KR20000026249A - Convergence purity magnet assembly and cathode ray tube using thereof - Google Patents

Abstract

PURPOSE: A convergence purity magnet assembly and a cathode ray tube using thereof are provided to converge a minimum amount of adjustment converge to 0 by spreading the range of purity adjustment of an electron beam and the range of adjustment of a static convergence. CONSTITUTION: A convergence purity magnet assembly(20) comprises a magnet placement part(21a,22a) where magnets are placed with a fixed interval and at least a pair of rings(21,22) installed in a neck part of a cathode ray tube. The direction of magnetization of the magnet placement part is sloped at a fixed angle toward the center of the ring. A cathode ray tube comprises a panel having a fluorescent film, a funnel having the neck part, and a convergence purity magnet which has at least a pair of rings and whose magnetization direction is sloped toward the center of the ring.

Description

Convergence Purity Magnet Assembly and Cathode Ray Tube Using the Same

The present invention relates to an inline type cathode ray tube, and more particularly, to a convergence purity magnet assembly and a cathode ray tube using the same installed in a neck portion of a cathode ray tube to adjust a movement path of an electron beam.

In general, in an inline cathode ray tube with an electron gun, the axes of the three electron guns are arranged on the same plane including the axis of the water tube and the paths of the outer two electron beams are symmetrical with respect to the central electron beam path. Therefore, it is advantageous to construct the electron gun assembly of the color cathode ray tube which makes the electron beam radiated from each electron gun gather in the center of the fluorescent surface located in front of the electron gun assembly in the undeflected state by the deflection means, thereby producing a clean image.

However, due to an error occurring in manufacturing a part of the cathode ray tube or a tolerance of the component size, the cathode ray tube has a practical difficulty in satisfying the above ideal conditions.

For this reason, cathode ray tubes have a slight dispersion in their properties. Therefore, it is necessary to provide a suitable means for correcting the dispersion in the nature of such cathode ray tubes. As is well known, such properties can be adjusted by modifying the trajectory of the electron beam. The orbital correction of the electron beam can be adjusted by a magnetic field. A magnetic field for adjusting the trajectory of the electron beam has been used for color adjustment as well as for static convergence adjustment of the electron beam.

For example, color purity can be achieved by installing a two-pole magnet assembly containing two overlapping ring-shaped two-pole permanent magnets on the outer circumferential surface of the neck of the cathode ray tube so as to surround the traveling path of three electron beams. It is adjusted by rotating the magnet relatively.

In addition, Static Convergence installs a four-pole magnet assembly containing two superimposed four-pole ring-shaped permanent magnets and a six-pole magnet assembly including two six-pole ring-shaped permanent magnets on the neck of the cathode ray tube to provide three electron beams. It can also be adjusted by enclosing the path of. This arrangement is disclosed in US Patent Application No. 217,757, filed by Radio Corporation (U.S.).

By adjusting the intensity of the magnetic field generated by each magnet of the purity magnet assembly, the electron beams from each electron gun are collected at the center of the fluorescent surface under the condition that they are not deflected. Regarding the amount of change in the electron beam on the fluorescent surface, it is necessary to adjust the intensity of the magnetic field of the magnet assembly within the range from the maximum change amount of the electron beam to the minimum change amount of the electron beam where the beam deviates from the ideal condition described above as much as possible. In more detail, when the cathode ray tube is ideally manufactured so that the electron beam is concentrated at the center of the fluorescent surface with high color purity, provision of a magnet assembly is unnecessary. Therefore, the magnet assembly must be manufactured so as not to affect the electron beam even when installed on the water pipe. In this case, the strength of the magnetic field generated by the magnet assembly does not need to be changed.

In order to change the strength of the magnetic field of the magnet assembly, it is common to construct a magnet assembly by superimposing two ring-shaped permanent magnets having the same polarity and the same magnetic flux density. The magnetic field strength of the magnet assembly is maximum when the polarities of the two permanent magnets are aligned in a row. On the other hand, the strength of the magnetic field of the magnet assembly is minimal when the two permanent magnets are rotated relatively at a predetermined angle, for example 180 °, 90 °, or 60 °.

