MXPA99003545A - Catodi rays tube - Google Patents

Abstract

The present invention relates to a cathode ray tube that includes a rectangular panel in which a fluorescent screen is formed, a neck in which an electron gun assembly emits three beams of electrons, is arranged, and a funnel formed adjacent to each other. of the neck and the panel, and having an electromagnetic deflection gasket that mounts the portion in which an electromagnetic deflection gasket is mounted. The cross section of the electromagnetic deflection joint mounting the portion realizes the following condition to the panel side end of the electromagnetic deflection joint mounting the portion. 1.0

Description

CATHODE RAY 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 reducing the power consumption of electromagnetic deflection. A CRT is a device for displaying an image on a screen by electron beams deflecting horizontally and vertically 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 mounted on an outer surface of a CRT funnel and which forms horizontal and vertical magnetic fields.

CRTs are generally used for color televisions (TVs), monitors and televisions of high definition (HDTV) and with the use increased of the CRT there is a need to reduce the length of the CRT to increase the brilliance and the display of image and to reduce the size of the final products, such as TVs, monitors and HDTVs. When reducing the length of the CRT, the electron beams must be deflected at wide angles, and the electromagnetic deflection frequency and the current supply to the electromagnetic deflection joint must be increased by wide-angle deflections of the electron beams. Like the electromagnetic deflection frequency and the current increase, the magnetic field of electromagnetic deflection tends to escape to the outside of the cathode ray tube and increase the power consumption. To reduce the electromagnetic deflection power and the magnetic field leak at the same time, 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 of the neck on which the deflection joint is mounted. electromagnetic, so that the field of electromagnetic deflection acts efficiently in the electron beams, however, when the diameter of the neck simply decreases, there are disadvantages that the resolution of the image deteriorates due to the reduced diameter of the electron gun , and external electron beams are suitable for bombarding the inner wall of the funnel, thus, the bombarded electron beams are not properly landed in the fluorescent layer of the screen. To solve these problems, US 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 rectangular shape substantially similar to that of the rectangular image produced in the panel to a circular shape. Therefore, the vertical and horizontal coils of the electromagnetic deflection joint are located closely to the passage of the electron beams, and they deflect the electron beams with reduced electromagnetic deflection power and without bombarding the electron beams to the inner wall of the electron beam. funnel. However, the funnel does not have sufficient strength to resist against external stress, such as pressure, so the funnel has to be designed to have a circular or rounded section. Meanwhile, Japanese Patent 7-30938388 which corresponds to US Pat. No. 5,763,995 discloses a funnel, whose cross section of the outer surface on the side of the neck is loaded from a circular shape to a non-circular shape, which It has a maximum diameter along the direction (diagonal direction) different from the horizontal direction and the vertical direction. In addition, the funnel is designed to meet the following condition. 0.3 < ? HV / L < 0.6 where L is a maximum diameter length, and? HV is a sum of? H and? V, and? H is a difference between L and a horizontal diameter of the funnel section, and? V is a difference between L and a vertical diameter of the funnel section. However, the funnel is defined or configured by three variables,? H,? V and L. Thus, for example, even when? H is set to a fixed value, two variables are not fixed or defined. As a result, it is difficult to designate the funnel having an optimal configuration and sufficient resistance against external stress. Meanwhile, Japanese Patent Laid-Open 10-149785 discloses a funnel whose cross-section of the outer surface is in a non-circular shape which has a maximum diameter along a direction (diagonal direction) different from the horizontal direction and the vertical direction. In addition, when the aspect ratio of a screen is M: N, the cross section of the funnel is designed to meet the following condition. (M + N) / (2 (M2 + N2) 1 2) < (SA + LA) / (2DA) < 0.86 where SA is a vertical diameter of an external surface of the funnel, and LA is a horizontal diameter of the external surface of the funnel, and DA is the maximum diameter of the external surface of the funnel. However, the funnel is also defined or configured by three variables, SA, LA and DA. In such a way, it is also difficult to designate the funnel that has the optimal configuration and sufficient resistance against external stress.

