KR100342051B1 - Electron gun for cathode ray tube - Google Patents

Abstract

Disclosed is an electron gun for a cathode ray tube. The main lens part of the electron gun is formed in the form of an in-line type electrode having a small, green, blue independent electron beam through hole, and a large diameter electron beam through hole attached to the front surface of the electrode to reduce spherical aberration and its edges. Auxiliary electrode is attached to the upper surface of the electrode having a main body of a plate shape looped along.

Description

Electron gun for cathode ray tube

The present invention relates to an electron gun, and more particularly, to a cathode ray tube electron gun restructured to change the shape of the electron beam passing hole through which the red, green, and blue electron beams emitted from the cathode pass.

Typically, a cathode ray tube encloses an electron gun in the neck portion of the bulb and emits an electron beam from a powered electron gun. The emitted electron beam is selectively deflected according to the scanning position by the deflection yoke installed in the cone portion of the bulb, and excites a fluorescent film applied to the inner surface of the panel forming the screen to realize an image.

The electron gun includes a cathode, a triode consisting of a control electrode and a screen electrode, a plurality of focus electrodes disposed to face the screen electrode to form a preliminary focusing lens portion, and a main focus lens portion disposed to face the focus electrode. And a final accelerating electrode.

Such a cathode ray tube has a cross-sectional view of the electron beam emitted from the electron gun in the direction of the nonuniform magnetic field of the deflection yoke in order to prevent the size of the electron beam spot landing on the fluorescent film from being increased or distorted due to the uneven deflection magnetic field of the deflection yoke. Various types of electron guns are employed, such as using an electron gun using a dynamic focusing method using a quadrupole lens that distorts in the reverse direction or changes the focus voltage of the electron beam when the electron beam is scanned at the center and periphery of the fluorescent film.

FIG. 1 shows a part of the electrode 10 forming the main lens part of the electron gun.

As shown in the drawing, the electrode 10 has red, green, and blue electron beam passing holes 11, 12, and 13 formed in independent small diameters so that electrons emitted from the cathode can pass therethrough. The electron beam passing holes 11, 12, 13 are formed in an inline shape on a common plane of the electrode 10.

The electrode 10 is a separate auxiliary electrode 14 is employed to improve the focusing characteristics in the main lens and to facilitate the adjustment of the converter. That is, the electrode 10 has a limit in enlarging the diameters of the electron beam passing holes 11, 12, 13 because the S value, which is the distance between the electron beams, is small. As a result, the magnification and spherical aberration of the electronic lens become large, thereby deteriorating the focus characteristic.

In order to overcome this, as mentioned above, the auxiliary beams having the electron beam passing holes 15, 16, 17 enlarged to face the electron beam passing holes 11, 12, 13 are formed on the front surface of the electrode 10. The electrode 14 is attached.

Attachment of the auxiliary electrode 14 having the enlarged electron beam passing holes 15, 16, 17 may occur when the diameter of the electron beam passing holes 11, 12, 13 of the electrode 10 is enlarged. Thermal and mechanical deformations due to the narrowed width between the electron beam passing holes 11, 12, 13 can be prevented, and the magnification of the lens can be reduced.

On the other hand, the reason why the large diameter commonly used for the electrode 10 is not adopted, in the case of the electron gun employed in the so-called mini neck having a narrow neck portion of the cathode ray tube, the rim portion and the bur when the electrode having the large diameter are employed. This is because the uniformity of the quality of the ring cannot be ensured. Accordingly, the auxiliary electrode 14 having the electron beam through holes 15, 16, 17 having a diameter larger than that of the electron beam through holes 11, 12, 13 is attached to the front surface of the electrode 10. do.

However, even when the auxiliary electrode 14 is attached in this way, the diameter of the electron beam through holes 15, 16, 17 is slightly increased due to the structural limitation, so that the lens magnification or spherical aberration is slightly reduced, and the effect is weak. Do. In addition, since the auxiliary electrode 14 also has electron beam through holes 15, 16 and 17 in the form of independent small diameters, there are manufacturing difficulties.

The present invention was devised to solve the above problems, and an object thereof is to provide an electron gun for a cathode ray tube that is easy to adjust focusing characteristics and a converter by changing the shape of an electrode of an electron gun enclosed in a narrow neck portion. .

1 is an exploded perspective view showing a part of an electrode of a conventional electron gun,

2 is an exploded perspective view illustrating a part of an electrode of an electron gun according to an embodiment of the present disclosure;

3 is a cross-sectional view of the electrode of FIG.

