KR100587894B1 - Glass panel for cathode ray tube - Google Patents

Abstract

The glass panel for cathode ray tubes is provided with the substantially rectangular face part in which an image is displayed, and the skirt part connected through a face part and a blend egg. The effective screen diameter in the diagonal direction of the face part is 500 mm or more, and the average radius of curvature of the outer surface of the face part is 10000 mm or more in the total radial direction passing through the face center part, and the face center part in the diagonal axis direction of the inner surface of the face part. The fall of the effective screen end is in the range of 9 mm to 17 mm.

Description

Glass panel for cathode ray tube {GLASS PANEL FOR CATHODE RAY TUBE}

1A is a plan view of a glass panel for a cathode ray tube according to an embodiment of the present invention, and FIG. 1B is a diagonal axial cross-sectional view.

Fig. 2 is an explanatory diagram showing the relationship between the drop in the face center portion and the effective screen end of the inner surface of the face portion and the thickness of the face center portion and the weight of the glass panel in the glass panel for cathode ray tube according to the embodiment of the present invention.

Fig. 3 is an explanatory view showing the relationship between the face center portion and the effective screen end drop on the inner surface of the face portion in the glass panel for cathode ray tubes of different sizes according to the embodiment of the present invention, the thickness of the face center portion and the weight of the glass panel.

4 is an explanatory view showing a relationship between a face center portion of an inner surface of a face portion and an effective screen end portion in a glass panel for cathode ray tubes according to an embodiment of the present invention, the thickness of the face center portion and the weight of the glass panel;

Figure 5 is a longitudinal cross-sectional view of the glass valve for the cathode ray tube.

This invention relates to the glass panel which comprises the glass valve for cathode ray tubes used for a television, a display tube, etc.

Usually, as shown in FIG. 5, the glass valve for cathode ray tubes is a glass panel 1 of the front surface in which the image was displayed, and the funnel 2 which seals with the glass panel 1 in the rear, and mounts a deflection yoke outside; And a neck 3 which is welded to the funnel 2 and in which an electron gun is stored.

In the case of a color cathode ray tube, it is integrally sealed using the frit glass 4 between the sealing cross section 11 of the glass panel 1 and the sealing cross section 21 of the funnel 2. Further, since the cathode ray tube is used in a high vacuum state by evacuating the inside, the vacuum valve is loaded by the pressure difference between the inside and outside of the glass valve.

Therefore, the shape and thickness of the glass valve are designed to withstand the vacuum stress caused by the pressure difference between inside and outside. In particular, the glass panel 1, which is susceptible to external impulses, becomes thick, and in particular, the vacuum stress is alleviated and dispersed by increasing the thickness at the effective screen end of the face portion 12.

However, in the conventional glass panel for cathode ray tubes, when the panel thickness is simply thickened, since the weight of a glass panel increases, handling property and workability worsened, and glass cost tended to become high.

Since the effective screen diameter in the diagonal direction of the face portion of the glass panel is larger, and the average curvature radius of the outer surface of the face portion is larger, that is, the higher the flatness, the weight increases synergistically, so the above tendency becomes more remarkable.                         

In addition, when the phosphor provided on the inner surface of the glass panel emits light by an electron beam, braking X-rays are generated in the cathode ray tube. In order to prevent the braking X-rays leaking out of the tube through the glass valve and adversely affecting the human body, a predetermined X-ray absorption performance is required for the glass panel.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cathode ray tube glass panel having a large size and having a flat outer surface with a high flat surface, which is lightweight while maintaining a predetermined mechanical strength and also satisfies a predetermined X-ray absorption performance. will be.

In order to achieve the above object, the present invention has a face portion on which the image is displayed, a skirt portion connected through the face portion and the blend egg portion, the effective screen diameter in the diagonal direction of the face portion is at least 500mm, the face portion inner surface A cathode ray tube glass panel having an average radius of curvature of 10,000 mm or greater in the total radial direction passing through the center of the face portion, wherein the difference between the face center portion and the end of the effective screen in the diagonal axis direction of the face portion is 9 mm. It provides a glass panel for a cathode ray tube, characterized in that in the range of ~ 17mm.

In the above configuration, when the effective screen diameter in the diagonal direction of the face portion is D (mm) and the thickness of the face center portion is t (mm), the X-ray absorption coefficient A (cm ^-1 ) at a wavelength of 0.06 nm. Is preferably A ≧ 1750 t / D.

