KR20000009617A - Shield piece for color crt - Google Patents

Abstract

PURPOSE: A shield piece for color CRT is provided to maintain the function of a CPM and shield the outside magnetic force due to a cathode supporter(105). CONSTITUTION: The present invention discloses a shield piece(106) for color CRT comprising: a panel consisting a display screen; a panel fused to the rear end of the panel to maintain the inside of a CRT in vacuum state; an electron gun(104) sealed to the neck(101) of the panel to radiate electron beam; a convergence purity magnet(102) fixed to the outer surface of the neck by a convergence purity magnet fixing holder for color purity and color agreement of the radiated electron beam; and a cylinder type shield having high permeability so as to minimize the influence of outside magnetic force due to the cathode supporter(105) and accelerating electrodes. The electron gun has a cathode and plural electrodes for controlling, accelerating and focusing thermions radiated from the cathode and the cathode is supported by a cathode supporter.

Description

Shield Specimen for Color Cathode Ray Tubes

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a convergence purity magnet (CPM) for color cathode ray tubes, and more particularly, to a structure of a CPM for maintaining the function of the CPM without affecting the magnetic flux of the CPM.

As shown in FIG. 1, a general color cathode ray tube is fused to a panel 2 coated with a fluorescent film 1 that realizes three colors and a rear end of the panel 2 to maintain the inside of the cathode ray tube in a vacuum state. A funnel (3), an electron gun (6) encapsulated in the neck portion (4) of the funnel (3), and radiates an electron beam (5), and an electron beam (5) emitted from the electron gun (6) to the front of the screen. A deflection yoke 7 for deflecting to an area, a shadow mask 8 having a color discriminating function of the electron beam 5, and a frame 9 for supporting the shadow mask 8 at an interval with an inner surface of the panel 2. It consists of.

At this time, a plurality of annular magnets 10 (convergence purity magnets) are mounted on the neck portion 4 of the color cathode ray tube for color purity and color matching of the three-color electron beams 5 emitted from the electron gun 6 as shown in FIG. 2. The three electron beams 5 emitted from the electron gun 6 are matched to the center of the screen, and these magnets consist of an annular magnet 10 of two poles 10a, four poles 10b, and six poles 10c. It is fixed to the neck portion 4 of the funnel 3 by a circular CPM fixing holder 11.

In addition, the shield specimen 12, which is a ferromagnetic material having high permeability, is attached to the CPM 10 in order to improve the shielding property against the external magnetic field around the neck portion 4, thereby minimizing the influence of the electron gun 6 on the external magnetic field. It could be.

When power is applied in the above configuration, the electron beam 5 is radiated from the electron gun 6, and the electron beam 5 is deflected to the entire screen area by the deflection yoke 7 and passes through the shadow mask 8. The image is reproduced by striking the fluorescent film 1 in the state of color selection.

In this process, the electron beam 5 is provided with a CPM 10 for matching the electron beam 5 to a specific point (center part of the screen) when the cathode ray tube is manufactured to achieve accurate landing or convergence. The action is as follows.

First, in the case of the two-pole magnet 10a, as shown in Fig. 3A, it is composed of two annular magnets magnetized at 180 ° intervals, and the red, green, and blue electron beams are directed in the same direction by the mutual effect of their magnetic fields. To adjust the color purity.

In the case of the 4-pole magnet 10b, as shown in FIG. 3 (b), it is composed of two annular magnets magnetized at 90 ° intervals, and the red and blue electron beams of the outer shell are moved in opposite directions by their mutual magnetic field effects. It is used to adjust convergence.

In the case of the 6-pole magnet 10c, as shown in Fig. 3 (c), it is composed of two magnets magnetized at 60 ° intervals, and converged by moving the red and blue electron beams in the same direction by the mutual magnetic field effect. It is used for adjustment.

In this case, the electron gun 6 is affected by an external magnetic field, because the negative electrode support 13 constituting the electron gun 6 uses a low-expansion magnetic material in consideration of thermal characteristics, and is fixed to solve this problem. In the three cathode ray tubes, a rod-shaped shield specimen 12 was prepared as a high permeability material and attached to each of the side portions of the neck portion 4 in the longitudinal direction of the electron gun 6.

However, the use of such shield specimens results in a deterioration of the convergence adjustment capability, which is the basic characteristic of CPM. This is because the material of the shield specimens constituting the CPM is a high permeability material. This is because the absorption amount of CPM has to be strengthened to compensate for this.

Thus, when the amount of magnetization of the CPM is increased, it is possible to improve the magnetic flux distribution as a side effect. As a result, there is a problem in that the convergence change is relatively large due to the deterioration of the CPM due to the convergence drift phenomenon.

The present invention has been proposed in view of such a point, and its purpose is to provide a shield specimen that can maintain the function of the CPM while shielding the external magnetic field caused by the cathode support.

In order to achieve the above object, the present invention uses a shield specimen made of a high permeability material to minimize the influence of an external magnetic field caused by a cathode support made of a low-expansion magnetic material. , 4 and 6-pole magnets are separated from a certain distance and at the same position as the cathode support.

1 is a block diagram of a general color cathode ray tube.

Figure 2 is a detailed view of the neck portion of a conventional color cathode ray tube,

(A) is a perspective view.

(B) section.