Accordingly, the present invention is directed to a cathode ray tube which evidences substantially one or more of the problems due to the limitations and disadvantages of the related art. An object of the present invention is to provide a cathode ray tube capable of minimizing the power consumption and preventing electromagnetic deflection magnetic fields from escaping to the outside of the cathode ray tube. Another object of the present invention is to provide a cathode ray tube which includes a funnel having an increased resistance against external stress. Furthermore, another object of the present invention is to provide a cathode ray tube suitable particularly for the flat panel cathode ray tube. To realize these and other advantages, the cathode ray tube includes a rectangular panel in which a fluorescent screen is formed, a neck in which an electron gun assembly is arranged to emit three electron beams, and a contiguous formed funnel both of the neck and the panel, and having a deflection joint that mounts the portion in which an electromagnetic deflection joint is mounted. The cross section of the electromagnetic deflection gasket that mounts the portion meets the following condition at the end of the panel side of the electromagnetic deflection gasket of the assembled portion. 1.0 < rh / rv < 1.3 where rh is a diameter of the funnel directed to a direction of an axis along the panel and rv is a diameter of the funnel directed to a direction of a short axis of the panel. The objects and other advantages of the invention must be realized and achieved by the structure indicated particularly in the written description and claims as well as the attached drawings. Also this is understood that both of the above general description and the following detailed description are exemplary and explanatory and are intended to provide additional explanation to the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide further understanding of the invention and are incorporated into 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 a diagonal line of a cathode ray tube panel; Figure 3 is a schematic diagram for illustrating the cross section of the funnel beside the neck according to an embodiment of the present invention; Figure 4 is a schematic diagram for illustrating the cross section of the funnel, taken along a position at which an electromagnetic deflection joint is mounted in accordance with an embodiment of the present invention; Figure 5 is a graph to illustrate the change of the rh / rv value according to the neck distance; Figure 6 is a graph to illustrate the relationship of bending power and the value rh / rv; and Figure 7 is a graph to illustrate the relationship of the magnetic field leak and the rh / rv value. The reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

As shown in Figures 1 and 2, a cathode ray tube is an emptied cover which is formed with a substantially rectangular panel 3, a funnel 7 formed contiguous to the panel 3, and a cylindrical neck 11 formed adjacent the end portion small diameter of the funnel 7. A fluorescent screen 1 is formed on the inner surface of the panel 3. An electromagnetic deflection joint 5 is mounted 'in the funnel 7 near the neck 11, and an assembly of the electron gun 9 to emit three Electron beams are arranged in the neck 11. The three electron beams emit from the electron gun assembly 9, are deflected by horizontal and vertical electromagnetic deflection fields generated by the electromagnetic deflection joint 5. The deflected electron beams reach the fluorescent screen 1 through a shadow mask 13 mounted on the inner surface of the panel 3, and displaying a color image. To effectively reduce the electromagnetic deflection power, the outer surface of the funnel 7, in which the electromagnetic deflection joint 5 is mounted, is designed to have a circular section to 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 along a diagonal direction different from the horizontal and vertical directions, for example, a rectangular section. In addition, the funnel 7 is designed so that the funnel cross-section 7 meets the following condition at the end of the panel side of the electromagnetic deflection joint 5. 1.0 < rh / rv < 1.3 where rh is a diameter of the funnel in the direction of the long axis (horizontal diameter), and rv is a funnel diameter in the direction of the short axis (vertical diameter). More preferably, the rh / rv value gradually decreases from the side of the panel to the side of the neck and sets to 1.0 at the position at which the funnel 7 connects to the neck 11. Figure 3 is a schematic diagram to illustrate the section cross section of the funnel 7 on the side of the neck. As shown in Figure 3, the diagonal diameter (rd) of the funnel directed to the direction of the diagonal axis (d) equal to the horizontal diameter (rh) of the funnel directed to the direction of the long axis (h) and the vertical diameter ( rv) of the funnel directed to the direction of the short axis (v). In this way, the cross section has a circular shape I Figure 4 is a schematic diagram for illustrating the cross section of the funnel 7 to which the electromagnetic deflection joint 5 is mounted. As shown in Figure 4, at the position in which assembles the electromagnetic deflection joint 5, the horizontal diameter (rh) and the vertical diameter (rv) decreases to be shorter than the diameter (rd). In this way, the cross section has a rectangular shape. The configuration of the funnel 7 of the present invention is derived by simulated tests to reduce the power of electromagnetic deflection and to increase the characteristic of BSN (neck striking the beam) of funnel 7 and the resistance against external pressure. More preferably, the funnel 7 is designed in such a way that the cross-section of the funnel 7 fulfills the following condition at the position of the reference line of electromagnetic deflection (R / L). 1.1 < rh / rv < 1.2 where rh is a diameter of the funnel in the direction of the long axis, and rv is a diameter of the funnel in the direction of the short axis. As shown in Figure 2, the reference line (R / L) is defined to lengthen the trajectories of the external electron beams which escape from the effect of the electromagnetic deflection joint 5, and by calculating the point that crosses the elongated trajectories. In this way, the reference line is formed in the middle and central portion of the electromagnetic deflection joint 5.