The present invention is a large size glass having a flatness of 10000 mm or more in an overall radial direction in which the effective screen diameter in the diagonal direction of the face portion is 500 mm or more, and the average curvature radius of the outer surface of the face portion passes through the face center portion. With respect to the panel, from the viewpoint of mechanical strength and light weight of the glass panel, the drop in the face center portion and the effective screen end portion in the diagonal axis direction of the inner surface of the face portion is prescribed in an appropriate range of 9 mm to 17 mm.

If the difference between the face center and the effective screen end in the diagonal direction of the inner surface of the face part is less than 9 mm, the so-called arch effect is small due to the large drop (by thickening) from the face center toward the effective screen end. In order to maintain the mechanical strength of the face, it is necessary to increase the thickness of the center of the face, so it is impossible to reduce the weight of the glass panel.

On the other hand, if the difference between the face center portion and the effective screen end portion in the diagonal direction of the inner surface of the face portion exceeds 17 mm, sufficient arch effect is obtained, so that the thickness of the face center portion can be thinned, but the predetermined mechanical strength is maintained. In order to achieve a certain thickness, it is impossible to reduce the weight of the glass panel.

In addition, as described above, when the total thickness of the glass panel is reduced by defining the fall of the face center portion and the effective screen end portion in the diagonal axis direction of the inner surface of the face portion in an appropriate range, the thickness of the face center portion becomes thin and there is a fear of X-ray leakage. If there is, the X-ray absorption coefficient of the glass panel is A? 1750 t / D, so that the predetermined X-ray absorption performance can be satisfied. At A <1750t / D, there is a concern that the glass panel may not satisfy the criteria for the X-ray leakage amount (36 dB / kg) determined by the EIAJ standard (ED2113A).

(Example)

Hereinafter, the Example of the glass panel for cathode ray tubes which concerns on this invention is described based on FIG.

As shown in FIG. 1, the cathode ray tube glass panel 1 includes a substantially rectangular face portion 12 on which an image is displayed, and a skirt portion 16 connected through the face portion 12 and the blend egg portion 15. Equipped. The effective screen diameter in the diagonal direction of the face portion 12 is D, the average curvature radius of the outer surface of the face portion 12 is R, and the free fall of the face center portion 13 and the effective screen end of the inner surface of the face portion 12 is determined. It is represented by H.

FIG. 2 shows a predetermined mechanical strength, that is, 0.34 MPa in a glass panel having an effective screen diameter (D) of 760 mm and an average curvature radius (R) of 100000 mm in any of the diagonal, long and short axes of the outer surface of the face portion. Figure 5 shows the relationship between the thickness of the face center and the weight of the glass panel when various drops (H) for maintaining the atmospheric pressure strength for 5 minutes were varied.

In FIG. 2, the sample of the Example which concerns on this invention was shown by O, the sample of the prior example was shown by (triangle | delta), and the sample of the comparative example which made the free fall (H) extremely large was shown by (square). By making the values of each sample similar in the polynomial, the weight of the glass panel was minimized to 25.0 kg at H = 11.2 mm. In addition, when H becomes 17 mm or more, as shown by (square) which is a sample of a comparative example, weight reduction cannot be carried out compared with the example shown by (triangle | delta) which is a sample of a prior art example.

In addition, a 13.1 mm glass panel having the thinnest face center portion of the sample of Example was made of glass having an X-ray absorption coefficient of 30.8 cm ^-1 at a wavelength of 0.06 nm to form a cathode ray tube, and then a tube voltage of 37.5 kV was obtained. When loaded, the X-ray leakage amount was 12 kW / kg, and the above-mentioned 36 kW / kg standard could be sufficiently satisfied. If A is obtained from t and D of this glass panel, it can be seen that A≥1750t / D = 30.2.

Thus, as a comparative example, when the same-shaped glass panel was made of glass having an X-ray absorption coefficient of 28.5 cm ^-1 at a wavelength of 0.06 nm to form a cathode ray tube, when the tube voltage of 37.5 kV was loaded, the X-ray leakage amount was 244. It became dl / kg and could not satisfy the above-mentioned criterion of 36 dl / kg.

Fig. 3 shows a predetermined mechanical strength, i.e., 0.34, for a glass panel having an effective screen diameter D of 860 mm and an average curvature radius R of 100000 mm in any of the diagonal, long and short axes of the outer surface of the face portion. The figure which shows the relationship between the thickness of a face center part, and the weight of a glass panel at the time of variously changing the fall (H) for maintaining atmospheric pressure intensity for 5 minutes in MPa.

In FIG. 3, the sample of the Example concerning this invention was shown by O, the sample of the example was represented by (triangle | delta), and the sample of the comparative example which made the free fall (H) extremely large was shown by (square). By making the values of each sample similar in the polynomial, the weight of the glass panel was minimized to 35.8 kg at H = 10.1 mm. When H becomes 17 mm or more, it becomes impossible to reduce weight compared with the example shown by (triangle | delta) which is a sample of a typical example, as shown by (square) which is a sample of a comparative example.

