MXPA99003546A - Catodi rays tube - Google Patents

Abstract

The present invention relates to a cathode ray tube which includes a rectangular panel in which a fluorescent screen is formed, a cylindrical neck in which an electron gun is disposed, and a funnel formed contiguous to the panel. The funnel includes a part of the cone whose inner surface has a circular section in the position adjacent to the neck. The circular section is deformed from the side of the neck to the panel side to have a non-circular section having a maximum diameter along a direction different from the horizontal and vertical axis, and distances from a funnel axis to the inner surface of the cone part are not linearly increased or decremented, and the vertical inner surface is convex to the funnel axis with the realization of the following condition, H / rd < 0.16 where rd represents a distance from the funnel axis to the interior surface of the funnel in the diagonal direction, and H represents a distance from a vertical line which connects the two adjacent splined points formed on the inner surface convex to the upper part of the funnel. the convex upper surface

Description

CATHODE RAYS TUBE DESCRIPTION OF THE INVENTION The present invention relates to a cathode ray tube (CRT) and more particularly, to a cathode ray tube capable of effectively deflecting electron beams and having increased resistance against internal stress. A CRT is a device for a display image on a screen by horizontally and vertically generated electromagnetic deflection electron beams generated from an electron gun and landing deflected electron beams on the fluorescent layers formed on the screen. The electromagnetic deflection of the electron beam is controlled by an electromagnetic deflection gasket that is mounted on an outer surface of a CRT funnel and forms magnetic fields vertically and horizontally. CRTs are generally used for color televisions (TVs), monitors and high definition televisions (HDTV). And with the increased use of CRTs, there is a need to reduce the length of the CRT to increase the brightness of the displayed image and to reduce the size of the final products, such as TVs, monitors and HDTVs. In a CRT with reduced length, the electron beams should be deflected with wider angles, and the electromagnetic deflection frequency and the current supply to the electromagnetic deflection joint should be increased for the deflections of wider angles of the electromagnetic beams. electrons Like the frequency of electromagnetic deflection and the increase of current, the magnetic field of electromagnetic deflection tends to escape to the outside of the cathode ray tube and to the increase of power consumption. For the reduction of the magnetic field leakage, a compression coil is generally mounted with the electromagnetic deflection joint. When, however, the compensation coil is used, the power consumption of the cathode ray tube is further increased. Alternatively, to reduce the consumption of electromagnetic deflection power and magnetic field leakage, it is conventionally preferable to reduce the diameter of the neck of the cathode ray tube and the outer diameter of the funnel near the side neck in which the electromagnetic deflection joint is mounted, so that the electromagnetic deflection field acts efficiently on the electron beams. When the diameter of the neck is simply reduced, there are disadvantages that the resolution of the image deteriorates due to the reduced diameter of the electron gun, and the outer electron beams are suitable for bombarding the inner wall of the funnel, and thus not they land properly on the fluorescent layer of the screen. To solve these problems, U.S. Patent No. 3,731,129 discloses a funnel having a wider peripheral portion sealed to the periphery of the panel, and an electromagnetic deflection portion whose cross-sectional configuration varies gradually from a substantially similar manner. to that of the rectangular image produced on the panel to a circular shape. Therefore, the horizontal and vertical coils of the electromagnetic deflection joint are placed closely to the passage of the electron beams, and they deflect the electron beams with the power of reduced electromagnetic deflection and without the electron beams bombarding the inner wall of the funnel. However, in US Pat. No. 3,731,129, the configuration of the interior surface of the funnel was not considered in designating the funnel having the rectangular cross section. Therefore, the electron beams are not effectively deflected, and the funnel resistance against external pressure is not satisfactory. To overcome the deficiency, Japanese Patent Laid-Open 10-154472 describes the funnel of a cathode ray tube having a cross-section shown in Figure 8. As shown in Figure 8, the funnel seal part 22 having a maximum diameter along a direction different from the horizontal axis (X) and the vertical axis (Y), for example, a rectangular section. In Figure 8, the Pi (?) Represents a point at which the inner surface of the joint part 22 and a drawn longitudinal line meet from the tube axis at an angle?. The Piv (?) And Pih (?) Represent distances from the point Pi (?) To the horizontal axis (X) and the vertical axis (Y), respectively. As shown in Figure 8, the inner surface of the joint part 22 is designated such that the Piv (?) And Pih (?) Are functions of? that do not increase or decrease linearly. Therefore, the Piv (?) And Pih (?) Change with at least one maximum value, and therefore the inner surface of the joint part 22 can be convex to the tube axis. However, Japanese Patent Laid-Open No. 10-154472 designates the inner surface of the yoke without considering the resistance to the cathode ray tube against external pressure and the path of the electron beams. Therefore, it is required to develop the optimal configuration of the inner surface to increase the resistance of the cathode ray tube and the effective electromagnetic deflection of the electron beams.