1 shows an example of a magnet assembly of such a cathode ray tube.

This is because a plurality of rings 12 and 12 'magnetized by two or six poles of the N pole and the S pole at predetermined angular intervals are laminated on the outer circumferential surface of the housing 11 fitted in the neck portion of the cathode ray tube at predetermined intervals. It is installed if possible. These rings 12 and 12 'have different magnetization amounts located in front of each other. That is, in the case of a fixed fish, the magnetization of the two magnetic magnetic fields located at the entrance side of the electron beam is magnetized to be 10 to 30% higher than the strength of the magnetic magnetic fields located at the exit side.

As shown in FIG. 2, the magnetization amounts are different from each other, and thus the magnetic field is actually cut because the distance from the magnet ring to the electron gun is short. In particular, the magnetic field loss of the magnet assembly on the socket side occurs more than the screen side of the cathode ray tube due to the thickness of the compensator composed of a pair of magnet assemblies. In addition, since the ring of the magnet assembly has a predetermined thickness, even if it overlaps with the opposite poles, the influence of the magnetic field on the electron beam does not become zero.

Due to this effect, since the minimum amount of movement of the electron beam by the magnet assembly is 0.1 to 0.3 mm, it is difficult to adjust the amount of electron beam movement below this. In addition, the paired magnet ring has to be magnetized to different strengths, so the magnetization process is complicated, and the assembly process is also made in consideration of the strength of the magnetization.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and spreads a range of electron beam purity adjustment and static convergence adjustment so that a minimum adjustment amount can be converged to zero and a cathode ray using the same The purpose is to provide a coffin.

1 is an exploded perspective view illustrating a conventional convergence purity magnet assembly;

2 is a graph showing the magnetic field relationship between a magnetic field and an electron gun by a magnet ring

3 is an exploded perspective view illustrating a cathode ray tube employing a convergence purity magnet assembly according to the present invention;

4 is a view showing the visible magnetic field formed by the magnet ring according to the present invention.

<Brief description of symbols for the main parts of the drawings>

20; Magnet assembly

21,22; Magnet rings 21a, 22a; Magnet

In order to achieve the above object, the present invention provides a magnetron tube convergence purity magnet having a magnetized portion magnetized at a predetermined interval and having at least one pair of rings installed on the neck portion of the cathode ray tube. The magnetization direction is characterized by being inclined at a predetermined angle with respect to the center of the ring.

In the present invention, the inclination direction of each magnetizing part is made in the same direction.

The cathode ray tube of the present invention includes a panel having a fluorescent film, and a funnel sealed to the panel and having a neck portion, and having at least one pair of rings installed at the neck portion, and the magnetization direction of the ring is about the center of the ring. It is characterized by being provided with a convergence purity magnet with an inclined angle.

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

3 illustrates an embodiment of a cathode ray tube equipped with a convergence purity magnet assembly on the outer circumferential surface of the neck portion 31 to which an inline electron gun is sealed.

As shown, the magnet assembly 20 is installed in the neck portion 31 of the funnel 30 encapsulated with a panel (not shown) in which a fluorescent film is formed, and the plurality of magnet parts 21a spaced apart from each other at predetermined intervals ( It consists of at least one pair of magnet rings 21, 22 having 22a).

The pair of rings 21 and 22 are made of a ferrite core, barium ferrite, alnico and the like, and the magnetizing portions 21a and 22a are made of an N pole or an S pole, which are alternated with each other. The pair of magnet rings may have a magnet of 2 poles, 4 poles or 6 poles. The magnetized parts 21a and 22a formed of the pair of magnet rings are magnetized with the same magnetic strength, and the magnetizing parts 21a and 22a are fitted in the magnet ring 21 and 22a according to the characteristics of the present invention. It is a direction inclined at a predetermined angle with respect to the center of the side or the side of the magnet ring. The magnetizer direction of each magnetizing part with respect to the one magnet ring is made in the same angle and the same direction.