Also, among the samples of the examples, the thinner 15.3 mm glass panel having the thinnest thickness of the face center portion was made of glass having an X-ray absorption coefficient of 32.1 cm ^-1 at a wavelength of 0.06 nm to form a cathode ray tube, and then a tube voltage of 38.0 kV was obtained. When loading, the X-ray leakage amount was 7 kV / kg, and the above-mentioned 36 kW / kg standard was sufficiently satisfied. When A is obtained from t and D of this glass panel, it can be seen that A≥1750t / D = 31.1.

Thus, as a comparative example, after the same-shaped glass panel was made of glass having an X-ray absorption coefficient of 28.5 cm ^-1 at a wavelength of 0.06 nm to form a cathode ray tube, when the tube voltage of 37.5 kV was loaded, the X-ray leakage amount was 1687. It became dl / kg and could not satisfy the above-mentioned criterion of 36 dl / kg.

FIG. 4 shows that the effective screen diameter is 660 mm, and the average curvature radius R is 100000 mm in any of the diagonal, long and short axes of the outer surface of the face portion, and has a predetermined mechanical strength, that is, 5 minutes at 0.34 MPa. The figure which shows the relationship between the thickness of a face center part, and the weight of a glass panel in the case of varying the fall (H) for maintaining the atmospheric pressure strength of this.

In FIG. 4, the sample of the Example which concerns on this invention was shown by O, the sample of the prior art was shown by (triangle | delta), and the sample of the comparative example which made the free fall (H) extremely large was shown by (square). By similarizing the values of each sample in the polynomial, the weight of the glass panel was minimized to 14.8 kg at H = 11.1 mm. In addition, when H becomes 17 mm or more, as shown by (square) which is a sample of a comparative example, weight reduction cannot be carried out compared with the example shown by (triangle | delta) which is a sample of a prior art example.

Also, among the samples of the examples, a 13.2 mm thin glass panel having the thinnest thickness of the face center portion was made of glass having an X-ray absorption coefficient of 35.0 cm ^-1 at a wavelength of 0.06 nm to form a cathode ray tube, and then a tube voltage of 37.0 kV. When X was loaded, the X-ray leakage amount was 16 kV / kg, and the above-mentioned 36 kW / kg standard was sufficiently satisfied. When A is obtained from t and D of this glass panel, it can be seen that A≥1750t / D = 35.0.

Thus, as a comparative example, after the same-shaped glass panel was made of glass having an X-ray absorption coefficient of 29.5 cm ^-1 at a wavelength of 0.06 nm to form a cathode ray tube, when the tube voltage of 37.0 kV was loaded, the X-ray leakage amount was 42668. It became dl / kg and could not satisfy the above-mentioned criterion of 36 dl / kg.

2 to 4, numerals inserted in the figure indicate the thickness of the face center portion. In all the embodiments, the ratio of the average radius of curvature in the diagonal, long and short axes of the inner surface of the face portion is in the range of about (11 to 13) :( 12 to 14): 3. In addition, it is preferable to form the curved surface from the face center portion to the effective screen end portion in the inner surface of the glass panel so as to be as smooth as possible in one or two R's.

According to the glass panel for a cathode ray tube of this invention, since the fall of the face center part and the effective screen end part in the diagonal axis direction of the inner surface of a face part was prescribed | regulated to the suitable range of 9 mm-17 mm, predetermined mechanical strength as a glass panel is hold | maintained. In addition, it exhibits the excellent effect which can implement | achieve the weight reduction of a glass panel. In addition, since the X-ray absorption coefficient of the glass panel is defined in an appropriate range on the basis of the shape of the light-weight glass panel, a safe glass panel can be realized without fear of X-ray leakage from a thin part.

Claims (2)

A face portion on which an image is displayed, a skirt portion connected through the face portion and the blend egg portion, the effective screen diameter in the diagonal direction of the face portion is at least 500 mm, and the average radius of curvature of the inner face portion of the face portion In the glass panel for cathode ray tube, which is 10,000mm or larger in total radial direction, The drop of the face center in the diagonal direction of the inner face of the face portion and the end of the effective screen is in the range of 9mm to 17mm, the glass panel for cathode ray tubes. The method of claim 1, When the effective screen diameter in the diagonal axis direction of the face portion is D (mm) and the thickness of the face center portion is t (mm), the X-ray absorption coefficient A (cm ^-1 ) at a wavelength of 0.06 nm is A≥. Glass panel for cathode ray tube, characterized in that 1750t / D.

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