The present invention is directed to a cathode ray tube which substantially demonstrates the limitations and disadvantages of the related art. An object of the present invention is to provide a cathode ray tube capable of effectively deflecting electron beams, and thereby reducing the power consumption of electromagnetic deflection and having increased resistance against external voltage. Another object of the present invention is to provide a cathode ray tube particularly suitable for the flat panel cathode ray tube. To realize these and other advantages, the cathode ray tube according to the present invention is comprised of a rectangular panel in which a fluorescent screen is formed, a cylindrical neck in which an electron gun is arranged, and a funnel formed adjoining the panel. The funnel includes a cone portion whose inner surface has a circular section in the position adjacent to the neck. The circular section is changed from the side of the neck to the side of the panel to have a non-circular section having a maximum diameter along a direction different from the horizontal and vertical axis, and the perpendicular distances from a funnel axis to the surface The interior of the cone part are not uniformly or linearly increased or decremented, and the vertical inner surface is convex to the funnel axis meeting the following condition. ? H / rd < 0.16 where rd represents a distance from the funnel axis to the interior surface of the funnel in the diagonal direction and HH represents a distance from a vertical line which connects the two adjacent cornered points formed on the inner surface convex to the upper part of the funnel. the internal part convex. In addition, the horizontal interior surface can be convexed to the funnel axis with the realization of the following condition,? V / rd < 0.34 where? V represents a distance from a horizontal line which connects the two adjacent splined points formed to the inner surface convexed to the upper part of the convex inner surface. The objects and other advantages of the invention must be realized and achieved by the structure particularly indicated in the written description and claims as well as the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate a particular embodiment of the invention and, together with the description, serve to explain the principles of the invention. In the drawings: Figure 1 is a perspective view of a cathode ray tube according to an embodiment of the present invention; Figure 2 is a sectional view of a cathode ray tube according to an embodiment of the present invention, taken along the diagonal line of a cathode ray tube panel; Figure 3 is a sectional view of a cathode ray tube according to an embodiment of the present invention, taken along line A-A of Figure 1; Figure 4 is a sectional view of a cathode ray tube according to another embodiment of the present invention; Figure 5 is a sectional view of a cathode ray tube according to another embodiment of the present invention; Figures 6 and 7 are graphs showing the relationships between the tensile strengths and the interior surface configurations of the cathode ray tube according to the embodiments of the present invention; and Figure 8 is a partial sectional view of a conventional funnel seal portion taken along the vertical line of the tube axis. The description should now be made in detail as the preferred embodiments of the present invention with the accompanying drawings. As shown in Figures 1 and 2, a cathode ray tube is formed with a rectangular panel 3 substantially, a funnel 5 formed contiguous to the panel 3 and a cylindrical neck 11 formed adjacent the end portion of the small diameter of the funnel 5. A fluorescent screen 1 is formed on the surface Inside the panel 3 and an electromagnetic deflection joint 7 is mounted on a part of the cone 5a of the funnel 5. An assembly of the electron gun 9 for emitting three electron beams are arranged on the neck 11. The three electron beams emitted from the electron gun assembly 9 are deflected by the horizontal and vertical electromagnetic deflection fields generated by the electromagnetic deflection gasket 7 to the vertical and horizontal directions of the panel 3, respectively. The deflected electron beams reach the fluorescent screen 1 through a shadow mask 13 mounted on the inner surface of the panel 3, and cause the fluorescence to emit colored light.

