JPS58198829A - Color cathode-ray tube - Google Patents

Abstract

PURPOSE:To obtain high positional accuracy when each of target electrodes is assembled, by arranging an annular permanent magnet that is magnetized so as to concentrate side beams, on the inner wall at the side of a phosphor screen from the lens electric field formation region of the target electrodes to which high voltage is applied. CONSTITUTION:A cylindrical body 53 is provided integratedly along the side of the phosphor screen of a partition wall 52 provided inside a target electrode 5 and an annular permanent magnet 6 is mounted on the inner wall of the aperture end at the side of the phosphor screen of this cylindrical body 53 so as to simultaneously enclose the peripheral section of three electron beams 9a to 9c. This annular permanent magnet is provided with magnetic poles 10a to 10c, 11a to 11c, 12a to 12c, and 13a to 13c whose specified polarity is magnetized on the vertical line and at the position of 45 degrees from the vertical line on a circumference around the central position of each of the side beams 9a and 9c. For magnetic poles 10 and 12 out of these magnetic poles, the inside of the permanent magnet 6 and the outside are magnetized to poles S and N, respectively. On the other hand, for magnetic poles 11 and 13, the inside and the outside are magnetized to poles N and S, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shadow mask type color cathode ray tube equipped with an in-line type electron gun.

This type of color cathode ray tube requires a technology to concentrate multiple (usually three) mutually off-axis electron beams generated from each cathode arranged in-line to a single point on the fluorescent surface. . Conventionally, such techniques include a method in which the paths of the electron beams are inclined to each other from the beginning, or a method in which the electron beams are initially emitted parallel to each other and are deflected and concentrated by an asymmetric electric field during the traveling path.

However, in the former method, it is difficult to assemble each cathode with precision, and in the latter case, the electrodes have electron beam transmission holes offset from each other to generate an asymmetric electric field. It is difficult to maintain assembly accuracy.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to provide a color cathode ray tube equipped with an electron beam concentration mechanism capable of obtaining high positional accuracy when assembling each electrode. There is a thing called K.

In order to achieve such an object, the color cathode ray tube according to the present invention has an annular structure magnetized to concentrate a side beam on the inner wall of the target electrode on the phosphor surface side of the lens electric field forming region to which a high voltage is applied. permanent magnets are arranged. Hereinafter, the color cathode ray tube of the present invention will be explained in detail using Examples.

FIG. 1 is a block diagram showing an electron gun assembly in an embodiment of a color cathode ray tube according to the present invention. In the same figure, three cathodes 1a * 1b arranged inline
Control electrodes 2 and 3, a focus electrode 4, and a target electrode 5 are sequentially arranged from r 1 c toward a fluorescent light surface (not shown). Each electrode is coaxially provided with electron beam passing holes arranged in-line corresponding to the cathodes 1a, 1b, 1a, respectively. The target electrode 5 has a bottom surface 51 that is convex toward the cathode side, and the bottom surface 51 is disposed opposite to the zenith surface 41 of the focus electrode 4 that is convex toward the fluorescent surface side. A high voltage is applied to the target electrode 5, and the corresponding electron beam passing holes 51a and 41 on the bottom surface 51 and the zenith surface 41 are
A main lens electric field is formed between a, 51b and 41b, and 51c and 41c. ! ,Target electrode 5
A partition wall 52 is provided inside the partition wall 52, and the partition wall 52 has electron beam passing holes 51a, 51 facing the bottom surface 51.
b.

Electron beam passing holes 52a and 52b are coaxial with 51c.
* 52c are provided respectively. Furthermore, a cylindrical body 53 is integrally provided extending to the luminescent surface side of the partition wall 52, and on the inner wall of the open end of the cylindrical body 53 on the luminescent surface side, there are three tubes as shown in the plan view in FIG. electron beams 9a+9b, 9
An annular permanent magnet 6 is attached so as to simultaneously surround the periphery of c. As shown in the same figure, the annular permanent magnet 6 is placed at a predetermined position on a vertical line and at a position of 45° from the vertical line on the circumference centered on the center position of each side and one arm 9a, 9e. Magnetic pole 1 with magnetized polarity
0a, 10b +10c 1 magnetic pole 11a * 11b
+110% magnetic poles 12a * 12b + 12C1 magnetic poles 13a, 13b, 13c are provided, and among these magnetic poles, magnetic poles 10a * 10b + 10c and magnetic poles 3- 12a, 12b, 12c are such that the inside of the annular permanent magnet 6 is the S pole. , the polarity is magnetized so that the outer side is the N pole, while the magnetic poles 11a + 11b + 11c and the magnetic poles 13a, 13b.

