KR100813501B1 - Cathode ray tube panel and method manufacturing the same - Google Patents

Abstract

과 페이스주변영역의 표면응력

이

의 관계를 만족하고, 페이스주변영역의 표면응력

과 페이스주변영역의 최대진공인장응력

이

의 관계를 만족한다. 본 발명에 의하면, 금형으로부터 취출한 직후 최대진공응력이 가해지는 판넬의 페이스주변영역을 공랭강화시킴으로써, 불필요한 영구인장응력을 제거하여 응력분포를 개선하고, 외부의 기계적인 충격에 잘 견디고, 방폭테스트시 보다 안전한 형태의 방폭특성을 보유한다. 이 결과, 음극선관의 평면화, 경량화와 슬림화가 용이해지는 효과가 있다.The present invention discloses a panel for a cathode ray tube and a method of manufacturing the same. The panel of the present invention is composed of a face portion for displaying an image and a skirt portion extending rearward from the edge of the face portion, and the surface stress of the face center region.

Surface Stress in Peripheral and Face Regions

this

Surface stress in the area around the face

Vacuum tensile stress in the area around the face and face

this

Satisfies the relationship. According to the present invention, by air cooling the area around the face of the panel to which the maximum vacuum stress is applied immediately after taking out from the mold, it eliminates unnecessary permanent tensile stress, improves stress distribution, and withstands external mechanical shock, and explosion-proof test. It has a safer form of explosion protection. As a result, there is an effect that the planarization, weight reduction and slimming of the cathode ray tube are facilitated.

Description

Cathode ray panel and its manufacturing method {CATHODE RAY TUBE PANEL AND METHOD MANUFACTURING THE SAME}

1 is a cross-sectional view showing a glass bulb for a cathode ray tube composed of a panel, channel and neck;

2 is a view showing a stress distribution acting on the glass bulb for the cathode ray tube,

3 is a cross-sectional view showing the configuration of a molding apparatus in order to explain a method for manufacturing a panel;

4 is a perspective view showing the configuration of a panel;

5 is a front view schematically showing a cooling apparatus for explaining a method of manufacturing a glass bulb according to the present invention;

6a and 6b are perspective views showing the configuration of a specimen for measuring the surface stress of the face center region and the face peripheral region of the panel,

7 is a graph showing temperature change of each panel region.

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

10: glass bulb 20: panel

21: face part 23: skirt part

24: blend round portion 25: long side                 

26: short side 7: face center area

28a to 28d: face peripheral area 30: channel

40: neck 60: mold

62: plunger 70: conveyor

80: cooling device 82: injection pipe

The present invention relates to a panel for a cathode ray tube, and more particularly, to a cathode ray tube panel and a method of manufacturing the same to improve the stress distribution of the face portion of the panel to maintain a safe form even mechanical impact.

As is well known, glass bulbs for cathode ray tubes used in the manufacture of color televisions and computer monitors basically consist of three components: panel, conical funnel and tubular neck. Neck) Panels, channels and necks are all made of glass, and in particular panels and channels are produced by press molding a molten glass mass called a gob in a desired size and shape.

Referring to the configuration of the glass bulb for the cathode ray tube based on FIG. 1, the panel 20 of the glass bulb 10 has a face portion 21 for displaying an image and a rear portion from the edge of the face portion 21. A skirt portion (23) having an extended and formed seal edge (22) and a blend round portion (24) connecting the face portion 22 and the skirt portion 23 are provided. have. The seal edge 31 of the conical channel 30 is joined to the seal edge 22 of the panel 20, and the neck 40 is fused to the vertex of the channel 30.

The tube axis 11 of the glass bulb 10 indicates an axis where the center of the face portion 21 of the panel 20 and the center of the neck 40 are connected. A shadow mask 50 having a plurality of holes is supported by the skirt portion 23 of the panel 20 by a stud pin 51, and the neck 40 is faced through a hole of the shadow mask 50. An electron gun 52 which emits an electron beam with an imaging phosphor coated on the inner surface of the part 21 is provided.

When the air is evacuated from the inside of the glass bulb 10 to become a vacuum, a compressive stress is generated on the inner surface of the glass bulb 10 due to the pressure difference between the inside and the outside, and there is a region where the tensile stress is generated on the outer surface. do. Since glass has a property that is vulnerable to tensile stress, it is accompanied by a problem that breakage or deflation occurs easily in a region where tensile stress is generated. In particular, the blend round portion 24 of the panel 20 has a very fragile structure in which the maximum tensile stress is applied by the pressure difference between the inside and the outside of the glass bulb 10.