To reduce the power consumption of electromagnetic deflection and increase the resistance of the cathode ray tube against external voltage, the cathode ray tube is formed as follows. The outer surface of the cone portion 5a has a circular cross-section at the position near the neck 11, and the circular section is gradually deformed from the side of the neck to the side of the panel to have a non-circular section having a maximum diameter at along a direction other than the vertical and horizontal axis, for example, a rectangular section. In this manner, a sectional view of the cathode ray tube taken along line AA of Figure 1 is shown as Figure 3, and the section of the cone portion 5a from a reference line (R / L ) to an outer portion of the cone portion 5a also has a rectangular shape substantially as shown in Figure 3. The reference line (R / L) is defined by the elongation of the trajectories of the external electron beams which they escape from the effect of the electromagnetic deflection joint 7, and by calculating the transverse point of the elongated trajectories. In this way, the reference line is formed in the middle and central portion of the cone portion 5a. The inner surface of the cone portion 5a also has a circular section in the position close to the neck 11, and the circular section is gradually changed from the neck side to the panel side to have a non-circular section having a maximum diameter at along a direction different from the horizontal and vertical axis. And the distances from the tube axis to the inner surface of the cone portion 51 are not linearly increased or decremented. The vertical inner surface is convex to the tube axis with the realization of the following condition. ? H / rd < 0.16 where rd represents a distance from the tube axis (Z) to the interior surface of the funnel to the diagonal direction, and? H represents a distance from a vertical line Lv connecting the two adjacent points formed to the inner surface convex to the upper part of the convex inner surface. The configuration of the inner surface of the present invention is determined and optimized to increase the strength of the CRT, the beam shadow neck (BSN) characteristic of the electron beams, and to decrease the electromagnetic deflection power. Therefore, the electromagnetic deflection power is reduced by changing the shape of the cone portion 5a, the maximized cathode ray tube resistance by optimally convexing the inner surface of the cone portion 5a.

The inner surface of the cone portion 5a is preferably formed such that the value? H / rd gradually increases as rd increases. Mainly,? H / rd preferably has the minimum value on the neck side, and they have the maximum value at the position which is closest to the panel. More preferably, the value? H / rd gradually increases with the largest slope after the reference line than before the reference line, and the inner surface of the cone part are symmetrically convexed along a line by which? H is defined. The configuration of the inner surface can also be formed on the horizontal surface as shown in Figure 4, and preferably it can be formed on both horizontal and vertical surfaces as shown in FIG.

Figure 5. As shown in Figure 4, the outer surface of the cone portion 5a has a circular section in the near position of the neck 11, and the circular section is gradually deformed from the neck side to the panel side to have a non-circular section, and the horizontal inner surface is convex with the realization of the following condition. ? H / rd < 0.34 where rd represents a distance from the axis of had (Z) to the interior surface of the funnel in the diagonal direction, and? V represents a minimum distance from a horizontal line Lh which connects the two adjacent splined points formed to the inner surface convex to the upper part of the convex inner surface. More preferably, the horizontal and vertical interior surfaces of the cone portion 5a are both convex with the embodiment of the conditions described in the foregoing. With this configuration, the electromagnetic deflection power is reduced more effectively, and increases the resistance of the cathode ray tube. The tensile strengths in the cathode ray tube are tested with the variation of? H / rd and? V / rd, and the tested results are shown in the following tables 1 and 2.

[Table 1] [Table 2] Figures 6 and 7 are graphs showing the relationship between the tensile strength and the interior surface configurations of the cathode ray tube according to the test results in Table 1 and 2. Lines A and B in the Figures 6 and 7 represent the optimal values of? H / rd and? V / rd in which the electron beams do not bombard the inner surface of the cone portion 5a, and the resistance of the mated cathode ray tube. By the configuration of the inner surface of the cone part according to the present invention, the resistance of the cathode ray tube increases. In this way, the amplitude of the glass cone portion 5a can be reduced to be smaller, as shown in the dotted lines in Figures 3, 4 and 5. The concept of the present invention can be applied for cone parts having sections of various polygonal shapes, and it should be apparent to those skilled in the art that various modifications and variations may be made in the present invention without departing from the spirit and scope of the invention. This application is based on application No. 98-38812 filed with the Korean Industrial Property Office on September 19, 1998, the content of which is incorporated herein by reference.