13c is polarized so that the inside of the annular permanent magnet 8 is the north pole and the outside is the south pole. In addition, the strength of these magnetizations is as follows for magnetic poles 10b, llb, 12b, 13
b are all the same, and the magnetic poles 10a, 10c,
11a, 11c.

12m + 12c + 13a * 13e are the magnetic poles 10b and 11b.

The magnetization is adjusted to be 1.4 times lower than that of 12b and 13b.

In a color cathode ray tube equipped with an electron gun structure having the above configuration, electron beams 9a, 9b, 9c emitted from each cathode 1a, 1b, 1o are transmitted to the control electrode 2.3, focus electrode 4, and target electrode 5. In the process of passing through each electron beam passage hole, the electron beam is converged and accelerated and reaches an optical surface (not shown). In this case, all the corresponding electron beam passing holes are arranged coaxially, so each cathode 1
The electron beams 9a, 9b+9c emitted from aa1b=1c proceed while maintaining a parallel state, and pass through the electron beam passage hole 81a r 51b + of the target electrode 5 at the final stage.
After passing through 51c, it proceeds in a uniform electric field. When passing through the inside of the annular permanent magnet 6 attached to the terminal end, it is affected by the magnetic field 14 generated by the permanent magnet 6, as shown in FIG. Electron beams 9 a r 9 e on both sides are deflected in the direction of the central axis 2 . In this case, the magnetic fields 14 acting on both side beams 9a and 9e have substantially uniform intensities and are in opposite directions, and the magnetic field 14 does not act on the center beam 9b, so that the beam shape is In-line 3 electron beams 9a+9b without causing any deformation.
, 9e can be obtained.

As explained above, according to the color cathode ray tube of the present invention, the side beam is magnetized so as to concentrate on the fluorescent surface side of the lens electric field forming region of the target electrode, which is the final focusing and accelerating electrode to which a high voltage is applied. By providing the annular permanent magnet, the electron beam can be deflected by magnetic fields in mutually opposite directions formed by the permanent magnet, so that a control electrode and a focus electrode corresponding to each cathode.

It becomes possible to arrange each electron beam passing hole of the target electrode coaxially. Therefore, an excellent effect can be obtained in that the positional accuracy of each electrode and cathode during assembly is improved.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing the electron gun structure of an embodiment of the color cathode ray tube according to the present invention on a plane parallel to the tube axis, and FIG. 2 shows the permanent magnet part of the electron gun structure of FIG. 1 perpendicular to the tube axis. FIG. 3 is a diagram showing the action of the permanent magnet shown in FIG. 2, as viewed from the same direction. 1a+1b11c fist...cathode, 4...fist/focus electrode, 4111 fist@@zenith surface, 41a, 41
b. 41c ---Electron beam passage hole, 5-hole fist target electrode, 51.Φ.. Bottom surface, 51a, 51.b. 51Q11ell・Electron beam passing hole, 521T...
Partition wall, 52tL, 52b, 52c...Electron beam passage hole, 11 53...Cylinder, 6 fists...Permanent magnet, 9a. 9b, 9c@+1@・Electron beam, IQa r 10b
r 10c+11a t 11b, 11c,
12a, 12b 112e r 13a + 13
b+13c...magnetic pole, 14...sound/magnetic field.

Claims (1)

[Claims] a focus electrode having a plurality of electron beam passing holes arranged in-line and having a convex zenith surface on the light surface side;
a cup-shaped target electrode having a plurality of electron beam passing holes corresponding to each of the electron beam passing holes of the focus electrode, having a convex bottom surface on the cathode side, and being located on the phosphor surface side of the focus electrode; A color cathode ray tube is provided with an electron gun structure that applies a high voltage to the target electrode and that has its bottom surface facing the zenith surface of the focus electrode to form a lens electric field therebetween. The inner wall of the electrode on the fluorescent surface side is magnetized in at least four locations symmetrically with respect to the vertical and horizontal lines passing through the tube axis, and the direction of magnetization is substantially in the vertical direction, opposite to each other, at the side beam position. A color cathode ray tube characterized in that it is provided with an annular permanent magnet that generates a magnetic field and has a substantially zero magnetic field at the central beam position.