The magnetization of the magnet ring magnetizer as described above may be magnetized by maintaining the magnetization angle of the electromagnet for magnetization at a predetermined angle.

The convergence purity magnet assembly 20 of the cathode ray tube constructed as described above is mounted in the neck portion and is in a landing state of the electron beam that is deflected by the deflection yoke and landed on the fluorescent film, that is, of the electron beam landing on the fluorescent film pattern. By correcting the degree of misalignment, the central axis of the paired 2-pole, 4-pole, and 6-pole magnet rings do not face the center of the magnet rings 21, 22 in the magnetization direction of the magnetized portions 21a, 22b. Since it is inclined at a predetermined angle with respect to the side of the magnet ring, the center of the magnet field formed by the magnetizing portions 21a and 22a of each magnet ring is positioned on the tube axis of the cathode ray tube. More specifically, as shown in FIG. 4, the magnetized portions 21a and 22a of each magnet ring are inclined at a predetermined angle to both sides with respect to the tube axis center of the magnet ring, so that the N and S poles are alternated. The center (C) of the magnet field is located at one point of the cathode ray tube axis. Therefore, the magnet field formed by the two magnet rings 21 and 22 is symmetric about an axis (X axis) perpendicular to the tube axis between the paired magnet rings, and the magnetic field strength is the magnet ring 21 ( 22) is maximized at the center between them, and weakens further away in both directions of the tube axis (Z). As the intensity of the magnetic field moves away from the tube axis, the rate of decrease decreases more rapidly than that of the conventional magnet ring.

As described above, the magnet field formed by the magnetization state of the magnetized part is uniformly formed at the right and left, and the reduction ratio of the magnetic field is relatively large, so that the magnet field can be narrowed, so that the magnet field is formed by the final acceleration electrode or shield cup of the electron gun. Can be blocked to prevent asymmetry. Therefore, it is not necessary to increase the magnetizing strength of the magnetized portion of the magnet ring located on the electron gun side of the paired magnet rings as in the related art.

As described above, the convergence purity magnet assembly of the cathode ray tube according to the present invention is formed to be inclined at a predetermined angle with respect to the tube axis direction in the magnetization direction of the magnet part of the paired magnet ring, thereby reducing the minimum amount of electron beam movement of the magnet ring. It may be a week, and the production of a plurality of the same ring of the same pair of magnet rings to be assembled so that the direction of the magnetized part opposite to each other, it is possible to improve the productivity.

The magnet assembly for adjusting the movement path of the electron beam of the cathode ray tube of the present invention is not limited to the above-described embodiment and can be modified by those skilled in the art within the technical scope of the present invention.

Claims (5)

In the convergence purity magnet of a cathode ray tube having a magnetized portion magnetized at a predetermined interval and having at least one pair of rings installed on the neck portion of the cathode ray tube, Convergence purity magnet assembly of the cathode ray tube, characterized in that the magnetization direction of the magnetizing portion is inclined at a predetermined angle with respect to the center of the ring. 2. The convergence purity magnet assembly of a cathode ray tube according to claim 1, wherein each magnetizing portion of the paired magnet rings is symmetrical about an X axis perpendicular to the direction of the tube axis between the magnet rings. The convergence purity magnet assembly of a cathode ray tube according to claim 1 or 2, wherein the magnetization part magnetization strength of each magnet ring is magnetized to the same intensity. Convergence purity magnet assembly of the cathode ray tube, characterized in that the magnetization direction of each magnetizing portion with respect to the one magnet ring is the same direction A panel having a fluorescent film, and a funnel sealed to the panel and having a neck portion, the conveyor having at least one pair of rings installed in the neck portion and having a magnetization direction of the magnetized portion of the ring inclined at a predetermined angle with respect to the center of the ring. Cathode ray tube, characterized in that provided with the presence purity magnet.