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

10,20,30 ... electrode

11,12,13,21,22,23,31,32,33 ... hole diameter electron beam through hole

14,24,34 Auxiliary electrode

15,16,17 ... enlarged electron beam through hole

24a ... body

25,35 ... Large diameter electron beam passing through

Electron gun for cathode ray tube according to an aspect of the present invention to achieve the above object,

Formed in the form of inline on the same plane of the electrode, when the electron beam emitted from the cathode passes, a predetermined power is applied to form the main lens portion, and has independent small-diameter electron beam passing holes for passing the red, green, and blue electron beams. electrode; And

And an auxiliary electrode attached to the front surface of the electrode and having an electron beam through-hole large in diameter to reduce spherical aberration by reducing a magnification of the lens.

In addition, the auxiliary electrode has a large diameter electron beam through hole formed to surround the independent electron beam through hole in the center, and is formed as a plate-shaped body looped along its edge, and the bottom surface of the main body is attached to the upper surface of the electrode. It is characterized by.

Hereinafter, an electron gun according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 illustrates a portion of an electrode according to an exemplary embodiment of the present invention, and FIG. 3 illustrates a state in which the electrode of FIG. 2 forming the main lens unit is disposed.

Referring to FIGS. 2 and 3, the electrode 20 has an independent small-diameter electron beam passing hole 21 and 22 to allow the three electron beams emitted from the cathode to pass through in an inline electron gun system of red, green, and blue. 23 is formed. The electron beam passing holes 21, 22, 23 are formed in an inline shape on a common plane of the electrode 20.

This in-line electron gun is limited by the diameter of the neck portion of the cathode ray tube having a limited inner diameter. Therefore, in order to obtain satisfactory focusing characteristics, it is desirable to enlarge the diameters of the electron beam through holes 21, 22 and 23, which are main lenses, but this is structurally and designally because the S value, which is a distance between electron beams, is structurally small. There is a limit to manufacturing.

In order to prevent this, according to the present invention, unlike the electron beam through holes 21, 22 and 23 on the front of the electrode 20 is an auxiliary electrode 24 having a large diameter electron beam through hole 25 So-called rat electrodes (lart apertures and thick metal electrodes) are employed.

This auxiliary electrode 24 has a single electron beam through hole unlike the conventional electrode 14. That is, the auxiliary electrode 24 has a large diameter electron beam through hole 25 formed in the central portion so as to completely surround the independent small diameter electron beam through holes 21 and 22 and 23. A main body 24a made of a plate material having a predetermined thickness looped along the edge of the electron beam through hole 25 is formed. In addition, the lower surface of the main body 24a is attached to the upper surface of the electrode 20.

The focusing characteristics of the cathode ray tube are greatly influenced by the magnification and aberration of the main lens, which greatly depends on the converging effect of the lens, and the lens magnification and spherical aberration are reduced by adopting the auxiliary electrode 24 having the large diameter 25. As a result, the beam spot size is reduced, thereby improving the focus characteristic.

In addition, as shown in FIG. 3, the electrode 30, which is disposed to face the electrode 20 and forms the main lens, also has electron beam passing holes 31, 32, 33 of independent small diameter shapes. The auxiliary electrode 35 is attached to the front surface of the electrode 30. As described above, the auxiliary electrode 35 has a shape of a large diameter electron beam through hole 35.

In this case, the S values of the electrodes 20 and 30 are different from each other. Even in this case, spherical aberration due to the enlargement of the aperture of the main lens unit is reduced, thereby improving the focus characteristic without employing a general large-diameter electrode.

As described above, the electron gun for the cathode ray tube of the present invention changes the shape of the auxiliary electrode attached to the front surface of the electrode forming the main lens portion of the electron gun enclosed in the neck portion of the cathode ray tube having a small diameter from an independent small diameter to a large diameter. By doing so, lens magnification and spherical aberration can be reduced, resulting in improved focusing characteristics.

In addition, it is possible to prevent the difficulty caused by the shape change of the rim portion or the burring portion that may occur when the electrode commonly used as a large diameter electrode, it is relatively easy to manufacture.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (3)

delete delete A first electrode having an independent small-diameter electron beam passing hole through which red, green, and blue electron beams can pass in an inline state on a surface from which the electron beam is emitted; A second electrode installed to face the first electrode to form a main lens unit and having an independent small-diameter electron beam passing hole through which red, green, and blue electron beams pass in an inline state on a surface on which the electron beam is incident; And The electron beam exit surface of the first electrode and the electron beam entrance surface of the second electrode are respectively provided, and a single large diameter electron beam through hole is formed to surround the independent small diameter electron beam through hole, and a loop is formed along the edge. Electron gun for cathode ray tube comprising a; auxiliary electrode having a main body of the plate shape.