KR950000650B1 - Electron gun for cathode-ray tube - Google Patents

Abstract

The electron gun improves the resolution of color pictures by reducing spherical aberration and improving the focusing characteristics. The electron gun comprises: (A) an external electrode (110) forming the first transit hole (113) of electron beams in a large aperture; (B) an internal electrode (120) forming the second transit hole (123) of electron beams in a large aperture but smaller in the horizontal width (W2) than that of the first transit hole fixed inside of the external electrode.

Description

Electron gun for cathode ray tube

1 is a cross-sectional view of an electron gun for a typical cathode ray tube.

2 is an exploded perspective view showing a common large-diameter electrode forming the main lens of a conventional electron gun for cathode ray tubes.

3 is an exploded perspective view showing a common large-diameter electrode of the cathode ray tube electron gun according to the present invention.

4 is a cross-sectional view showing a state in which the electrostatic lens is formed by the common large diameter electrode in the present invention.

* Explanation of symbols for main parts of the drawings

110: external electrode member 112: electron beam passing plane

113: first large-diameter electron beam through hole

120: internal electrode member 123: second large diameter electron beam through hole

The present invention relates to an electron gun for a cathode ray tube, and more particularly, to an electron gun for a color cathode ray tube in which a common large diameter electrode constituting a main lens system is improved.

Typically, there are various kinds of electron guns for color cathode ray tubes according to the characteristics of cathode ray tubes, and FIG. 1 shows an example of such an electron gun for cathode ray tubes.

It forms the main lens system with the cathode (2), the control electrode (3) and the screen electrode (4) forming the anterior triode, and the focus electrode (5) having the independent small-diameter electron beam passing holes (5H) and 6H, respectively, and the final lens system. It is comprised with the accelerating electrode 6. In the electron gun 1 configured as described above, as a predetermined potential is applied to each electrode, a prefocus lens is formed between the screen electrode 4 and the focus electrode 5, and the focus electrode 6 and the final acceleration electrode ( 6) The main lens is formed between. Accordingly, the electron beam emitted from the cathode 2 is preliminarily focused and accelerated while passing through the prefocus lens, and finally focused and accelerated while passing through the main lens, and landed at each fluorescent point of the fluorescent film to form one pixel. These pixels combine to form a screen. However, in the electron gun for the conventional cathode ray tube as described above, the electron beam through-holes 5H and 6H formed between the focus electrode 5 and the final acceleration electrode 6 forming the main lens have an emission side of the focus electrode 5. And since it is formed in the limited area of the incident side of the final acceleration electrode (6) there is a problem that the magnification of the electrostatic lens formed by them can not be large because the electron beam through hole can not be large. As described above, when the magnification of the main lens is increased, the electron beam passing therethrough undergoes a lot of spherical aberration, and thus, the resolution of the cathode ray tube employing the same may be inherent.

In order to solve the above problems, as shown in FIG. 2, a large-diameter electron beam passing hole 11H is formed in which three electron beams of red, green, and blue signals pass through the focus electrode and the final acceleration electrode constituting the main lens. It is well known that the external electrode member 11 and the internal electrode member 12 which are inserted into and fixed in the external electrode member 11 and have three independent electron beam through holes 12H are formed in an in-line arrangement are used. Is true. The electrode as described above is formed by the electrostatic lens formed by the large-diameter electron beam passing hole (11H) and the small-diameter electron beam passing hole (12H), that is, the main lens is formed by double-diameter and small-diameter electron beam through hole (11H) (12H) Therefore, the overall magnification is reduced by forming a low magnification electrostatic lens in a composite state, but the electrode formed as described above has the following problems.

first ; Since the size of the large-diameter electron beam through hole 11H formed in the external electrode member 11 is limited, the eccentric distance between the independent small-diameter electron beam through holes 12H formed in the inner electrode member 12 cannot be increased. There is a limit to lowering.

second ; The outer side of the electron beam passing through the outer electron beam passing hole 12H of the inner electrode member 12 is cut by the edge of the large-diameter electron beam passing hole of the outer electrode member 11, thereby distorting both electron beam cross sections.

third ; Since the size of the three electron beams landing on the fluorescent film is different because the electron beam is distorted, the luminance of the fluorescent film emitted by the central electron beam is different from that of the fluorescent film emitted by the surrounding electron beam, and thus, uniform luminance cannot be obtained from the typical fluorescent film. The resolution of the cathode ray tube is reduced.

fourth ; Since three independent electron beam through holes are formed in the inner electrode member, the assembly and dispersal with the outer electrode are severe and the lens distortion is severe.

