the above experiments were carried out with a 29〃 flat lightweight panel with OAH / (USD / 2) = 0.22. The optimum width of the reinforcing band was 56 ~ 62㎜.

As can be seen from the above, the wider the width of the reinforcing band is, the more advantageous it is, and the width of the panel should have an appropriate width according to the degree of weight reduction, and it is preferable to satisfy the following equation.

In the above described and illustrated with respect to the embodiment of the specific case of the present invention, it will be apparent that the present invention can be variously modified by those skilled in the art. In addition, the modified embodiments of the present invention should not be individually understood from the technical spirit or the prospect of the present invention, and the modified embodiments shall fall within the claims of the present invention.

As described above, the present invention improves the explosion-proof characteristics of the panel by providing an optimal reinforcing band that is matched with a flat lightweight panel by adjusting the width of the reinforcing band, thereby ensuring user stability, and quality standards of UL / CSA. By satisfying this, the national competitiveness of the product can be increased, and the application of the straight band can achieve low cost and high efficiency.

Claims (1)

When the shortest distance from the end of the skirt to the extension plane of the outer surface of the panel is called OAH, and the diagonal length of the effective screen is USD, the panel satisfies 0.19 <OAH / (USD / 2) <0.30 and the inner surface has a constant curvature. A panel having a substantially flat outer surface, a funnel connected to the panel, an electron gun mounted to a neck portion of the funnel to emit an electron beam toward the phosphor screen, and a predetermined distance from the phosphor screen on the inner surface of the panel In the color cathode ray tube comprising a shadow mask disposed to serve as a color screening, a frame for fixing and supporting the shadow mask, and a reinforcing band installed around the side surface of the panel to prevent external impact, When the width of the reinforcing band W is the color cathode ray tube, characterized in that the following formula.