3 is an explanatory view of the operation of a general convergence purity magnet,

(A) is a 2-pole magnet.

(I) is 4-pole magnet.

(C) is 6-pole magnet.

4 is a configuration diagram of a convergence purity magnet for color cathode ray tubes according to the present invention;

(A) is a side cross-sectional view.

(B) is axial sectional view.

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

101: neck 102: convergence purity magnet

102a: 2-pole magnet 102b: 4-pole magnet

102c: 6-pole magnet 103: CPM fixed holder

104: electron gun 105: cathode support

106: Shield Specimen

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

4 is a configuration diagram of a convergence purity magnet for a color cathode ray tube according to the present invention, wherein the neck portion 101 of the cathode ray tube is composed of a 2-pole, 4-pole, and 6-pole magnet 102a, 102b, and 102c. The (CPM) 102 is fixed by the CPM fixing holder 103.

The CPM 102 is a periphery of the electron gun 104 in order to match the electron beam to any particular point (center of the screen) to which the electron beam is referenced during fabrication of the cathode ray tube so that the electron beam emitted from the electron gun 104 can achieve accurate landing or convergence. And the magnetic flux of each magnet 102a, 102b, 102c to adjust the color purity and convergence characteristics of the cathode ray tube to an optimal state.

At this time, between the CPM fixed holder 103 and the neck portion 101 is to place a shield specimen 106 for shielding the external magnetic field due to the cathode support 105, the shield specimen 106 is easy to assemble It was made in the cylindrical shape for the closest position to the cathode support 105, that is to be assembled in the lower portion of the CPM fixed holder 103.

The shield specimen 106 is a ferromagnetic material made of a high permeability material, the reason for placing the shield specimen 106 in the closest portion to the negative electrode support 105 as described above is due to the external magnetic field of the negative electrode support 105 which is a magnetic material. To minimize the impact.

At this time, when the shield specimen 106 and the 2, 4, 6 pole magnets 102a, 102b, 102c are close in position, the shield specimen 106 is a ferromagnetic material, so the 2, 4, 6 pole magnets 102a ( Because the magnetic flux of 102b) and 102c is affected and the performance of the CPM 102 is degraded, the distance between the shield specimen 106 and the 2, 4 and 6 pole magnets 102a, 102b and 102c is maintained at a constant distance. It is important that this problem is solved by assembling the shield specimen 106 in the lower portion of the CPM fixing holder 103.

That is, since the shield specimen 106 is located below the CPM fixed holder 103, the shield specimen 106 is spaced apart from the 2, 4, and 6 pole magnets 102a, 102b, and 102c in position. In this way, the magnetic flux of the two-, four-, and six-pole magnets 102a, 102b, and 102c is not affected, thereby preventing the CPM 102 from functioning down.

In addition, in the prior art, when designing the shield specimen 12, it was necessary to consider both minimizing the influence of an external magnetic field and appropriately distributing the functional degradation of the CPM 10, so that the width, length, Although there are many design limitations for the thickness, according to the present invention, since the shield specimen 106 and the CPM 102 are spaced apart from each other by a predetermined distance, the functional degradation of the CPM 102 can be excluded, so that the optimized design of the shield specimen 106 is achieved. There is also the advantage of being easier.

In another embodiment of the present invention, the CPM fixing holder 103 is formed of a ferromagnetic material having a permeability of about 900 to 1200, so that the CPM fixing holder 103 fixes the CPM 102 to the shield specimen 106. It can also be configured to act as a.

In this case, when the magnetic permeability is 900 or less, the external magnetic shielding property becomes weak, and when the magnetic permeability is 1200 or more, the magnetic flux of the CPM will be affected.

As described above, in the present invention, since the position of the shield specimen is close to the cathode support and is spaced apart from the CPM, the influence of the external magnetic field caused by the cathode support can be minimized, and the performance of the CPM can be maintained as it is. By configuring the shield specimen in a cylindrical shape, there is an effect that can be easily applied to the cathode ray tube of the conventional structure.

Claims (4)

A panel constituting the display screen, a funnel fused to the rear end of the panel to maintain the inside of the cathode ray tube in a vacuum state, an electron gun encapsulated in the neck portion of the funnel to emit an electron beam, color purity of the electron beam emitted from the electron gun, A convergence purity magnet fixed by a convergence purity magnet fixing holder is provided at an outer diameter of the neck portion for color matching. In the color cathode ray tube, the cathode is supported by a cathode support, In order to minimize the influence of the negative electrode support made of low-expansion magnetic material and the external magnetic field generated by the control and acceleration electrode parts, a substantially cylindrical shield means having a high permeability is spaced apart from the convergence purity magnet at a distance and close to the negative electrode support. Shield specimen for color cathode ray tube, characterized in that located in. The method of claim 1, The shield means is shielded specimen for color cathode ray tube, characterized in that inserted between the neck of the cathode ray tube and the fixing holder for fixing the convergence purity magnet. The method of claim 1, Shield specimen for color cathode ray tube, characterized in that the outer portion of the neck portion is provided with a convergence purity magnet fixing holder having a high permeability. The method according to claim 1 or 3, The convergence purity magnet fixed holder is a shield specimen for color cathode ray tube, characterized in that having a magnetic permeability range of 900 ~ 1200.