Claims (9)

1. CLAIMS 1. A cathode ray tube characterized in that it comprises: a rectangular panel in which a fluorescent screen is formed; a cylindrical neck in which an electron gun is arranged; and a funnel formed contiguous to the panel, wherein the funnel includes a cone portion whose inner surface has a circular section in the position adjacent to the neck, and the circular section is deformed from the neck side to the panel side to have a section not circular having a maximum diameter along a direction other than the horizontal and vertical axis, and the distances from a funnel axis to the inner surface of the cone part are not linearly increased or decremented, and the vertical inner surface is convexed to the funnel axis with the realization of the following condition. ? H / rd < 0.16 where rd represents a distance from the funnel axis to the interior surface of the funnel in the diagonal direction, and? H represents a distance from the vertical line which connects the two adjacent splined points formed to the convex inner surface at the top of the inner surface convexed to the upper part of the convex inner surface.
2. 2. The cathode ray tube according to claim 1, characterized in that? H / rd increases when the rd is increased.
3. 3. The cathode ray tube according to claim 1, characterized in that the inner surface of the cone part is symmetrically convexed along a line by means of which? H is defined.
4. 4. The cathode ray tube characterized in that it comprises: a rectangular panel in which a fluorescent screen is formed; a cylindrical neck in which an electron gun is arranged; and a funnel formed contiguous to the panel, wherein the funnel includes a cone portion whose inner surface has a circular section in the position adjacent to the neck, and the circular section is deformed from the neck side to the panel side to have a section not circular having a maximum diameter along a direction other than the horizontal and vertical axis, and the distances from a neck axis to the inner surface of the cone part are not linearly increased or decreased, and the horizontal inner surface is convexed to the funnel axis with the realization of the following condition,? V / rd < 0.34 where rd represents a distance from the funnel axis to the interior surface of the funnel in the diagonal direction, and? V represents a distance from a horizontal line connecting the two adjacent splined points formed on the convex inner surface of the upper part of the funnel. the convex inner surface.
5. 5. The cathode ray tube according to claim 4, characterized in that? V / rd is increased when the rd is increased.
6. The cathode ray tube according to claim 4, characterized in that the inner surface of the cone part is symmetrically convexed along a line by which? V is defined.
7. 7. A cathode ray tube characterized in that it comprises: a rectangular panel in which a fluorescent screen is formed; a cylindrical neck in which an electron gun is arranged; and a funnel formed contiguous to the panel, wherein the funnel includes a cone portion whose inner surface has a circular section in the position adjacent to the neck, and the circular section that is deformed from the neck side to the panel side to have a non-circular section that has a maximum diameter along a direction different from the horizontal and vertical axis, and the distances from a funnel axis to the inner surface of the cone part are not linearly increased or decremented, and the vertical inner surface is convexed to the funnel axis with the realization of the following condition,? H / rd <; 0.16 where rd represents a distance from the funnel axis to the interior surface of the funnel in the diagonal direction, and? H represents a distance from a vertical line connecting the two adjacent splined points formed to the inner surface convex to the upper part of the funnel. the convex inner surface and the horizontal inner surface is convexed to the funnel axis with the realization of the following condition. ? V / rd < 0.34 where? V represents a distance from a horizontal line which connects the two adjacent splined points formed on the inner surface convexed to the upper part "of the convex inner surface
8. 8. The cathode ray tube according to claim 1, characterized because? H / rd and? V / rd increase when the rd is increased.
9. 9. The cathode ray tube according to claim 1, characterized in that the inner surfaces of the cone part are symmetrically convexed along the lines by means of which? H or? V are defined.