In recent years, the traditional spherical or aspherical cathode ray tube has been enlarged and planarized. The enlargement and planarization of the cathode ray tube inevitably increases the thickness and weight of the glass bulb and thus involves many difficulties in the manufacture of the glass bulb. Therefore, many studies are being actively conducted to reduce the thickness and weight of the glass bulb. The reduction of the thickness and weight of the glass bulb improves the shape of the panel to reduce or reduce the distribution of vacuum tensile stress due to the pressure difference, and to strengthen and chemically strengthen the physical stress method to form a compressive stress layer on the glass surface. It is performed by the method.

The glass bulb for cathode ray tube of U.S. Patent No. 5,445,285 has a physically strengthening method to form a compressive stress layer on the surface of the panel to improve the mechanical strength of the glass and to respond to the maximum vacuum tensile stress caused by the pressure difference between the inside and outside of the glass bulb. Techniques for preventing thermal breakage during the manufacture of the bulb and fatigue breakdown after completion have been proposed.

According to the range of compressive stress by the physical reinforcement method proposed in this technique, the mechanical strength of glass is improved by the compressive stress layer, but it inevitably leads to an increase in strain energy, resulting in an expansion of the glass bulb when it breaks, In other words, there is a serious problem that explosion-proof properties such as explosion and shrinkage and scattering of panels and channels, as well as spontaneous breakage due to surface defects generated in a specific portion of the glass bulb due to the imbalance of stress.

Moreover, in the panel manufactured by the physical strengthening method, the temporary stress formed when molded from the product is controlled in a slow cooling furnace to cool to room temperature. This technique of forming compressive stress on the surface could not have a uniform stress distribution. In particular, since the distribution of air flow in the heated slow cooling furnace is different in the face region and the skirt region, excessive temporary stresses are generated around the skirt region, which causes the blend round portion of the panel to be damaged even by a small mechanical impact on the outside. . In addition, the explosion-proof characteristics of the UL standard (Underwriters Laboratories Inc.) is greatly reduced.

The present invention has been made in order to solve the various problems of the prior art as described above, the object of the present invention is to improve the stress distribution by the air cooling of the peripheral face area, to withstand the mechanical shock of the outside, explosion-proof The present invention provides a panel for a cathode ray tube and a method of manufacturing the same having a safer explosion-proof property when tested.

Another object of the present invention is to provide a cathode ray tube panel and a method for manufacturing the cathode ray tube which are very easy to planarize, lighten, and slim.

과 페이스주변영역의 표면응력(

)이

의 관계를 만족하고, 페이스주변영역의표면응력

과 페이스주변영역의 최대진공인장응력

이

의 관계를 만족하도록 페이스주변영역을 공랭강화시키는 음극선관용 판넬 제조방법에 있다.A feature of the present invention for achieving the above object is a method for manufacturing a cathode ray tube panel consisting of a face portion for displaying an image and a skirt portion extending rearward from the edge of the face portion, wherein the face portion is the surface of the face center region. Stress

Surface Stresses in the Peripheral and Face Regions

)this

Surface stress in the area around the face

Vacuum tensile stress in the area around the face and face

this

In the method for manufacturing a cathode ray tube panel to air-cool the area surrounding the face to satisfy the relationship.

과 페이스주변영역의 표면응력

이

의 관계를 만족하고, 페이스주변영역의 표면응력

과 페이스주변영역의 최대진공인장응력

이

의 관계를 만족하는 응력분포를 갖는 음극선관용 판넬에 있다.According to another aspect of the present invention, there is provided a panel for cathode ray tubes comprising a face portion for displaying an image and a skirt portion extending rearward from an edge of the face portion, wherein the face portion has a surface stress in the face center region.

Surface Stress in Peripheral and Face Regions

this

Surface stress in the area around the face

Vacuum tensile stress in the area around the face and face

this

It is a panel for cathode ray tube with stress distribution satisfying the relationship of.

Hereinafter, a preferred embodiment of a cathode ray tube panel and a method of manufacturing the same according to the present invention will be described in detail with reference to the accompanying drawings.