Figure 5 is a graph to illustrate an example of the funnel 7 according to the present invention, and shows the change of the rh / rv value of the funnel 7 along the axis of the tube of the funnel 7. The funnel 7 shows in the Figure 5, the rh / rv value in the reference line is 1.14 and the outer surface of the funnel 7 is convex to the tube axis before the reference line (R / L) and the outer surface is concave to the axis of the tube after the reference line (R / L), The Figure. 6 is a graph to illustrate the relationship of the electromagnetic deflection power and the rh / rv value. As shown in Figure 6, when the rh / rv value is between 1.0 and 1.3 the electromagnetic deflection power of cathode-ray tube gradually decreases. In addition, as shown in Figure 7, when the rh / rv value is less than 1.3, the magnetic field leak is maintained below a predetermined value (horizontal line in Figure 7). The present invention is particularly suitable for the electromagnetic deflection of the wide angle of the cathode ray tube in which the angle of electromagnetic deflection is 90 ° or 100 °. In detail, the rh / rv value is preferably maintained between 1.0 and 1.3 when the electromagnetic deflection angle is 90 °, and the rh / rv value is preferably maintained between 1.0 and 1.25 when the electromagnetic deflection angle is 100 °. To configure the shape of the funnel, according to the present invention, the cathode ray tube of the present invention has sufficient tension against external pressure and consumes less electromagnetic deflection power, and magnetic field leakage is prevented. It will 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. Thus, it is intended that the present invention cover modifications and variations of this invention with the proviso that it comes within the scope of the appended claims and their equivalents. This application is based on application No. 98-38811 filed with the Korean Industrial Property Office on September 19, 1998, the content of which is incorporated herein by reference.

Claims (1)

CLAIMS 1. A cathode ray tube characterized in that it comprises: a rectangular panel in which a fluorescent screen is formed; a neck in which an electron gun assembly is arranged to emit three electron beams; and a funnel formed contiguous to both of the neck and the panel, and having an electromagnetic deflection gasket that mounts the portion in which an electromagnetic deflection gasket is mounted, wherein a cross section of the electromagnetic deflection gasket assembles the The portion performs the following condition at the end of the panel side of the electromagnetic deflection gasket that mounts the portion. 1.0 < rh / rv < 1.3 where rh is a diameter of the funnel directed to the direction of a long axis of the panel, and rv is a diameter of the funnel directed to a direction of a short axis of the panel. 2. The cathode ray tube according to claim 1, characterized in that the rh / rv value decreases gradually from the panel side to the neck side. 3. The cathode ray tube according to claim 2, characterized in that the cross section of the funnel performs the following condition to the electromagnetic deflection reference line. 1.1 < rh / rv < 1.2 where rh is a diameter of the funnel directed to the direction of the long axis and rv is a diameter of the funnel directed to the direction of the short axis. 4. The cathode ray tube according to claim 1, characterized in that the cross section of the funnel performs the following condition to a reference line. 1.1 < rh / rv <

1.2 where rh is a diameter of the funnel directed to the direction of the long axis and rv is a diameter of the funnel directed to the direction of the short axis.