Created to solve the above problems of the present invention, it is possible to prevent the electron beam cross-section is distorted by the large-diameter electron beam through hole, and to reduce the spherical aberration of the lens by reducing the magnification of the main lens to reduce the focus characteristics Its purpose is to provide an electron gun for cathode ray tubes that can be improved.

In order to achieve the above object, the present invention forms an electrostatic lens, and includes an external electrode member having a first large-diameter electron beam passing hole through which three electron beams pass through, and fixedly installed inside the external electrode member, and having a thin electron beam on the plane of the electron beam passing hole. It is characterized in that it comprises an internal electrode member formed with the second large-diameter electron beam passing hole passing through.

In the present invention, it is preferable that the horizontal width of the first large-diameter electron beam passing hole is larger than the horizontal width of the second large-diameter electron beam passing hole.

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

In FIG. 3, the electrode forming the main lens of the cathode ray tube electron gun according to the present invention is illustrated, which is formed of a cross-section in which three electron beams pass through an electron beam passage plane 112 provided on an upper surface of a can-shaped body 111. 1 The large-diameter electron beam passing hole 113 is formed and the outer electrode member 110 and the outer electrode member 110 having the flange portion 114 formed on the lower edge of the body 111, the outer electrode member 110 is fixed to be installed therein The inner electrode member 120 is formed on the electron beam passing plane 122 of the body 121 in which an electron beam passing hole 123 of a horizontal shape through which three electron beams pass through is formed. The horizontal width W1 of the first large-diameter electron beam passing hole 113 may be wider than the horizontal width W2 of the second large-diameter electron beam passing hole 123.

In order to form the main lens as the electrode of the electron gun configured as described above, as shown in FIG. 4, two electrodes are disposed to face each other, and different predetermined voltages are applied to each other. The large-diameter electron beam passing holes 123 of the electrode member 120 are alternately formed so as to asymmetrically form the large-diameter lens formed therebetween so as to convert the electron beams of both sides passing therethrough.

The operation of the electron gun electrode for the cathode ray tube according to the present invention configured as described above will be described in detail with reference to FIG.

Electrodes 100 constituting the main lens according to the present invention have first and second large diameters in which three electron beams pass through each of the electron beam passing planes 122 and 112 of the inner electrode member 120 and the outer electrode member 110. Since the electron beam passing holes 123 and 113 are formed, the electrostatic lens formed by them, that is, the main lens, can not only significantly reduce the magnification thereof, but also the electron beam passing through the outer sides of the first large diameter electron beam passing hole 113. It is possible to prevent the cutting by the outer edge of the. In more detail, as shown in FIG. 4, the main lens formed by the electrode 100 of the electron gun has a small diameter electron beam through hole formed in the inner electrode member, and the inner electrode member 120 is not formed as in the prior art. Since an independent second large-diameter electron beam passing hole 123 is formed, a single electrostatic lens is formed without dividing the electrostatic lens, thereby reducing the magnification of the lens, and in particular, the eccentric distance of the small-diameter electron beam passing space of the internal electrode member. Since the limitation due to this can be fundamentally solved, the diameter of the lens can be increased. Therefore, it is possible to greatly reduce the spherical aberration of the electrostatic lens passing through it. The horizontal width W2 of the second large-diameter electron beam through hole 113 formed in the electron beam passing plane 122 in the inner electrode member 120 is defined by the first large-diameter electron beam through hole 123 of the outer electrode member 110. Since it is formed narrower than the horizontal width (W1) it is possible to prevent the cutting of both electron beams passing through the outside.

In addition, the electrode formed by the electrode of the electron gun according to the present invention alternately forms the first and second large-diameter electron beam passing holes 113 and 123 of the outer electrode member 110 and the inner electrode member 120 or adjusts the size thereof. As a result, the outer portion of the electrostatic lens formed by these can be formed asymmetrically to converge both outer electron beams.

As described above, the electrode of the electron beam gun for the cathode ray tube of the present invention can greatly reduce the spherical aberration of the electrostatic lens formed by the electron beam through hole of the inner and outer electrode members forming the main lens with a large diameter. There is an advantage that can be improved to improve the resolution of the cathode ray tube employing it.

Claims (2)

By forming an electrostatic lens, the external electrode member 110 having the first large-diameter electron beam passing hole 113 through which three electron beams pass through is formed, and fixedly installed inside the external electrode member 110, An electron gun for a cathode ray tube, characterized in that it comprises an internal electrode member (120) having a second large-diameter electron beam passing hole (123) through which the electron beam passes. The electron gun for cathode ray tube according to claim 1, wherein the horizontal width (W1) of the first large diameter electron beam through hole (113) is wider than the horizontal width (W2) of the second large diameter electron beam through hole (123).