First, referring to FIG. 3, the manufacturing method of the panel 20 shown in FIG. 1 is supplied. After supplying a product of about 1,000 ° C. that is melted in the mold 60, the ram 61 is operated to operate the plunger. When the product is pressurized by 62, the panel 20 of a desired size and shape is formed by cooperation of the mold 60 and the plunger 62. As shown in FIG. At this time, since the panel 20 maintains about 600 ° C., the cooling air is supplied by a forced draft cooling device (not shown), cooled, and then transferred from the mold 60 to a subsequent pin sealing station. Take out.

As shown in FIG. 4, the face portion 21 of the panel 20 is formed in a substantially rectangular shape having a long side 25 and a short side 26 and forms a face center region constituting an effective screen displaying an image ( Face Center Area 27 and four Face Wedge Areas 28a to 28d proximate to the skirt 23. The face center region 27 is made thinner than the face peripheral regions 28a to 28d. In the panel 20 having such a configuration, the region where the maximum vacuum tensile stress is applied is the face peripheral regions 28a to 28d close to the short sides 26.

As shown in the graph of FIG. 7, the surface temperature of the panel 20 immediately after molding and taking out the mold 60 is raised again due to reheating by internal heat and the internal temperature is decreased. When the surface temperature of the panel 20 falls below the annealing point of the glass, the cooling speed of the face center region 27 is lower than that due to the difference in thickness between the face center region 27 and the face peripheral regions 28a to 28d. The cooling rate of the face peripheral areas 28a to 28d becomes slow. Unnecessary permanent tensile stress is largely formed in the face peripheral areas 28a to 28d.

Referring to FIG. 5, in the characteristic embodiment of the present invention, the panel 20 immediately after being taken out of the mold 60 is followed by a pin sealing station by the conveyor 70 so that the face portion 21 faces upward. Transfer to. At this time, the face periphery areas 28a to 28d of the panel 20 are rapidly cooled for several seconds by the cooling air supplied from the forced draft cooling device 80 to enhance air cooling. Preferably, the air cooling step is performed in the face peripheral areas 28a and 28b proximate the short side 26 to which the maximum vacuum tensile stress is applied.

On the other hand, the panel 20 immediately after taking out from the metal mold | die 60 has the surface temperature of the face part 21 about 475-520 degreeC, and the temperature of the cooling air supplied from the cooling device 80 is about 20 degreeC. to be. The cooling device 80 includes an air supply unit 81 for supplying cooling air, and an injection pipe 82 for ejecting air supplied from the air supply unit 81 to the face peripheral areas 28a to 28d of the panel 20. It consists of. The air supply unit 81 of the cooling device 80 may be configured as an air compressor.

과 페이스주변영역(28a∼28d)의 표면응력

이 In the present invention, the surface stress of the face center region 27 by forced air cooling

And surface stresses in the face peripheral areas 28a to 28d

this

Satisfy the relationship

과 페이스주변영역(28a∼28d)의 표면응력

이Maximum vacuum tensile stress in the peripheral face area (28a to 28d)

And surface stresses in the face peripheral areas 28a to 28d

this

The panel 20 that satisfies the relationship was manufactured.

In order to determine the degree to which the glass bulb 10 employing the panel 20 manufactured by forced air cooling of the present invention corresponds to an external mechanical shock, UL standard explosion-proof test was performed. UL standard explosion-proof test is to determine the mass of the glass fragments of the panel 20 or channel 30, which is scattered by hitting the designated hitting point of the panel 20 by a ball-type or missile-type hitting body having an energy of 7 ~ 20J. The measurement is made, and only the glass bulb 10 having a mass of the glass piece smaller than the reference amount is judged to pass, thereby ensuring safety.

The results of the explosion-proof test of the UL standard is shown in Table 1. In Comparative Examples 1 to 3 and Examples 1 to 3 of Table 1, a glass bulb was formed using a 32-inch panel having a long side and a short side of 16: 9. In addition, the panel has a thickness of the face center region of 16.0 mm and the thickness of the skirt portion of 19.3 mm, which is thinner than the panel of the existing glass bulb, but the embodiment of the present invention is not limited thereto. In addition, the explosion-proof tests of Comparative Examples 1 to 3 and Examples 1 to 3 were carried out on ten glass bulbs having the same conditions.

과 페이스주변영역(28a∼28d)의 표면응력

각각의 크기를 측정하기 위한 측정용 시편(90, 91)이 도시되어 있다. 측정용 시편(90, 91) 각각은 측정부위, 즉 페이스중앙영역(27)과 페이스주변영역(28a∼28d)을 폭 대략 10mm, 길이 대략 50mm로 절단하여 구성하였다. 페이스중앙영역(27)의 표면응력

과 페이스주변영역 (28a∼ 28d)의 표면응력

은 세나르몽법(Senarmont Method)에 의하여 측정하고, 그 결과는 표 1에 나타냈다. 6A and 6B, the surface stress of the face center region 27 is shown.

And surface stresses in the face peripheral areas 28a to 28d

Measurement specimens 90, 91 for measuring each size are shown. Each of the test specimens 90 and 91 was formed by cutting the measurement site, that is, the face center region 27 and the face peripheral regions 28a to 28d into approximately 10 mm in width and approximately 50 mm in length. Surface stress in the face center region (27)

And surface stresses in the peripheral face areas 28a to 28d

Was measured by the Senarmont Method, and the results are shown in Table 1.

Comparative Example 1 Example 1 Example 2 Example 3 Comparative Example 2 Comparative Example 3 Cooling time (seconds) 0 5 10 20 30 40 σfw (MPa) -5.5 -8.9 -10.2 -13.2 -18.4 -25.2 σfc (MPa) -18.0 -17.8 -18.2 -19.1 -20.5 -20.8 σfc / σfw                                              3.3 2.0 1.8 1.4 1.1 0.82 2σts- ｜ σfw ｜                                              12.5 9.1 7.8 4.8 -0.4 -7.2 Explosion proof test pass rate 2/10 10/10 10/10 10/10 5/10 1/10

As shown in Table 1, it can be seen that the glass bulb adopting the panel which was taken out from the mold according to Comparative Example 1 and which did not harden the air in the periphery of the face area was 20%. In Examples 1 to 3, all panels satisfying the relationship between Equations 1 and 2 passed the explosion proof test. Comparative Example 2 and Comparative Example 3 did not pass the explosion-proof test beyond the relationship between Equations 1 and 2 due to excessive cooling time of the panel.

The embodiments described above are merely to describe preferred embodiments of the present invention, the scope of the present invention is not limited to the described embodiments, those skilled in the art within the spirit and claims of the present invention It will be understood that various changes, modifications, or substitutions may be made thereto, and such embodiments are to be understood as being within the scope of the present invention.

As described above, according to the panel for a cathode ray tube according to the present invention and a method for manufacturing the same, an air gap is strengthened around the face of the panel to which the maximum vacuum stress is applied immediately after taking out from the mold, thereby eliminating unnecessary permanent tensile stress and thereby reducing stress distribution. It improves, withstands mechanical shocks externally, and has a safer form of explosion-proof characteristics when testing explosion-proof. As a result, the planarization, weight reduction and slimming of the cathode ray tube can be easily achieved.

Claims (5)

In the manufacturing method of the cathode ray tube panel consisting of a face portion for displaying an image and a skirt portion extending rearward from the edge of the face portion, The face portion has surface stress in the face center region

Surface Stresses in the Peripheral and Face Regions

)this

The surface stress of the face peripheral area

And maximum vacuum tensile stress in the area around the face

this

Method of manufacturing a panel for cathode ray tubes, characterized in that to air-cool the surface surrounding area to satisfy the relationship. The method for manufacturing a cathode ray tube panel according to claim 1, wherein the air cooling of the face peripheral area is made by cooling air at 20 ° C when the surface temperature of the panel is approximately 475 to 520 ° C. The method for manufacturing a cathode ray tube panel according to claim 1 or 2, wherein the air cooling of the face peripheral area is made on a short side of the panel to which the maximum vacuum tensile stress is applied. The method for manufacturing a cathode ray tube panel according to claim 1 or 2, wherein the thickness of the face peripheral area is thicker than that of the face center area. In the cathode ray tube panel consisting of a face portion for displaying an image and a skirt portion extending rearward from the edge of the face portion, The face portion has surface stress in the face center region

Surface Stress in Peripheral and Face Regions

this

The surface stress of the face peripheral area

And maximum vacuum tensile stress in the area around the face

this

Cathode ray panel characterized in that it has a stress distribution satisfying the relationship of.

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